2. part of the gastrointestinal tract
following the stomach and followed
by the large intestine
where much of the digestion and
absorption of food takes place
primary function is to absorb the
nutrients and minerals found in food
3.
4. average length of the small intestine
in an adult male
- 22 feet 6 inches (6.9 m)
in the adult female
- 23 feet 4 inches (7.1 m)
5. The small intestine is where most
digestion takes place.
It is structurally divided into three
parts:
› duodenum
› jejunum
› ileum
6.
7. major distinguishing feature is the presence of duodenal
(Brunner's) glands in the submucosa
where most of the breakdown of food in the small
intestines occurs.
mucous cells of these glands produce an alkaline secretion
protects the duodenal lining from the acidity of the chyme
raises the luminal pH to the optimum level for pancreatic
enzyme activity
also the point of entry for the bile and pancreatic ducts
exhibits fingerlike or leaflike villi
few goblet cells
8. The duodenum consists of four parts, with
the first three forming a "C" shape.
› first or superior part begins at the pylors, passing
laterally for a short distance before curving into the
superior duodenal flexure
› second or descending part passes from the superior
into the inferior duodenal flexure
› third or inferior part passes from the inferior
flexure, crossing the major artery and the major
vein and also the spinal column
› forth or ascending part passes over the aorta, and
curves past the pancreas to the duodenojejunal
flexure
10. has long leaflike vilii
many plicae circulares
an intermediate number of goblet cells
The key to its identification is that although it
has villi (part of the small intestine), it
doesn’t contain Brunner's glands or Peyer's
patches.
11.
12. final and longest section of the small intestine
jejunum and ileum both suspended by a double
layer of peritoneum that allows these parts to
move more freely within the abdomen
responsible for the final stages of protein and
carbohydrate digestion
has fewer villi, which are short and broad-
tipped (clublike)
relatively abundant goblet cells