L9: Adrenocortical Hormones

Question 1

What are the 3 types of corticosteroids that adrenal cortex secretes?

Answer 1

1. Mineralocorticoids (electrolyte balance)
2. Glucocorticoids (glucose balance, protein, and fat metabolism)
3. Androgens

Question 2

two main steroids released from adrenal cortex

Answer 2

aldosterone and cortisol

Question 3

What are all human steroid hormones synthesized from?

Answer 3

cholesterol

Question 4

How are steroid hormones synthesized from?

Answer 4

• they are synthesized from cholesterol.
• 80% of cholesterol is provided by low-density lipoproteins (LDL) which are circulating the plasma
• LDL then moves from the blood and into IF to bind to receptors on adrenocortical cell membranes, which are then internalized by endocytosis
• LDL is then delivered to mitochondria where it can be cleaved into various steroid hormones produced by adrenal cortex

Question 5

What is the rate limiting step in the process of steroid hormones synthesis?

Answer 5

cleavage

Question 6

Which of the two main steroid hormones synthesized by adrenal cortex have a longer half-life in blood?

Answer 6

cortisol

Question 7

What does high concentrations of aldosterone in the plasma lead to?

Answer 7

it increases renal tubular reabsorption of Na and secretion of K

Question 8

One of the main roles of aldosterone in the body

Answer 8

retain Na within the body

Question 9

Does aldosterone cause a rise or a drop in arterial pressure?

Answer 9

it causes a rise in arterial pressure

Question 10

Pressure naturesis

Answer 10

an increase in kidney excretion of salt due to the rise in arterial pressure which is due to aldosterone

Question 11

Pressure diuresis

Answer 11

an increase in kidney excretion of water due to the rise in arterial pressure which is due to aldosterone

Question 12

What part of the adrenal cortex is responsible for the secretion of aldosterone, cortisol and androgens?

Answer 12

aldosterone -> cells in the zona glomerulosa
cortisol -> cells in the zona fasciculata
androgens -> cells in the zona reticularas

Question 13

Does the regulation of aldosterone secretion act independently or dependently of the regulation of cortisol and androgens?

Answer 13

it acts independently

Question 14

4 main factors that play a role in regulation of aldosterone secretion

Answer 14

1. Increase in K+ in extracellular fluid.
2. Increase in angiotensin II in extracellular fluid
3. Increase in Na+ in extracellular fluid
4. ACTH from anterior pituitary is necessary, but does not control rate of secretion.

Question 15

Which two of the four factors work together to cause a great increase in aldosterone secretion?

Answer 15

increase in potassium and angiotensin II in extra cellular fluid (1 +2)

Question 16

Renin-Angiotensin-Aldosterone System (RAAS)

Answer 16

• hormone system within the body which is essential for regulation of blood pressure and fluid balance
• comprised of renin, angiotensin II, and aldosterone
• primarily regulated by rate of renal blood flow

Question 17

Two ways in which cortisol effects carbohydrate metabolism

Answer 17

1. Stimulation of gluconeogenesis ( this is done in two ways - cortisol increases the enzyme required to convert amino acids into glucose in the liver cells, and cortisol mobilized amino acids from muscle)
2. Adrenal diabetes

Question 18

adrenal diabetes

Answer 18

• presence of cortisol leads to increase in gluconeogenesis and decrease of glucose utilization by tissues causing plasma concentration of glucose to increase
• this leads to pancreas secreting insulin, however tissues are not as sensitive to insulin
• tissues aren’t as sensitive to insulin so injection of insulin is not going to have the same effect as for pancreatic diabetes

Question 19

Two ways in which cortisol effects protein metabolism

Answer 19

1. Reduction of cellular proteins in all cells bu liver (two ways in which this can occur - decreased protein synthesis and increased catabolism of proteins)
2. Increased protein production in liver

Question 20

Two ways in which cortisol effects fat metabolism

Answer 20

1. Promotes mobilization of fatty acids from adipose tissue
2. Enhanced oxidation of fatty acids in the cells
   - these two traits together shift the metabolic systems of the cells from glucose for energy to fatty acids

Question 21

main stress hormone

Answer 21

cortisol

Question 22

What is an anti-inflammatory hormone?

Answer 22

Cortisol is also an anti-inflammatory hormone which means it prevents the widespread tissue and nerve damage associated with inflammation

Question 23

Is cortisol expressed in the same amounts during day and night?

Answer 23

no, cortisol is expressed in higher amounts throughout the day than at night