Endocrinology

Question 1

Define endocrinology

Answer 1

Study of hormones (+ their gland of origin), receptors, intracellular signalling pathways, + associated diseases

Question 2

Describe insulin activation

Answer 2

1. Binds to insulin receptors
2. Results in phosphorylation of receptor + activation of secondary messenger - TYROSINE KINASE
3. Phosphorylation of signal molecules
4. Cascade of effect
5. Glucose uptake

Question 3

Give 3 examples of amine hormones

Answer 3

Dopamine, adrenaline, noradrenaline

Question 4

Is T3 or T4 more active?

Answer 4

T3

Question 5

Is T3 or T4 more abundant in the body?

Answer 5

T4

Question 6

Where do peptide hormones bind?

Answer 6

Receptors on cell membrane

Question 7

Where do steroid hormones bind?

Answer 7

Cytoplasmic receptors

Question 8

Normal blood glucose?

Answer 8

3.5-8.0 mmol/L

Question 9

Why is the brain the MAIN consumer of glucose?

Answer 9

FFAs can’t cross the BBB so the brain can’t convert them into ketones (–> acetyl-CA for Krebs)

Question 10

Pathophysiology of DKA

Answer 10

1. Hyperglycaemia –> osmotic diuresis
2. More peripheral lipolysis –> more FFAS
3. More acetyl-CoA –> more ketones
4. Metabolic acidosis –> vomiting
5. Dehydration impairs renal excretion of H+ + ketones
6. pH-dependent processes impaired
7. Worsened by ‘stress hormones’

Question 11

Define ketoacidosis

Answer 11

A state of uncontrolled catabolism associated with insulin deficiency

Question 12

What is hyperosmolar hyperglycaemia?

Answer 12

Life-threatening emergency characterised by marked hyperglycaemic, hyperosmolality, + mild/no ketosis

Question 13

What is the metabolic emergency characteristic of uncontrolled T2DM?

Answer 13

Hyperosmolar hyperglycaemic state

Question 14

Give 3 possible presentations of pituitary tumour

Answer 14

Pressure on local structures - e.g. bitemporal hemianopia
Pressure on normal pituitary - HYPOpituitarism
Functioning tumour - HYPERpituitarism

Question 15

List 3 functioning tumours (hyperpituitarism)

Answer 15

Prolactinoma
Acromegaly
Cushing’s

Question 16

Give 5 possible causes of hyperthyroidism

Answer 16

Grave’s disease
Toxic multinodular goitre
Solitary toxic adenoma (benign)
De quervain’s thyroiditis (post-viral)
Drug-induced hyperthyroidism

Question 17

Treatment of Graves’ opthalmopathy?

Answer 17

IV methylprednisolone

Question 18

Causes of primary hypothyroidism?

Answer 18

Primary atrophic hypothyroidism (PAH)
Hashimoto’s thyroidits
Postpartum thyroiditis
Iatrogenic (thyroidectomy, radioactive iodine therapy)
Drugs (e.g. carbimazole, lithium, amiodarone)
Iodine deficiency

Question 19

Cause of secondary hypothyroidism?

Answer 19

Hypopituitarism

Question 20

Most common cause of hypothyroidism?

Answer 20

Primary atrophic hypothyroidism (PAH)

Question 21

What drug can cause both hyperthyroidism + hypothyroidism?

Answer 21

Amiodarone

Question 22

Main complication of hypothyroidism?

Answer 22

Myxoedema coma

Question 23

Most common type of thyroid carcinoma?

Answer 23

Papillary

Question 24

Clinical presentation of thyroid carcinoma?

Answer 24

Thyroid nodules
Thyroid gland increases in size, becomes hard, + is irregular in shape
Dysphagia
Hoarse voice

Question 25

Treatment of thyroid carcinoma?

Answer 25

Levothyroxine (T4) Thyroidectomy

Question 26

What is the most common hormonal disturbance of the pituitary?

Answer 26

Hyperprolactinemia

Question 27

Causes of hyperprolactinemia?

Answer 27

Prolactinoma Pituitary stalk damage Drugs Pregnancy Stress

Question 28

What is hyperprolactinemia?

Answer 28

Too much prolactin in the blood of women who aren't pregnant + in men

Question 29

Treatment for adrenal crisis?

Answer 29

IV hydrocortisone

Question 30

What is serum calcium controlled by?

Answer 30

PTH + vitamin D

Question 31

Is hypercalcaemia or hypocalcaemia more common?

Answer 31

Hypercalcaemia

Question 32

What is calcitriol stimulated by?

Answer 32

Low plasma calcium Low plasma phosphate PTH

Question 33

K+ levels for hypokalaemia?

Answer 33

Serum K+ <3.5 mmol/L (>2.5 mmol/L is a MEDICAL EMERGENCY)

Question 34

Describe carcinoid tumours

Answer 34

These tumours originate from the enterochromaffin cells (neural crest) + are capable of producing serotonin

Question 35

What is carcinoid crisis?

Answer 35

When a caricnoid tumour outgrows its blood supply mediators flow out + this is LIFE-THREATENING

Question 36

Treatment of carcinoid crisis?

Answer 36

High dose somatostatin analogue (e.g. octreotide)

Question 37

Sulphonylureas: examples + indications

Answer 37

Gliclazide T2DM

Question 38

Glitazones: examples

Answer 38

Pioglitazone

Question 39

Glitazones: mechanisms

Answer 39

Activates PPARs which bind FFAs + induce genes that enhance insulin action

Question 40

Antithyroid drugs: examples + indications

Answer 40

Carbimazole Grave's + before thyroid surgery

Question 41

Antithyroid drugs: mechanisms

Answer 41

Prevents thyroid peroxidase from iodinating tyrosine residues so reduces production of T3 + T4

Question 42

GH receptor antagonists: examples + indications

Answer 42

Pegvisomant Acromegaly

Question 43

GH receptor antagonists: mechanisms

Answer 43

Blocks action of GH at its receptor to reduce production of IGF-1

Question 44

Vasopressin antagonists: examples + indications

Answer 44

Tolvaptan Euvolemic/Hypervolemic hyponatraemia

Question 45

Vasopressin antagonists: mechanisms

Answer 45

Inhibits V2 so increases fluid excretion

Question 46

Vasopressin analogue: examples + indications

Answer 46

Desmopressin DI + distinguish cranial from nephrogenic DI

Question 47

Adrenal corticosteroid inhibitors: examples

Answer 47

Metyrapone Cushing's + diagnose adrenal insufficiency

Question 48

Adrenal corticosteroid inhibitors: mechanisms

Answer 48

Blocks cortisol synthesis by reversibly inhibits the enzyme that stimulates ACTH secretion

Question 49

Adrenal corticosteroid inhibitors: SEs

Answer 49

GI disturbances Headache Dizziness Drowsiness

Question 50

What is a NFPA?

Answer 50

Benign tumour of the pituitary which doesn't produce excess hormones