Adrenal disorders

Question 1

What can abnormal amounts of messengers cause

Answer 1

Abnormal amounts of messenger cause cells to misbehave all over the body: syndromes of excess and deficiency
Adrenal failure = Addison’s
Excess cortisol = Cushing’s

Question 2

Describe the anatomy of the adrenal gland

Answer 2

Left adrenal vein drains into renal vein
Right adrenal vein drains into IVC
Both adrenals have many arteries but only one vein
So the left indirectly feeds and the right directly feeds.

Question 3

Describe the passage of the arteries in the adrenal glands

Answer 3

The arteries pass through the cortex and pick up all the hormones that the adrenal gland makes. This is then delivered to the central vein.

Question 4

What is the risk associated with a left adrenalectomy

Answer 4

Spleen at risk with left adrenalectomy
therefore immunise with HIB (haemophilus influenzae (B)) and pneumovax before elective left adrenalectomy
(HIB and pneumovax are common in people who have lost their spleen).

Question 5

What is pneumovax

Answer 5

pneumococcal vaccination against several strains of Step. Pneumococcus

Question 6

Describe the different layers of the adrenal gland

Answer 6

o Glomerulosa – Aldosterone. o Fasciculata – Cortisol. o Reticularis – Androgens (but doesn’t really do much as it’s a remnant from evolution). o Medulla – Catecholamines (e.g. adrenaline).

Question 7

What is the precursor of the adrenal gland secretions

Answer 7

Cholesterol

Question 8

What is meant by a hormone

Answer 8

Blood borne (circulating) messenger

Question 9

Describe the different types of hormone

Answer 9

Peptides (prolactin, GH, ACTH)
steroids (testosterone, cortisol)
amines (adrenaline, thyroxine.)

Question 10

Are all steroid hormones derived from cholesterol

Answer 10

No, they can be derived from other raw materials too.

Question 11

Draw cholesterol

Answer 11

See diagram

Question 12

Describe how different products are produced from cholesterol

Answer 12

Protein that catalyses a specific reaction
various enzymes present in cells
specific enzymes catalyse the synthesis of particular alterations to the molecule- different enzymes in different layers of adrenal gland alter cholesterol differently, giving rise to different products.

Question 13

What is the production of cortisol controlled by

Answer 13

ACTH

Question 14

Why are the adrenal glands not as important in the production of sex hormones

Answer 14

The gonads have evolved to do this

Question 15

What does cortisol have a negative feedback effect on

Answer 15

The production of ACTH
Direct on pituitary
Indirect on hypothalamus

Question 16

In the synthesis of the adrenal hormones from cholesterol, what is the base of all the enzymes

Answer 16

P450c

Question 17

What is the role of P450c21

Answer 17

Converts progesterone into 11 deoxycorticosterone

Converts 17 OH progesterone into 11 deoxycortisol

Question 18

What is the role of p450c17

Answer 18

Converts progesterone into 17 OH progesterone

Question 19

What is the role of P450c11

Answer 19

Converts 11 deoxycorticosterone into corticosterone

Converts 11 deoxy cortisol into cortisol

Question 20

What is the role of P450c18

Answer 20

Converts corticosterone into aldosterone

Question 21

Draw HPA axis

Answer 21

See diagram

Question 22

Describe the production of cortisol

Answer 22

Cortisol control by ACTH: ▪ Cortisol is needed when under stress (e.g. physical or trauma) and ACTH turns on the correct ENZYMES needed to make cortisol. ▪ On the other hand, if you needed aldosterone, you can turn on the enzymes using the reninangiotensin system. ▪ I.E. If you turn on different enzymes, you make different hormones.
Binding of hormone receptor turns on that enzyme pathway

Question 23

Describe POMC

Answer 23

POMC = pro-opio-melanocortin
POMC is a large precursor protein that is cleaved to form a number of smaller peptides, including ACTH, MSH (Melanocyte stimulating hormone) and endorphins
Thus people who have pathologically high levels of ACTH may become tanned

Question 24

Where does the tan appear

Answer 24

Everywhere, even in the mouth

Question 25

Describe Addison’s disease

Answer 25

Primary adrenal failure
autoimmune disease where the immune system decides to wipe out the adrenal cortex (UK)
tuberculosis of the adrenal glands (commonest cause worldwide)

Question 26

What is an indication of Addison’s disease

Answer 26

High levels of ACTH.

Question 27

Describe some of the symptoms of Addison’s disease

Answer 27

o Skin pigmentation (inappropriate). o Freckling. o GI disturbances. o Postural Hypotension (standing up) – lack of cortisol and aldosterone to manage. o Hypoglycaemia. o Weight loss. o Autoimmune vitiligo.

Question 28

What is autoimmune vitiligo

Answer 28

Autoimmune disease of the skin; autoimmune candidates often come together.

Question 29

What are the treatments for Addison’s disease

Answer 29

Rehydrate with normal saline
Give dextrose to prevent hypoglycaemia which could be due to the glucocorticoid deficiency
give hydrocortisone or another glucocorticoid

Question 30

Summarise the key features of Addison’s

Answer 30

Summary includes: Cortisol deficiency, salt loss, hypotension, eventual death if untreated.

Question 31

What does a low Na+ conc as a result of Addison’s cause

Answer 31

Low blood pressure and hence weakness

Question 32

What is the disease caused by excess cortisol production called

Answer 32

Cushing’s syndrome

Question 33

Describe the biological actions of excess cortisol

Answer 33

Impaired glucose tolerance (diabetes)
weight gain (increase fat, lose protein)

thin skin and easy bruising
striae (stretch marks)
proximal myopathy (muscle weakness)
mental changes (depression)

Hypertension
fat redistribution
moon face
buffalo hump (interscapular fat pad)

Question 34

Can Cushing’s syndrome be caused by an excess of any other glucocorticoid

Answer 34

The main reason for Cushing’s syndrome is an excess of cortisol but it can be ANY OTHER glucocorticoid

Question 35

Describe the symptoms of Cushing’s syndrome

Answer 35

Impaired glucose tolerance (diabetes)
weight gain
hirsutism (facial hair) and acne
thin skin and easy bruising
striae (stretch marks)
proximal myopathy (muscle weakness)
mental changes (depression)

Question 36

What are the 4 causes of Cushing’s syndrome

Answer 36

Taking steroids by mouth (common)
pituitary dependent Cushing’s disease (pituitary adenoma)
Ectopic ACTH (lung cancer)
adrenal adenoma or carcinoma

Question 37

What is meant by ectopic ACTH

Answer 37

Some lung cancer cells start to produce ACTH (removal of cells removes the symptoms of Cushing’s syndrome)

Question 38

Describe pituitary adenoma

Answer 38

adenohypophysis produces too much ACTH.

Question 39

What is the difference between Cushing’s syndrome and Cushing’s disease

Answer 39

Cushing’s DISEASE is associated ONLY with a pituitary adenoma; every other cause gives rise to Cushing’s SYNDROME.

Question 40

What are the side effects of steroids

Answer 40

Hypertension
Diabetes
Osteoporosis
reactivation of infection (immunosuppression)
easy bruising
poor wound healing, thin skin
The side effects of ‘steroids’ is more or less the same as the symptoms of Cushing’s Syndrome.

Question 41

Why do patients with Cushing’s syndrome present with thin skin

Answer 41

Cortisol drives the body to make fat, but no protein, hence the skin becomes thinner.

Question 42

Describe aldosterone producing adenoma

Answer 42

Conn’s syndrome
Hypertension (difficult to treat)
oedema
low potassium