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Flashcards in Adrenal Deck (69):
1

What are the layers of the adrenal gland?

(superficial)
capsule
cortex
medulla
(deep)

2

What are the three zones of the cortex? What do they secrete?

Zona glomerulosa-mineralocorticoids
Zona fasciculata- glucocorticoids
Zona reticularis- adrenal androgens

3

What is contained in the adrenal medulla? What is secreted?

chromaffin cells secrete catecholamines, medullary veins, splanchnic (sympthetic) nerves

4

What are the corticosteroids made from in the adrenal cortex?

cholesterol

5

Whatis the end corticosteroid from
a) z. glomerulosa
b) z fasciculata
c) z. reticularis

a) aldosterone
b) cortisol
c) DHEA and androstendione

6

How is the production of
a) aldosterone
b) cortisol
c) androgen
regulated?

a) RAAS and plasma K+
b) hypothalamus and ant. pit.
c) hypothalamus and ant. pit

7

What is the cortisol/androgen axis?

Hyp: CRH+
Pit: ACTH+
Adrenal cortex:Cortisol

NB, negative feedback

8

How does the RAAS system work?

Fall in BP
Renin released from kidneys
Turns angiotensinogen to angiotensin 1
ACE turn it to angiotensin 2
(vasoconstriction=direct)
Angiotensin 2 causes aldosterone to be released from adrenal
Aldosterone increases salt retention (indirect)
BP rises

9

What is the mechinism of action in corticosteroids?

Steroid hormones binds to intracellular receptor
DNA is bound to affect transcription

10

What are the metabolic affect of cortisol?

increase blood sugar
increased lipolysis (central distribution)
increased proteolysis

11

What are the CVS effects of cortisol?

Increased CO
Increased BP
increased renal blood flow and GFR

12

What are the MSK effects of cortisol?

accelerates osteoporosis
reduced serum Ca2+
reduced collagen
reduced wound healing

13

What are the immunological effects of cortisol?

reduced capillary permeabilty
reduced leukocytes
reduced macrophages
reduced cytokines

14

What are the main uses of corticosteroids?

suppress inflammation
suppress immune system
replacement treatment

15

Where are Mineralocorticoid receptors found?

kidneys
salivary glands
gut
sweat glands

16

What are the effects of aldosterone?

K+/H+ excretion
increased Na+ reabsorption
BP regulation
Regulates ECF volume

17

What can cause adrenal insuffieciency?

Inadequate adrenal function
Primary insufficiency
Secondary insufficiency

18

What are causes of primary adrenal insufficiency?

Addison's
Congenital adrenal hyperplasia
Adrenal TB
Malignancy

19

What can cause secondary adrenal insufficiency?

lack of ACTH stimmulation
iatrogenic steroids
Pituitary/Hypothalamic disorders

20

What is the commonest cause of primary adrenal insufficiency?

Addison's

21

What is the aetiology of addison's?

Autoimmune destruction of adrenal cortex
Autoantibodies in 70%
Low cortisol levels

22

How much of the adrenal will be destroyed before symptoms of addison's appear?

90%

23

With what other conditions is addison's associated?

T1DM
Pernicious anaemia
Autoimmune thyroid

24

What are the symptoms of addison's?

Anorexia
Weight loss
Fatigue
Dizziness
Low BP
Abdo pain
Vomiting
Diarrhoea
Skin pigmentation (ACTH)

25

What are the diagnositic features of addison's?

low Na+
high K+
Anbormal synacthen
Hypoglycaemia
Increased ACTH
increased renin/reduced alsdosterone
Adrenal sutoantibodies

26

What dynamic test would be used to test for addison's? How does it work?

Short SynATCHen test
-measure before and 30 mins after iv ACTH injection
-before >250nmol, after>480 is normal

27

What is the management for addison's?

Hydrocortisone to replace cortisol( IV if unwell, 15-30mg daily, mimic diuinal rhythm)
Fludrocortisone to replace aldosterone (monitor BP and K)

28

What education do patients treated for adrenal insufficiency need?

sick day rules
do not stop suddenly
wear identification

29

How is secondary adrenal insufficiency characterised?

lack of CRH or ACTH

30

What is the most common cause of secondary adrenal insufficiency?

exogenous steroids
(mimcs negative feedback)

31

How is secondary adrenal insufficiency different to addison's?

Pale skin (no inc ACTH)
Aldosterone intact (no RAAS involvement)

32

How is secondary adrenal insufficiency treated?

Hyrdocortisone only
(no need for fludrocortisone)

33

How is cushing's syndrome defined?

excess cortisol secretion

34

what is the etiology of cushing's?

women
20-40years

35

What are the symptoms of cushing's?

easy bruising
striae
facial plethora
proximal muscle weakness

36

What are the adrenal causes of cushing's?

adrenal adenoma/carcinoma

37

What is the most common cause of Cushing's?

iatrogenic high dose steroids=chronic suppression of ATCH and adrenal atrophy

38

What is primary aldosteronism?

Autonomus production of aldosterone independent of regulators(angiotensin 2/K)

39

What are the CVS actions of aldosterone?

increased cardiac collagen
increased sympathetics
Na+ retention
Cytokine synthesis
Altered endothelial function

40

What are the CVS responses to aldosterone?

inc BP
-LVH
-Atheroma

41

What are the clinical features of primary aldosteronism?

Significant hypertension
Hypokalaemia
Alkalosis

42

What are the causes of primary aldosteronism?

adrenal adenoma (Conn's syndrome)
Bilateral hyperplasia (commonest)
Genetic mutation (KCNJ5 channel)
Unilateral hyperplasia(rare)

43

How is primary aldosteronism diagnosed?

1)-measure ARR (aldosterone renin ratio)
->750 then saline suppression test
-failure to suppress saline by 50%=PA

2)confirm subtype
-Adrenal CT
-adrenal vein sample to confirm adenoma s true source

44

How is primary aldosteronism managed?

Surgical laproscopic adrenalectomy if adenoma.
Spironolactone if bilateral hyperplasia (MR antagonist)

45

What is congenital adrenal hyperplasia?

defect with enzymes in steroid pathway

46

What is the most common enzyme deficiency in CAH?

21a hydroxylase

47

How is CAH diagnosed?

Basal/stimulated 17-OH progesterone levels

48

How do males with CAH classically present?

Adrenal insufficiency (2-3 weeks)
poor weight gain
Addison's biochemical pattern

49

How do females with CAH classically present?

genital ambiguity

50

What is the non-classical presentation of CAH?

Hirsuites
Acne
Oligomaenhorroea
Precocious puberty
Infertility/subfertility

51

What is the principles of treatment of CAH in children?

Timely recognition
Gluco/mineralocorticoid replacement
surgical correction
Acheive maximum growth potential

52

What are the principles of treatment in CAH adults?

Control androgen excess
Restore fertility
Avoid steroid overreplacement

53

What is the weight of an adrenal gland in healthy adults?

4g

54

What is phaeochromocytoma?

rare tumour of adrenal medulla
Increased catecholamines
10% tumour

55

Why do adrenals look brown in phaeochromocytoma?

chromaffin cells reduce chrome salts to metal chromium

56

Why is it important to diagnose phaeochromocytoma?

Curable hypertension
surgical risks
pregnancy risks
potentially fatal

57

What are the symptoms of phaeochromocytoma?

Triad: hypertension (50%paroxysmal), headache, sweating
palpitations
breathless
constipation
anxiety
weight loss

58

What are the signs of phaeochromocytoma?

hypertension
postrual hypotension (50%)
pallor
arrythmia
pyrexia

59

What are the biochemical abnormalities in phaeochromocytoma?

hyperglycaemia
low K
raised Hb
mild hypercalcaemia
lactic acidosis

60

Who should be investigated for phaeochromocytoma?

family memebers with syndromes
resistant hypertension
<50 yrs patient with HT
HT and Hyperglycaemia

61

How can phaeochromocytoma be confirmed?

confirm catecholamine excess
Urine catecholamine samples 2x24hr

62

How can you identify the source of catecholamine excess in phaeochromocytoma?

MRI
PET
MIBG scans

63

How is phaeochromocytoma treated?

alpha and beta blockade
fluid+/- blood replacement
total excision where possible
chemotherapy if malignant

64

What conditions are associated with phaeochromocytoma?

Multiple endocrine neoplasia 2
Succinate dehydrogenase mutations
Neurofibromatosis
Tuberose sclerosis

65

What is MEN2?

Autosomal dominant
mutation of tyrosine kinase receptor

associated:MTC, parathyroid hyperplasia, bilateral phaeochromocytoma

66

What is Von Hippel Lindau syndrome?

Mutation HIF1-a
Autosomal dominant
Vascular tumour
SDH genes stabilise HIF1-a

67

What are the signs of neurofibromatosis?

Axillary freckling
Cafe au lait patches
Neurofibromas

68

What is the apperance of phaeochromocytoma?

Zellballen (cells form nests)

69

Where do phaeochromocytomas metastasise to?

bones
regional lymph nodes
liver
lung