Functions of digestive structures Flashcards
MOUTH:
Describe the esophagus and its function.
Long, muscular tube
Carries food from pharynx to stomach
MOUTH:
What is peristalsis? What is its function?
The rhythmic, involuntary wave-like contractions of the GI tract’s smooth muscles
Ensures the movement of food through the GI tract
MOUTH:
What are enzymes and what do they do?
A protein chemical produced by cells. Increase the rate of biochemical reactions in the body
MOUTH:
Where is the enzyme amylase found? What does it do?
Enzyme found in saliva
Breaks down starch into simple sugars
MOUTH:
What is mucus (what does it act as)? What membrane does it form?
Protective secretion produced by epithelial cells. Acts as a lubricant
Forms the mucous membrane
MOUTH:
Where is mucus found in the mouth? What is its function here?
Found in saliva
Aids in swallowing
STOMACH:
What are sphincters? What do they do?
Circular muscles
Contract to close an opening in the body. Control movement of food into and out of stomach.
STOMACH:
Where is the gastroesophageal sphincter located?
What is its function when relaxed and contracted?
Located where esophagus joins stomach
Relaxed: allows food to enter stomach
Contracted: prevents food from moving back into esophagus
STOMACH:
Where is the plyoric sphincter located?
Located where stomach meets duodenum of small intestine.
STOMACH:
What are the three types of muscle that make up the stomach’s muscularis, from outermost to innermost?
Longitudinal, circular, oblique
STOMACH:
Longitudinal muscle runs ________ along the stomach.
longitudinally
STOMACH:
Circular muscle wraps _______ the stomach.
around
STOMACH:
What is an important characteristic of oblique muscle in the stomach? What is its function?
Has small wavy ridges called gastric folds which allow the stomach to expand as well as grip to food as it churns
STOMACH:
What is chyme? What is it produced by?
Semi liquid mixture of food and gastric juice.
Produced by the smooth muscles that compose the muscularis
STOMACH:
What is pepsin?
A protein-digesting enzyme produced in the stomach
SMALL INTESTINE:
What are villi (sing. villus) and where are they located?
Small finger-like projections
Located in the inner layer of the small intestine
SMALL INTESTINE:
What are microvilli?
What does the combined effect of microvilli and villi do?
Microscopic projections on the cell membrane of the epithelial cells that make up villi
Combined effect increases the surface area for absorbing nutrients greatly
SMALL INTESTINE:
What are lacteals?
Where are they located?
Small vessels through which digested fats enter the circulatory system
Located within a villus
SMALL INTESTINE:
What is the pancreas nestled in between?
Stomach and duodenum
SMALL INTESTINE:
What passes through the pancreatic duct? Where does it end up?
Substances secreted by the pancreas
Enters the duodenum
SMALL INTESTINE:
What do exocrine cells do in the pancreas?
Secrete pancreatic enzymes
SMALL INTESTINE:
What do endocrine cells do in the pancreas?
Secrete hormones into the bloodstream that regulate the absorption and storage of glucose from the blood
SMALL INTESTINE:
What is the duodenum? What is added to the small intestine by it?
First segment of the small intestine
Where most enzymes are added to the small intestine
SMALL INTESTINE:
What is cholecystokinin or CCK (when is it secreted)?
What is it secreted by?
What does it signal?
The hormone secreted when fat-rich chyme enters the duodenum.
Secreted by special cells in the mucosa of the duodenum
Signals stomach to slow down digestion speed to let the small intestine effectively digest the fats