NEW non-LO

Question 1

CCK

Answer 1

Stimulus: drop in pH, fatty acids, amino acids

Location: Small Intestine

ACTION: Bile Secretion, Pancreatic Enzymes

Question 2

Secretin

Answer 2

Stimulus: fatty acids, amino acids, drop in pH

ACTION:
Pancreatic bicarbonate ion release
Enhances CCK
Pepsin secretion

Question 3

What stimulates insulin release?

Answer 3

Gastrin Inhibitory Peptide (GIP)

Question 4

What does does GIP stimulate?

Answer 4

insulin release

Question 5

Why is mastication important?

Answer 5

Digestion, especially of foods that include indigestible contents such as cellulose membranes in fruit and raw vegetables.

Question 6

Regulation of Gastric Juice secretion - phases?

Answer 6

Cephalic:

• sight or thought of food, stimulation of taste and smell receptors
• loss of appetite, depression

Gastric:

• stomach distension activates stretch receptors, food chemicals activate chemoreceptors.
• excessive axcidity, decline in gastric secretion

Intestinal:

• presence of partially digested food in intestines
• Enterogastric reflex

Question 7

Where do nutrients go after digestive tract?

Answer 7

Into the hepatic portal circulation:
Non-fat, water-soluble: portal circulation to liver

Fats: absorbed into the intestinal lymphatics, travel to systemic circulation through thoracic duct bypassing the liver

Question 8

What does the liver do with nutrients?

Answer 8

Absorbs for processing/storage before releasing back into circulation.
50-75% of nutrients absorbed.

Question 9

What happens to blood supply during digestion?

Answer 9

Increased
- Hormonal vasodilators released from the GI mucosa (CCK, gastrin, secretin)

• GI glands release vasodilators (kallidin & bradykinin)
• Dec. PO2 in gut wall increases blood flow 50-100%

Sympathetic innervation causes widespread vasoconstriction in GI tract

Question 10

Control of ADH secretion:

Answer 10

Inc ADH:
Inc. plasma osmolarity
dec. blood volume, pressure
nausea
hypoxia
drugs: morphine, nicotine, cyclophosphamide

Dec. ADH:
Dec blood osmolarity, inc blood volume, pressure
Drugs: Alcohol, hypertensives, dopamine blocker