Term
| The digestive system consists of 2 subsections. What are they? |
|
Definition
| The alimentary canal and the accessory organs. |
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Term
| What organs constitute the alimentary canal? |
|
Definition
1) Mouth
2) pharynx
3) esophagus
4) stomach
5) small intestines
6) large intestines
7) anal canal |
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Term
| Beginnings of alimentary canal organs. |
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Definition
|
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Term
| What are accessory organs? |
|
Definition
1) Salivary glands
2) Liver
3) Gallbladder
4) Pancreas |
|
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Term
| Mnemonic for accessory organs. |
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Definition
|
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Term
| What's the function of the salivary glands in digestion? |
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Definition
| Secrete saliva, which contains enzymes that breakdown carbs. |
|
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Term
| What's the function of the MOUTH in digestion? |
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Definition
| Mechanical breakdown of food. Begins chemical digestion of carbs. |
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Term
| What's the function of the PHARYNX in digestion? |
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Definition
| Connects mouth & esophagus |
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Term
| What's the function of the ESOPHAGUS in digestion? |
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Definition
| Peristalsis pushes food to stomach. |
|
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Term
| What's the function of the STOMACH in digestion? |
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Definition
| Secretes acid and enzymes. Mixes food with secretions to begin enzymatic digestion of proteins. |
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Term
| What's the function of the LIVER in digestion? |
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Definition
Produces bile which emulsifies fats.
It also stores glycogen. |
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Term
| What's the function of the GALLBLADDER in digestion? |
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Definition
| Stores bile and introduces it into the small intestines. |
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Term
| What's the function of the PANCREAS in digestion? |
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Definition
| Produces/secretes pancreatic juice, containing digestive enzymes & bicarbonate ions, into small intestines |
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Term
| What's the function of the SMALL INTESTINES in digestion? |
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Definition
| Mixes food with bile and pancreatic juice. Final enzymatic breakdown of food molecules. MAIN SITE of nutrient absorption! |
|
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Term
| What's the function of the RECTUM in digestion? |
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Definition
| Regulates elimination of feces woo |
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Term
| What's the function of the LARGE INTESTINES in digestion? |
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Definition
| Absorbs water and electrolytes to form feces |
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Term
| Alimentary canal is a muscular tube that is BLANK meters long |
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Definition
8 m
(and considering we're usually 1.7 meters tall, its folded a lot!) |
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Term
| Alimentary canal wall has 4 layers: |
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Definition
Deepest: Mucosa
Submucosa
Muscular layer
Superficial: Serosa |
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Term
|
Definition
Have Villi, extensions into the lumen.
May contain glands that secrete digestive enzymes. |
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Term
|
Definition
Contains loose connective tissue.
Contains, glands, blood.vessels, lymph.vessels, nerves...
Provides NOURISHMENT for tissue & carry away nutrients. |
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Term
|
Definition
Consists of 2 layers of smooth muscle.
Provide movements of the Alimentary tube.
Circular layer (inner): When contracted, the diameter of the tube decreases.
Longitudinal layer (outer): when contracted, the length of the tube decreases |
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Term
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Definition
Covering of the tube, continuous with visceral peritoneum.
Some cells in this layer secrete serous fluid: DECREASES FRICTION to allow free movement of the tube |
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Term
Segmentation.
Mixes how?
Pattern? |
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Definition
Mixes by contracting and relaxing different parts of the tube.
No set pattern.
Does not push food down the tube. |
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Term
|
Definition
| Wave-like contractions of the tube to move the food through it. |
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Term
|
Definition
| connects tongue to floor of mouth |
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Term
Palate is...
Anterior HARD palate is formed by...
Posterior SOFT palate is formed by... |
|
Definition
the roof of the mouth.
maxillary & palatine bones
muscular & uvula |
|
|
Term
| Pharyngeal tonsils (adenoids) |
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Definition
| located on the posterior wall of the pharynx, behind the nasal cavity, above soft palate |
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Term
|
Definition
| Located in the back of mouth on both sides (what we typically think of) |
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Term
| Esophagus length, location, |
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Definition
| 25 cm long, posterior to trachea in thorax, contains many mucus glands, Lower esophageal sphincter: circular smooth muscle fibers that close the entrance to the stomach |
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Term
|
Definition
Cardia - small area near esophageal sphincter
Fundus - balloon-like superior part Body - main part
Pylorus - distal portion, connects to duodenum |
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Term
| Pyloric sphincter closes: |
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Definition
|
|
Term
3 types of cells in gastric glands.
(All 3 secretions combine to form gastric juice!) |
|
Definition
Mucus cells
Chief cells: secrete pepsinogen
Parietal cells: secrete HCl |
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Term
| Gastric secretions: pepsinogen --> pepsin by |
|
Definition
HCl
(Pepsin breaks down proteins into smaller polypeptides) |
|
|
Term
| Follow the path of food down digestive tract. |
|
Definition
| (mind/senses) --> mouth --> pharynx --> esophagus --> [esophageal sphincter] --> stomach --> [pyloric sphincter] --> duodenum -> jejunum -> ilium --> [ileocecal sphincter] --> cecum --> ascending colon --> [hepatic flexure] --> Transverse colon --> [splenic flexure] --> Descending colon --> sigmoid colon --> rectum --> anal canal --> anus |
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Term
| 3 Parts of the Small intestines & some characteristics |
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Definition
Duodenum - shortest portion
Jejunum - middle.
Ileum - distal portion; more lymph nodules & bacteria |
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Term
| Mesentery - what's its deal? |
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Definition
| It suspends jejunum & ileum from posterior abdominal wall. It contains blood vessels, nerves, & lymphatic vessels |
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Term
| Greater omentum - where does it drape over? |
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Definition
| it drapes from stomach over colon (LI) and small intestines |
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Term
| Villi in duodenum. what are they? what's their purpose? |
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Definition
are tiny projections into lumen.
their purpose is to increase surface area for increased absorption. |
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Term
| Which are the secretions in the small intestines? |
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Definition
1) mucus-secreting glands (aka Brunner's glands)
2) intestinal glands (peptidase, lipase, sucrase, maltase, lactase) |
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Term
| small intestines absorbs almost all nutrients and water. This includes amino acids, lipids, carbs. |
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Definition
|
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Term
| Amino acid absorption in small intestines is by what method? |
|
Definition
| absorbed by active transport. |
|
|
Term
| Where does protein digestion begin? |
|
Definition
|
|
Term
|
Definition
| almost entirely by enzymes of the small intestines and pancreas (bile) |
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Term
| Fat absorption. Series of steps: |
|
Definition
1) Fatty acids are absorbed by epithelium of villi
2) ER uses acids to synthesize fat molecules
3) Fat molecules collect in clusters and become encased in protein (=lipoprotein.) (which is aka CHYLOMICRON).
4) Move towards LACTEALS of villi
5) Smooth muscle contractions move chylomicrons into lymph |
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Term
| What are lacteals of villi? |
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Definition
| a Lacteal is a lymphatic capillary that absorbs dietary fats in the villi of the small intestine |
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Term
|
Definition
| It is another name for lipoprotein. which are clusters of fats encased in proteins ready to be absorbed by body. (they eventually move into lymph). Once in blood, chylomicrons transport dietary fats to muscle & adipose tissue |
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Term
|
Definition
| a cavity in the small intestines. |
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|
Term
Carbohydrate Absorption.
-what type of transport?
-where does carb digestion start in? |
|
Definition
-faciliated diffusion or active transport
-Carb digestion starts in MOUTH |
|
|
Term
| What's the fate of excess dietary carbs? |
|
Definition
| turn into triglycerides. And Very-low (VLDL) carries them. |
|
|
Term
| Where does VLDL convert to LDL? by what? |
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Definition
| when VLDL reaches adipose tissue, it's converted. By Lipoprotein lipase. |
|
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Term
| LDL delivers BLANK to BLANK |
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Definition
| LDL delivers CHOLESTEROL to TISSUES |
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Term
| HDL removes BLANK from BLANK and brings it to the BLANK |
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Definition
| HDL removes CHOLESTEROL from TISSUE and brings it to the LIVER |
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Term
| Cholesterol enters the BLANK by receptor-mediated endocytosis. Where is this cholesterol used? |
|
Definition
enters the LIVER.
this cholesterol is either used to make bile salts or secreted in bile. |
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Term
| How are things absorbed (easily, poorly) |
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Definition
1) Na, K, Cl, Nitrate, and Bicarbonate are easily absorbed by SI
2) Ca, Magesium, and Sulfate are poorly absorbed
3) Electrolytes are usually absorbed by active transport
4) Water is usu absorbed by osmosis |
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Term
| Peristalsis is slow thru the small intestine. How long does it take? |
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Definition
| 3-10 hours to move from duodenum to large intestine |
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|
Term
|
Definition
| If SI become irritated or bloated, a strong peristaltic rush may pass the chyme through to the large intestine. Therefore, water and nutrients are not absorbed --> diarrhea |
|
|
Term
| what's the gastroileal reflex? |
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Definition
| when food enters the empty stomach, there is an increase in motility of ileum (last part of SI) & ileocecal valve opens |
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|
Term
| What's does the gastroileal reflex do (repeated question, little different of an answer) |
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Definition
| it increases peristalsis and relaxes the ileocecal sphincter (aka opens) - (when not open, sphincter limits movement into LI. duh. |
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Term
Large intestine
-how long? What's it do?
Begins in the lower right quadrant (so left in pictures) ascends on right, descends on left into the pelvis |
|
Definition
1.5 meters long
Absorbs any remaining water, electrolytes, remnants of digestive secretions.
Forms and stores feces (like last stage) |
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|
Term
| Order the parts of the colon include the two flexures |
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Definition
| ascending colon --> colic/hepatic flexure --> transverse colon --> colic/splenic flexure --> Descending colon --> Sigmoid colon |
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|
Term
Anal canal
-how long?
-how many sphincters/where/what kind of muscle |
|
Definition
lasts 2.5 - 4 cm
-1 internal anal sphincter - smooth muscle
-1 external anal sphincter - skeletal muslce |
|
|
Term
|
Definition
-Lacks villi
-Fibers are in distinct "teniae coli" that runs throughout
-Pouches from tension form = called "haustra"
-small collections of fat in serosa = called "epiploic appendages"
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Term
| Functions of Large Intestine |
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Definition
-Has little digestive function
-mucus glands scattered throughout LI
-mechanical stimulation from chyme and parasympathetic impulses control mucus secretion
-mucus protects wall from abrasions |
|
|
Term
what goes on in the LI?
-what's chyme made of at this point?
-what does it absorb? |
|
Definition
Chyme is now undigested material, water, electrolytes, mucus & bacteria - NO NUTRIENTS LEFT
-Absorption is limited to H20 & electrolytes |
|
|
Term
What else happens in the large intestines?
(hint: intestinal flora's role and cellulose's fate) |
|
Definition
intestinal flora is a bacteria that lives there and synthesizes vitamines K, B12, thiamine & riboflavin
&
LI break down molecules ex. cellulose that can't be digested by human enzymes
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|
|
Term
Peristalsis occurs how many times a day?
|
|
Definition
| 2 to 3 times a day (slow) |
|
|
Term
| when feces is pushed into anal canal, what happens to each of the anal sphincters? |
|
Definition
| 1st internal a.s. relaxes then 2nd external a.s. relaxes |
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|
Term
| What is feces composed of? |
|
Definition
| Undigested or unabsorbed stuffs: water, electrolytes, mucus, & bacteria |
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|
Term
Salivary glands. Each gland contains varying amounts of 2 cell types:
|
|
Definition
1) serous cells - secrete salivary amylase
2) mucus cells - secrete mucus, which is a lubricant for swallowing |
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|
Term
Salivary glands.
3 types. Sizeish. where and what are they made of? |
|
Definition
1) Parotid glands - Largest. Anterior to each ear. Produces saliva high in amylase.
2) Submandibular glands - In floor of mouth, inside mandible. Mixture of mucus & salivary amylase.
3) Sublingual glands - Smallest. In floor of mouth, inferior to tongue. Saliva high in mucus. |
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Term
| Pharynx. Connects nasal cavity to esophagus. 3 parts: |
|
Definition
Nasopharynx (superior to soft palate
Oropharynx (right behind mouth)
Laryngeopharynx |
|
|
Term
| What's momentarily inhibited when the swallowing reflex is triggered (when bolus is forced down the pharynx by the tongue) |
|
Definition
Breathing!
Scarf. scarf. scarf. |
|
|
Term
| What occurs during the swallowing reflex? |
|
Definition
Soft palate raises to keep bolus from entering nasal cavity.
& Tongue presses against soft palate to close oral cavity from nasal cavity.
-Hyoid & larynx elevate.
-Epiglottis covers trachea (so you dont breath in food).
-Longitudinal layer of muscle of pharynx contracts, which pulls the pharynx closer to the mouth.
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|
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Term
| swallowing reflex - what's the deal with the constrictors? |
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Definition
You swallow, inferior constrictors relax, opening the esophagus.
Superior constrictors contract, initiating peristalsis.
Bolus enters the esophagus & peristalsis continues until the bolus reaches the stomach. |
|
|
Term
| where are the pharyngeal constrictor muscles located, roughly? They're big. |
|
Definition
superior is in cheek area.
Inferior is in throat, kinda by adam's apple |
|
|
Term
|
Definition
| 25 cm long about 10 inches |
|
|
Term
Stomach
-has an additional layer of BLANK |
|
Definition
| of oblique fibers. (inner-most) in the muscular layer of wall. |
|
|
Term
|
Definition
| small openings that house gastric glands. |
|
|
Term
| What are the 3 types of cells in gastric glands? |
|
Definition
1) Mucus cells
2) Chief cells: secrete pepsinogen
3) Parietal cells: secrete HCL
(All 3 secretions combine to form gastric juice) |
|
|
Term
| what are the gastric secretions? |
|
Definition
1) pepsinogen
2) gastric lipase (breaks down fats) |
|
|
Term
| What do parietal cells secrete? |
|
Definition
-Intrinsic factor - needed for vitamin B12 absorption
and HCl |
|
|
Term
| What does somatostatin do? |
|
Definition
| In the stomach, it inhibits secretion of gastric juices. |
|
|
Term
|
Definition
| In the stomach, gastrin stimulates secretion of gastric juices. (parasympathetic stimulation) |
|
|
Term
| What are the 3 gastric secretion phases? |
|
Definition
1) Cephalic phase
2) Gastric phase
3) Intestinal phase |
|
|
Term
| Cephalic phase. Describe it. |
|
Definition
Begins before food reaches the stomach.
Prepares stomach for food.
30-50 % secretory response to food! |
|
|
Term
| Gastric phase. Describe it. |
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Definition
Begins when food enters the stomach.
40-50% of secretions. |
|
|
Term
| Intestinal phase. Describe it. |
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Definition
Begins with food leaves the stomach.
About 5% of secretory response. |
|
|
Term
|
Definition
Stomach is not well-adapted to absorb nutrients. What is? some salts, some lipid-soluble drugs are absorbed.
Alcohol is absorbed at the stomach (and SI) |
|
|
Term
| What causes a stomach-ache? |
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Definition
| Pain receptors are stimulated when food is stretching the stomach. |
|
|
Term
|
Definition
| mix of food particles and gastric juices. |
|
|
Term
Peristalsis pushes the food toward BLANK.
Pyloric sphincter BLANKS, stomach contractions push chyme in small amounts in duodenum |
|
Definition
Peristalsis pushes the food toward pylorus.
P.S. RELAXES so now stomach pushes chyme. |
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Term
|
Definition
| inhibits chyme from the stomach from emptying into duodenum, if d.d. is overloaded |
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|
Term
|
Definition
| reflex that empties the stomach due to distension (stretched out) or irritation |
|
|
Term
|
Definition
| nerves in or near vomitting center of medulla oblongata --> stomach movements diminish and chyme may move from duodenum into stomach (BACKWARDS) |
|
|
Term
| PANCREAS: where does it empty into |
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Definition
| Empties into duodenum at same location as bile duct |
|
|
Term
| Pancreas's exocrine portion secretes pancreatic juices. |
|
Definition
|
|
Term
|
Definition
| posterior to stomach. kinda by duodenum. |
|
|
Term
| Acinar cells secrete substances into BLANK |
|
Definition
|
|
Term
| Pancreatic juice consists of: |
|
Definition
1) Pancreatic amylase
2) Pancreatic lipase
3) Trypsin, chymotrypsin, & carboxypeptidase - break down proteins
4) Nucleases - break down DNA |
|
|
Term
| Trypsinogen is activated by BLANK and activates BLANK and BLANK |
|
Definition
| activated by enterokinase. Activates chymotrypsin & carboxy peptidase. |
|
|
Term
| What two things increase pancreatic secretion? |
|
Definition
| parasympathetic stimulation and Secretin. |
|
|
Term
| what's the largest internal organ? |
|
Definition
|
|
Term
| What divides the liver into right and left lobes? |
|
Definition
|
|
Term
| What are the two names of the lobes of the liver (NOT RIGHT AND LEFT)? And what is each near? |
|
Definition
Quadrate lobe: near gallbladder
Caudate lobe: near Inf Vena Cava |
|
|
Term
| What extends from the central vein? |
|
Definition
| Hepatic sinusoids. They separate hepatic cells (?) |
|
|
Term
| What lines the sinusoids? And what do they do? |
|
Definition
| Kupffer cells. they remove bacteria. |
|
|
Term
| What do hepatic cells (LIVER) secrete? |
|
Definition
|
|
Term
| Bile BLANK merge to form bile BLANK which merge to form BLANK, which merge again to form BLANK. ha good luck. go. |
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Definition
| Bile CANALICULI merge to form bile DUCTULES which merge to form HEPATIC DUCTS, which merge agin to form COMMON HEPATIC DUCT. |
|
|
Term
| What two chemical substances does the liver respond to? |
|
Definition
|
|
Term
| Does the liver play any role at all in lipid metabolism? |
|
Definition
|
|
Term
| What are some substances the liver stores? |
|
Definition
| iron, vitamin A, vitamin D, and vitamin B12 |
|
|
Term
| In what form is iron stored as in the liver? |
|
Definition
|
|
Term
| The liver removes toxins from the blood stream, including: |
|
Definition
| alcohol, damaged RBCs, foreign antigens |
|
|
Term
|
Definition
| a liquid that hepatic (LIVER) cells secrete. It comes water, bile salts, bile pigments, cholesterol & electrolytes (Bile salts are also made from cholesterol) --> and bilirubin & biliverdin (products of broken down hemoglobin) |
|
|
Term
|
Definition
| sac organ on the inferior surface of liver. Stores & concentrates bile by reabsorbing water. |
|
|
Term
| Bile duct, of gallbladder, is formed by BLANK and cystic duct merging. Travels to BLANK |
|
Definition
1) common hepatic duct
2) travels to DUODENUM |
|
|
Term
| Regulation of bile release |
|
Definition
| stimulated to be released by proteins & fats entering the duodenum |
|
|
Term
|
Definition
1) Chyme with fat enters duodenum
2) Cells from the intestinal mucosa secrete the hormone CCK into the bloodstream
3) CCK stimulates muscular layer of gallbladder wall to contract
4) Biles passes down the cystic duct and common bile duct to duodenum
5) Hepatopancreatic sphincter relaxes and bile enters duodenum |
|
|
Term
| What are the functions of bile salts? |
|
Definition
aid digestive enzymes
emulsification: break down lipids into droplets
enhance absorption of fatty acids and cholesterol
Bile salts are absorbed by small intestines and brought back to liver |
|
|
Term
| Small intestine. -how long - function |
|
Definition
6 meters long
receives secretions from pancreas & liver
completes digestion of nutrients in chyme
absorbs products of digestion
transports left over to LI |
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