Term
| functions of digestive system |
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Definition
Ingestion via the mouth
• Mechanical processing via the tongue, teeth and digestive tract
• Digestion by chemical and enzymatic breakdown
• Secretion by the pancreas, small intestine, gallbladder and
stomach
• Absorption of organic molecules, electrolytes, vitamins and
water by the digestive epithelium
• Excretion by the liver and gastrointestinal tube
• Compaction-
Defense |
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Term
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Definition
progressive dehydration of indigestible materials
and organic wastes prior to elimination |
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Term
| what are the components and functions of the mucosa of the digestive tract |
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Definition
| the components of the mucosa are 1. the mucosal epithelium 2. the lamina propria, aeolar tissue underlying epithelium 3. the muscularis mucosae, bands of smooth muscle fibers arranged in concentic layers. the mucosa of the digestive tract is an example of a mucous membrane, serving both absorptive and secretory functions |
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Term
| what is the functions of mesenteries |
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Definition
| mesenteries provide an access route for the passage of blood vessels, nerves, and lymphatics to and from digestive tract. they also stabilize the relative positions of the attached organs |
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Term
| what are the functional differences between peristalsis and segmentation |
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Definition
| peristalsis is waves of muscular contractions that move substances the length of the digestive tube. segmentation activities churn and mix the contents of the small and large intestines but do not produce net movement in a particular direction |
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Term
| what is important about the lack of organization in the contractile filaments of smooth muscle cells |
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Definition
| this allows the stretched smooth muscle to adapt to its new shape and still have the ability to contract when needed |
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Term
| what type of epithelium lines the oral cavity? |
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Definition
| the oral cavity is lined by the oral mucosa, which is composed of nonkertantinized stratified squamous epithelium |
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Term
| What are the functions of saliva? |
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Definition
| at mealtime, salvia lubericates the mouth and dissolves chemicals that stimulate the taste buds. Saliva contains the digestive enzyme salivary amylase which begins the chemical breakdown of carbohydrates |
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Term
| What nutrient begins its chemical breakdown in the mouth? |
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Definition
| carbohydrates are broken down by the salivary amylase in the mouth |
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Term
| pretend you are eating a apple. summarize the action of the teeth? |
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Definition
| the incisors cut away a section of a apple, which then enters the mouth. The cuspids tear at the rough skin and pulp of the apple. The apple then moves to the biscupid and molars through mashing and grinding before being swallowed. |
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Term
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Definition
| Mesenteries- fused, double sheets of peritoneal membrane |
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Term
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Definition
| Falciform ligament- between the liver and diaphragm |
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Term
| Greater omentum location and function |
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Definition
Greater omentum- hangs from the greater curvature of
the stomach
• Stores fat, cushions the organ |
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Term
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Definition
lesser omentum- between the lesser curvature of the
stomach and liver |
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Term
| Peritoneum location and function? |
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Definition
All but the first 25 cm of the small intestine is suspended by a
thick mesenterial sheet named the mesentery proper
• Provides stability but permits independent movement |
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Term
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Definition
| Mesocolon- mesentery attached to the large intestine |
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Term
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Definition
• Submucosa
• Layer of dense, irregular connective tissue
• Contains larger blood vessels- absorbed molecules the pass
through the columnar epithelial cells of the mucosa enter
the vessels in the submucosa
• |
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Term
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Definition
Submucosal plexus- network of nerve fibers located along
the out margin of the submucosa |
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Term
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Definition
Lined by the oral mucosa
• Stratified squamous epithelium |
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Term
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Definition
• Functions
• Mechanical processing of food
• Manipulation to assist in chewing and prepare material for
swallowing
• Sensory analysis (touch, temperature, taste receptors)
• Secretion of mucins and enzymes |
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Term
| How much salvia is produced daily? |
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Definition
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Term
| Desribe what saliva is made up with? |
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Definition
| 99.4% of saliva is water plus ions, buffers, metabolites and enzymes |
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Term
| How is salvia transported? |
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Definition
• Transported by a network of fine ducts to a single large duct
• Opens into the surface of the oral mucosa |
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Term
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Definition
• Functions
• At mealtimes- lubricate the mouth, moisten food and
dissolve chemicals
• At other times- flushes oral surfaces and helps to control oral bacteria |
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Term
| Describe Partoid salivary gland and function |
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Definition
Parotid
• Largest salivary glands (25% of secretions)
• Between the zygomatic arch and the sternocleidomastoid
• Duct pierces the buccinator between the skin and masseter |
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Term
| Describe location of sublinguial salivary glands location and % of saliva secretions |
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Definition
• Sublingual
• Ducts found under the tongue
• 5% of secretions |
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Term
| Describe submandibular saliva glands location and % of salvia secretions |
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Definition
Submandiublar
• Along the medial surfaces of the mandible
• 70% of secretions |
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Term
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Definition
Mastication- breaks down tough
connective tissues and plant fibers |
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Term
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Definition
| Incisors- clipping or cutting |
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Term
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Definition
| Cuspids (canines)- tearing or slashing |
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Term
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Definition
| Bicuspids- crushing, mashing and grinding |
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Term
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Definition
| Molars- crushing and grinding |
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Term
| Deciduous teeth decribe and # |
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Definition
Deciduous teeth- baby teeth, usually
there are 20 |
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Term
| Permanent teeth- # what extra teeth appear |
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Definition
Permanent teeth- usually have 32
• 3 additional molar appear on each
side of the upper and lower jaw |
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Term
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Definition
Common passageway for food, liquids and air
• Pharyngeal muscle cooperate with the muscle of the oral
cavity and esophagus to initiate the swallowing process also
known as deglutition |
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Term
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Definition
swallowing process also
known as deglutition |
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Term
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Definition
Pharyngeal constrictors- push the bolus toward the
esophagus |
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Term
| Palatopharyngeus function |
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Definition
| Palatopharyngeus- elevates the larynx |
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Term
| function of Palatal muscles |
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Definition
| Palatal muscles- raise the soft palate |
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Term
| Esophagus -decribe; location; passes through; and length |
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Definition
Hollow muscular tube that
transports foods and liquids to
the stomach
• Posterior to the trachea in the
mediastinum
• Passes through the esophageal
hiatus in the diaphragm to
reach the stomach
• Approximately 25 cm long and
2 cm in diameter |
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Term
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Definition
Mucosa- contains stratified
squamous epithelium
• Mucosa and submucosaform
large folds that permit
expansion during the
passage of a large bolus
• Smooth muscle of the
muscularis mucosae
gradually thickens as it
approaches the stomach
• No serosa |
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Term
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Definition
• Functions
• Bulk storage of ingested food
• Mechanical breakdown of ingested food
• Chemical digestion of ingested food by acids and enzymes |
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Term
| Stomach divided into 4 sections |
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Definition
• Divided into 4 regions
• Cardia
• Fundus
• Body- largest region
• Pylorus
• Pyloric sphincter regulates release into the duodenum |
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Term
Stomach-
Lesser curvature
Greater curveature |
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Definition
Anatomy
• Lesser curvature- medial surface
• Greater curvature- lateral surface |
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Term
| small interstine primary role? |
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Definition
Primary role in the
digesting and absorption
of nutrients |
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Term
| Small intestine (3 parts) and average length |
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Definition
Averages 20 feet in
length
• Duodenum
• Jejunum
• Ileum |
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Term
SMALL INTESTINEDUODENUM
Describe |
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Definition
• First segment of the small intestine
• Shortest (10 inches) and widest
• Connected to the pylorus of the stomach
• Receives chyme from the stomach and digestive juices from
the liver and pancreas |
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Term
SMALL INTESTINE- JEJUNUM
Describe /function and length |
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Definition
• Jejunum
• Second portion of the small intestine
• Approximately 8 feet long
• Bulk of chemical digestion and nutrient absorption occurs
here |
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Term
| Ileum- location/length/ends? |
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Definition
• Ileum
• Third portion
• Averages 12 feet in length
• Ends at the ileocecal valve which controls the flow of
materials from the ileum to the cecum |
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Term
SMALL INTESTINE HISTOLOGY
Describe villi, micro villi and purpose |
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Definition
• Intestinal villi
• Fingerlike macroscopic folds of the mucosa that project into
the lumen
• Covered by simple columnar epithelium
• Microvilli- microscopic projections formed by the folding
of each epithelial membrane
• Increases the surface area for absorption |
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Term
| SMALL INTESTINE HISTOLOGY |
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Definition
• Intestinal crypts
• Extend deep into the lamina propria
• Near the base of each crypt stem cell division continually
produce new generations of epithelial cells
• Inner lining of the intestine is replaced every 3-6 days |
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Term
| SMALL INTESTINE HISTOLOGY |
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Definition
Lamia propria
• Forms the connective tissue
core of each villus
• Contain an extensive network of
capillaries and lymphatic vessels |
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Term
| In the Small intestine what does the capillaries absorb |
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Definition
Capillaries- absorbs sugar and
amino acids (carries nutrients
to the hepatic portal
circulation |
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Term
| What does lymphatic vessels absorb |
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Definition
• Lymphatic vessels (lacteal)-
absorb fatty acids |
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Term
SMALL INTESTINE HISTOLOGY
• Regional specializations
Duodenum |
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Definition
Duodenum- numerous mucous
glands, prominent plica |
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Term
SMALL INTESTINE HISTOLOGY
• Regional specializations
Jejunum |
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Definition
Jejunum- prominent plica over
the first half, plica diminish in size
and number to the end of the
ileum |
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Term
SMALL INTESTINE HISTOLOGY
• Regional specializations
Ileum |
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Definition
• Ileum- masses of lymph tissue
(protect the ileum from large
numbers of potentially harmful
bacteria) |
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Term
LARGE INTESTINE
Begins at ?
How long? |
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Definition
• Begins at the ileum and ends at the anus
• About 5 feet in length |
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Term
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Definition
Cecum- collects and stores arriving material, begins
compaction
• |
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Term
Appendix
(made up of?)
Function? |
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Definition
Appendix- abundance of lymphatic tissue that may serve to
resist infection |
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Term
| Ascending colon (location) |
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Definition
| Ascending colon- along the right abdominal wall |
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Term
| Transverse colon (location) |
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Definition
| Transverse colon- crosses the abdomen from right to left |
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Term
| Descending Colon- location |
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Definition
| Descending colon- along the left abdominal wall |
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Term
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Definition
| Sigmoid colon- begins at the iliac fossa, s-shaped |
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Term
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Definition
• Rectum
• Forms the last 15cm of the digestive tract
• Expandable organ for the temporary storage of fecal
material |
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Term
| Anal canal- Internal anal sphincter |
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Definition
Anal canal
• Internal anal sphincter- smooth muscle of the muscularis
externa |
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Term
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Definition
External anal sphincter- ring of skeletal muscle fibers,
voluntary control |
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Term
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Definition
| Anus- external opening of the anal canal |
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Term
Special features of Large intesitine
Taeniane coli |
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Definition
Taeniae coli- three separate longitudinal ribbons of smooth
muscle on the outer surface |
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Term
Special features of Large intesitine
Haustra |
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Definition
Tone in this muscle creates haustra
• Haustra- pouches that permit considerable distention and
elongation |
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Term
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Definition
| Lined by a simple columnar epithelium |
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Term
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Definition
Mucous layer- protects the epithelium against the acids and
enzymes in the lumen |
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Term
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Definition
Gastric pits- shallow depressions that open onto the gastric
surface of the lumen |
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Term
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Definition
| Gastric glands- tubular glands dominated by secretory cells |
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Term
Cells of the gastric glands
Parietal |
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Definition
Parietal
• Secrete intrinsic factor and
hydrochloric acid |
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Term
Cells of the gastric glands
Chief |
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Definition
Chief
• Secrete pepsinogen
• Infants- rennin and gastric lipase |
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Term
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Definition
G-cells
• Secrete gastrin (hormone) |
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Term
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Definition
| The fauces is the opening between the oral cavity and the pharynx |
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Term
| What is occuring when the soft palate and larynx are elevated and the glottis closes |
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Definition
| the process that is being described is deglutition or swallowing |
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Term
| What stage of swallowing is voluntary |
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Definition
| the buccal phase is the only voluntary phase of swallowing |
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Term
| When someone experiences heartburn what is happening in the espophagus? |
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Definition
| when someone experiences heartburn their lower esophagealsphincter may not have closed completely and powerful stomach acids are entering the lower esophagus causing uncomfortable acid reflux |
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Term
| What are the function of the greater omentum |
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Definition
| the greater omentum provides support to the surrounding organs, pads the organs from the surface of the abdomen, provides an important energy reserve, and provides insulation |
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Term
| How do cells that line the stomach keep from becoming damagaed in such an acidic enviroment |
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Definition
| the epithelium produces a carpet of mucus that covers the interior surfaces of the stomach, provideing protection against the powerful acids and enzymes. any cells that do become damaged are quickly replaced |
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Term
| What do chief cells secrete? |
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Definition
| chief cells secrete pepsinogen. In infants, they also secrete rennin and gastric lipase. |
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Term
| What hormone stimulates the secretion of parietal and chief cells |
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Definition
| gastrin produced by enteroendocrine cells, stimulates the secretion of parietal and chief cells |
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Term
| Which histological features of the small intestine facilitae the digestion and absorption of nutrients? |
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Definition
| The characterstic lining of the small intestine contain plicae circulares, which support intestinal villi. the villi are covered by a simple columnar epithelium whose apical surfaceis covered by microvilli. This arrangement increases the total area for digestion and absorption to more than 200 m |
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Term
| What is the function of plicae? |
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Definition
| Plicae are folds in the lining of the intestine that greatly increasethe surface area available for absorption |
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Term
| What are the functions of intestinal crypts? |
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Definition
| intestinnal crypts house the stem cells that produce new epitheial cells which renew the epithelial surface and add intracellular enzymes to the chyme. In addition, intestinal crypts contain cells that produce several intestinal hormones. |
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Term
| Which secretion of the small intestine serves as a "mixing bowl" |
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Definition
| the duodeum acts as a mixing bowl for the chyme entering from the stomach |
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Term
| The condition of cystic fibrosis interferes with the digestion of sugars, starches, lipids, nucleic acids and protiens? |
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Definition
| the condition of cystic fibrosis interferes with the digestion of sugars, lipids, nucleic acids and protiens |
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Term
| The liver act as a metabolic regulator by extracting nutrients and toxins from the blood before it enters the bloodstream. It also regulates the blood, serving as a blood resevior, phagocytizing old damaged RBC's and synthesizing plasma protiens. Finally the liver synthesizes and secretes bile |
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Definition
| the liver acts as a metabolic regulator by extracting nutrients and toxins from the blood before it enters the bloodstream. It also regulates the blood, serving as a blood reserviour, phagocytizing old or damaged RBC's and synthesizing plasma protiens. Finally, the liver synthesizes and secretes bile |
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Term
| contraction of the hepatopancreatic sphincter seals off the passagways between the gallbladder and the small intestine and keeps bile from entering the small intestine |
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Definition
| contraction of the hepatopancretic sphincter seals off the passageway between the gallbladder and the small intestine and keeps bile from entering the small intestine |
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Term
| the pancreas produce digestive enzyme and buffers (exocrine functions) and hormone (endocrine functions) |
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Definition
| the pancreas produces digestive enzymes and buffers (exocrine functions) and hormones (endocrine functions) |
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