Histology Of Lower GI-1/8/16 Flashcards
___ are folds of the mucosa projecting into the lumen of the SI. These increase the absorptive surface of the mucosa
Villi
What are the 4 degrees of folding of the SI?
1) Plicae circulares
2) Intestinal villi
3) Intestinal glands (of Lieberkuhn)
4) Microvilli on the apical surface of enterocytes
___ are permanent folds of the mucosa and submucosa that begin in the duodenum, distinct in the jejunum, and disappear mid-ileum
Plicae circulares
____ are finger-like projection of the mucosa covering the entire surface of the SI (increase the surface area)
Villi
Villi extend deep into the mucosa to form ____ ending at the muscularis mucosae
crypts of lieberkuhn
____ are simple tubular glands that increase the intestinal surface area. They are formed by invaginations of the mucosa between adjacent intestinal villi
Crypts of Lieberkuhn
What are the cell types of the crypts?
Absorptive
Goblet
Paneth
Enteroendocrine
____ are evaginations of the apical part of the enterocytes to increase surface area. They produce a brush border on the apical border of enterocytes
Microvilli
This layer of the SI wall is responsible for segmentation and peristalsis:
Muscularis externa
This layer of the SI wall is a thin layer of loose CT covered by visceral peritoneum (mesothelium)
Serosa
This layer of SI wall is the site for the main distribution of blood and lymphatic flow:
Submucosa
This capillary plexus supplies the intestinal villus and upper part of the crypts of lieberkuhn:
Villus capillary plexus
This capillary plexus supplies the lower half of the crypts of lieberkuhn
Pericryptal capillary plexus
___ are within a villus and convey chyle (lymph containing lipids absorbed from the meal and package in chylomicrons) from the intestine to the lymphatic circulation and thereby to the thoracic duct and then to the systemic blood circulation
Lacteals
Motility of the SI is controlled by ___ through submucosal and myenteric plexi
ANS