Digestive system Flashcards
What is digestion?
breaking down larger food molecules into smaller ones
What is absorption?
passage of these molecules into blood and lymph
Layers of the alimentary canal?
- mucosa 2. submucosa 3. muscularis 4. serosa
where is MALT located?
lamina propria of the mucosa layer
What is mastication?
chewing
saliva does?
moistens food, is a solvent and a buffer. Is 99.5% water and amylase
What is deglutition?
swallowing
What are the ranges for the stomach?
50 ml to 4 L
Chief cells?
pepsinogen
Gastric juice+food=
chyme
Chemical digestion
H coming together with Cl. activate pepsinogen to pepsin, which digests proteins.
Gastric absorption is impermeable except to?
water, ions, aspirin, alcohol
What does the liver emulsify?
fat
Kupffers cells?
fixed macrophages
What is the pH of Bile?
7.6-8.6
what are micelles?
fatty acids+bile salts+cholesterol in a ball
Small intestine is divided how?
- duodenum 2. jejunum 3. Ilieum
Plicae circulares?
increase surface area in the small intestine
MALT
mucosa associated lymphoid tissue
Peyers patches?
lymphoid tissue in the lamina propria
what percentage of absorption occurs in the small intestine?
90%
Carbs are digested how?
facilitated diffusion or active transport
lipids are digested how?
simple diffusion
vitamins are digested how?
simple diffusion
