Physiology of the Pituitary Gland

Question 1

Which hormones are secreted by the anterior pituitary?

Answer 1

ACTH 
TSH 
FSH
LH 
PRL
GH

Question 2

What hormones are stored in the posterior pituitary?

Answer 2

ADH

Oxytocin

Question 3

Which hormones are involved in baseline pituitary tests?

Answer 3

TSH 
fT4 
LH 
FSH 
Testosterone 
GH 
IGF-1 
PRL

Question 4

Briefly what are dynamic tests?

Answer 4

Stimulate or suppress the hormone that you want to know something about. These are done after baseline pituitary tests

Question 5

What is the short synacthen test and what results would you expect to be normal and abnormal?

Answer 5

Patient given synthetic ACTH and blood cortisol measured at 0, 30 and 60mins.
30min cortisol >600nmol/L = normal
30mincortisol <400nmol/L = abnormal

Question 6

What does an abnormal synacthen test suggest and , what should then be done?

Answer 6

Suggests adrenal insufficiency
Measure ACTH - low = pituitary disease
High = adrenal disease

Question 7

Describe the water deprivation test.

Answer 7

Patient is given nothing to drink all day to see if they can concentrate their urine (should be twice serum concentration). If this is not possible then diabetes insipidus can be diagnosed

Question 8

What is the insulin stress test and what is it used for?

Answer 8

Try to get blood sugar really low by giving insulin. This stresses pituitary out to produce more hormones.
Best test for steroid response.

Question 9

What are normal results from the insulin stress test?

Answer 9

Cortisol and GH response every 30 min for 2-3 hrs​
Normal cortisol >500​
Normal GH >7ug/l​

Question 10

What is prolactin controlled by?

Answer 10

Negative dopamine control

Question 11

What lies directly above the pitutary gland?

Answer 11

Optic chiasma