Steroid Hormones

Question 1

Where is the adrenal gland located?

Answer 1

Above the kidney

Question 2

What gland produces steroid hormones?

Answer 2

The adrenal gland

Question 3

What part of the adrenal gland produces steroid hormones?

Answer 3

The adrenal cortex

Question 4

What type of steroid hormones does the G zone of the adrenal cortex produce and what do they effect?

Answer 4

Mineralcorticoids e.g aldosterone, effect salt and water balance

Question 5

What type of steroid hormones does the F zone of the adrenal cortex produce and what do they effect?

Answer 5

Glucocorticoids e.g cortisol, effect glucose metabolism, blood pressure, immune system

Question 6

What type of steroid hormones does the R zone of the adrenal cortex produce?

Answer 6

Androgens (sex hormones)

Question 7

What layer of the adrenal cortex produces aldosterone?

Answer 7

Zona glomerulosa

Question 8

What is the action of aldosterone?

Answer 8

Stimulates Na+ reabsorption from the distal convoluted tubules of the kidney in exchange for K+ or H+

Question 9

Describe the synthesis of aldosterone.

Answer 9

Renin-angiotensin system: renin cleaves angiotensinogen in the plasma to angiotensin 1, which is converted to angiotensin II in the lungs by converting enzyme, which acts on the adrenal gland to synthesize aldosterone

Question 10

What system controls the synthesis of aldosterone?

Answer 10

The Renin-angiotensin system (RAAS)

Question 11

What stimuli signal the release of renin from the kidney to ultimately cause the synthesis of aldosterone?

Answer 11

1. Decreased renal perfusion pressure
2. Na+ loss or restriction
3. Neural stimuli

Question 12

What stimuli signal the adrenal gland to produce aldosterone?

Answer 12

Angiotensin II, ACTH, and raised plasma K+

Question 13

What is the general action of cortisol?

Answer 13

Regulates carbohydrate, protein, and lipid metabolism

Question 14

What are the 4 metabolic effects of cortisol?

Answer 14

1. Catabolic - protein breakdown in muscle
2. Catabolic - lipolysis in adipose tissue
3. Immune system - suppresses function
4. Anabolic - gluconeogenesis in the liver

Question 15

How does cortisol increase blood glucose?

Answer 15

Stimulates gluconeogenesis in the liver by increasing sysnthesis of enzymes involved in gluconeogenesis

Question 16

Describe the different cortisol binding proteins.

Answer 16

80% of cortisol is bound to cortisol binding globulin which has low capacity but high affinity
15% of cortisol is bound to albumin which has high capacity but low affinity
5-10% of cortisol is free and biologically active

Question 17

Describe the capacity of cortisol binding globulin?

Answer 17

Low capacity but high affinity = once capacity is full then free cortisol builds up in the plasma