Adrenal gland

Question 1

What are the roles of the adrenal glands?

Answer 1

Responding to acute and chronic stress.

Question 2

What type of stress might the adrenal glands respond to?

Answer 2

Infection, intense temperatures, prolonged exercise, sleep deprivation, fright, emotional stress.

Question 3

What does the medulla secrete?

Answer 3

Epinephrine and noepinephrine (adrenaline and noradrenaline).

Question 4

What are the three zones of the outer cortex region of the adrenal gland?

Answer 4

Mineralocorticoid, glucocorticoid and androgen precursors.

Question 5

What is an example of a mineralcorticoid?

Answer 5

Aldosterone.

Question 6

What is an example of a glucocorticoid?

Answer 6

Cortisol.

Question 7

What is an example of androgen precursors?

Answer 7

Dehydroepiandosterone.

Question 8

What effects do catecholamines cause?

Answer 8

Bodily symptoms (adrenaline).

Question 9

What effects do glucocorticoids cause?

Answer 9

Metabolic effects.

Question 10

What effects do mineralocorticoids cause?

Answer 10

Sodium effects - blood volume.

Question 11

What part of the nervous system is the adrenal medulla a part of?

Answer 11

Sympathetic division of the autonomic nervous system.

Question 12

What type of neurones makes up the adrenal medulla?

Answer 12

Postganglionic neurones.

Question 13

What is secretion from the adrenal medulla controlled by?

Answer 13

Sympathetic preganglionic nerve fibres.

Question 14

What is the fight-or-flight response?

Answer 14

Activation of the sympathetic nervous system during stress - release of adrenal medullary hormones.

Question 15

What is the process in which adrenal catecholamines are released?

Answer 15

The hypothalamus is stimulated by stress, physical activity or low blood glucose which sends action potentials through the sympathetic division of the autonomic nervous system which causes the adrenal medulla to release adrenaline and noradrenaline.

Question 16

What are mineralocorticoids synthesised from?

Answer 16

Cholesterol.

Question 17

What is cortisol synthesised from?

Answer 17

17-hydroxy-pregnenolone

Question 18

What does aldosterone do?

Answer 18

Stimulates the reabsorption of Na+ and the excretion of K+ in the cortical collecting ducts, and decreases the ratio of Na/K in sweat and saliva. It increases the reabsorption of Na in the colon and excretion of K+ in the faeces.

Question 19

What drug is an aldosterone antagonist?

Answer 19

Spironolactone which is a potassium-sparing diuretic.

Question 20

What are ACE inhibitors?

Answer 20

Captopril and enalapril.

Question 21

What is an ATII antagonist?

Answer 21

Losartan, simular to ACE inhibitors

Question 22

What is ACTH?

Answer 22

Adreno cortico trophic hormone.

Question 23

What causes fluctuations in cortisol secretion?

Answer 23

Fluctuations in ACTH secretion from the pituitary gland.

Question 24

What is addison’s disease?

Answer 24

A cortisol deficiency.

Question 25

What effect does reduced cortisol have on salt balance?

Answer 25

Reduced sodium, increased potassium.

Question 26

What effect does reduced cortisol have on the cardiovascular system?

Answer 26

Vasodilation, hypotension, reduced blood volume, anaemia and lymphocytosis,

Question 27

What effect does reduced cortisol have on cellular metabolism?

Answer 27

Hypoglycaemaia and weight loss.

Question 28

What effect does reduced cortisol have on the inflammatory and immune system?

Answer 28

Tendency towards autoimmune disease.

Question 29

What effect does reduced cortisol have on the CNS?

Answer 29

Fatigue, anorexia.

Question 30

What effect does cortisol have on the liver?

Answer 30

Increased glycogen formation and storage, increase gluconeogenesis, increased plasma glucose and increased plasma proteins.

Question 31

What do corticosteroids do to plasma glucose levels?

Answer 31

They cause them to rise - they are released from the liver and cause increased gluconeogenesis.

Question 32

What is the result of increased proteolysis due to corticosteroids?

Answer 32

Muscle wasting and skin thinning.

Question 33

What else do corticosteroids do?

Answer 33

Fat redistribution (Cushing syndrome), moon face and buffalo hump.

Question 34

What do corticosteroids do to triglycerides?

Answer 34

Increased breakdown leading to a rise in plasma fatty acid levels.

Question 35

What is corticosterone synthesised from?

Answer 35

Cholesterol.

Question 36

What are sex steroids synthesised from?

Answer 36

17-hydrozy-pregnenolone.

Question 37

What is the renin-angiotensin system?

Answer 37

A hormone system that regulates blood pressure and electrolyte and fluid balance.

Question 38

What is CRH?

Answer 38

Corticotrophin releasing hormone.

Question 39

What is ACTH?

Answer 39

Adreno cortico trophic hormone.

Question 40

What causes the hypothalamus to release CRH?

Answer 40

Stress such as acute trauma, major surgery or infection.

Question 41

What happens when CRH reaches the pituitary?

Answer 41

ACTH is released.

Question 42

What does ACTH act on?

Answer 42

The adrenal glands.

Question 43

What does CRH act on?

Answer 43

The pituitary gland.