Adrenal glands

Question 1

Where are the adrenal glands located?

Answer 1

Above the kidney – retroperitoneal

Question 2

Name the 3 layers of the adrenal cortex and what they produce

Answer 2

1. Zona glomerulosa (outer layer) – mineralocorticoids e.g. aldosterone
2. Zona fasciculate (middle layer) - glucocorticoids e.g. cortisol
3. Zona reticularis (inner layer) – androgens (sex hormones)

Question 3

What does the adrenal medulla secrete?

Answer 3

Catecholamines e.g. adrenaline and noradrenaline

Question 4

What are the key steps in the hypothalamic-pituitary-adrenal axis?

Answer 4

1. Corticotrophin-releasing hormone (CRH) released by the hypothalamus
2. CRH stimulates ACTH release from the pituitary
3. ACTH stimulates cortisol and androgen production by the cortex

Question 5

How do the kidneys influence adrenal secretion?

Answer 5

The zona glomerulosa (aldosterone secretion) responds to renin release by the juxtaglomerular cells of the afferent arterioles of the kidney

Question 6

What is another name for primary hypoadrenalism?

Answer 6

Addison’s disease

Question 7

What is the definition of Addison’s disease?

Answer 7

Destruction of the entire adrenal cortex resulting in mineralocorticoid (aldosterone), glucocorticoid (cortisol) and sex steroid (androgens - precursors of sex hormones) deficiency

Question 8

Give 6 causes of Addision’s disease

Answer 8

1. Autoimmune adrenalitis
2. Tuberculosis
3. Adrenal metastases
4. Long-term steroid use
5. Opportunistic infections in HIV e.g. CMV
6. Adrenal haemorrhage/infarction

Question 9

What are the most common causes of Addison’s disease in the UK and worldwide?

Answer 9

• UK = autoimmune adrenalitis

* Worldwide = TB

Question 10

Give some clinical presentations of Addison’s disease

Answer 10

• Lethargy, depression, low mood & self esteem
• Anorexia & weight loss
• Vitiligo and skin pigmentation
• Nausea and vomiting
• Diarrhoea, constipation and abdominal pain
• Impotence/amenorrhea
• Postural hypotension, dizziness and dehydration

Question 11

What are signs of critical deteriation of Addison’s disease?

Answer 11

• Shock - decreased BP, tachycardia

* Raised temperature and coma

Question 12

How would you diagnose Addison’s disease?

Answer 12

• Blood tests
• Short ACTH stimulation test
• Adrenal antibodies
• Morning (e.g. 9am) ACTH levels = inappropriately high in Addison’s
• Adrenal/chest X-ray if there is TB history

Question 13

Give some features you would see in a blood test of someone with Addison’s disease

Answer 13

• Hypoaldosternonism leading to hyponatraemia & hyperkalaemia
• Low cortisol leading to hypoglycaemia
• Uraemia
• Raised Ca2+
• Eosinophilia
• Anaemia

Question 14

How would you treat Addison’s disease?

Answer 14

• Adrenal crisis/hypotensive on arrival - immediate IV hydrocortisone (+saline and glucose to increase BP)
• Steroids 3x daily

Question 15

How does secondary hypoadrenalism differ to primary hypoadrenalism?

Answer 15

Secondary is an issue with the pituitary rather than an adrenal issue

Question 16

What are the causes of secondary hypoadrenalism?

Answer 16

• Usually iatrogenic - due to long-term steroid use

* Due to hypothalamic-pituitary disease resulting in decreased ACTH production

Question 17

How does secondary hypoadrenalism present clinically?

Answer 17

• Vague symptoms of feeling unwell

* No skin hyperpigmentation since ACTH is reduced

Question 18

How would you diagnose secondary hypoadrenalism?

Answer 18

Low ACTH levels with mineralcorticoid production intact

Question 19

How would you treat secondary hypoadrenalism?

Answer 19

• Wean off long-term steroids slowly to allow adrenals to recover
• Oral hydrocortisone