Pituitary

Question 1

List the hormone(s) produced by the anterior pituitary glad

Answer 1

TSH, ACTH, LH & FSH, GH and prolactin

Question 2

Describe the structure of cortisol

Answer 2

Member of the C21 family, lipophilic.

Question 3

How is cortisol synthesised?

Answer 3

Synthesised from cholesterol via progesterone in a series of enzyme catalysed reactions

Question 4

Where is the pituitary gland located?

Answer 4

Base of the brain - suspended by a stalk (pituitary fossa)

Question 5

How does cortisol affect target cells?

Answer 5

Crosses plasma membrane and binds to cytoplasmic receptors, complex enters the nucleus to interact with specific regions of DNA which alters the rate of transcription of specific genes

Question 6

List the hormone(s) produced by the posterior pituitary

Answer 6

ADH

Question 7

How is ACTH release controlled?

Answer 7

CRF

Question 8

Describe an insulin tolerance test

Answer 8

Best test of GH reserve. IV insulin injection which induces hypoglycaemia. ACTH and GH should be released to counter this

Question 9

Describe a GH suppression test

Answer 9

75g glucose orally - failure to suppress GH suggests acromegaly

Question 10

Explain how ACTH can lead to increased pigmentation of certain parts of the body

Answer 10

POMC is the precursor for ACTH, when present in excess ACTH has some MSH-like activity because MSH sequence is contained within ACTH