MEH - Adrenal Glands

Question 1

What are the three general areas of the kidney called?

Answer 1

Capsule, cortex, medulla (innermost)

Question 2

What are the three parts of the cortex called?

Answer 2

Zona glomerulosa, zona fasiculata, zona reticularis

Question 3

What is found in the medulla of the kidney?

Answer 3

Chromaffin cells, which secrete adrenaline and noradrenaline

Question 4

What does the zona glomerulosa secrete?

Answer 4

Mineralocorticoids, eg aldosterone

Question 5

What does the zona fasiculata secrete?

Answer 5

Glucocorticoids such as cortisol

Question 6

What does the zona reticularis secrete?

Answer 6

Androgens

Question 7

What are steroid hormones synthesised from?

Answer 7

Cholesterol, in the adrenal glands and gonads

Question 8

Steroid hormones are lipid soluble, true or false?

Answer 8

True

Question 9

How do steroids interact with cells?

Answer 9

They bind to nuclear receptors to modulate gene transcription

Question 10

How do corticosteroids exert their actions?

Answer 10

• diffuse across plasma membrane
• bind to glucocorticoid receptors which causes dissociation of chaperone proteins
• receptor ligand complex translocates to nucleus and dimerises with other receptors
• receptors bind to GREs or other transcription factors

Question 11

What class of steroid is aldosterone?

Answer 11

It is the most abundant mineralocorticoid

Question 12

Where is aldosterone made?

Answer 12

Synthesised and released by the zona glomerulosa of the adrenal cortex

Question 13

Which proteins are used to transport aldosterone?

Answer 13

Serum albumin and transcortin

Question 14

What is aldosterone’s main action?

Answer 14

Promotes expression of the Na+/K+ pump in the nephron, which influences water retention and blood volume and therefore blood pressure

Question 15

What triggers aldosterone release from the kidneys?

Answer 15

Angiotensin II

Question 16

What is hyperaldosteronism?

Answer 16

Too much aldosterone produced by the body

Question 17

What are the two categories of hyperaldosteronism?

Answer 17

Primary - defect in adrenal cortex

Secondary - overactivity of the RAAS

Question 18

What are the signs of hyperaldosteronism?

Answer 18

• high blood pressure
• left ventricular hypertrophy
• stroke
• hypernatraemia
• hypokalaemia

Question 19

How is hyperaldosteronism treated?

Answer 19

Aldosterone-producing adenomas can be removed by surgery, or spironolactone can be given

Question 20

How does spironolactone work?

Answer 20

It is a mineralocorticoid receptor antagonist

Question 21

What class of steroid is cortisol?

Answer 21

Most abundant corticosteroid

Question 22

Where is cortisol synthesised?

Answer 22

In the zona fasiculata, in response to ACTH

Question 23

What is cortisol’s carrier protein in plasma?

Answer 23

Transcortin

Question 24

What are the actions of cortisol?

Answer 24

• increases protein breakdown in muscle, gluconeogenesis in the liver and lipolysis in fat
• in charge of resistance to stress
• anti-inflammatory effects (inhibits macrophages and mast cell degranulation)
• depression of immune response

Question 25

Describe the sequence of events from the hypothalamus to release of cortisol from the kidneys

Answer 25

• hypothalamus produces corticotropin releasing hormone (CRH)
• anterior pituitary releases adrenocorticotropic hormone in response to this (ACTH)
• adrenal cortex releases cortisol

Question 26

What are the net effects of glucocorticoids on metabolism?

Answer 26

• increased glucose production
• breakdown of protein
• redistribution of fat

Question 27

What is Cushing’s Syndrome?

Answer 27

Chronic excessive exposure to cortisol

Question 28

What are the signs and symptoms of Cushing’s syndrome?

Answer 28

• moon shaped face
• buffalo hump fat pad
• abdominal obesity
• purple striae
• acute weight gain
• hyperglycaemia
• hypertension

Question 29

What are the external causes of Cushing’s syndrome?

Answer 29

Prescribed glucocorticoids (most common cause)

Question 30

What is the difference between Cushing’s disease and Cushing’s syndrome?

Answer 30

Cushing’s disease is due to a benign pituitary adenoma secreting ACTH, while Cushing’s syndrome is an umbrella term for excessive cortisol exposure

Question 31

What are steroid drugs used for?

Answer 31

Used to treat inflammatory disorders such as asthma, IBD, RA, etc.

Question 32

What is Addison’s disease?

Answer 32

Chronic adrenal insufficiency, usually caused by autoimmune response

Question 33

What are the signs/symptoms of Addison’s disease?

Answer 33

• postural hypotension
• lethargy
• weight loss
• anorexia
• increased skin pigmentation
• hypoglycaemia

Question 34

Why does hyperpigmentation occur in Addison’s?

Answer 34

• decreased cortisol means that negative feedback on the anterior pituitary is reduced
• this means that more POMC (building block) is required to form ACTH
• POMC makes both ACTH and MSH (which forms melanin), so to maintain ACTH levels, more MSH is made as a byproduct

Question 35

What is an Addisonian crisis?

Answer 35

Life threatening emergency due to adrenal insufficiency caused by severe stress, infection, trauma, cold, abrupt withdrawal of steroids, salt deprivation etc

Question 36

What are the symptoms of an Addisonian crisis?

Answer 36

Nausea, vomiting, pyrexia, hypotension, vascular collapse

Question 37

What is the treatment for an Addisonian crisis?

Answer 37

Fluid replacement and cortisol

Question 38

What are the androgens that are released from the zona reticularis?

Answer 38

DHEA and androstenedione

Question 39

What do 20% of chromaffin cells in the adrenal medulla lack?

Answer 39

N-methyl transferase, meaning they secrete noradrenaline instead of adrenaline

Question 40

Which GCPRs can adrenaline act on?

Answer 40

B1 and B2, a1 and a2

Question 41

What are the effects of adrenaline on the heart, lungs and blood vessels?

Answer 41

Heart - increase heart rate and contractility (B1)
Lungs - bronchodilation (B2)
Blood vessels - vasoconstriction in skin and gut (a1) or vasodilation (B2) in skeletal muscle

Question 42

What is a pheochromocytoma?

Answer 42

Chromaffin cell tumour which secretes noradrenaline. It may cause life-threatening hypertension. Symptoms of anxiety, weight loss, headaches etc