Alimentary Canal Anatomy (second Half) Flashcards
1
Q
Stomach
A
- bolus converted into chyme
- food enters cardioesophogeal sphincter from the esophagus, then leaves into small intestine at the pyloric sphincter
- C-shaped, very elastic
- has cardia, fundus, greater and lesser curvature, and pyloric valve
2
Q
Stomach histology
A
- mucosa: simple columnar (almost all mucous cells)
- gastric pit: surface epithelium, leading to gastric glands that secrete gastric juice
- mucosa lined by mucosal barrier
- muscularis includes a third layer (oblique, allowing churning)
3
Q
Stomach mucosa cells (in gastric pit)
A
- chief cells
- parietal cells
- mucous neck cells
- enteroendocrine cells
4
Q
Chief cells
A
-produces protein-digestive enzymes (pepsinogens)
5
Q
Parietal cells
A
-produces HCl that activates enzymes
6
Q
Mucosa neck cells
A
-produces thin mucus (different from the ones produced by the mucous cells of the mucosa)
7
Q
Enteriendocrine cells
A
-produced local hormones (gastrin)
8
Q
Small intestine
A
- 2-4 m
- major site of chemical digestion and absorption
- muscular tube extending from pyloric sphincter to the ileocecal valve
- suspended from the posterior abdominal wall by the mesentary
- splits into: duodenum, jejenum and ileum
9
Q
Histology of small intestine
A
- all three regions have similar histology with some structural adaptations:
- increased surface area for food absorption that decrease in number towards the end
- has villi, microvilli, circular folds, and intestinal crypts
10
Q
Villi
A
-fingerlike projections formed by the mucosa
11
Q
Microvilli
A
-tiny projections of the PM with brush border enzymes
12
Q
Circular folds
A
- (plicae circulares)
- deep folds of the mucosa and submucosa. Causes chyme to spiral
13
Q
Intestinal crypts
A
-secretes intestinal juice and hormones
14
Q
Large intestine
A
- 1.5 m
- from ileocecal valve to the anus
- absorbs H2O, molecules made by bacteria, stores and eliminates residue
- parts: cecum, appendix, colon, and rectal Valves
15
Q
Cecum
A
-sac-like first part
