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Question 1

four elements of regulatory system

Answer 1

• system variable (body temp)
• set point (36.5)
• detector (body temp detectors)
• correctional mechanism (sweating)

Question 2

osmometric thirst vs volumetric thirst

Answer 2

Osmometric: The interstitial fluid draws
water out of cells, detected by osmoreceptors. (salty meals, evaporation)
Volumetric: Loss of water body due to bloodloss, diarrhea, vomiting etc; triggers angiotensin, which stimulates thirst, inhibits secretion water and causes sodium hunger.

Question 3

Short term reservoir

Answer 3

Supplies nutrients to the brain during brief periods of fasting. It is located in the liver, where energy is stored in glycogen molecules until needed.

Question 4

Long term reservoir

Answer 4

The long-term reservoir supplies nutrients to the brain and body during prolonged periods of fasting. It is located in the adipose tissue, where energy is stored in triglyceride molecules until needed.

Question 5

Fasting phase

Answer 5

Unused glucose, fat, and amino acids are stored in the liver and adipose tissues for later use during the fasting phase. During this phase, level of insulin falls, liver converts glycogen into glucose triglycerides into fatty acids. CNS is reserved for CNS when insulin is absent.

Question 6

Absorptive phase

Answer 6

Glucose, amino acids and fats are received from the intestines. Insulin level is high, which permits all cells to metabolize glucose. Liver and the muscles convert glucose to glycogen, which replenishes the short-term reservoir. Excess carbohydrates and amino acids are converted to fats, and fats are placed into the long-term reservoir in the adipose tissue.

Question 7

Ghrelin

Answer 7

Peptide hormone released by the stomach when empty, it is a potent stimulator of food intake. Ghrelin levels are low during the absorptive phase, and increase before a meal.