L70: Hypothalamic-Pituitary Relationship

Question 1

What artery supplies the portal system of the anterior pituitary?

Answer 1

Superior hypophyseal artery

Question 2

Hypothalamic releasing factors all target

Answer 2

anterior pituitary

Question 3

What brain nucleus is dopamine synthesized in?

Answer 3

Arcuate nucleus

Question 4

Table of hypothalamic releasing hormones…

Answer 4

See table

Question 5

Bonus: how many peptides long is GnRH

Answer 5

10aa’s! It is HIGHLY CONSERVED among vertebrates.

Question 6

Bonus: how many peptides long is TSH?

Answer 6

3aa’s only!

Question 7

What kind of receptor binds GnRH?

Answer 7

GPCR

Question 8

GnRH neurons fail to cross cribriform plate into CNS during development

Answer 8

Kallman’s syndrome

Question 9

Pulsatility of GnRH mirrors pulsatility of

Answer 9

LH release

Question 10

When GnRH pulse rate decreases, what happens to LH and FSH secretion?

Answer 10

LH decreases, FSH increases

Question 11

The hypothalamic releasing hormone regulates WHAT SUBUNIT of a pituitary glycoprotein hormone?

Answer 11

B-subunit varies and is regulated. Alpha-unit is conserved.

Question 12

GnRH binds GPCR in a pulsatile manner. Does this promote the synthesis of hormones, or the release of hormones?

Answer 12

Both!

IP3/Ca2+ pathway: promotes hormone release

DAG/PKC pathway: promotes hormone synthesis

Question 13

The pulsatility of GnRH is significant because

A. It maximizes the availability of the receptor

B. Promotes differential release of hormones

C. Promotes differential synthesis of hormones

D. All of the above

Answer 13

D. All of the above

Question 14

Neurohypophysial tract

Answer 14

Neurons whose axons terminate in the posterior pituitary

Question 15

Which send axons to the median eminence, into capillary system?

A. Tuberoinfundibular system

B. Neurohypophysial tract

Answer 15

A.

Question 16

Histologically, posterior pituitary tissue is derived from

Answer 16

Neural tissue derived from neuroectoderm

Question 17

Histologically, the anterior pituitary is derived from

Answer 17

Glandular tissue (epithelial cells) from embryonic foregut (endoderm just fyi)

Question 18

This is the pituitary. The dark cells above are

Answer 18

Glandular, thus anterior pituitary (pars distalis)

Question 19

This is the pituitary. The lighter cells below are

Answer 19

Neural. Posterior pituitary (pars nervosa)

Question 20

What are magnocellular neurosecretory cells?

Answer 20

Cell bodies of the posterior pituitary located in the hypothalamus, that secrete OT, NP, and AVP into the post. pit. capillary bed

Question 21

What is the blood supply for the post. pit?

A. Inf. hypophysial a.

B. Sup. hypophysial a.

Answer 21

A. INFERIOR hypophysial a.

Question 22

What are the darkly (purple) stained cells here?

Answer 22

Pituicytes - the glial cells of the post. pit

Question 23

What are these red stained bodies?

Answer 23

Herring bodies - unmyelinated axon terminals in the posterior pituitary, that originated in magnocellular neurosecretory cells from the neurohypophysis.

Question 24

What’s another word for the anterior pituitary?

Answer 24

Adenohypophysis

Question 25

What is the interface for all hypophysiotrophic hormones?

Answer 25

Median eminence. Lies outside the BBB and forms the floor of 3rd ventricle.

Question 26

Dopamine promotes milk production or ejection?

Answer 26

Production. Oxytosin promotes milk ejection

Question 27

GnRH. What brain nuclei?

Answer 27

POA mostly

Question 28

CRH. What brain nuclei?

Answer 28

PVN (parvocellular)

Question 29

TRH. What brain nuclei?

Answer 29

PVN

Question 30

GHRH. What brain nucleus?

Answer 30

Arcuate nucleus. (think of a giant doing pullups on the St. Louis Arch)

Question 31

Somatostatin

Answer 31

Periventricular nucleus (PeVN) not paraventricular (think of Katy PERI STOPPING the half-time show)

Question 32

Dopamine. What brain nucleus?

Answer 32

Arcuate nucleus (the giant doing pullups on the St. Louis Arch is high on DOPE)

Question 33

Hormone RELEASE. Is this IP3/Ca2+ or DAG/PKC?

Answer 33

IP3/Ca2+

Question 34

What part of FLAT PiG is basophiles?

Answer 34

FLAT

Question 35

What part of FLAT PiG is acidophiles?

Answer 35

PiG

Question 36

Which are the most numerous cell type in anterior pituitary?

Answer 36

Acidophiles (prolactin and GH secreting)

Question 37

Whats a parvicellular neuron

Answer 37

Terminates on median eminence, releasing FLAT PiG

Question 38

What is a magnocellular neuron

Answer 38

Terminates in neurohypophysis (posterior pituitary) releasing AVP and OT

Question 39

What catecholamine suppresses the release of prolactin?

Answer 39

Dopamine

Question 40

What catecholamine suppresses the SYNTHESIS of milk?

Answer 40

Dopamine inhibits prolactin, which promotes milk synthesis

Question 41

What 3 parts compose the anterior pituitary?

Answer 41

Pars distalis (90%) Pars intermedia Pars tuberalis

Question 42

What are the anatomical parts of the posterior pituitary?

Answer 42

Pars nervosa Infundibulum (stalk)