Endocrinology 3- Hypothalamus And Pituitary Relationship

Question 1

Where is the hypothalamus

Answer 1

At base of brain but above pituitary gland (which is outside of the brain)

Question 2

What can we consider the hypothalamus as, as far as role?

Answer 2

An integration center - limbic system processes emotion and fear, sensory system, reticular activating system is part of brain stem, viscera takes in things coming from organs, hormones are in blood, and chemical substrates are all going to be integrated here and processed to have a correct response.

Question 3

What are the 4 hypothalamic nuclei she wants us to know

Answer 3

PVN (blood pressure)
SO (Thirst)
ARC ( feeding behavior, satiety)
POA (Body temperature)

Question 4

Can pituitary release hormones without hypothalamus

Answer 4

Hypothalamus is absolutely required for pituitary function

Question 5

What is the area where hypothalamus axons converge toward where they will dump hormone into the pituitary portal system

Answer 5

median eminance

Question 6

What is kallan syndrome

Answer 6

GnRH hormones fail to enter CNS –> Reproductive failure and asomnia (no smell) – x linked

neurons get stuck in cribriform plate

Question 7

Why is pulsitility of hormone release important?

Answer 7

So that you aren’t just downregulating the receptors on target organs – you need to release in a manner so that those receptors are replaced

Question 8

A hypothalamic hormone binding to the anterior pituitary gland will lead to what two outcomes

Answer 8

Release and synthesis of hormoen

Question 9

What is the hypophysial portal system

Answer 9

Vascular connection between hypothalamus and pituitary gland

Question 10

How was the hypophysial portal system discovered

Answer 10

When the pituitary gland was transplanted to other regions of the body it didn’t work, but when it was reimplanted beneath hypothalamus it worked

Question 11

Do the anterior and posterior pituitary have the same blood supply

Answer 11

NO

Question 12

Does the posterior pituitary have a portal system

Answer 12

NO

Question 13

Tuberoinfundibular system

Answer 13

Tract of neurons that goes to anterior pituitary - project to median eminance, deposit hormones into portal system

Question 14

Neurohypophysial tract

Answer 14

Neurons whose axons terminate in posterior pituitary

Question 15

3 regions of anterior pituitary gland

Answer 15

pars distalis, pars tuberalis, pars intermedia

Question 16

2 regions of posterior pituitary

Answer 16

Pars nervosa, infundibulum (stalk)

Question 17

Pars tuberalis - what is here?

Answer 17

Median eminance

Question 18

What is the big bulb of the anterior pituitary called

Answer 18

Pars tuberalis

Question 19

What are the “hypophysis” names for anterior and posterior pituitary gland?

Answer 19

Adenohypophysis: Anterior pituitary
Neurohypophysis: Posterior pituitary

Question 20

What kind of tissue makes up the adenohypophysis (anterior pituitary)

Answer 20

Glandular tissue, cords of epithelial cells

Question 21

What kind of tissue makes up neurohypophysis/posterior pituiary

Answer 21

Neural tissue - terminal axons and glial cells

Question 22

Major hormones frm posterior pituitary gland

Answer 22

Arginine vasopressin/antidiuretic hormone (AVP/ADH) and oxytocin (OXY)

Question 23

Cell bodies from the posterior pituitary are where? What is the name for their cell type?

Answer 23

Hypothalamus - mangocellular

Question 24

What is the lobe of the pituitary that is basically just termination from long axons from the hypothalamus

Answer 24

posterior pituitary gland

Question 25

Axons for cell bodies in posterior pituitary gland terminate where? What is this location called?

Answer 25

Near fenestrated capillaries - into structures called herring boddies

Question 26

What exactly are herring bodies

Answer 26

dilations of unmyelinated axons near their terminals containing either AVP or OXY + a binding protein, neurophysin

Question 27

What is the median eminance?

Answer 27

The interface for all hypophysiotrohic hormones - it lies outside of the blood brain barrier. This is where axons will converge from hypothalamus for the anterior pituitary gland

Question 28

Is the median eminance inside or ouside the blood brain barier

Answer 28

outside

Question 29

5 cell types in anterior pituitary which are activated by portal system

Answer 29

``` Lactotrophs (make prolactin) somatotrophs (make growth hormone) thyrotrophs (tsh) gonadotropes (lh/fsh) corticotropin ```

Question 30

Acidophils

Answer 30

Most abundant of hormone producing cells, include somatotrophs and lactotrophs

Question 31

Basophils

Answer 31

Corticotrophs, gonadotrophs, and thyrotrophs

Question 32

Chromophobes

Answer 32

Paracrine cells

Question 33

Where are GH and PRL releasing cells primarily located

Answer 33

On the outside parts of the pituitary

Question 34

Where are ACTH releasing cells located

Answer 34

On the inner part of the anterior pituitary (middle)

Question 35

Where are TSH releasing cells primarily located

Answer 35

At the most far part of the pituitary from the neurohypophysis in the middle

Question 36

Where are FSH and Lh released from in anteiror pituitary

Answer 36

everywhere sprinkled around

Question 37

Do pituitary hormones have a circadian rhythm

Answer 37

Yes