002 Hypopituitary Axis

Question 1

Which tract are oxytocin and ADH transported down?

Answer 1

Hypothalamic hypophyseal tract

Question 2

Which two neurophysial hormones are released from the posterior pituitary?

Answer 2

ADH and Oxytocin –> released with neurophysins

Question 3

Which type of neurons synthesize ADH or oxytocin, and from which two nuclei?

Answer 3

Magnocellular neurons

From the supraoptic nucleus and the paraventricular nucleus (SON and PVN)

Question 4

In a histological slide of adenohypophysis, which 3 cell types can be seen and which color?

Answer 4

Acidophils: red/orang
Basophils: blue
Chromophobes: poor stain

Question 5

What do acidophils contain and name 2 types of cell population and their associated hormone?

Answer 5

Polypeptide hormones

• -> Somatotrophs: somatotrophin
• -> Lactotropes: prolactin

Question 6

What do basophils contain and name 3 types of cell population and their associated hormones

Answer 6

Glycoprotein hormones

• -> Thyrotropes: TSH
• -> Gonadotrophs: FSH, LH
• -> Corticotrophs: ACTH

Question 7

What are chromophobes?

Answer 7

Either degranulated basophils or acidophils that have lost their hormone, or stem cells that have not yet differentiated into hormone producing cells.

Question 8

What is the common structure in all basophils? What is their specific structure?

Answer 8

TSH, LH, FSH all contain the same alpha subunit but different beta subunits.

Question 9

How many amino acids is ACTH?

Answer 9

39 amino acids

Question 10

Where is melanocyte stimulating hormone secreted?

Answer 10

Pars intermedialis, which is closely associated with the Pars nervosa but separated from pars distalis by hypophyseal cleft.

Question 11

What is the ragais pouch?

Answer 11

This is the hollow pouch that separates anterior pituitary from posterior pituitary as it encircles it.

Question 12

Put these hormone releasing factors in order according to size: CRH, GHRH, GnRH, TRH

Answer 12

TRH < GnRH < CRH < GHRH

Question 13

Which pathway does TRH act by?

Answer 13

Increase intracellular Ca2+ by PLC pathway

Question 14

Which pathway does CRH act by?

Answer 14

Increase synthesis and secretion via AC- cAMP - PKA - CREB pathway

Question 15

Which pathway does GHRH act by?

Answer 15

Increase synthesis and secretion via AC- cAMP - PKA - CREB pathway

Question 16

Which pathway does GnRH act by?

Answer 16

Increase intracellular Ca2+ by PLC pathway

Question 17

How can stress affect having a baby?

Answer 17

Stress can inhibit GnRH and GHRH, reducing success rates of having children.

Question 18

What is kallman’s syndrome?

Answer 18

Delayed or absent puberty and an impaired sense of smell. This disorder is a form of hypogonadotropic hypogonadism, which is a condition resulting from a lack of production of certain hormones that direct sexual development.

Question 19

Which tract are anterior pituitary releasing hormones transported down?

Answer 19

Infundibulum from parvocellular neurons.