Term
| List 4 basic features that characterize mature enamel |
|
Definition
1)Stria of retzius,
2)perikymata,
3)neonatal line incremental lines
4) bands of hunter and schrager
5)gnarled epithelium,
6)enamel spindles
*Note more than one; but some other PHYSICAL features that change is the the increase level of mineral (29%-95%), merged papillary layer from stratum intermedium and stellate reticulum, ameloblast cycling and a protective state (ameloblast layer + papillary layer) condensed to form REDUCED DENTAL EPITHELIUM; aka NASMYTH'S MEMBRANE |
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Term
| What is the basic structural unit of enamel? What are the dimensions? How are they oriented? |
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Definition
| Enamel rods (prisms), 5 microns in diameter and 2.5 mm in length, they run from the dento-enamel junction to the surface. |
|
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Term
| Name the 3 major stages of amelogenesis, and the substages of each. |
|
Definition
1. Pre-Secretory stage (1. Morphogenesis phase 2. Differentiation phase)
2. Secretory Stage (1. Initial enamel 2. Tomes’ process)
3. Maturation stage (1. Transition 2. Ameloblast cycling 3. Protective stage) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
Shape of the crown is determined? |
|
Definition
| Pre-secretory stage ( morphogenesis phase) |
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|
Term
In which stage (and substage) of amelogenesis do the following occur?
1/2 the ameloblasts undergo apoptosis |
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Definition
| Maturation stage (transition phase) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
initial layer of enamel is deposited |
|
Definition
| Secretory stage (initial enamel phase) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
interrods are formed |
|
Definition
| Secretory Stage (Tomes' process) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
Nasmyth's membrane is worn away |
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Definition
| Maturation stage (protective stage) and more so when soon after ERUPTION |
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|
Term
In which stage (and substage) of amelogenesis do the following occur?
Dentin induces secretion to begin |
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Definition
| Secretory stage (initial enamel); note that dentin induces amelogenesis to produce initial enamel here |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
matrix protein is initially mineralized |
|
Definition
| Secretory stage (initial enamel) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
Tomes' processes form |
|
Definition
| Secretory stage (Tomes process) |
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|
Term
In which stage (and substage) of amelogenesis do the following occur?
initial basal lamina fragments |
|
Definition
| Pre-secretory stage (Differentiation phase) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
new basal lamina formed on enamel surface |
|
Definition
| maturation stage (ameloblast cycling) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
papillary layer forms |
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Definition
| Maturation stage (transition phase) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
cells of internal dental epithelium (IDE) are cuboidal |
|
Definition
| Pre-secretory stage (morphogenesis phase) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
enamel becomes fully mineralized |
|
Definition
| Maturation stage (ameloblast cycling) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
matrix proteins are degraded and resorbed |
|
Definition
| Maturation stage (ameloblast cycling) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
cells of internal dental epithelium become columnar |
|
Definition
| Pre-secretory stage (differentiation phase) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
mineralization begins at cusp |
|
Definition
| Maturation stage (ameloblast cycling) |
|
|
Term
In which stage (and substage) of amelogenesis do the following occur?
reduced dental epithelium is formed (= Nasmyth's membrane) |
|
Definition
| Maturation stage (protective phase) |
|
|
Term
| Which is formed first: rods or interrods? |
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Definition
|
|
Term
| How do maturation stage ameloblasts receive nourishment? |
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Definition
| From the papillary layer (formed by the combination of the stratum reticulum, stratum intermedium and outer dental epithelium). Because we know that the papillary layer is invaginated by blood vessels |
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|
Term
| Compare the composition of secretory and mature enamel. Give the % of protein matrix, water and mineral for each |
|
Definition
Secretory enamel
66% protein matrix (soft)
5% water
29% mineral
Mature enamel
4% protein
1% water
95% mineral |
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|
Term
| How is the reduced dental epithelium formed? In what area does it persist in the adult? |
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Definition
| Reduced enamel epithelium is formed by the combination of the papillary layer and the ameloblast layer.. In adults it persists as jucnctional epithelium as your tooth erupts ( may stain brown?) |
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Term
| Draw a diagram of the enamel layer as seen in a ground section of a tooth crown. Draw the orientation of the rods. Draw the orientation of the striae of Retzius. |
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Definition
| on your ppt. (know it, if Dr. Shaw says it) |
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|
Term
| How fast is human enamel deposited? How long does it take for each stria of Retzius to be deposisted? |
|
Definition
| Enamel is deposited at a rate of 4 microns per day. Stria of retzius is deposited weekly |
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|
Term
|
Definition
| Perikymata are little ridges on surface of tooth where the stria can be seen. |
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|
Term
| Draw in a neonatal line on your diagram. What causes it to be more visible? |
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Definition
| Again look at ppt. Any metabolic disturbance (fevers, birth etc.) during mineralization will cause the neonatal line to be more visible |
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|
Term
| What is gnarled enamel, and where does it occur? |
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Definition
| Gnarled enamel is areas where enamel is twisted over each other rather than being arranged radially. It occurs at the cusps. |
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|
Term
| Why can we see enamel tufts? |
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Definition
| Hypocalcified defects (seen on histo slide) in enamel surface, with higher protein content. Possible avenues for caries. |
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|
Term
| Why would enamel lamellae be involved in some caries invasion? |
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Definition
| It is also a region of hypocalcified region so there is room for cares invasion. |
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|
Term
| What makes enamel spindles? Which cells do they come from? |
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Definition
| Enamel spindles are made by odontoblast processes penetrating into the ameloblast layer and being trapped there as eneamel spindles. |
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|
Term
Compare dentin to enamel, as to the following features:
Hardness |
|
Definition
| Enamel is harder than dentin |
|
|
Term
Compare dentin to enamel, as to the following features:
Resilience |
|
Definition
| dentin is more resilient than enamel |
|
|
Term
Compare dentin to enamel, as to the following features:
Crystal size |
|
Definition
| enamel has bigger crystals than dentin |
|
|
Term
Compare dentin to enamel, as to the following features:
Vitality (blood vessels?) |
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Definition
| Dentin is LIVING with blood vessels, and enamel no blood vessels |
|
|
Term
Compare dentin to enamel, as to the following features:
Sensitivity (nerves?) |
|
Definition
| Dentin has nerves, and enamel has no nerves |
|
|
Term
Compare dentin to enamel, as to the following features:
Time period of formation? |
|
Definition
Dentin is formed first, then enamel
*Note Dentin grows thru lifetime |
|
|
Term
Compare dentin to enamel, as to the following features:
Ability of repair |
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Definition
| repair dentin has an ability to repair itself, enamel has none |
|
|
Term
Compare dentin to enamel, as to the following features:
% compostion of mineral, protein matrix and water |
|
Definition
Dentin
Mineral 70%
protein 20%
water 10%
Enamel
Mineral 95%
protein 4%
water 5% |
|
|
Term
| What kind of cell forms dentin? What embryological germ layer did they come from? |
|
Definition
| Predentin, and predentin is formed from odontoblasts… ectoderm (embryonic mesenchymal cells) |
|
|
Term
In what order do these events occur?
Ameloblast differentiation
Enamel secretion
Odontoblast differentiation
Predentin secretion |
|
Definition
1) Ameloblast differentiation
2) Odontoblast differentiation
3) Predentin secretion
4) Enamel secretion
*May want to double check |
|
|
Term
| When pre-odontoblasts differentiate into odontoblasts, describe how they change in appearance. |
|
Definition
| When they differentiate into odontoblasts they become longer and grow odontoblast processes surrounded by odontoblast tubules of dentin. There is also an increase in rER and golgi as the cells gets ready to secrete the matrix. |
|
|
Term
| Which part of the odontoblast secretes matrix? |
|
Definition
|
|
Term
| Describe the collagen that is initially secreted to form mantle dentin: what type is it, where are the fibers seen, how are they oriented, what are they called? |
|
Definition
| The collagen that is initially secreted is type III collagen and are found between the odontoblasts. They are arranged perpendicular to the DEJ. They are called Korff’s fibers. Then secrete matrix of collagen type I fibrils parallel to DEJ = predentin. |
|
|
Term
| Compare the initial collagen to later collagen secretion: what type collagen is it, where are the fibers seen, how are they opriented? |
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Definition
| Initial collage is type III (von Korff’s fibers), later collage is type I and are oriented parallel to DEJ. |
|
|
Term
| How much dentin is deposited each day? |
|
Definition
|
|
Term
| Where are the blood vessels that nourish dentinogenesis? What is unusual about them? |
|
Definition
| The blood vessels are in the odontoblasts. They are fenestrated |
|
|
Term
| Contrast linear vs globular mineralization: where is each likely to occur, how does each appear? |
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Definition
| Linear appears in a line and globular appear in little goblets. Linear (slow growing) more likely to appear in the root, while globular (fast growing) more likely to appear in the crown. |
|
|
Term
| Define the 4 dentin regions. |
|
Definition
Mantle – outer dentin, secreted first
Primary – bulk of the circum-pulpal dentin
Secondary – formed after teeth occlude (slowly narrows the pulp)
Tertiary -- formed in response to injury |
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|
Term
| How are enamel spindles formed? |
|
Definition
| Formed by odontoblast tubules that extend into the enamel past the DEJ |
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|
Term
| How would the primary curvature of odontoblast tubules affect the spread of caries? What orientation would the tubules have on the floor of a cavity prep? Does this depend on location? How? |
|
Definition
| **The more curvature there is to it, the tougher it is for caries to spread. On the floor of a cavity prep they may be cut obliquely rather than transversely. (double check this answer) |
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|
Term
| Where is dentin more permeable; at DEJ or near the pulp? Why? |
|
Definition
| Dentin is more permeable near the pulp because the tubules are widest at their base. |
|
|
Term
| Where is peritubular dentin formed, and how is it different from other dentin? |
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Definition
| Peritubular dentin is formed around the odontoblast tubules. It differs from other dentin because it is hypermineralized. |
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|
Term
| What is sclerotic dentin? Is it harmful? |
|
Definition
| Scelortic dentin is dentin that has occluded the odontoblast tubules. It is not harmful, it protects the pulp. But as you age the more built up the more reduced pulp chamber. |
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|
Term
| Globular mineralization is disturbed under what dietary condition? What makes it look different? |
|
Definition
| Vitamin D. deficiency. It looks different because it has no peritubular dentin. |
|
|
Term
| Why should you be careful not to administer tetracycline to a pregnant woman or young child? What would the result look like? How does this occur? |
|
Definition
| Because tetracycline binds to forming dentin. It causes dark incremental lines. |
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|
Term
| Draw a diagram of a ground section of a tooth. Indicate the orientations of tubules and incremental growth lines. Include a neonatal line. |
|
Definition
|
|
Term
| Under what conditions does tertiary dentin forms? How is it produced? Does it have tubules? |
|
Definition
| Tertiary dentin forms in response to injury. It is formed by differentiation from pulp due to the injury. Yes it has tubules that may be irregulary arranged. |
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|
Term
| Where would you find the granular layer of Tomes? Draw a diagram on your own |
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Definition
| It is found on the external edge of the root right under the Cementum (hypomineralized) |
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|
Term
| Explain the current hypothesis on how dentinal nerves are activated. How would this work under conditions of hot/cold? |
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Definition
| Currently they think that the nerves enter the tubule but do not synapse with the tubules. They are activated by fluid movement through the tubules which deform the nerve. Under both hot/cold conditions, a person feels PAIN. |
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|
Term
| How would you explain a pink tooth? Where do the offending cells come from? |
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Definition
| A pink tooth can be explained by odontoclasts destroying the dentin around the pulp and the pulp tissue being visible through the transparent enamel. |
|
|
Term
| Do all animal embryos form a neural crest? |
|
Definition
|
|
Term
| List 4 kinds of cells derived from trunk neural crest. |
|
Definition
| Autonomic ganglia, dorsal root ganglia, melanocytes, adrenal medulla. |
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|
Term
| What is the difference between mesenchyme and ectomesenchyme? |
|
Definition
| Mesenchyme is a type of loose connective tissue derived from all three germ layers, while ectomesenchyme is derived from neural crest cells. |
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|
Term
| List all structures derived from cranial neural crest. |
|
Definition
| Odontoblasts, connective tissue of head and neck, non-neural part of eyeball, dermis and hypodermis of face and anterior neck, truncoconal septum, parts of sensory and autonomic ganglia, intramembranous bone of skull, cartilages of pharyngeal arches, connective tissue sheaths of muscles. |
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|
Term
| If you stuffed first pharyngeal arch with ectomesenchyme from the trunk, would a mandible form? Discuss positional identity. |
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Definition
| ** My guess is that it wouldn't because you need epidermal basal lamina to direct regrowth and the right genes to develop. |
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|
Term
| Describe Meckel’s cartilage. When does it form? What type of tissue is it? Describe its position. |
|
Definition
| Meckel’s cartilage is cartilage of the mandible that arises as 2 hyaline cartilage rod. It forms from the 1st branchial arch. Meckel’s cartilage forms in the 6th week of embryological development. It is hyaline cartilage (connective tissue). It is located in the mandibular swelling. |
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|
Term
| Is there a cartilage like Meckel’s in the formation of the upper jaw? |
|
Definition
| No there is no cartilage forming in the upper jaw. |
|
|
Term
| Does Meckel’s cartilage turn into mandibular bone? How does mandibular bone form? Describe its mechanism, where and when ossification begins, and how it spreads. |
|
Definition
| No. meckel’s cartilage ends up degenerating. Mandibular bone is formed through intramembranous ossification. It forms lateral to meckel’s cartilage. Ossification begins during the 7th week right where mandibular nerve branches into incisive and mental nerves. Intramembranous ossification travels posteriorly to the ramus and spread laterally away from meckel’s cartilage at site of future lingula. Inside the bone, meckel’s cartilage degenerates and does not become part of the mandibular bone |
|
|
Term
| What adult structure represents the remnant of Meckel’s cartilage perichondrium? |
|
Definition
| Sphenomandibular ligament |
|
|
Term
| Describe the formation of the first arch ossicles. Name them. How are they formed? What is the role of their intervening joint in the embryo? |
|
Definition
| They are formed by endochondral bone formation. Malleus and incus. The joint between them becomes the primary jaw joint. |
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|
Term
| If the muscles of mastication were paralyzed by an in utero stroke, would the mandible still develop its normal shape? Explain. |
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Definition
| No, because the secondary cartilages will not form into bone without their respective muscles. |
|
|
Term
| Is there any endochondral bone formation in the mandible? |
|
Definition
|
|
Term
| When do the two halves of the mandible ossify into one bone? |
|
Definition
| At one year of age the symphyseal cartilage disappears |
|
|
Term
| What types of cells are involved in bone remodeling? On which surfaces of the mandible is bone deposited vs. resorbed? |
|
Definition
| Osteoblasts and osteoclasts. The posterior and lateral surfaces have bone deposition occurring, while the anterior and medial have bone resorption occurring. |
|
|
Term
| What forms the primary palate? Does it have a preformed cartilage? A center of ossification? |
|
Definition
|
|
Term
| When do the palatal shelves elevate? Describe the process, and current thought on the mechanism. |
|
Definition
| The palate shelves elevate during the 7th week of development. GAG are required because it is speculated that they elevate via changes in linkages of GAGs and concurrent elevation of the head off the thoraci wall enables the tongue to drop down from between the shelves. |
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|
Term
| Name 5 environmental influences that increase the risk of cleft palate. Would a woman realize she was pregnant at this stage? |
|
Definition
| Smoking, drinking, drugs, x-rays, excess vitamin A , deficient folic acid. Not always. NO a woman would realize she was pregnant at this stage because it happens at 7-8 weeks of pregnancy. |
|
|
Term
| Define the primary epithelial band. |
|
Definition
| Primary epithelial band is the arch shaped plate of odontegenic epithelium (mandible 2 zones fuse. Maxilla 4 zones (2 on medial nasal processes and 2 on maxillary processes) fuse) |
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|
Term
| Which layer provides the initial instruction to begin tooth formation? Does this change later? |
|
Definition
| The ectomesenchyme by the ectodermal cells of the first arch. Yes will change later when it secrete new transcription factors. These new factors will, in turn, cause changes in the epithelium. |
|
|
Term
| Which layer do ameloblasts come from? Which layer do odontoblasts come from? |
|
Definition
| Ameoloblasts come from the ectodoerm. Odontoblasts come from ectomesenchyme |
|
|
Term
| Could you grow either ectoderm or ectomesenchyme separately in tissue culture, and see teeth form? Explain. |
|
Definition
| I don't think so, just b/c Dr. Shaw emphasizes that there must be a CONTACT b/t layers to induce communication b/t layers and induce genes and differentiation of cells. |
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|
Term
|
Definition
| You see it at the bell stage; where you have the reation of crown shape (# of cusps) |
|
|
Term
|
Definition
| From the enamel organ region; secretes glycosaminoglycans, osmotically pull water into the enamel organ |
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|
Term
| What is the first visible sign (with a microscope…) of tooth initiation? When does it form? How is it created? |
|
Definition
| The first sign of tooth initiation with a microscope is the primary epithelial band (a horse shoe shaped epithelial band. It is formed during the 6th week in utero. It is created by altered plane of cleavage of epithelial basal cells |
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|
Term
| When does the vestibular lamina form? What does it become? Describe the process. |
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Definition
| The vestibular lamina forms during the 7th week. It becomes the oral vestibule. Primary epithelial cells proliferate and enlarge, surface cells degenerate and create a cleft. That cleft will become the oral vestibule. |
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|
Term
| Describe the dental lamina. What are the swellings that appear along the lamina? When do the swellings form? |
|
Definition
| The dental lamina is an invagination that is created by the underlying mesenchymal tissue dividing and growing upward to create a dental lamina. The swellings that appear along the dental lamina are developing teeth. They form during the 8th week |
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|
Term
| Draw a diagram of a tooth germ at bud stage. Label the dental lamina, tooth bud, ectomesenchyme condensation and oral epithelium. Highlight the position of the basement membrane. |
|
Definition
Know it! off ppt
Note that the basement membrane is b/t the epithelium and the ectomesenchyme layers |
|
|
Term
| Draw a diagram of a tooth germ at cap stage. Label the enamel organ, the dental papilla, the dental follicle (sac). Highlight the position of the basement membrane. |
|
Definition
| Guess what? Draw b/c Dr. Shaw wants you to know it cold. |
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|
Term
| Draw a diagram of the enamel organ in late cap stage, showing how histodifferentiation has created outer dental epithelium, inner dental epithelium and stellate reticulum. When does this occur? |
|
Definition
| Draw it!! Late cap stage occurs during the 12 week. |
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|
Term
Match the structures in the top line with the correct derivatives below:
Central condensed ectomesenchyme / peripheral condensed mesenchyme / epithelium
Enamel organ / dental papilla / dental follicle |
|
Definition
Epithelium with enamel organ
Central condensed ectomesenchyme with dental papilla
Perpheral condensed mesenchyme with Dental follicle |
|
|
Term
| Draw a diagram of the bell stage enamel organ. Portray it at high enough power to show the cell shapes of ODE, IDE, stellate reticulum and stratum intermedium. |
|
Definition
|
|
Term
| What increases the volume of the stellate reticulum? What keeps the cells attached to each other? |
|
Definition
| Water (b/c the stellate reticulum secretes GAG which pull water into the enamel organ. The cells are kept attached to each other by desmosomes. |
|
|
Term
| How are the cells of the IDE nourished? Where are the blood vessels? |
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Definition
| The cells of the IDE are nourished by glycogen granules found inside them. The BVs are located in the dental pulp. |
|
|
Term
| What is the cervical loop? Name 2 functions of this area. |
|
Definition
| The cervical loop is the area where the internal and external dental papillae meet at rim of enamel organ. 1. Stem cells for internal dental epithelium 2.gives rise to epithelial component of root formation. |
|
|
Term
| What major event occurs at late bell stage? |
|
Definition
| Beginning of dentin and enamel formation |
|
|
Term
| Where do the first signs of dentin formation occur? |
|
Definition
| The first signs of dentin formation occur at the tips of the future cusps |
|
|
Term
| What induces cells of the dental papilla to differentiate into odontoblasts? |
|
Definition
| The IDE developing into pre-ameloblast |
|
|
Term
| What induces the ameloblasts to start producing enamel? |
|
Definition
|
|
Term
| Describe the position of the permanent tooth bud on the dental lamina, and its relation to the primary tooth. |
|
Definition
| They are located deep within the ectomesenchyme of the dental lamina. SPECIFICALLY by the lateral dental lamina that leads to the general dental lamina. SO FINAL ANSWER, is within the general dental lamina |
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|
Term
| What occurs if the general lamina does not fully degenerate? |
|
Definition
| They may form epithelial pearls |
|
|
Term
| What is the role of the enamel knot? At which stage is it active? How does it affect cells of the IDE? |
|
Definition
| The enamel knot is active at the cap stage. It produces a signaling molecule which tells cells of the underlying IDE to stop proliferating and differentiate into ameloblasts. |
|
|
Term
| When are the incisors initiated? |
|
Definition
|
|
Term
| When are the successional permanent teeth initiated? |
|
Definition
|
|
Term
| When are the permanent molars initiated? |
|
Definition
|
|
Term
| What structure induces odontoblasts for root dentin formation? What is it an extension of? |
|
Definition
| HERS (Hertwig’s epithelial root sheath). It is an extension of the cervical loop |
|
|
Term
| Explain the relationship between the epithelial diaphragm and the apical foramen. |
|
Definition
| The epithelial diaphragm is the rim of the HERS which goes around the pulp to enclose it from the follicle. The opening that allows nerve bundles and bv into the pulp is the apical foramen. |
|
|
Term
| In the initial stages of eruption, the enamel organ collapses to form what structure? |
|
Definition
| Reduced enamel epithelium |
|
|
Term
| What is the fate of the reduced enamel epithelium? |
|
Definition
| It fuses with oral epithelium and they end up degenerating except at edges where they form the JUNCTIONAL EPITHELIUM so there is never a break in the epithelial seal. |
|
|
Term
| Compare the “hardness” and mineralization of enamel, dentin, cementum and bone. |
|
Definition
| Enamel is the hardest and most mineralized tissue followed by dentin, bone and finally Cementum. |
|
|
Term
| What are 4 functions of cementum? |
|
Definition
| Seal dentinal tubules, provide attachment for PDL, prevent and repair root resorption, adjust to continued tooth eruption. |
|
|
Term
| Why do dentin tubules need to be sealed? |
|
Definition
| Because within them they contain nerves that would be sensitive if exposed to oral environment. |
|
|
Term
| Explain the role of HERS in the formation of cementum. What are its remnants called? |
|
Definition
| HERS remnants are called epithelial cell rests of malassez. HERS breaks up into the epithelial cell rests of malassez once it has induced dentin formation in the root which allows the follicle cells to contact the predentn which stimulates Cementum formation or the HERS themselves may induce formation of cementoblasts |
|
|
Term
| What is the origin of cementoblasts? |
|
Definition
| Cementblasts may originate from the follicular cells (ectomesenchyme) or from epithelial cells of HERS (ectorderm from enamel organ) |
|
|
Term
| Compare the structure of cementum around the cervical root vs that found at the apex. Compare terminology, thickness, cell content, source of fibers, speed of matrix deposition. |
|
Definition
| Cementum is thicker around the root apex than it is at the cervical root. The cell content is greater at the root apex than it is at the cervical root. |
|
|
Term
| in acellular cementum, which cells make the fibers? What are the fibers called when mineralized? |
|
Definition
| In acelluar Cementum the fibroblasts from the PDL makes the fibers. When it is mineralized it is called Acellular excrinsic fiber Cementum (AEFC) |
|
|
Term
| Compare cementocytes and osteocytes, describing their lacunae, canaliculi and nourishment. How might this affect their relative resistance to resorption? |
|
Definition
| Cementocytes and osteocytes both are found in lacunae and communicate with each other via canaliculi. In osteocytes, the canaliculi face every which way because they receive their nutrition from a network of blood vessles but in cementocytes they face toward the PDL because that is where they receive their nutrition. Since there is no blood vessels in Cementum the cementocytes in the deeper lacunae usually die. This makes the cementocytes less resistant to resorption than bone or dentin. |
|
|
Term
| In cellular cementum, which cells make the matrix fibers? |
|
Definition
| The cementoblasts secrete the matrix fibers. |
|
|
Term
| Where would you find alternating layering of AEFC and CIFC? |
|
Definition
|
|
Term
| Describe the 3 ways cementum abuts with enamel at the CEJ, and give the % occurrence of each arrangement. |
|
Definition
| Overlap (60%), Meet (30%), Gap (10%) |
|
|
Term
| Which is most resistant to absorption: dentin, cementum orbone? How does this influence orthodontia? |
|
Definition
| Cementum is the most resistant to absorption. It means that orthodontists can move teeth around |
|
|
Term
| What does a reversal line signify? |
|
Definition
| A reversal line signifies an area where the cementoblasts repaired pockets of root resorption where odontoclasts destroyed Cementum and dentin. |
|
|
Term
| How might cementum deposition kill a tooth? |
|
Definition
| By blocking the apical foramen |
|
|
Term
| What is hypercementosis? What disease would you advise a patient to be tested for if you encountered hypercementosis? |
|
Definition
| Hypercementosis is when the cemetoblasts are over active and you produce too much Cementum. Paget’s disease. |
|
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Term
|
Definition
| A calcified body appearing in Cementum or PDL. |
|
|
Term
|
Definition
| This is the type of joint that the PDL forms with the tooth- it is a peg and socket joint |
|
|
Term
| Explain the significance of the PDL as a path of infection. |
|
Definition
| The PDL is connected to the gingiva, the bone and the pulp of the tooth. When an infection gets in it, it can travel to all those connections. |
|
|
Term
| List 4 functions of the PDL |
|
Definition
| Nourish the Cementum and bone, Suport the teeth against forces of mastication, sensory input for proprioception and protective reflexes, adaptation to tooth movement |
|
|
Term
| Describe the composition of the principal fiber bundles of the PDL, including the % of each component. |
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Definition
| The principle fiber bundle is made up 80% type 1 collage and 15% type III collagen. The collagen needs vitamin C-dependant enzymes to help stabilize it or else will lead to scurvy. |
|
|
Term
| Draw a diagram of a tooth with its PDL. Indicate the location and orientation of oblique, apical, circumferential and horizontal fibers. |
|
Definition
| draw or view on your own. |
|
|
Term
| What are oxytalin fibers? Add some to the above diagram, to indicate their orientation. What may be their function? |
|
Definition
| Oxytalin fibers are elastic fibers that run longitudinally along the roots but parallel to the gingiva fibers. They may help in regulating vascular flow during mastication Also aids in Innervation! |
|
|
Term
| What kind of cell makes the principal fiber bundles? What is its embryological origin? |
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Definition
| the principle bundle fibers are made from fibroblast. Mesenchyme |
|
|
Term
| Are there epithelial cells in the PDL? What is the clinical significance of this? |
|
Definition
| Yes there are (epithelial cell rests of malassez. They may cause cycts or tumors |
|
|
Term
| What type of immune system cells would you expect to see in the PDL? |
|
Definition
| Eosinophils, mast cells, and macrophages |
|
|
Term
| In what areas would you find blood vessels and nerves running in the PDL? |
|
Definition
| Interstitial spaces – spaces between the fibers |
|
|
Term
| What is unusual about the capillaries of the PDL? |
|
Definition
| They are fenestrated capillaries |
|
|
Term
| Describe the neural basis of pain sensation from the PDL; include the morphology of the nerve endings, where the cell bodies lie, and where they synapse in the brain stem. |
|
Definition
| The PDL has Nociceptors and mechanoceptors. The nociceptors are free nerve endings and constitute 75% of the nerves in the PDL. Their cell bodies are located in the trigeminal ganglion. The mechanoceptors are ruffini like coils and spindle and make up 25% of the nerves in the PDL. They have their pseudounipolar cell bodies in the mesencephalic nucleus |
|
|
Term
| Describe the neural basis of proprioception from the PDL; include the morphology of the nerve endings, where the cell bodies lie, and where they synapse in the brainstem. |
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Definition
| The mechanoceptors are ruffini like coils and spindle and make up 25% of the nerves in the PDL. They have their pseudounipolar cell bodies in the mesencephalic nucleus |
|
|
Term
| Draw a diagram of a coronal section through the mandible, showing the inner and outer cortical plates, trabecular bone and alveolar bone proper. Would it be different if you drew a mid-sagittal section, through the anterior teeth? |
|
Definition
|
|
Term
| What is the term for loss of maxillary bone over the root apex? Over the cervical root? |
|
Definition
Root apex = fenestrations
Cervical root = dehiscence |
|
|
Term
| Where is the cortical plate the thickest? What significance does this have for dental anesthesia? |
|
Definition
| The cortical plate is thickest thickest on buccal aspect of mandibular premolars and molars: thinnest in the maxilla. On the mandible it is easier to do a nerve block because the anesthesia has a difficult time diffusing through the bone. Opposite for maxilla. |
|
|
Term
| Could you use mandibular bone marrow for a marrow transplant? |
|
Definition
| No because it is not hematopoetic; it is yellow marrow |
|
|
Term
| Why is alveolar bone proper sometimes called a cribriform plate? What passes through these? |
|
Definition
| Because it is perforated with many foramina. Nerves and blood vessels go through the cribiform plate. |
|
|
Term
|
Definition
| Bundle bone is alveolar bone proper b/c it receives the principal fiber bundles of the PDL |
|
|
Term
| What makes the lamina dura seen in an x-ray? |
|
Definition
| Alveolar bone proper............ which is call dura lamina!! |
|
|
Term
| Under what circumstances do teeth move? List 5. |
|
Definition
1. Horizontal growth of mandible
2. Mesial drift of mandible
3. orthodontia
4. When your face grows your teeth are repositioned outwardly
5. Periodontal disease |
|
|
Term
| How does alveolar bone respond to compression forces? What cells are involved? Where do these cells originate? |
|
Definition
| Compression = resorption (osteoclasts- they originate in the bone marrow as monocytes |
|
|
Term
| How does alveolar bone respond to tension? What cells are involved? Where do these cells originate? |
|
Definition
| Tension = bone deposition (osteoblasts –originate from mesenchymal cells)) |
|
|
Term
| With advancing age, how will the PDL and alveolar bone change? What happens if teeth are lost? What happens if there is periodontal disease? |
|
Definition
| With advancing age the PDL is lost which will lead to bone resorption. IF there is periodontal disease, osteoclast activity increases which will lead to bone resorption as well. |
|
|
Term
| What type of tissue is pulp? What is its function? What is unusual about it? |
|
Definition
| Pulp is loose connective tissue. It functions to maintain and repair dentin. Pulp continues to function throughout life. |
|
|
Term
| What germ layer is pulp derived from? When does it become recognizable as pulp, rather than a dental papilla? |
|
Definition
| Pulp is derived from ectomesenchyme (neural crest cells). It becomes known as pulp when dentinal apposition begins in late bell stage. |
|
|
Term
| Describe 3 regions of the pulp chamber. |
|
Definition
Pulp horns – pulp extending into the cusps
Coronal pulp – pulp found in the crown
Radicular pulp – pulp found in the roots that communicate with the periodontal ligament through the apical foramen or at times may have accessory canal. |
|
|
Term
| Why is it important to consider pulp horns when planning a cavity prep? |
|
Definition
| Because they extend into the cusps |
|
|
Term
| What passes through the apical foramen? The accessory canals? |
|
Definition
| Nerves and blood vessels as well as infections pass through the apical foramen. Blood vessels pass through accessory canals. |
|
|
Term
| How might accessory canals complicate endodontic procedures? How many people have them? |
|
Definition
| They might act as a way for the infections to spread into the pulp. About 33% of the population have accessory canals. |
|
|
Term
| Compare the appearance of the odontoblastic zone in the crown vs the root. |
|
Definition
| In the crown they look like pseudostratified epithelium (BUT NOT EPITHELIUM!) while in the root they are simple cuboidal. |
|
|
Term
| What is the functional role of the cell junctions between the odontoblasts? |
|
Definition
| Desmosomes and tight junctions might form a variable barrier to diffusion. Gap junctions form with other odontoblasts and underlying fibroblasts to allow coordination of function when needed. |
|
|
Term
| What is in the cell-free zone of Weil? |
|
Definition
| Nerves endings and capillaries |
|
|
Term
| List all cell types that can be found in the pulp core. |
|
Definition
| Never cells, fibroblasts (stellate and spindle shaped), blood vessels. |
|
|
Term
| Within the pulp core, where are collagen fibers most dense? How might this affect root canal prep? |
|
Definition
| Collagen fibers are the most dense at the roots. |
|
|
Term
| Explain the resonse of the pulp to infection? Which cells increase? Can dentin be repaired? How? What signals the lymph nodes that infection is present? |
|
Definition
| When there is an infection in the pulp, macrophages, lymphocytes and leukocytes accumulate in the pup. Dentin can be repaired tertiary repair denting. Dendritic antigen presenting cells signal the lymph node that infections are present. |
|
|
Term
| What is the plexus of Raschko, and where is it found? |
|
Definition
| The plexus of raschko is a plexus of nerves that enter in the root and branch just deep to the odontoblasts cells in cell-free zone. |
|
|
Term
| Where are the nerve endings for this plexus of Raschko? Where are the cell bodies? Where do they project in the brainstem? |
|
Definition
The nerve endings are found in the dentinal tubules. The cell bodies can be found in the pup horns. They project to the pons.
Most axons are trigeminal afferents, with cell bodies in the trgeminal ganglion. |
|
|
Term
| Explain how neuropeptides may mediate the repair of damaged dentin |
|
Definition
| Neuropeptides releases a signaling molecule in the pulp that controls local blood flow and repair of dentin. |
|
|
Term
| Explain the hydrodynamic theory of dentinal pain. |
|
Definition
| With cold stimuli, the odontblast moves out and with hot stimuli, the odonto blast moves in. that movement in the Odontoblast causes the nerves to act as mechanoceptors and detect theose stimuli. |
|
|
Term
| What are pulp stones? When might they cause problems? |
|
Definition
| Pulp stones are round calcified masses found in pulp. They might cause a problem during root canal therapy. |
|
|
Term
| List 3 possible causes of a darkened tooth. |
|
Definition
| Trauma that kills the nerve, closure of apical foramen with Cementum, obscure of sclerosed blood vessels. |
|
|
Term
| What changes take place in aging pulp? Does the tooth become more or less sensitive? More or less able to repair itself? Why? |
|
Definition
| Aging pulp gets smaller. The tooth becomes less sensitive but also less able to repair itself because it loses a lot of its vasculature and nerves. |
|
|
Term
| Name the 2 tissue types that make up the oral mucosa. Name the layer that often underlies these, and list 3 features it may contain. |
|
Definition
| Stratified squamous epithelium and Lamina Propria (connective tissue layer). The submucosa often underlies the oral mucosa and it may contain adipose tissue, blood vessels, nerve tissue. |
|
|
Term
| What are the functions of the oral mucosa? |
|
Definition
| The oral mucosa acts to protect deeper tissues from mechanical forces of mastication and from organisms. It also acts as a means of sensation such as taste, texture, temperature and exploration. Finally the oral mucosa is able to secrete via minor and major glands. |
|
|
Term
| Compare the features of masticatory mucosa with those of the lining mucosa. Prepare a table comparing their: |
|
Definition
|
|
Term
| Describe the special features of the mucocutaneous junction. Where is it? Why is the vermillion border so red? What are Fordyce’s spots, and where are they found? |
|
Definition
| It is at the junction between the moist oral mucosa and vermillion zone of outer lip. The vermilion border is red because it is thin and translucent and reveals underlying red. Fordyce’s spots are sebaceous glands found at the angles of the mouth and sometimes on the buccal mucosa. ??? |
|
|
Term
| Describe the special features of the mucogingival junction. Where is it? Prepare a table comparing the following features of attached gingival vs alveolar mucosa: |
|
Definition
|
|
Term
| Describe the special features of the free gingiva. Where is it? What does it look like? What layers does it have? What is the free gingival groove? How does it alter with age? |
|
Definition
| It is the free gingiva that is not directly attached to tooth.it is Lighter in color and smoother than attached gingiva. It has an epithelial layer (non-keratinized) and lamina propria but no submucosa. The free gingival groove indicates where the gingival sulcus is located. The free gingival groove increases with age |
|
|
Term
| Describe the special features of the dentogingival junction |
|
Definition
a) draw a diagram and label the sulcular vs junctional epithelium
b) what type of epithelium is found in each
• non-keratinized stratified squamous epithelium
c) compare the structure of the sulcular and junctional epithelium
• the sulcular enamel has more folded interface with lamina propria while the junctional epithelium flattens to just 3 layers thick with smooth connective tissue fold.
d) describe how the junctional epithelium adheres to the tooth
• junctional epithelium is attached to tooth surface by an epithelial attachement
e) name the features of the junctional epithelium that make it more permeable
• epithelial cells of the JE are more loosely packed with fewer desmosomes and more extracellular space = danger area b/c bacteria can just as easily go through this layer
f) compare the external and internal basal lamina
• internal basal lamina looks like a standard lamina but it lacks type four collage, laminin and anchoring fibrils. It still has hemidesmosomes attaching the cells to the basal lamina
h) what is gingival crevicular fluid and what are its constituents.
• It is a fluid occurring in minute amounts in the gingival crevice. It contains immunoglobulins, white blood cells, tissue exude, epithelial cells as well as plaque.
i) define the interdental col and describe the structure of its epithelium
• the interdental col is a depression in the interdental papilla. Its epithelium is thin and non-keratinized (identical to the JE)
g) what is the embryological origin of the junctional epithelium. How is this reflected in the cell differentiation? Is there ever a break in the epithelium when a tooth erupts?
• The JE is derived from reduced enamel epithelium. The cells have a more embryologic characteristic so they are less differentiated. There is never a break in the epithelium when the cell erupts. |
|
|
Term
| Describe the special features of the hard palate. What type of mucosa is it? What type of epithelium? What layers are present, at the raphe vs laterally? |
|
Definition
| The hard palate is masticatory mucosa. It has orthokeratinized or parakeratinized stratified squamous epithelium. Epithelium, lamina propria, and submucosa laterally. At the raphe only the epithelium and lamina propria exist. |
|
|
Term
| Describe the special features of the soft palate. What type of mucosa is it? What type of epithelium? Describe the special features of the lamina propria and the submucosa here, and how they affect function? |
|
Definition
| The soft palate is lining mucosa. It has non-keratinized stratified squamous epithelium. The lamina propria is thick and has tons of elastic fibers. The submucosa is thin and allows firm attachment to muscles to allow for speech and swallowing. |
|
|
Term
| Name the 4 types of lingual papillae, and indicate where they are located, whether they have taste buds, and what type of epithelium they have. |
|
Definition
Filiform – in the middle of tongue, no taste buds and it has a thick keratinized stratified squamous epithelium
Fungiform – between filiform papillae on tip of tongue, taste buds on their superior surface, and it has a non-keratinized stratified squamous epithelium
Circumvallate – posterior part of tongue, they have taste buds, they have both keratinized and non-keratinzed epithelium
Foliate – on margin of posterior tongue, few taste buds, non-keratinized epithelium (you lose these with age) |
|
|
Term
| Draw a diagram of a taste bud, and label the 3 kinds of cells, the taste pore, and the location of the synapse. |
|
Definition
1) Neuroepithelial
2) Supporting cells
3) Basal stem cells |
|
|
Term
| What are von Ebner’s glands, what type of gland are they, where are they found, and what is their function? |
|
Definition
| Von ebners glands are serous minor glands. They are found in the circumvallate papillae and they function to cleanse taste buds |
|
|
Term
| Define turnover time. Give approx. times for turnover of skin, hard palate, cheek and junctional epithelium. |
|
Definition
Turnover time is the time necessary to replace all cells
Skin – 27 days
Hard palate – 24 days
Cheek – 14 days
Junctional epithelium – 5-6 days |
|
|
Term
| What is caviar tongue? Black hairy tongue? Geographic tongue? |
|
Definition
|
|
Term
|
Definition
Plasma:
The top layer of anticoagulated blood (i.e. unclotted blood), above the a. white buffy coat of white blood cells and platelets and b. red blood cell hematocrit ,that is produced after undergoing centrifugation
It contains 90% water, 8% proteins (albumin, fibrinogen, immunoglobulins, lipoproteins), 1% inorganic salts, 0.5% lipids, and 0.1% sugar as its main components
The three main groups of protein in plasma are the blood coagulation proteins, albumin, and the globulins
Globulins consist of the following: alpha globulins – proteases, antiproteases & transport proteins; beta globulins – transferrin and other transfer proteins; and gamma globulins, which are mainly immunoglobulins
The plasma proteins are almost all derived from the synthesis of the liver—except for immunoglobulins, which are derived from plasma cells, I.e. special types of white blood cells that produce antibodies
Serum:
The predominant, top layer of protein-rich, coagulated (or clotted) blood that undergoes centrifugation
Unlike plasma, there are neither white blood cells nor red blood cells here, as well as there is NO fibrinogen in serum; but serum DOES contain albumin, immunoglobulins and other components similarly to plasma |
|
|
Term
|
Definition
Fibrin, i.e. Factor Ia, is the active, non-globular, fibrous clotting protein that is made by the inactive glycoprotein fibrinogen, when triggered by thrombin, during blood coagulation
It is critical in producing a mesh-like clot, with the help of platelets, over wounded areas, wound sites (like plugs that are used to prevent water from going down the drain of a sink or tub)
Fibrin’s involved in signal transduction, platelet activation, blood coagulation and protein polymerization |
|
|
Term
|
Definition
The lowest layer of unclotted/anticoagulated blood produced after centrifugation, containing just red blood cells/erythrocytes (Dr. Leak’s range: 43-47%; other ranges show that it’s normally 38% for women and 48% for men)
It’s an important part of a patient’s complete blood count, or CBC
Synonymous terms: packed cell volume (PCV) or erythrocyte volume fraction (EVF) |
|
|
Term
|
Definition
The thinnest layer (1%) of unclotted/anticoagulated blood produced after centrifugation
It contains white blood cells/leukocytes (which are granulocytes – neutrophils, eosinophils, basophils; agranulocytes – monocytes, lymphocytes ) and platelets/thrombocytes
BOTTOMLINE: WBC + Platelets |
|
|
Term
|
Definition
| A predominant, globular protein found in serum (about 65% of serum proteins are albumin) that is responsible for blood osmolarity and viscosity |
|
|
Term
|
Definition
| An inactive, soluble plasma (glyco)protein found in serum that is converted into the wound-protecting fibrin, when triggered by the serine protease thrombin, during blood coagulation |
|
|
Term
|
Definition
One of the three types of serum proteins (some are also contained in plasma), along with albumin and fibrinogen, which are synthesized in the liver as well as in the immune system
They are a heterogeneous mix of proteins with high molecular weight with lower solubility and electrophoresis migration rates than albumin
Globulins come in four subgroups or categories:
Alpha 1 and Alpha 2 globulins - plasma proteins that are mobile in highly charged solutions/inhibit blood protease activity, e.g. anti-trypsin, anti-chymotrypsin, protein C, angiotensinogen;
Beta globulins - plasma proteins that are less mobile than alpha globulins but faster than gamma globulins, e.g. transferrin;
and
Gamma globulins – mainly immunoglobulins, which are serum proteins, functioning as antibodies in the immune system that locate and attack bacteria and viruses |
|
|
Term
|
Definition
A fibrous protein located in the cytoskeleton that is necessary for lining the intracellular side of the plasma membrane in geometric (meaning pentagonal and hexagonal) arrangements
It plays an important part in the structuring or scaffolding, as well as the upkeep, of the plasma membrane and cytoskeleton
* FLEXIBLE ASPECT OF RBC |
|
|
Term
| Azurophilic granules vs specific granules |
|
Definition
All leukocytes have primary granules which are azurophilic and correspond to lysosomes. Sulfated glycoproteins in azurophilic granules account for the blue staining. Azure dyes are metachromatic basic blue dyes. Granulocytes are named for the presence of specific granules (secondary granules).
Specific granules are smaller and more numerous than primary azurophilic granules. MAY INCLUDE LYSOZYMES |
|
|
Term
|
Definition
| Also known as primary granules, the first granules to appear during neutrophil differentiation. They contain a number of microbicidal agents including neutrophils defensins. They are believed to contribute to the degrading of engulfed microbes |
|
|
Term
|
Definition
| The movement of white blood cells/leukocytes out of blood into the connective tissue when tissue is damaged or infected |
|
|
Term
|
Definition
One of four major proteins contained in the specific granules of eosinophils
It is an arginine-rich, basic protein localized in the crystalloid body accounting for the intense acidophilia of the granule |
|
|
Term
|
Definition
A nitrogen-rich chemical compound (amine), which is activated in immune response to allergens
It is produced by both basophils and mast cells
Histamine makes blood vessels permeable to white blood cells and proteins with the purpose of eliminating antigens that invade infected issue |
|
|
Term
|
Definition
The process of forming pluripotent blood stem cells in the bone marrow into differentiated mature blood cells
In this formation, what begins as a hemocytoblast gradually splits into A. common myeloid progenitor and B. common lymphoid progenitor
The common myeloid progenitor later divides into 1. megakaryocytes, from which platelets/thrombocytes are derived; 2. red blood cells/erythrocytes; 3. mast cells; and 4. myeloblasts (which become basophils, neutrophils, eosinophils monocytes macrophages)
The common lymphoid progenitor later divides into the main immune system leukocytes: 1. large, granular lymphocytes/natural killer cells; and 2. small, agranular lymphocytes T lymphocytes; and B lymphocytes, from which plasma cells are derived |
|
|
Term
|
Definition
| (inner most layer) – thin layer of simple squamous epithelial cells called endothelium because it lines the blood vessel. This layer provides the lumen of the blood vessel |
|
|
Term
|
Definition
| layer of smooth muscle alternating with interstitial components of either collagen fibers or small meshwork of elastic fibers. |
|
|
Term
|
Definition
| connective tissue. Contains the Vasa Vasorum (vessel of the vessels) |
|
|
Term
|
Definition
| - Usually seen in the arterioles and much larger vessels. This layer contains elastic components. |
|
|
Term
|
Definition
| a simple layer of squamous epithelium cells which lines the lumen of the blood vessel. |
|
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Term
|
Definition
cells which serve a similar purpose to the smooth muscle cells. It is thought that they may actually be the precursors to form more smooth muscle cells.
Ex. If you have a disruption in the blood vessel, the pericytes will first accumulate followed by the formation of smooth muscle at that site.
*come from mesenchymal cells |
|
|
Term
|
Definition
- Modification of a small area of a capillary cell wall where a lot of the cytoplas has been removed forming a window.
- These fenestrations are found in organs where large volumes of fluids and electrolytes are exchanged (Ex. Kidney, Mucosa of GI tract etc) |
|
|
Term
|
Definition
(Discontinuous Blood capillaries)
- Contain actual pores which allow large components to pass through.
- These are gaps between endothelial cells. |
|
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Term
|
Definition
- Used to secure Lymphatic capillaries to the surrounding connective tissue.
- These filaments attach to the surface of the lymphatic endothelial cell and extend out and are embedded between collagen bundles
o This holds capillaires intact with the surrounding connective tissue to keep them from collapsing when they fill up with fluid. |
|
|
Term
|
Definition
- “Vessel of the vessels” located in the Tunica adventitia
- Blood vessels which are embedded in the Tunica adventitia |
|
|
Term
| Name the major classes of blood vessels. |
|
Definition
Macrovascular Structures
- Elastic arteries
- Muscular arteries
- Large/medium sized muscular veins
Microvascular Structures
- Aterioles
- Capillaries
- Postcapillary venules |
|
|
Term
| Draw and compare the 3 types of blood capillaries. How do their different structures reflect their different functions? |
|
Definition
- Continuous Capillary
- Fenestrated
- Sinusoidal (Discontinuous) |
|
|
Term
| What are the components of lymph? |
|
Definition
| Lymphatic vessels contain a colorless fluid, lymph. it is composed of plasma proteins ( immunoglobulins, lipoproteins), cells (lymphocytes, dendritic cells monocytes |
|
|
Term
| Describe 4 features of a lymph capillary. |
|
Definition
1) Endothelial lining
2) Intercellular junctions
3) Anchoring filaments
4) Lymphatic-interstitial interface= Lacks continuous basal lamina |
|
|
Term
| How do lymph get from the connective tissues into the lymph capillaries? |
|
Definition
| Lacteal – purpose is to take chylomicrons, which have been processed inside the intestines, up into the lymphatic's and back into circulation. |
|
|
Term
| Draw a tEM of a lymphatic capillary and compare it to a tEM of a blood capillary. Point out FOUR features |
|
Definition
|
|
Term
| How does the structure of a lymph collecting vessel differ from a lymph capillary? |
|
Definition
|
|
Term
| Describe the classification of the TMJ, both structurally and dynamically |
|
Definition
A. synovial: capsule is lined with synovial membrane that secretes a slippery synovial fluid into joint spaces
B. sliding-ginglymoid
1. upper joint space = sliding
2. lower joint space = ginglymoid (hinge-like)
C. articular disk |
|
|
Term
| Where are the mechanical forces exerted between the condyle and the temporal bone; against the mandibular fossa or the articular eminence? |
|
Definition
|
|
Term
| Where is the pterygoid fovea, and what attaches there? (be specific) |
|
Definition
| In the Mandible, the pterygoid fovea is for the attachment of inferior head of lateral pterygoid muscle |
|
|
Term
| Describe the layers of tissue on the adult condyle articular surface (5 layers) |
|
Definition
1. collagenous fibrous tissue
2. cell rich area with fibroblasts
3. fibrocatilagenous layer
4. calcified cartilage
5. bone
6. fibrocartilage layer serves as the grow center for the condyle, like a multidimensional epiphyseal plate |
|
|
Term
| What is unusual about the covering of the articular surfaces of the TMJ, compared to most other joints? |
|
Definition
| Unlike most synovial joints (whose articular surfaces are covered with hyaline cartilage), the articular surfaces of the TMJ are covered with a layer of fibrous connective tissue |
|
|
Term
| What tissue type makes up the articular disk? |
|
Definition
| Articular disk is also fibrous (not cartilaginous) |
|
|
Term
| How does growth occur in the condyle? |
|
Definition
| Condyle grows smoother, thicker and wider with age |
|
|
Term
| Describe the changes in the condyle between birth and adulthood |
|
Definition
Postnatal condyle: thick cartilaginous layer
Adolescent condyle: thinner, but still hypertrophic with developing bone
Adult condyle: thin cartilage layer, not hypertrophic, but still retains remodeling ability
Development of fossa: flat at birth, but tubercle, eminence and fossa become more accentuated with development |
|
|
Term
| What tissue type makes up most of the capsule? |
|
Definition
| Dense fibrous connective tissue (except superior posterior lamella) |
|
|
Term
| What are the functions of the capsule? |
|
Definition
Seals joint space
Provides some stability
Proprioceptive
Continuous with intra-articular disk |
|
|
Term
| Where does the anterior portion of the capsule attach, both superiorly and inferiorly? Posterior portion? Lateral edges? |
|
Definition
Anterior capsule: attaches to anterior condyle and the anterior-most surface of the articular eminence
Posterior capsule: attaches to posterior neck of condyle and to squamotympanic fissure (lateral to petrotympanic fissure) |
|
|
Term
| What is unique about the superior lamella of the posterior capsule? |
|
Definition
| Superior lamella of the posterior capsule is the ONLY portion that contains elastic fibers |
|
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Term
| Compare the capsule that encloses the superior joint space with that enclosing the inferior joint space. How is this difference important to the functioning of the joint??? |
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Definition
Superior compartment: capsule is lax
Inferior compartment: capsule is tightly attached to lateral and medial edges of condyle |
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Term
| When the jaw opens, what happens to the retrodiscal pad? How might this affect function? |
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Definition
| As the disc is moved anteriorly with opening, blood fills the space and the volume increased 5X. |
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Term
| What is the major component making up the disk; by weight? By volume? |
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Definition
Type I collagen = 80% dry weight
Water = 80% volume |
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Term
| Describe the cells of the disk, in detail. How do they get their nourishment? |
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Definition
| Cells look like plump fibroblasts with long processes that may connect to each other by gap junctions; since the disk is avascular except at its edges, this may be to nourish the inner cells |
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Term
| What is unusual about the collagen fibers of the disk and condyle? |
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Definition
| Collagen fibers of both disk and condyle are crimped, which would help to withstand tension |
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Term
| How does the tissue of the disk change with maturation? |
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Definition
| In the newborn, the disk is very cellular and well vascularized; later it becomes mostly collagen fibers |
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Term
| Where in the TMJ is synovial membrane found? |
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Definition
| Capsule (but NOT the disk or articular surfaces) is lined with synovial membrane, which secretes synovial fluid |
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Term
| Describe synovial membrane as a tissue – what kinds of cells does it have? Is it smooth? Does it have a basement membrane? |
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Definition
Yes it's smooth. A loose connective tissue with a layer of fibroblast-like cells mixed with macrophage like cells, resting on a vascular layer.
No basement membrane – not an epithelium |
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Term
| What artery is the major supplier to the TMJ? |
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Definition
| Supplied mainly by branches of superficial temporal artery, with contributions from other external carotid branches |
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Term
| Describe the distribution of blood vessels in the disk, capsule and retrodiscal pad. |
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Definition
Disk is avascular in adults, except around the edges. Most of the capsule is poorly vascularized, but…
Posterior superior lamella (retrodiscal pad) is very rich in blood |
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Term
| What nerves (3) supply the TMJ? |
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Definition
Supplied by three branches of V3:
Auriculotemporal
Deep temporal
Masseteric nn. |
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Term
| Where do the cell bodies of these afferents lie? Where do they project in the brainstem? |
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Definition
| Cell bodies of these afferents lie in both trigeminal ganglion (pain) and mesencephalic nucleus (proprioception) |
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Term
| Describe 4 types of nerve endings found in joints, along with their function. |
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Definition
4 types of nerve endings present in joints
1. Ruffini’s corpuscle : position sense
2. Pacinian corpuscle: vibration and joint movement
3. Golgi tendon organ: extreme position
4. free nerve endings: pain |
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Term
| Where are these endings found in the joint? |
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Definition
Central disk has no nerves
Peripheral disk has only free nerve endings (pain)
Free nerve endings also found in capsule and ligaments
Encapsulated endings found in capsule and ligaments |
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Term
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Definition
| By altering adhesion properties, the ectodermal cells of the neural crest detach from the epithelium and become Ectoemesnchyme |
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Term
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Definition
| Certain genes will be expressed according to their postion along the retro-caudal axis. Positonal identity allows the migrating cells to respond to the arch ectoderm. VIA BASAL LAMINA |
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Term
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Definition
| arises as 2 solid hyaline cartiladge rods (ear to symphisis but do not meet). Does not become the mandible when it degenerates but its perichondrium becomes Sphenomandibular ligament. Malleus and Incus come from Endochondral ossification of Meckels Cartiladge. |
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Term
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Definition
| Joint between Malleus and Incus when they are derived from the Endochondral ossification of Meckels cartiladge |
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Term
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Definition
Condylar car: Endochondral formation of condyle at TMJ
Coronoid Procces: dependent of the Temporalis
Angular Area: Dependent on the Massater and Medial Pterygoid
Alveoalar Process: Dependent on Teeth formation and function
Symphyseal cartilage: connect anterior ends of mandible: ossify at 1 year |
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Term
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Definition
| Primary palate forms form fused medial nasal process of fronto nasal process. Palatal shelves initially form beside the tongue, oriented superiorly and inferiorly then elevate rapidly to become horizontal (unknown but GAG is required) then elevation of the head off the thoracic wall, enables tongue to drop down between shelves |
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Term
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Definition
| When shelves fuse to form hard palate they adhere via a sticky glycoprotein. Then surface cells die and slough off. Then basal cells of the epithelium fuse into one SEAM, with a basal lamina on both sides. |
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Term
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Definition
| In Mandible, 2 zones fuse to form one continues Primary epithelial band |
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Term
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Definition
| Serum protease secreted by striated duct |
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Term
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Definition
For Bacterial/viral protection in the saliva*** Found in neutrophils.
Inhibits colony formation by granulocytes and macrophages. |
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Term
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Definition
| For yeast protection in saliva* |
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Term
| Orthokeratinized, parakeratinized, non-keratinized |
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Definition
| contains really thick keratin layer(masticatory mucosa), contains keratin layer with pyknotic cells (masticatory mucosa), no keratin layer (lining mucosa) – all are stratified squamous epithelium |
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Term
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Definition
| – when the lamina propria is directly attached to bone – no submucosa present(as in masticatory mucosa) |
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Term
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Definition
| – cells look like they’re dying |
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Term
| Papillary and reticular layers of lamina propria |
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Definition
– papillary layer is made of LCT and dominates
in the masticatory mucosa where it forms impressive interdigitations. Reticular layer is made of
DICT and it predominates in lining mucosa |
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Term
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Definition
contained within the granular layer (stratum granulosum). It contains aggregates of profillagrin (highly phosphorylated) which can be cleaved into filagrin which can help to
package the keratin |
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Term
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Definition
| thin transluscent keratinzed zone that together with the oral mucosa make up the mucocutaneous junction |
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Term
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Definition
| sebaceous glands that are found on the angles of the buccal mucosa. They look like pale yellow spots and increase with age |
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Term
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Definition
| an area of potential space between a tooth and the surrounding gingival tissue. It is indicated by the free gingival groove |
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Term
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Definition
| fluid that seeps through the the JE and accumulates in the sulcus. It contains Immunoglobulins, plaque bacteria and tissue exudate |
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Term
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Definition
| a depression in the interdental papilla that follows the contours of the crown. Identical to JE. |
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Term
| Caviar tongue, black hairy tongue, geopgraphic tongue |
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Definition
| varicosities (normal with age),indicates lack of normal shedding, reflects changes in keratinzation of filiform papillae (not dangerous) |
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Term
| What is the difference, in composition and how they are obtained, between plasma and serum? |
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Definition
| Plasma is obtained through centrifugation with an anticoagulant while serum is obtained through centrifugation without an anticoagulant. Plasma contains albumin, hormones, salts, fibrinogen, IgG, lipids and vitamins while serum lacks fibrinogen but contains albumin, hormones, salts, IgG, lipids and vitamins. |
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Term
| Describe the roles of the plasma proteins, albumin and globulins. |
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Definition
| Albumins – act to control blood viscosity: Globulins- act as antibodies as well as transporters and storage. |
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Term
| What are the azurophilic granules and what do they contain? |
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Definition
| Azurophilic granules are the primary granules contained within WBC. They all contain lysososomal enzymes as well as microbicidial agents. |
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Term
| What specific granules does each granulocyte contain? |
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Definition
Eosinophil – MBP (major basic protein, histamine, collagenase and cathepsins
Neutrophil – bactericidal agents in specific granules
Basophil – histamine, heparine sulfates, leukotrines |
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Term
| What is the role of neutrophils? Eosinopils? Basophils? In the immune system. |
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Definition
o Neutrophils act at sights of infection to engulf bacteria, viruses, debris, and infected cells.
o Eosinophils may act as first line of defense against parasitic infections, allergic reactions and chronic inflammation.
o Basophil – mediate inflammation, modulate immune response of others cells and may serve a role against certain intestinal parasitic infectons. |
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Term
| Phagocytosis of opsonized bacteria? |
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Definition
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Term
| Describe the origin, contents and role of platelets. |
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Definition
| Platelets originate from megakaryocytes (they live for 5-10days). They contain factors responsible for intrinsic clotting mechanism. They play a role in blood clot formation by binding to injured vessel, aggregate with RBC and forming a hemostatic. When they are activated these substances are released (Platelet derived growth factor, fibrinogen, serotonin and ADP). |
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Term
| What is the role of lymphocytes, once they are transformed to plasma cells? Where would you find plasma cells? |
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Definition
| Plasma cells produce immunoglobulins (anti-bodies). (Seems, still unclear, b/c we know B-cells become plasma cells, but then i think they signal T-cell formation)........refer to textbook |
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Term
| What is the role of monocytes? Name three cell types that we have studied that are derived from them. |
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Definition
| Monocytes are part of the body’s immune response. Macrophages, osteoclasts, microglia? |
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Term
| Where does hematopoiesis primarily take place in adults? |
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Definition
| Pelvis, vertebrae, skull, ribs, end of long bones. |
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Term
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Definition
| undifferentiated cell that serves to support BVs. Can act as blood flow regulators (esp. in capillaries) – can also act as a stem cell. Found in capillaries and post capillary venules. |
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Term
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Definition
| layer of elastic tissue that forms the outermost part of the tunica intima of BV. |
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Term
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Definition
| small pores within endothelium that facilitate exchange across wall (50-80nm) (eg. Endocrine, kidney, mucosa of G.I) |
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Term
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Definition
| aka discontinous; large trans-cellular pores through endothelium (.5-3µm) found in specialized cells of the liver. (eg. Liver, bone marrow) |
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Term
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Definition
| – collagen, elastic fibers (little), macrophages, fibroblasts, blood vessels (vasa vasorum) nerves (nervi vascularis) |
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Term
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Definition
| regulate flow to the capillary bed and reduce pressure |
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Term
| Describe the structure and function of a post-capillary venule. |
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Definition
| Post capillary venules have very thin walls (very little SM present and poorly developed occluding junctions) pericytes, and are very permeable. They are the site of exchange of cells and molecules between blood and tissues. |
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Term
| Describe the walls of veins, in comparison with arteries. |
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Definition
| Veins contain very thin intima, less SM and elastic fibers but more collagen fibers in both media and adventitia. Arteries contain thicker intima, and media. |
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Term
| What are the components of lymph? |
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Definition
| Plasma proteins (IgG, lipoproteins), cells (lymphocytes, dendritic cells, monocytes) |
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Term
| How do these components get from the connective tissues into the lymph capillaries? |
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Definition
| They get into the lymph capillaries from connective tissue by way of the lymphatic-interstitial interface where there is a discontinuous basal lamina. |
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Term
| Describe 4 special features of a lymph CAPILLARY. |
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Definition
1. Endothelial lining
2. Anchoring filaments – made of fibrilin.
3. Intercellular junctions
4. No basal lamina at lymphatic-interstitial interphase |
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Term
| Draw a tEM of a lymphatic capillary and compare it to a tEM of a blood capillary. Point out 4 features that differ. |
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Definition
1. Lymphatic capillary lacks a basal lamina
2. Void of smooth muscles
3. Has anchoring filaments that anchor it in the connective tissue
4. Blood capillary has some organelles and contains blood while the lymphatic capillary does not
*Note lymphatic capillary does have layer |
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Term
| How does the structure of a lymph collecting vessel DIFFER from a lymph capillary? |
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Definition
| A lymph collecting vessel has 3 layers (intima, media and tunica) while the lymph capillary only has an endothelial layer. |
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|
Term
Time line of human tooth development for:
Dental lamina formation |
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Definition
|
|
Term
Time line of human tooth development for:
Bud stage: deciduous incisors, canines, and molars |
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Definition
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|
Term
Time line of human tooth development for:
Bell stage for decidious teeth; bud stage for permanent teeth |
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Definition
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|
Term
Time line of human tooth development for:
Dentin and functional ameloblasts in deciduous teeth |
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Definition
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|
Term
Time line of human tooth development for:
Dentin and functional ameloblasts in permanent first molars |
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Definition
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Term
Aberrations of development:
Initiation Stage |
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Definition
Anodontia= absence of teeth
Supernumerary teeth = extra teeth |
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Term
Aberrations of development:
Bud Stage |
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Definition
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|
Term
Aberrations of development:
Cap Stage |
|
Definition
Dens in dentia = misformed enamel organ produces a pit.
Gemination = doubled crown
Fusion = large tooth with doubled pulp cavity
Tubercle = extra cusp |
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Term
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Definition
| Macrophages, mast cells and eosinophils, as in other c.t. |
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