Gastrointestinal System Flashcards
saliva
contains enzymes that initiate the breakdown of starch in digestion
digestion begins in the ____ and once food is swallowed it moves down to the ____, into the ____ and is en route to the ____
mouth; pharynx; esophagus; stomach
what are the 3 main functions of the stomach?
- mixing and storing food
- dissolving and degrading food via secretions
- controlling passage of food into the small intestine
where does protein digestion begin?
stomach
peristalsis
smooth muscle moves food, contracting and relaxing to move nutrients along
where does absorption occur?
small intestine
the liver is the largest ____ and largest ____
- where is it located?
solid organ; gland
- below the diaphragm on the right side of the chest
what is the liver made up of?
- how is it secured to the diaphragm and abdominal walls?
4 lobes: right, left, quadrate, and caudate lobes
- by 5 ligaments that are falciform (form a membrane- like barrier between the right and left lobes): coronary, right triangular, left triangular, and round ligaments
what does the liver do?
processes all of the blood that passes through the digestive system
what role does the hepatic portal vein play in digestion?
- hepatic artery?
- hepatic veins?
supplies the liver with nutrient rich blood
- supplies the liver with oxygen rich blood
- how blood leaves the liver
what is the livers functional unit?
lobules (made up of layers of liver cells)
how does blood enter the lobules?
through branches of the portal vein and hepatic artery, then the blood flows through small channels called sinusoids
what 3 things does the liver produce?
- bile
- certain blood plasma proteins
- cholesterol
what does the liver store?
excess glucose in the form of glycogen
what does the liver regulate?
amino acids and blood clotting
what does the liver process?
hemoglobin (to store iron)
the liver converts ____ to ____
ammonia; urea
what does the liver purify?
blood
how does the liver control infection?
by boosting immune factors
where is the pancreas located?
at the back of the abdomen, behind the stomach
what is the wider, right side of the pancreas called?
- the narrower, left side?
head
- tail
the head of the pancreas lies near the ____ and the tail near the ____
duodenum
- spleen
what kind of tissues is the pancreas made up of?
exocrine and endocrine tissues
what does the exocrine tissue in the pancreas do?
secretes digestive enzymes from a series of ducts that collectively form the main pancreatic duct
where is the main pancreatic duct located?
it connects to the common bile duct near the duodenum
what does the endocrine tissue in the pancreas do?
secretes hormones into the bloodstream
how does blood reach the pancreas?
from the splenic artery, gastroduodenal artery, and the superior mesenteric artery
what role does the pancreas play in digestion?
it secretes enzymes to the small intestine that help to break down many foods, especially fats and proteins
zymogens
precursors to the enzymes that the pancreas secretes; are produced by acini (a group of exocrine cells)
what happens once zymogens enter the small intestine?
they are converted to active enzymes (such as pancreatic lipase and amylase)
why does the pancreas secrete large amounts of sodium bicarbonate?
to neutralize the stomach acid that reaches the small intestine
where do the exocrine secretions of the pancreas go?
- where are they delivered from there?
wirsung’s duct (main pancreatic duct)
- the duodenum
where is bile stored between meals?
gallbladder
what is the lining of the small intestine covered with?
villi, tiny absorptive structures that increase the surface area for interaction with chyme (semi liquid mass of partially digested food)
microvilli
- what is microvilli’s role in the small intestine?
epithelial cells at the surface of villi
- increase the ability of the small intestine to serve as the main absorption organ of the digestive tract
what is the large intestine AKA?
- what does it do?
colon
- concentrates, mixes and stores waste material
where is the colon located?
ascends on the right side of the abdominal cavity, cuts across transversely to the left side, descends and attaches to the rectum
rectum
short tube for waste disposal
what needs to be stimulated to facilitate the expelling of waste?
a muscle sphincter at the end of the anus
