10. Effects of Adrenal Hormones

Question 1

What are the 3 zones in the adrenal glands?

Answer 1

Zona glomerulosa
Zona fasciculata
Zona reticularis

Question 2

Name a mineralocorticoid

Answer 2

Aldosterone

Question 3

Name a glucocorticoid

Answer 3

Cortisol

Question 4

What is the main sex hormone made in the adrenal cortex?

Answer 4

DHEA

Question 5

What zone are mineralocorticoids made in?

Answer 5

Glomerulosa

Question 6

What zone are glucocorticoids made in?

Answer 6

Fasciculata

Reticularis

Question 7

Where are the adrenal sex hormones produced?

Answer 7

Fasciculata

Reticularis

Question 8

Why are only small amount of adrenal hormones found in adrenocortical cells at a given time?

Answer 8

Cells produce and secrete them on demand rather than storing them

Question 9

How are adrenocortical steroids transported?

Answer 9

Plasma proteins

eg. CBG, albumin

Question 10

What is the function of aldosterone?

Answer 10

Acts at distal and collecting tubes of kidney
-Retains Na+, expanding ECF volume
-K+ elimination
Regulation of BP

Question 11

What increases aldosterone secretion?

Answer 11

RAAS system

Direct stimulation of adrenal cortex by a rise in plasma K+

Question 12

What are the metabolic functions of cortisol?

Answer 12

Inhibits glucose uptake by tissues
Increases hepatic gluconeogenesis
Stimulates protein degradation (more AAs for gluconeogenesis)
Facilitates lypolysis

Question 13

What are the non-metabolic functions of cortisol?

Answer 13

Enhances the capacity of glucagon and catecholamines
Stress adaptation
Anti-inflammatory and immuno-suppressant

Question 14

When is glucocorticoid therapy used?

Answer 14

Rheumatoid arthritis

Prevent organ transplant rejection

Question 15

What increases cortisol secretion?

Answer 15

Diurnal rhythm (highest in the morning)
Stress
ACTH

Question 16

What is Conn’s syndrome?

Answer 16

Primary hyperaldosteronism

Hypersecreting adrenal tumour of the aldosterone-secreting cells

Question 17

What is secondary hyperaldosterism?

Answer 17

Inappropriately high activity of RAAS

Question 18

What are the symptoms of hyperaldosteronism?

Answer 18

Increased whole body Na+, fluid and circulating blood volume
Hypokalaemia leading to weakness and fatigue
Hypertension

Question 19

What is Cushing’s syndrome?

Answer 19

Cortisol hypersecretion

Question 20

What are the causes of Cushing’s syndrome?

Answer 20

Adenomas of anterior pituitary hypersecreting ACTH (Cushing’s disease)
Abnormal function of the hypothalamus
Ectopic secretion of ACTH by tumour somewhere else in the body
Adenomas of the adrenal cortex

Question 21

What are the symptoms of Cushing’s syndrome?

Answer 21

Hyperglycaemia
Glucosuria
Protein shortage (muscle weakness and fatigue)
Body fat deposited in abdomen, above shoulder blades and face
Stretch marks on abdomen
Easy bruising and poor wound healing
Increased adrenal androgens

Question 22

What is Addison’s Disease?

Answer 22

All layers of the adrenal cortex are undersecreting

Aldosterone and cortisol deficient

Question 23

What is the cause of Addison’s Disease?

Answer 23

Autoimmune destruction of the adrenal cortex

Question 24

What are the symptoms of aldosterone deficiency in Addison’s disease?

Answer 24

Hyperkalaemia (disturbs cardiac rhythm)
Hyponatraemia
Hypotension

Question 25

What are the symptoms of cortisol deficiency in Addison's disease?

Answer 25

Poor response to stress Hypoglycaemia Hyperpigmentation

Question 26

What is the cause of hyperpigmentation in Addison's Disease?

Answer 26

Excessive secretion of ACTH Uninhibited due to low cortisol so no negative feedback High levels of ACTH can bind to closely related a-MSH receptors in skin

Question 27

What is the result of combined lack of glucocorticoid and mineralocorticoid deficiency in Addison's Disease?

Answer 27

Vascular collapse Shock Death

Question 28

What is the treatment for Addison's Disease?

Answer 28

Large volumes of .9% saline or 5% dextrose in saline Cortisol Daily glucocorticoid and mineralocorticoid replacement

Question 29

What are the causes of secondary adrenocortical insufficiency?

Answer 29

Pituitary or hypothalamus abnormality | Only results in a cortisol deficiency

Question 30

What type of cells are found in the adrenal medulla?

Answer 30

Modified postganglionic sympathetic neurons called chromaffin cells

Question 31

What is produced by the adrenal medulla?

Answer 31

Adrenaline | Noradrenaline

Question 32

What are the effects of catecholamines on organs?

Answer 32

Produce the 'flight-or-fight' response Increase rate and strength of cardiac contraction Increases CO and BP Reduce digestive activity and inhibit bladder emptying Adrenaline causes vasodilation of coronary and skeletal muscle blood vessels -dilates airways

Question 33

What are the metabolic effects of catecholamines?

Answer 33

``` Stimulates hepatic gluconeogenesis, glycogenolysis Muscle glycogenolysis Lipolysis Inhibits insulin Stimulates glucagon ```

Question 34

What are the effects of catecholamines on the CNS?

Answer 34

State of arousal and increased alertness Sweating Flatten lens and dilate pupil

Question 35

What is catecholamine secretion controlled by?

Answer 35

Sympathetic input to the gland