HPA

Question 1

Function of FSH

Answer 1

Stimulate ovarian follicle development

Question 2

Function of LH

Answer 2

In women: causes midcycle ovulation
In Men: drives testosterone secretion from leydig cells

Question 3

Function of GnRH

Answer 3

Stimulates FSH and LH release

Question 4

Inhibitors of LH and FSH

Answer 4

Testosterone
Prolactin
Estrogen

Question 5

Prolactin inhibitor

Answer 5

Dopamine

Question 6

Stimulator of prolactin release

Answer 6

TRH
This explains why patient with primary hypothyroidism can have galactorrhea and also infertility because prolactin inhibit FSH and LH

Question 7

Effect of pituitary tumor

Answer 7

Compressive effect of the optic chasm leads to bitemporal hemianopsia
Hypo or hyper secretion

Question 8

Cortisol has a circadian rhythm

Answer 8

Peaks in the morning
Lowest at midnight
This explains why early morning cortisol (8am cortisol) is used to assess for deficiency of cortisol
Midnight salivary cortisol use to check for excess cortisol

Question 9

Synacthen test

Answer 9

Stimulatory test used to evaluate for cortisol deficiency , primary adrenal failure and Pituitary ACTH reserve

Not to used in acute situations like pituitary apoplexy or post pituitary surgery

Question 10

Mediator of growth hormone function

Answer 10

IGF.1

Question 11

Dynamic pituitary test

Answer 11

Used to assess hormones that have pulsatile secretion circadian rhythm

Question 13

Insulin tolerance test

Answer 13

Gold standard test for ACTH and GH reserve
Cortisol response’> 550nmol /l
GH response : 3ug/dl

Contraindications: IHD
Epilepsy

Question 14

Pituitary macroadenoma

Answer 14

> 1cm

Question 15

Pituitary microadenoma

Answer 15

<1cm

Question 16

Secondary causes of hypertension

Answer 16

Acromegaly
Hyperthyroidism
Hyperaldosteronism
Cushing syndrome
Pheochromocytoma

Question 17

Oral glucose tolerance test for acromegaly

Answer 17

75g OGTT causes GH suppression by < 1ug/l in normal people and failure to suppress suggests autonomous secretions and diagnosis of acromegaly

Question 18

Somatostatin analogue

Answer 18

Octreotide
Lanreotide
Pasireotide

Given monthly