Adrenal Disorders Flashcards
1
Q
What is the adrenal gland made up of?
A
Cortext
Medulla
2
Q
Where is the capsule of the gland?
A
Outside of the gland
3
Q
What are the three zones in the cortex?
A
Zona glomerulosa
Zona fasiculata
Zona reticularis
4
Q
What are the cells in the medulla?
A
Chromaffin cells
5
Q
Where are mineralocorticoids made?
A
Zona glomerulosa
6
Q
What is an example of a mineralocorticoid?
A
Aldosterone
7
Q
What regulate the zona glomerulosa?
A
Potassium
8
Q
Where are glucocortioids made?
A
Zona fasciculata
9
Q
What regulates the zona fasciculata?
A
ACTH
10
Q
What is an example of a glucocorticoid?
A
Cortisol
11
Q
What is made in the zona reticularis?
A
Adrenal androgens
12
Q
What regulates the zona reticularis?
A
ACTH
13
Q
Where is adrenaline made?
A
Medulla
14
Q
What is on the top of the cortext?
A
Capsule
15
Q
What is the rate limiting step in the synthesis of production of aldosterone?
A
Cholesterol to pregnenolone
16
Q
What regulates aldosterone?
A
Renin-angiotensin system
17
Q
Which organ regulates cortisol?
A
Hypothalamus
18
Q
Which hormone does the hypothalamus release?
A
Corticotropin releasing hormone
19
Q
Where does CRH act on?
A
Anterior pituitary
20
Q
What does the anterior pituitary produce?
A
ACTH
21
Q
Where does ACTH act on?
A
Adrenal cortext
22
Q
Which part of the adrenal cortext does cortisol come from?
A
Zone fasciculata
23
Q
When is cortisol at the peak?
A
9AM
24
Q
What hormone is released when blood pressure falls?
A
Renin
25
Where does renin act?
Acts on angiotensinogen to produce more angiotensin I
26
What converts angiotensin 1 to angiotensin 2?
Angiotensin converting enzyme (ACE)
27
Where does angiotensin II act upon?
Adrenal cortex to product aldosterone
| Also causes a direct vasoconstriction - increases BP
28
How does aldosterone cause a rise in BP?
Causes salt retention
29
Where is the receptor for steroids?
Intracellular.
30
Why might Cushing's syndrome induce diabetes?
Excess cortisol increases blood sugar
31
Why might Cushing's induce infection?
Decreased leukocyte migration due to reduced capillary dilation
32
Where are mineralocorticoid receptors located?
Kidneys
Salivary glands
Gut
Sweat glands
33
Why is hyperpigmentation in Addison's disease?
Too much ACTH which breaks down into MSH which causes pigmentation
34
Where is the pigmentation in Addison's disease most prominent?
Skin folds and creases
| Buccal mucosa
35
What biochemistry points to Addison's?
Decreased Na+
Increased K+
Hypoglycaemia
36
Does Addison's have too much cortisol or too little?
Too little.
| An adrenal insufficiency
37
What other autoimmune diseases are associated with Addison's?
DM1
Pernicious anaemia
Autoimmune thyroiditis
38
What are the clinical features of Addison's?
```
Anorexia and wt loss
Fatigue
Low BP
Abdo pain
D&V
Hyperpigmentation
```
39
Which tests are done to confirm Addison's?
Synacthen test.
| Adrenal antibodies
40
Why does increased ACTH mean reduced cortisol?
Negative feedback loop.
| Too much ACTH cuts out the adrenal cortex from producing cortisol
41
How is adrenal insufficiency managed acutely?
IV hydrocortisone
42
What is given as an aldosterone replacement?
Fludrocortisone
43
Why might steroids cause secondary adrenal insufficiency?
Too much cortisol turns off negative feedback therefore lack of ACTH
44
What is Cushing's syndrome?
Excess cortisol secretion
45
What are the symptoms of Cushing's syndrome?
```
Buffalo hump
Moon face
Central obesity
Abdominal striae
Skin atrophy
Proximal myopathy
```
46
What is the primary cause of Cushing's syndrome?
Pituitary adenoma
47
What is the definitive diagnostic test for Cushing's syndrome?
Low dose dexamethasone suppression test.
48
What is involved in the low dose dexamethasone suppression test?
0.5mg every 6 hours for 48 hours.
| Should be able to suppress below 50
49
What is the commonest cause of Cushing's syndrome?
Steroids of any kind
50
What is the treatment of Cushing's?
Long term steroids which cannot be stopped suddenly
51
When will extra doses of steroid be required for Cushing's syndrome?
When ill or when having surgery
52
What does hypertension and hypokalaemia point towards?
Conn's syndrome.
53
What is Conn's syndrome?
Primary hyperaldosteronism
54
What is the name of the potassium channel which is common in Conn's syndrome?
KCNJ5
55
What is the most common cause of Conn's syndrome?
Adrenal adenoma
56
When is surgical removal of the adenoma not appropriate?
If bilateral adenomas
57
How is aldosterone excess confirmed?
Aldosterone:renin ratio
58
What is the commonest cause of a congenital adrenal hyperplasia?
21 alpha hydroxylase deficiency
59
There are higher levels of testosterone in congenital adrenal hyperplasia. What does this cause?
Phallic enlargement
| Early development of pubic hair
60
Which hormones are not made in congenital adrenal hyperplasia?
Aldosterone
| Cortisol
61
What is phaechromocytoma?
Tumour which produces catecholamine within the adrenal medulla
62
What are common symptoms of phaechromocytoma?
Headaches
Sweating
Palpitations
Hypertension
63
What biochemical abnormalities may be present in phaechromocytoma?
Hyperglycaemia
Low potassium
High haematocrit
64
Which scanning is sensitive only for phaechromocytomas?
MIBG scan
65
What reproductive abnormality is important to recognise in congenital adrenal hyperplasia?
Ambiguous genitalia
66
What does the angiotensin:renin ratio need to be before Conn's can be diagnosed?
Over 750
67
What diagnostic test is done for Conn's?
Saline suppression test.
| 2 litres of saline over 4 hours
68
What result from saline suppression can confirm Conn's?
Aldosterone levels should fall by 50% if normal
69
How is Conn's syndrome treated?
Surgical excision
70
What if there is a bilateral adrenal hyperplasia?
Surgical excision should be avoided and spironolactone given instead
71
What can be given if spironolactone cannot be tolerated
Eplerenone
72
What kinds of ectopic cancers can cause Cushing's?
Lung, thymus or pancreas can release ACTH and cause increase in cortisoll
73
Why might libido decrease in Cushing's?
ACTH also controls zona reticularis which controls sex hormones.
74
Which pro-hormone is made in the zona reticularis?
DHEA
75
Which cardiac receptors are acted on by adrenaline?
B1
76
If B1 receptors are activated what is the action?
Increased heart rate and force
77
Which vascular receptors are acted on by adrenaline?
alpha 1
78
If alpha 1 receptors are activated what is the action?
Vasoconstriction
79
True or False
| Polyuria is unusual in phaechromocytoma
False.
| Increased adrenaline means more gluconeogenesis and less insulin use so polyuria common
80
Which genetic disorder is phaechromocytoma linked with?
MEN2
81
How is phaechromocytoma treated?
Surgical removal of tumour
82
What other treatment should be given in phaechromocytoma?
Alpha and beta blockers
