Chapter 22partB

Question 1

The primary targets (organ/cells) of insulin are what?

Answer 1

skeletal muscle, adipocytes, liver

Question 2

The primary stimulus for insulin secretion is what? Further describe the stimulus by listing a quantitate value.

Answer 2

Parasympathetic NS (High blood glucose levels)
normal: 100mg/dL
too high: 200mg/dL
too low: 50mg/dL

Question 3

The precise name of the cells that secrete insulin is what? They are found where?

Answer 3

beta cells in the Islet of Langerhans in the pancreas

Question 4

Describe each effect insulin has on its targets (include the substrate and product where appropriate). For each substrate list its primary source in the body.

Answer 4

Skeletal muscle:
Increases protein synthesis
Increases glycolysis (glucose -> pyruvate)
Increases glycogenesis (glucose -> glycogen)
Adipocytes:
Increase lipogenesis (glucose -> triglycerides)
Liver:
Increase protein synthesis (e.g. albumin)
Increase glycolysis (glucose -> pyruvate)
Increase glycogenesis (glucose -> glycogen)

Question 5

How do the effects of insulin on its targets maintain homeostasis?

Answer 5

??

Question 6

What effect does insulin have on blood glucose levels?

Answer 6

It decreases blood glucose levels by converting the glucose to other forms of energy.

Question 7

The primary target (organ/cells) of glucagon is what?

Answer 7

Liver

Question 8

The precise name of the cells that secrete glucagon is what? Where are they found?

Answer 8

alpha cells in the islet of Langerhans in the pancreas

Question 9

The primary stimulus for glucagon secretion is what? Further describe the stimulus by listing a quantitate value.

Answer 9

Sympathetic NS (Low blood glucose levels)
normal: 100mg/dL
too high: 200mg/dL
too low: 50mg/dL

Question 10

Describe each of the effects glucagon has on the target (include the substrate and product where appropriate). For each substrate list its primary source in the body.

Answer 10

Liver:
glycogenolysis (glycogen -> glucose)
gluconeogenesis (glycerol, some AA, pyruvate -> glucose)
ketogenesis (fatty acids -> acetyl CoA -> ketone bodies)

Question 11

How do the effects of glucagon on its targets maintain homeostasis?

Answer 11

??

Question 12

What effect does glucagon have on blood glucose levels?

Answer 12

It increases and maintains blood glucose levels