L25 - adrenal function

Question 1

where are the adrenal glands located

Answer 1

above kidneys

Question 2

what does adrenal cortex secrete

Answer 2

steroid hormones (glucocorticoids , mineralocorticoids

Question 3

what does adrenal medulla secrete

Answer 3

catecholamines (NA, A , dopamine)

Question 4

name the 2 corticosteroids

Answer 4

glucocorticoids , mineralocorticoids

Question 5

which part of the adrenal gland is part of the HPA axis

Answer 5

cortex

Question 6

list functions of corticosteroids

Answer 6

involved in: 
metabolism 
blood pressure and vol 
nutrient uptake and storage 
fluid and electrolyte balance 
inflammatory and immune response

Question 7

name the layers of the cortex

Answer 7

1. zona reticularis (inner, above medulla)
2. zona fasiculata (middle)
3. zona glomerulosa (outer of cortex)

Question 8

what is secreted from the zona glomerulosa

Answer 8

mineralocorticoids (aldosterone)

Question 9

where is aldosterone synthesised

Answer 9

zona glomerulosa - outer layer of the adrenal cortex

Question 10

what is made and secreted from the zona fasiculata

Answer 10

cortisol and androgens

Question 11

what is the thickest layer of the adrenal cortex

Answer 11

zona fasiculata (middle)

Question 12

what is made and secreted from the zona reticularis

Answer 12

cortisol and androgens

Question 13

what stimulates the adrenal medulla?

Answer 13

SNS impulses from hypothalamus

Question 14

what surrounds entire adrenal gland

Answer 14

connective tissue capsule

Question 15

give an example of a mineralocorticoid

Answer 15

aldosterone

Question 16

what do steroid steroid secreting hormones contain

Answer 16

lipid droplets containing cholesterol

Question 17

what is cortisol ?

Answer 17

glucocorticoid

Question 18

what is aldosterone?

Answer 18

minerlocorticoid

Question 19

function of mineralocorticoids eg aldosterone

Answer 19

1. control of electrolyte homeostasis

Question 20

what effect does aldosterone (mineralocorticoid) have on the kidney

Answer 20

1. increases Na reabsorption
2. increases K+ excretion

indirectly affects water retention and therefore blood pressure and volume

Question 21

what triggers aldosterone release?

Answer 21

1. high [k+]
2. low [Na+]
3. low blood volume/ pressure
4. angiotensin 2

Question 22

what system regulates aldosterone levels in response to low blood volume and how

Answer 22

renin - angiotensin system in juxtaglomerular cells

angiotensin 11 produced from this process stimulates aldosterone release from adrenal cortex

Question 23

function of glucocorticoids (cortisol)

Answer 23

1. regulates glucose metabolism

2. responds to stress

Question 24

what are the effects of cortisol on target tissues?

Answer 24

1. promotes glycogen breakdown in muscles
2. promotes gluconeogenesis in liver
3. promotes protein breakdown to AA
4. inhibits inflammatory and immune response

Question 25

what is overall effect of cortisol?

Answer 25

increases plasma [glucose] and [ketones]

Question 26

what controls adrenal function?

Answer 26

1. hypothalamus

2. renin angiotensin system

Question 27

explain how the renin angiotensin system is involved in adrenal function

Answer 27

1. renin converts angiotensin into angiotensin 1
2. angiotensin 1 is converted into angiotensin 2 in tissues
3. angiotensin 2 stimulates aldosterone release from adrenal cortex (zona glomerulosa)

Question 28

explain HPA axis

Answer 28

1. CRH released from hypothalamus to anterior pituitary
2. ACTH released from anterior pituitary to adrenal cortext
3. ACTH binds to zona fasiculata & reticularis
4. cortisol released

Question 29

what is congenital adrenal hyperplasia

Answer 29

disease where genetic mutations lead to lack of 1 or more enzymes involved in the production of steroid hormones

Question 30

what are the effects of congenital adrenal hyperplasia

Answer 30

most serious - no cholesterol - no sexual differentiation

hypertension
absent/early puberty

Question 31

what is Addison’s disease

Answer 31

acquired autoimmune destruction of adrenal gland cells

Question 32

effects of Addison’s disease

Answer 32

1. hypotension (no aldosterone)
2. tiredness
3. weakness

Question 33

how is Addison’s disease treated

Answer 33

with steroid hormone administration

Question 34

what is cushings syndrome

Answer 34

overproduction of glucocorticoids

Question 35

effects of cushings syndrome

Answer 35

1. high blood [glucose]
2. weight gain (especially in face&neck)
3. risk of type 2 diabetes
4. muscle wasting
5. reduced healing & increased bruising

Question 36

usual cause of cushings syndrome?

Answer 36

pituitary/adrenal tumour causing excess ACTH production