GI tract
a series of hollow mucous membrane-lined muscular organs
what is the key function of the GI system?
fluid and electrolyte balance
where does the GI tract receive fluids from?
ingested fluids
food
gallbladder
pancreas
upper esophageal sphincter
a circular muscle that prevents air from entering the esophagus and food from refluxing into the
throat
peristalsis
a contraction that propels food through the length of the GI tract
cardiac sphincter
lies between the esophagus and the upper end of the stomach. it prevents reflux of stomach contents
back into the esophagus
what 3 tasks does the stomach perform?
storage of swallowed food and liquid
mixing of food with digestive juices into chyme
regulated emptying of of contents into small intestine
what does pepsin and HCL help to do?
digest proteins
what does mucus do in the stomach?
it helps protect the stomach from acidity and enzyme activity
what does the intrinsic factor do?
it is essential in the absorption of vitamin B12
what are the 3 sections of the small intestine?
duodenum
jejunum
ileum
how long is the duodenum and what does it do?
8-11 inches
, continues to process fluid from the stomach
how long is the jejunum and what does it do?
8 feet
absorbs carbohydrates and proteins
how long is the ileum and what does it do?
12 feet
absorbs water, fat, and bile salts
how long is the large intestine?
5-6 feet
what parts is the large intestine divided into?
cecum
ascending colon
transverse colon
descending colon
sigmoid colon
rectum
ileocecal valve
a circular muscle layer that prevents regurgitation back into the small intestine
what are the 3 functions of the colon?
absorption, secretion, and elimination
what does the colon do?
it absorbs a large volume of water and significant amounts of sodium and chloride daily
constipation
occurs when peristaltic contractions slow down, and water continues to be absorbed
hemorrhoid
occurs when veins in the rectum become distended from pressure during straining
what are the physiological factors essential to bowel function?
normal GI tract function
sensory awareness of rectal distention
voluntary sphincter control
adequate rectal capacity and compliance
what factors influence bowel elimination?
age
diet
fluid intake