T1 L6 Adrenal cortex - hormones and physiology

Question 1

What male sex hormones are produced by the outer adrenal cortex?

Answer 1

Dehydroepiandrosterone
Androstenedione
Testosterone
Oestradiol

Question 2

What enzyme is contained in the outer zona glomerulosa?

Answer 2

18-hydroxylase enzyme

Question 3

What hormone is synthesised by outer zona glomerulosa?

Answer 3

Aldosterone

Question 4

What hormone is synthesised by middle zona fasciculata?

Answer 4

Cortisol

Question 5

What hormone is synthesised by inner zona reticularis?

Answer 5

Androgens

Question 6

What are steroids synthesised from?

Answer 6

Cholesterol from the diet or synthesised within the adrenal gland

Question 7

Give an example of a glucocorticoid

Answer 7

Cortisol

Question 8

Give an example of a mineralocorticoid

Answer 8

Aldosterone

Question 9

When is ACTH secretion at its highest?

Answer 9

Early in the morning

Increased secretion during times of prolonged stress

Question 10

When is ACTH secretion the lowest?

Answer 10

In the middle of the night

Question 11

What percentage of cortisol is bound to plasma proteins?

Answer 11

90%

Question 12

Describe the plasma proteins that cortisol is bound to

Answer 12

Corticosteroid binding globulin (CBG) - 75%

Albumin - 15%

Question 13

Why is pregnancy associated with an increase in CBG?

Answer 13

It is a compensatory increase in circulating plasma cortisol concentration so the levels remain stable

Question 14

What converts cortisol to inactive cortisol?

Answer 14

11-B-hydroxysteroid dehydrogenase contained in aldosterone sensitive tissue

Question 15

How does cortisol elevate blood glucose?

Answer 15

Antagonises effects of insulin. on cellular uptake of glucose
Stimulates glycogenolysis
Stimulates hepatic gluconeogenesis

Question 16

What actions does cortisol have on metabolism?

Answer 16

Elevates blood glucose
Stimulates lipolysis and mobilisation of fatty acids
Stimulates amino acid uptake in the liver
Inhibits amino acid uptake and protein synthesis in the periphery

Question 17

What happens if there is excess cortisol?

Answer 17

Fat synthesis and deposition in novel anatomical sites such as the face, trunk and intrascapular region of the shoulders

Question 18

What is the effect of glucocorticoids on the immune response?

Answer 18

Suppress lymphoid tissue
Reduce antibody production
Inhibit cellular immune system
Stabilise leucocyte membranes and reduce release of proteolytic enzymes
Inhibit phospholipase A2 and reduce synthesis of inflammatory mediators

Question 19

What happens during an injury?

Answer 19

Pain alerts sufferer to damage
Oedema
Infiltration by leucocytes
Antibodies inactivate foreign proteins
Tissue repair enhanced by prostaglandins

Question 20

How does adrenocortical stress response decrease the inflammatory response?

Answer 20

Removes pain
Decreases immobilisation induced by oedema
Steroid-induced sedation leading to lack of awareness of severity of the situation
Individual can continue to perform despite presence of injury or infection

Question 21

What is the main role of mineralocorticoids?

Answer 21

Control sodium and potassium

Question 22

What controls the secretion of aldosterone?

Answer 22

Renin-angiotensin system

Question 23

What can directly stimulate release of aldosterone?

Answer 23

Trauma
Anxiety
Hyperkalaemia
Hyponatraemia

Question 24

What inhibits the secretion of aldosterone?

Answer 24

Atrial natriuretic peptide (ANP)

Question 25

Where does aldosterone have an effect?

Answer 25

``` Distal tubule of kidney Collecting duct Proximal tubule Ascending loop of Henle Colon Sweat Salivary glands ```

Question 26

What are some pharmacological uses of glucocorticoids?

Answer 26

``` Replacement therapy Immunosuppressive Anti-inflammatory effects Arthritis, asthma or allergies Treatment of proliferative conditions e.g. leukaemia ```

Question 27

What are some adverse effects of glucocorticoids?

Answer 27

Steroid usage may suppress wound healing Exacerbate infections due to their immunosuppressive effects Long term use in children can inhibit growth Long term use in adults can cause osteoporosis Development of DM and other symptoms of Cushing's syndrome Suppression of HPA Menstrual disturbances

Question 28

What can happen if steroids are stopped abruptly?

Answer 28

Adrenal cortex is unable to secrete endogenous hormones leading to Addisonian crisis which can be fatal

Question 29

What pharmacological uses does hydrocortisone have?

Answer 29

Hormone replacement therapy Anti-inflammatory agents Immunosuppressants

Question 30

What adverse effects does hydrocortisone have?

Answer 30

Hyperglycaemia Osteoporosis Cushing's syndrome