ENDO 128 Gen Endocrine

Question 1

What hormones are secreted from the Thyroid Gland?

Answer 1

T3 & T4

Calcitonin

Question 2

Where are the parathyroid glands and what do the secrete?

Answer 2

4 glands that sit on the thyroid, secretes PTH

Question 3

What hormones are released from the adrenal medulla?

Answer 3

Adrenaline and Noradrenaline

Question 4

What stimulates production and release of T3 and T4 and where is it secreted from?

Answer 4

TSH from the anterior pituitary

Question 5

What are the actions of TSH?

Answer 5

Increase iodine uptake by the thyroid, stimulates T3 and T4 production, stimulates thyroid growth

Question 6

What is TSH release stimulated by and controlled by?

Answer 6

Stimulated by TRH from hypothalamus and controlled by negative feedback of T3 and T4 levels

Question 7

Name some general actions of thyroid hormones

Answer 7

Increases basal metabolic rate: 0xygen use and heat production

Stimulates protein degradation/production

Potentiate insulin effects: glycogenolysis, glucose use

CVS: increase CO, HR, force and syst BP
vasodilatation so decrease diastolic BP

Question 8

What is the function of Calcitonin?

Answer 8

To prevent hypercalcaemia by inhibiting osteoclasts in bone

Question 9

What hormone stimulates the release of cortisol from the adrenal gland?

Answer 9

ACTH from anterior pituitary

Question 10

What does CRH do?

Answer 10

Stimulate ACTH release from anterior pituitary

Question 11

What is the disease of Cortisol insufficiency?

Answer 11

Addison’s Disease

Question 12

What is the disease of excess cortisol?

Answer 12

Cushing’s syndrome

Question 13

Where are adrenaline and noradrenaline stored?

Answer 13

In chromaffin cells in the adrenal medulla

Question 14

What is phaecromocytoma?

Answer 14

Tumour of the adrenal medulla causing constant secretion of catecholamines

Question 15

What are some of the signs and symptoms of phaecromocytoma?

Answer 15

Anxiety, forceful heartbeat, hypertension and tremor

Question 16

What is the function of aldosterone and where is it released from?

Answer 16

Released from the adrenal cortex an acts to regulate sodium and fluid volume

Question 17

What is Conn’s syndrome?

Answer 17

hyperaldosteronism - excess sodium and water retention therefore increasing blood pressure

Question 18

What are some causes of hyperthyroidism?

Answer 18

Grave’s disease - autoantibody that stimulates thyroid release
Pituitary adenoma releasing TSH
Thyroid follicular cell tumour

Question 19

Name some of the clinical presentations of hyperthyroidism

Answer 19

weight loss despite increased appetite, increased resting heart rate, bounding pulse, heat intolerance, eye protrusion, atrial fibrillation

Question 20

What are some causes of hypothyroidism?

Answer 20

Hashimoto’s thyroiditis - an organ speific autoimmune disease against thyroid epithelial cells
Pituitary hypofunction -lack of TSH (non producing pituitary adenoma)
Thyroid hormone resistance

Question 21

Name some clinical presentations of hypothyroidism

Answer 21

myxodema (thickening and swelling of the skin), tiredness, lethargy, weight gain, slow mental state, hypothermia and constipation

Question 22

Describe some of the mechanisms of Cushing’s syndrome

Answer 22

Pituitary adenoma - produces excess ACTH = Cushing’s Disease
Adrenal cortex adenoma
Excess ACTH or glucocorticoid administration

Question 23

Briefly describe the clinical features of Cushing’s syndrome

Answer 23

Central obesity, depression, hirsutism, bruising, thick skin, striae

Question 24

How would you investigate suspected Cushing’s syndrome?

Answer 24

• 24 hour urinary free cortisol
• 9am cortisol level
• 48hour low dose dexamethasone test
• High dose dexamethasone test

Question 25

What would lack of cortisol suppression of a 48 hour low dose dexamethasone test indicate?

Answer 25

Cushing's syndrome

Question 26

What would suppression and non-suppression of cortisol indicate in a high dose dexamethasone test?

Answer 26

Suppression: pituitary dependant tumour Failure: ectopic source of ACTH or adrenal tumour

Question 27

Describe the clinical features of an Addisonian crisis

Answer 27

Hypotension | Hyponatraemia, hyokalaemia, hypoglycaemia and dehydration

Question 28

How would you investigate Suspected Addison's

Answer 28

Short ACTH stimulation test: absent or impaired cortisol response Electrolytes and urea Adrenal auto-antibodies 9hour plasma ACTH level

Question 29

What response would you expect to see in a 9 hour plasma ACTH test for Addison's

Answer 29

High ACTH with low/normal cortisol = confirmed primary hypoadrenalism

Question 30

What are some of the causes of Hypercalcaemia?

Answer 30

Excessive PTH secretion Malignancy Excess Vitamin D Drugs e.g. thiazide diuretics, lithium, vitamin A

Question 31

What are some fo the clinical features of hypercalcaemia?

Answer 31

Stones (renal and billiary); Bones (pain); Groans (abdominal pain, nausea and vomiting); Thrones (polyuria); Psychic moans (depression, coma) Possible arrhythmias

Question 32

What are some causes of hypocalcaemia

Answer 32

Increased phosphate levels (CKD); hypoparathyroidism, vitamin D deficiency, PTH resistance, Drugs, Acute pancreatitis, Low plasma albumin

Question 33

What are some of the clinical features of hypocalcaemia

Answer 33

Neuromuscular irritability: parasthesia, circumoral numbness, cramps, anxiety and tetany Chvostek's sign: tapping on facial nerve causes ipsilateral facial muscles to twitch Trousseau's sign: When inflating BP cuff above systolic for 3 minutes induces tetanic spasm of fingers and wrist

Question 34

How would you investigate hypocalcaemia?

Answer 34

Serum and urine creatinine, PTH levels, PTH antibodies, Vitamin D and magnesium levels

Question 35

How might an androgen deficiency present in an adult?

Answer 35

Small/absent testes, gynaecomastia, sexual dysfunction, small prostate, reduced hair growth

Question 36

What is PTH released in response to?

Answer 36

falling plasma calcium

Question 37

How does PTH work?

Answer 37

By increasing loss of phosphate Increasing calcium reabsorption Increasing metabolism to active Vitamin D Stimulates calcium flux from bone by activating osteoclasts

Question 38

What does Vitamin D do?

Answer 38

increases whole body calcium | increases uptake of calcium in gut

Question 39

Name some actions of cortisol (glucocorticoids)

Answer 39

Carbohydrate, protein and lipid metabolism (glucose production) Increases vascular tone and permeability Sodium and potassium retention immunosuppressive