adrenal gland Flashcards
1
Q
Adrenal glands: where are they?
A
Above the kidney, Ad RENAL- protected by the ribs
2
Q
how many arteries do they have- right and left
A
lots
3
Q
how many veins for the left and right adrenal glands
A
1
4
Q
where does the left adrenal vein drain into
A
renal vien
5
Q
right adrenal vein
A
into inferior vena cava
6
Q
draw the adrenal gland and the adjacent structure
A
draw
7
Q
name the 2 main regions of the adrenal glands
A
adrenl cortex
adrenal medulla
8
Q
what does the adrenal cortex relese
A
Secretes Corticosteroids
9
Q
adrenal medulla
A
Secretes catecholamines
10
Q
name the 3 regions of teh adrenal cortex
A
Zona glomerulosa
Zona fasciculata
Zona reticularis
11
Q
draw it
A
draw it
12
Q
what regions makes Catecholamines
A
Adrenal medulla (neuroendocrine/chromaffin cells)
13
Q
Adrenal cortex
A
Corticosteroids
14
Q
what is the origine of adrlaline and noradrelaline
A
dpoamine
15
Q
nora
A
no meythl group
16
Q
examples of Catecholamines
A
Adrenaline/epinephrine (80%)
Noradrenaline/norepinephrine (20%)
[Dopamine]
17
Q
examples of Corticosteroids
A
Mineralocorticoids (Aldosterone) Glucocorticoids (Cortisol Sex steroids (Androgens, oestrogens)
18
Q
what does the Zona glomerulosa make
A
Aldosterone
19
Q
what do teh Zona fasciculata
Zona reticularis
A
cortisol
20
Q
what is a significance of one vein
A
all hormones released will travel through same vein
21
Q
what are steriods
A
Steriod is an hormone based on a cholesterol/ comes from cholestrol
22
Q
Adrenal gland secretions precursor
A
cholesterol
23
Q
how many carbons in cholestrol
A
27
24
Q
What is an enzyme?
A
Protein that catalyses a specific reaction
Protein that catalyses a specific reaction
1
25
what precourous do all steriods make
pregnenolone- basic steriod
26
first step to form aldestron (mineralocorticoid)
Side chain cleavage
| --> Pregnenolone
27
next
3 beta Hydroxy Steroid Dehydrogenase
| --> Progesterone
28
what positions are oxidised by hrdoxylases (OH group added)
| name the enzymes
21 Hydroxylase
11 Hydroxylase
18 hydroxylase
29
how to form glucocorticoid
same until forming Progesterone
30
what are hydroxled (OH group added)
17 hydoxylase
21 hydoxylase
11 hydoxylase
31
final product
CORTISOL
32
cholesterol to aldosterone with all intermediates
```
cholesterol
progesterone
11-deoxy corticosterone
corticosterone
aldosterone
```
33
to make cortisol
```
cholesterol
progesterone
17-OH prog
11-deoxy deoxycortisol
cortisol
```
34
to make S steroids
```
cholesterol
progesterone
17-OH prog
Sex steroids
(androgens)
(oestrogen)
```
35
What does aldosterone do?
Major net effect is to conserve body sodium by stimulating its reabsorption
Increased sodium reabsorption water reabsorption,
raising blood volume, regulating blood pressure
36
how does it work
Stimulates Na+ reabsorption in distal convoluted tubule and cortical collecting duct in kidney (and in sweat glands, gastric glands, colon)
Stimulates K+ and H+ secretion, also in distal convoluted tubule and cortical collecting duct
switches on ATPase
37
what is released when blood pressure fails
Renin release when blood pressure falls
38
what releases renins
Juxtaglomerular apparatus
39
when bp is high
Blood pressure high suppress renin
40
when bp is low
Blood pressure low suppresses renin secreated
41
How is aldosterone regulated?
low bp
| renin relased
42
what do the renins do
convert angiotensinogen (from liver) to Angiotensin I
43
next
A1 concerted by ACE to angiotensin 2
44
affects of a2
vasoconstriction
| acts on adrenals
45
what happens in the adrenal glands
```
Activation of the following enzymes
Side Chain Cleavage
3 Hydroxysteroid dehydrogenase
21 hydroxylase
11 hydroxylase
18 hydroxylase
to make aldetsrone
```
46
summary of Aldosterone
Summary of aldosterone action:
Controls blood pressure, sodium and lowers potassium
47
How is cortisol secretion regulated?
ACTH
48
Physiological effects of cortisol
```
Normal stress response
Metabolic effects
peripheral protein catabolism
hepatic gluconeogenesis
increased blood glucose concentration
fat metabolism (lipolysis in adipose tissue)
enhanced effects of glucagon and catecholamines
Weak mineralocorticoid effects
Renal and cardiovascular effects
excretion of water load
increased vascular permeability
```
49
how is increased cortisol suprresed
Cortisol feedbacks negatively
50
how is it released
CRH --> ACTH --> cortisol
51
draw a HPA axis
Remember to add backwards arrow wwhen cortisol negatively effects pit and hyp
52
Effects of ACTH on the adrenals
```
Activation of the following enzymes
Side Chain Cleavage
3 Hydroxysteroid dehydrogenase
21 hydroxylase
11 hydroxylase
17 hydroxylase
cortisol
```
53
what sort of variation does cortisol
Cortisol has diurnal rhythm
Tells youre tissue/hormone what time of day it is
Peaks at 8 30
Low at midnight
54
This is cortisol, and the only difference between prednisolone and cortisol is this double bond here. What this does is it gives prednisolone a longer half life, more potency, and a binding affinity of over twice that of cortisol
This is cortisol, and the only difference between prednisolone and cortisol is this double bond here. What this does is it gives prednisolone a longer half life, more potency, and a binding affinity of over twice that of cortisol
55
what is Addison’s disease
Primary adrenal failure
| Autoimmune disease where the immune system decides to destroy the adrenal cortex (UK)
56
most common cause
Tuberculosis of the adrenal glands (commonest cause worldwide)
57
sympotoms/sign
```
hyperpigmentation
low bp
weakness
weight loss
diahorrea
vomitting
vitilago
```
58
adrenal crisis signs/sypm
```
fever
syncope
convulsion
hypoglecemia
hyponatremia
severe vomiting and diarrhea
```
59
what affect does it have on other hormones
Pituitary starts secreting lots of ACTH and hence MSH
60
why low blood pressure
No cortisol or aldosterone
61
Why do patients with Addison’s disease have a good tan?
POMC is a large precursor protein that is cleaved to form a number of smaller peptides, including ACTH, MSH and endorphins
Thus people who have pathologically high levels of ACTH may become tanned
62
main dangers of addisons
```
Cortisol deficiency
Aldosterone deficiency
Salt loss
Low blood pressure
Eventual death
```
63
how to prevent death
Rehydrate with normal saline
Give dextrose to prevent hypoglycaemia which could be due to the glucocorticoid deficiency
Give hydrocortisone or another glucocorticoid
64
What happens if you have too much cortisol?
Your metabolism changes and you put on weight…
65
What can cause too much cortisol?
A tumour of the adrenal
-Excess cortisol
A tumour of the pituitary
-Excess ACTH
66
what is Cushing’s syndrome
Cushing's syndrome is a condition caused by having too much of a hormone called cortisol in your body. It can be serious if it's not treated.
67
signs/symptoms
```
big torso/fat but skinny arms and legs
Red cheeks
Easy bruising
Thin skin
Red Striae (stretch marks)
Poor wound healing
Adrenal gland gets bigger
Interscapular fat
Diabetes, hypertension and osteoporosis
Immunosuppression (reactivation of TB
Proximal myopathy weak muscle
```
68
hormone cause
Occurs due to an excess of cortisol or other glucocorticoid
69
List four possible causes of Cushing’s syndrome
Taking steroids by mouth (common) (glucocorticoid)
pituitary dependent Cushing’s disease (pituitary adenoma)
Ectopic ACTH (lung cancer)
adrenal adenoma or carcinoma
§
70
examples of Catecholamines
Adrenaline/epinephrine (80%)
| Noradrenaline/norepinephrine (20%)
71
what is the precoursor for adr and na sythesis
tyrosine
72
where is it stored
in cytoplasmic granules & released in response to ACh from preganglionic sympathetic neuronesq
73
Role of catecholamines
Fight or flight response’ e.g. tachycardia, sweating, increased blood glucose, alertness, vasoconstriction
74
how do adr and na circulate the blood
NA & Adr circulate bound to albumin
75
how do they get degraded
Degraded by two hepatic enzymes: monoamine oxidase & catechol-O-methyl transferase
