Absorption

Question 1

Basics of Absorption

Answer 1

Most absorption takes place in the duodenum and jejunum.
Molecules are absorbed by specialized cells and tissues (intestinal villi and interstitial epithelial cells).
Nutrient absorption occurs through simple diffusion, facilitated diffusion, and active transport.

Question 2

Interstitial Villi

Answer 2

Involved in absorption in the small intestine.

Question 3

Absorption in the Mouth

Answer 3

Small amounts of some vitamins, glucose, and drugs.

Question 4

Stomach Absorption

Answer 4

Stomach absorbs water, alcohol, some medium-chain fatty acids, and aspirin and other drugs.
Enteric coated drugs don’t dissolve until the small intestine.

Question 5

Small Intestine

Answer 5

95% of absorption takes place in duodenum and jejunum.
Involves peptides and amino acids, glucose, fructose, and galactose, fatty acids, most vitamins, water and alcohol, and minerals including calcium, magnesium, and iron.

Question 6

Absorption in the Large Intestine

Answer 6

Water, sodium, and potassium.
Short chain fatty acids.
Bacteria synthesize and absorb some vitamin B and lots of vitamin K.

Question 7

Regulation of Digestion

Answer 7

Enteric nervous sytem (ENS) under hormonal and parasympathetic control.
ENS works with the CNS.