L21: Adrenal Function

Question 1

2 glands that composes the adrenal glands

Answer 1

1) adrenal cortex: secretes steroid hormones
2) Adrenal medulla: secretes catecholamines

Question 2

3 layers of the adrenal cortex

Answer 2

1) zona glomerulosa: produces aldosterone
2) zona fasciculata: produces glucocorticoids
3) zona reticularis: produces androgens

Question 3

What does the adrenal medulla produce?

Answer 3

Adrenaline & noradrenaline

Question 4

What does all steroid hormones derive from?

Answer 4

Cholesterol

Question 5

Which hormones are secreted by the adrenal cortex?

Answer 5

Cortisol and aldosterone

Question 6

What is the primary role of glucocorticoids like cortisol in the body?

Answer 6

Response to “stress”

Question 7

What role do catecholamines play in the body?

Answer 7

To mediate “fight or flight” responses

Question 8

What is synthesised from cholesterol?

Answer 8

Pregnenolone

Question 9

What is pregnenolone converted into in the synthesis of steroid hormones?

Answer 9

1) glucocorticoids
2) mineralcorticoids
3) androgens

Question 10

Metabolism of glucocorticoids (cortisol)

Answer 10

1) Increases protein catabolism (muscle breakdown)
2) Stimulates gluconeogenesis (liver production of glucose)
3) Increase blood glucose levels

Question 11

Structure of zona glomerulosa (outer)

Answer 11

Small, closely packed cell

Question 12

Role of zona glomerulosa

Answer 12

Regulates Na+ & K+ balance
Controls blood pressure & fluid balance
Regulated by RAAS

Question 13

Structure of zona fasciculata

Answer 13

Larger cells arranged in long cords

Question 14

Role of zona fasciculata

Answer 14

Regulates metabolism
Suppresses inflammation & immune response
Controlled by HPA axis

Question 15

Structure of zona reticularis

Answer 15

Small cells arranged in short cords

Question 16

Role of zona reticularis

Answer 16

Precursors for testosterone & estrogen
Sexual development
Anti-ageing effects

Question 17

What cells does the adrenal medulla contain?

Answer 17

chroaffin cells (modified neurons)

Question 18

What 2 catecholamines does the adrenal medulla secrete?

Answer 18

1) Adrenaline
2) Noradrenaline

Question 19

Role of mineralocorticoids (aldosterone)

Answer 19

Regulates electrolyte balance

Question 20

Actions of mineralocorticoids in the kidney

Answer 20

1) Increase Na+ reabsorption
2) increase K+ excretion
3) Increase blood volume & pressure

Question 21

What is mineralocorticoid regulated by?

Answer 21

Renin-angiotensin system

Question 22

Action of renin in response to reduced plasma volume

Answer 22

1) renin released by kidney in response to reduced plasma volume
2) Renin converts angiotensinogen into angiotensin I
3) Angiotensin I converted to angiotensin II
4) ATII acts on glomerulosa cells to stimulate aldosterone production
5) Aldosterone increases Na+ reabsorption

Question 23

What is corticosteroid effects on the cardiovascular system?

Answer 23

Inhibition of inflammatory responses
Suppression of immune responses

Question 24

Role of androgens

Answer 24

• Development of secondary sexual characteristics at puberty
• Preventing changes in ageing

Question 25

Describe role of ACTH in response to stress

Answer 25

1) ACTH released from anterior pituitary in response to stress 2) ACTH binds to receptors in faciculata & reticularis to stimulate cortisol production 3) Cortisol affects metabolism

Question 26

Effects of cortisol in the role of ACTH in response to stress

Answer 26

1) Affects metabolism 2) Anti-inflammatory 3) Inhbitory feedback on hypothalamus & pituitary

Question 27

Functions of catecholamines (adrenaline, noradrenaline)

Answer 27

1) fight-or-flight responses 2) increase heart rate & blood pressure 3) mobilise glucose & fatty acids

Question 28

Describe the action of HPA axis on CRH

Answer 28

1) Stress triggers CRH from hypothalamus 2) CRH stimulates anterior pituitary to release ACTH 3) ACTH stimulates cortisol production in fasciculata Negative feedback: Cortisol inhibits CRH & ACTH release to prevent overproduction

Question 29

2 hypofunction adrenal disorders

Answer 29

1) Congenital Adrenal Hyperplasmia 2) Addison's Disease

Question 30

2 hyperfunction adrenal disorders

Answer 30

1) Cushing's Syndrome (too much cortisol) 2) Hyperaldosteronism (too much aldosterone)

Question 31

How does Congenital Adrenal Hyperplasmia function, what is its effects?

Answer 31

Disrupts steroid hormone synthesis Effects: - Severe forms cause no sexual differentiation - Ambiguous genitalia

Question 32

What does Addison's Disease cause , what are the symptoms?

Answer 32

Cause: - Autoimmune destruction of adrenal glands - Tuberculosis affecting adrenal cortex Symptoms: - Hypotension, fatigue - Hyperpigmentation

Question 33

Cause and symptoms of Cushing's Syndrome

Answer 33

Cause: Excess ACTH Excess cortisol Symptoms: - Weight gain - Muscle & bone loss - High blood sugar

Question 34

causes and symptoms of hyperaldosteronism

Answer 34

Causes: Adrenal adenoma Renin-angiotensin overactivity Symptoms: Hypertension (high blood pressure) Hypokalemia (low K+ levels)