Lecture 8 Flashcards
Role of Stomach
To digest food and control the flow of its contents into the intestine
Stomach properties
Acts as a food reservoir
Processes food into fluid chyme for nutrient absorption
Regulates food delivery to intestine
Gastric emptying half-time is about
30 minutes
Three primary regions of stomach
Fundus- contains gas and makes contractions to move stomach contents
Body-reservoir for ingested food and fluids
Antrum-lowest part of the stomach, funnel shaped, contains the pyloric region and controls flow into the small intestine
Transit times
Mouth to anus - 24-32 hours
Small intestine - 3 hours
T/F: Colon drug absorption mainly occurs in the ascending region nearest to the SI`
True
Intestine Characteristics
Most transporters are located in SI
Upper Si = mixing
Lower SI = electrolyte
Colon = fluid and electrolyte absorption
Intestinal Absorbing Surface Area
Area of cylinder - 1
Folds of Kerckring X3
Villi X 30
Microvilli X 600
T/F: Things can get stuck in villi
False
T/F: Columnar epithelial cells form a single continous layer of absorptive cells?
True
Crypt region
3x more crypt than villi, comprised of undifferentiated cells that proliferate
Goblet cells - mucus secreting; Paneth cells-regulate microflora
Villus Region
Absorptive enterocytes
Few goblet cells do appear
Cells from crypt migrate to villus tip
Colon Characteristics
125 cm long from caecum to anus, with transport being much slower than in small intestine
Colon thickness
Varies from 2.5 Cm in the sigmoid region to 8.5 cm in the caecum
T/F: Ileocecal valve limits food flow from the ileum into the caecum vice-versa
True
