Hypothalamic-Pituitary Relationships 1

Question 1

What hormones does the posterior pituitary make?

Answer 1

None!

But it stores ADH and Oxytocin

Question 2

HPG Axis

Answer 2

Hypothalamus releases GnRH to AntPit

Anterior Pit releases LH and FSH

LH goes to Ludwig cells in males (testosterone), theca in females (androgens)

FSH goes to Sertoli cells in males (spermatogenesis) and Granulosa in females (estrogen)

Question 3

Growth Hormone

Answer 3

Produced by somatotropes in APit
-targets liver and bone
—Receptor is GHR, linked to JAK-STAT

Inhibited by IGF-1 and somatostatin

Question 4

HPG Axis Deficiency

Answer 4

1-no IGF release, but high GH

2-no IGF or GH, but high GHRH

3-none of the associated hormones

Question 5

Growth Promoting Factors in Fed State

Answer 5

1. Adequate insulin and AAs
2. Liver makes IGF-1
3. mitogenesis, lipolysis, differentiation

Question 6

Increase carbs but low protein effects on GH

Answer 6

GH inhibited, so no IGF-1
-leads to lipogenesis and carb storage
=weight gain

Question 7

High protein, low carb effect on GH

Answer 7

GH increases, IGF-1 produced

-lipolysis, ketogenic metabolism, diabetogenic (insulin insensitivity)

Question 8

How to diagnose acromegaly

Answer 8

Elevated GH and IGF-1 levels

And

Failure to suppress GH in response to oral load glucose

Question 9

When does GH peak?

Answer 9

During sleep is highest, but high during exercise

Question 10

Prolactin feeds back to cause?

Answer 10

Increase in DA-to suppress more prolactin

Decrease in LH and FSH to lower sex drive and decrease reproductive function

Question 11

Actions of Oxytocin

Answer 11

Milk ejection due to sight, sound, smell of infant

Uterine contraction when in labor