(25) Hypothalamus/Anterior Pituitary

Question 1

1. Hypothalamic-Pituitary Regulates what glands?

Answer 1

1. thyroid, adrenal, and reproductive glands

Question 2

1. posterior pituitary = ?
2. anterior pituitary = ?

Answer 2

1. pars nervosa or neurohypophysis
2. pars distalis and adenohypophysis

Question 3

1. How does hypothalamus get its hormones to posterior pituitary?
2. How does it get hormones to anterior?

Answer 3

1. direct neuronal connection
2. through vascular network

Question 4

(Pars Intermedia)

1. Predominant hormone secreted?

Answer 4

1. melanocyte stimulating hormone (MSH)

Question 5

1. What is pituitary pars intermedia dystfunction (PPID) also known as?
2. occurs in what
3. What’s a big sign?
4. Caused by what?

Answer 5

1. Equine Cushing’s Disease
2. old horses
3. really hairy (also weight loss and laminitis)
4. hypothalamic neuron degeneration (oxidative stress)

Question 6

(Equine cushing’s disease)

1. What is the single cell type in pars intermedia? what does it make? What happens to this?

Answer 6

1. melanotrope; POMC (also made by corticotropes in anterior); processed to give different things

Question 7

(POMC)

1. What does it stand for?
2. Corticotropes tend towards what?
3. Melanotropes?

Answer 7

1. proopiomelanocortin
2. ACTH and B-endorphin
3. MSH and B-endorphin

Question 8

(POMC)

1. MSH does what?
2. B-endorphin?

Answer 8

1. anti-inflammatory, skin pigment in amphibians, appetite and fat metabolism
2. opiod that affects analgesia behavior; suppresses immune

Question 9

What controls the secretion of POMC in the intermediate zone? what kind of control? from where via what?

In cushings is too much or too little POMC being produced? What does this say about dopamine?

Answer 9

1. dopamine; inhibitory; from HT neurons via dopamine receptors
2. too much; there isn’t enough of it

Question 10

1. What happens physiologically to the pars intermedia in PPID (3 things)?
2. How treated?

Answer 10

1. hypertrophy, hyperplasia, and adenoma

(enlarged pitutaries - secrete large quantities of pars int peptides)

2. dopamine agonist (pergolide)