The Adrenal Gland

Question 1

vertebral level of adrenals

Answer 1

t12

Question 2

difference between venous drainage of adrenals

Answer 2

left –> left renal vein

right –> IVC

Question 3

3 types of hormone secreted by adrenal cortex

Answer 3

mineralocorticoids
glucocorticoids
sex hormones

Question 4

3 layers of cortex and what they secrete

Answer 4

zona glomerulosa - mineralocorticoids
zona fasciculata - glucocorticoids
zona reticularis - sex hormones

Question 5

which of the cortex layers is most external

Answer 5

zona glomerulosa

Question 6

what type of hormones are those secreted by adrenal cortex

Answer 6

steroid (dervied from cholesterol)

Question 7

what hormones are secreted by the adrenal medulla

Answer 7

epinephrine, norepinephrine and dopamine

Question 8

what type of hormones are secreted by the adrenal medulla

Answer 8

amine –> tyrosine –> catecholamines

Question 9

where is cortisol secreted from

Answer 9

adrenal cortex –> zona fasciculata

Question 10

DHEA is a pre-hormone of what two sex hormones

Answer 10

testosterone and oestrogen

Question 11

defects in what enzyme causes adrenal hyperplasia and cortisol and aldosterone deficiency

Answer 11

21-hydroxylase

Question 12

what would consequences of 21-hydroxylase deficiency be

Answer 12

inability to regulate blood pressure, unable to cope with bodily stresses and genital ambiguity at birth

Question 13

why is there an excess of sex hormones in 21-hydroxylase deficiency

Answer 13

because cortisol and aldosterone cannot be produced but there is an excess of adrenal stimulation by ACTH so activity gets shunted to producing sex hormones

Question 14

why is ACTH in greater excess than CRH in 21-hydroxylase deficiency

Answer 14

because there is no feedback inhibtion on ACTH from cortisol but there is feeback inhibition on CRH from ACTH

Question 15

how is cortisol transported in blood

Answer 15

95% is bound to carrier protein

Question 16

process of steroid hormone cell response

Answer 16

lipophillic so passes through membrane –> cytoplasmic/nucleic receptors –> formed complex binds to DNA –> genes altered/expressed –> response produced through proteins

Question 17

when are cortisol levels highest and why

Answer 17

between 6-9am, need cortisol to deal with oncoming stresses at the start of the day

Question 18

what glucose counter-regulatory hormone is cortisol permissive to

Answer 18

glucagon

Question 19

can glucagon respond to hypoglycaemia alone

Answer 19

no it need the other ones to help and for their permissive effects

Question 20

actions of cortisol on metabolism

Answer 20

gluconeogensis, proteolysis, lipolysis and decreased insulin sensitivity

Question 21

how does proteolysis and lipolysis help the brain

Answer 21

give other bodily tissues a source of energy so that glucose can be spared for brain

Question 22

what tissues does cortisol reduced insulin sensitivity in

Answer 22

muscle and fat

Question 23

action of cortisol on Ca2+ absorption

Answer 23

decreases its absoprtion in gut while increasing its resorption in bone

Question 24

action of cortisol on norepinephrine

Answer 24

permissive: especially in vascular smooth muscle (i.e. aids vasocontriction)

Question 25

what effect would low cortisol have on blood pressure

Answer 25

low cortisol –> reduced permissive effect on norepinephrine –> less vasocontriction –> hypotension

Question 26

effect of cortisol on mood

Answer 26

low mood and impaired cognition

Question 27

what does cortisol do to the immune system

Answer 27

it suppresses it, clinically useful in autoimmune?

Question 28

what is cushings disease

Answer 28

over secretion of cortisol resulting in peripheral protein and fat breakdown with central (trunk and face) getting bigger

Question 29

what two levels of cortisol pathway most commonly cause cushings

Answer 29

an overactive pituitary gland (2nd degree) and overactive adrenal cortex (1st degree)

Question 30

what is hyposecretion of cortisol called

Answer 30

addison’s disease

Question 31

what hormones are undersecreted in addison’s

Answer 31

all adrenal steroid hormones (from cortex)

Question 32

what triggers CRH and ACTH release

Answer 32

stress

Question 33

what embryological structure does the adrenal medulla form from

Answer 33

the neural crest tissue

Question 34

what embryological structure does the adrenal cortex form from

Answer 34

the mesoderm

Question 35

true/false the postganglionic cells in adrenal medulla have no axons

Answer 35

true - they release their neurohormones directly into the bloodstream

Question 36

pheochromocytoma?

Answer 36

rare tumour of adrenal medulla and causes excess catecholamine secretion –> diabetogenic and increase BP

Question 37

what is a consequence of withdrawing long term glucocorticoids

Answer 37

inducing adrenal insufficiency (enhanced negative feedback of supplement cortisol on ACTH causes adrenal atrophy, so withdrawal will leave an adrenal not up to job, so do slow and give it tie to grow from ACTH stimulation)