Choudhury - Intestines, Rectum, and Anal Canal Flashcards
Where are enteroendocrine cells localized and what do they produce?
Where are Paneth cells localized and what do they produce?
found in base of intestinal crypts
contain large acidophilic granules
function is not well defined secrete enzyme lysozyme & peptide defensins degrade components of bacterial cell wall
Where are goblet cells localized and what do they produce?
What type of neuronal cell bodies (division and order) are in ganglia of the submucosal plexus?
What type of neuronal cell bodies (division and order) are in ganglia of the myenteric plexus?
Describe and relate the functional significance of plicae circulares
Describe and relate the functional significance of villi
evaginations of mucosa, w/ core of lamina propria, project into lumen
distinguishing characteristic of small intestine
ABSORPTION as well
Describe and relate the functional significance of microvilli
increase in surface area involves 3 magnitudes of “folding” for ABSORPTION
“Extreme” evagination and invaginations
Gastric glands in stomach
Crypts in intestine
Structure & function of plicae ciculares
circular folds of entire mucosa , w/ core of submucosa
permanent projections into lumen
begin in proximal duodenum
maximized in distal duodenum & proximal jejunum
diminish until virtually absent in distal half of ileum
plicae consists of multiple villi
“Great big villi”
Structure & function of plicae semilunares
LARGE INTESTINE
incomplete (half-moon) folds in intestinal wall
(do not form complete circular fold, as plicae in small intestine do)
produce characteristic sacculation (haustra)
Structure & function of plicae transversales
What is the importance of the lacteal in the intestinal villi?
Are villi found in the large intestine?
NO
What type of mucus is secreted in the jejunum region?
Basic mucus
Where are enteroendocrine cells found?
In the stomach and small intestine…usually in crypts
What do the enteroendocrine cells produce?
products include:
incretins (K-cells) (hunger, **increase insulin secretion**) GIP (L-cells)
serotonin (enterochromaffin cells)
somatostatin
motilin (gut sound in PCM!)
cholecystokinin neurotensin VIP substance P endorphins (opiates)
What do incretin cells (K-cells) increase?
They increase insulin secretion…before a big meal, when hungry
What causes parastalsis and gut sounds?
Motilin (protein secreted from small intestine enteroendocrine cells)