T7. MOTILITY, ABSORPTION AND SECRETION IN THE COLON Flashcards
(65 cards)
Where does the colon begin?
At the cecum, just after the ileocecal valve
What attaches to the lower end of the cecum?
The appendix
What follows the cecum in the colon?
The ascending colon
What colon sections frame the small intestine?
Ascending, transverse, and descending colon
What comes after the descending colon?
The sigmoid colon
Where does the sigmoid colon lead?
Down into the pelvis
What follows the sigmoid colon?
The rectum
Where does the large intestine end?
At the anal canal and anus
How long is the anal canal?
About 3 cm
What happens in the anal canal during defecation?
Mucus is released
What does the gross anatomy of the colon include?
Cecum, appendix, ascending, transverse, descending, sigmoid colon, rectum, anal canal
Where does the duodenum begin and end?
First 25–30 cm, ends at the duodenojejunal flexure
What does the duodenum receive?
Stomach contents, pancreatic juice, and bile
What occurs in the duodenum with stomach acid?
It is neutralized
What happens to fats in the duodenum?
They are emulsified by bile salts
What happens to pepsin in the duodenum?
It is inactivated by increased pH
What enzymes take over digestion in the duodenum?
Pancreatic enzymes
How much of the small intestine is the jejunum?
40% of the postduodenal small intestine
What is the wall of the jejunum like?
Thick and muscular
Where does most digestion and absorption occur?
In the jejunum
How much of the small intestine is the ileum?
60% of the postduodenal small intestine
What are structural characteristics of the ileum?
Thinner, less muscular, less vascular
What is the ileocecal junction?
Where the ileum joins the cecum of the large intestine
What is the ileocecal valve?
A sphincter regulating passage of residue into the large intestine
