Investigations endocrine

Question 1

How to measure testosterone

Answer 1

Have to measure SHBG - sex hormone binding globulin

Question 2

How to measure hormones assess balance negtaive feedback system

Answer 2

Measure simultaneous trophic and primary hormones - ACTH, TSH, FSH/LH

Question 3

Tests for cushings

Answer 3

Midnight cortisol - high
Dexamethasone supression test
24 urine cortisol tests

Question 4

Acromegaly investigation tests

Answer 4

IGF-1 + OGTT
Monring IF GH level

Question 5

Thyrotoxicosis measurement

Answer 5

T3+T4

Question 6

Phaeochromocytoma investigaiton

Answer 6

Plasma and urine catecholamine levels

Question 7

Hyperparathyroidism investigations

Answer 7

Sim plasma calcium and PTH hormone levels

Question 8

Addisons investigations

Answer 8

Cortisol + synacthen stimulation test
Measure cortisol at 9am (max)

Question 9

GH defiency investigation

Answer 9

GH levels + stress stimulation eg exercise

Question 10

Hypogonadism investigations

Answer 10

End organ hormones and trohic - LH/FSH
Testosterone 9-10am
Ostrogen, progesterone - cycle dependent

Question 11

Diabetes insipidus investigation

Answer 11

ADH insuffieicency - water deprication test or hypertonic sodium chloride infusion test

Question 12

Low ACTH casues

Answer 12

Secndary
Adrenal excess/exogenous steroids

Question 13

High ACTH causes

Answer 13

Secondary
Pituitary excess/ectopic secretion, adrenal gland failure

Question 14

Low 9am cortisol causes

Answer 14

Primary - adrenal/pituitary insufficiency or exogenous steroids
High 12mn cortisol = adrenal/pituitary excess or ectopic secretion

Question 15

What hormones does pituitary produce

Answer 15

• pituitary → systemic circulation
• TSH → thyroid gand
• ACTH → adrenal cortex → corticosteroids
• Gonadotrophins → gonads
• Prolactin → breast tissue
• Growth hormone → bone and muscle growth
• MSH → dermatocytes

Question 16

Vascular signalling originates from what part of pituitary

Answer 16

Anterior

Question 17

Neural signalling originates from what part of pituitary

Answer 17

Posterior

Question 18

Supply to the pituiatry

Answer 18

Internal carotid

Question 19

When does cortisol peak and when at lowest

Answer 19

Peak - 9am
lowest at midnight

Question 20

What substances positively feedback for CRH on the hypothalmus

Answer 20

Serotonin, gluatamate, histmaine, catecholamines

Question 21

What -> negative feedback on hypothalamus

Answer 21

Cortiosl
GABA

Question 22

What happens in the follicuar phase

Answer 22

Oestrogen surge -> LH release

Question 23

What happens in the mid luteal phase

Answer 23

LH pulses -> progesterone release

Question 24

What inhibits GnRH secretion from hypothalamus

Answer 24

Prolactin

Question 26

Role of FSH and LH in men

Answer 26

FSH -> spermatogenesis
LH -> testosterone production

Question 27

FSH and LH role in women

Answer 27

FSH -> follicle development
LH -> ovulation

Question 28

Testosterone effet on hypothalamus

Answer 28

Negative