Pathophysiology

Question 1

Reidel’s Thyroiditis (3)

Answer 1

1. Chronic inflammation

and

2. Fibrous infiltration

of the thyroid gland leading to a hard goitre and

3. Hypothyroidism

Question 2

5-Alpha-Reductase Deficiency (4)

Answer 2

1. Deficiency in this enzyme means…
2. Inability to turn Testosterone into Dihydrotestosterone (DHT)

DHT is key for male sexual characteristc development so these kids have:

3. Ambiguous Genetalia
4. 46 XY Autosomal Recessive

Question 3

Androgen Insensitivity Syndrome (5)

Answer 3

1. 46 XY - X-Linked Recessive
2. Defect in Androgen receptor means end-organ resistance to testosterone
3. Causes genetic males to have female or ambiguous genetalia
4. Rudementary testes or vagina
5. Levels of androgens (test, oest, LH are ELEVATED bc they are made in surplus to attempt to stimulate the unresponsive genetal receptors)

Question 4

Nephrogenic DI (4)

Answer 4

1. Kidneys are screwed fro another illness - hypertension, diabetes, ckd, esrd etc etc
2. Resulting in reduced or no sensitivity to ADH in collecting ducts
3. Resulting in dilute urine unresponsive to Desmopressin or water deprivation test (remains dilute after all DI testing)

and creates the symptoms

4. Polydypsia, polyuria, chronic dry mouth, nocturia

Question 5

WHY does cushing’s syndorme cause a Hypokalaemic Metabollic Alkalosis? (3)

Answer 5

1. HIGH cortisol levels stimulate action of aldosterone
2. Aldosterone increases Na+ reabsorption and K+/H+ excretion
3. Thus a Low K+ Low H+ = metabollic hypokalaemic alkalosis