Hypothalamus and Pituitary Gland Flashcards
What is the medial eminence?
It is the floor of the hypothalamus and the convergence point for axons and it is outside of the blood brain barrier so it can sense peripheral information outside of the blood brain barrier
What is Kallman syndrome?
It is an X-linked disease where GnRH neurons that develop in nose fail to go through the cribriform plate and it causes:
- Anosmia
- Reproductive Failure
What is Kallman syndrome?
It is an X-linked disease where GnRH neurons that develop in nose fail to go through the cribriform plate and it causes:
- Anosmia
- Reproductive Failure
How is GnRH released?
It is released with pulsatility
What hormones does GnRH release from the pituitary?
FSH and LH
What happens to the hormone levels released with increased GnRH pulsing?
Faster pulsing will have more LH than FSH released.
What happens to the hormone levels with decreased GnRH pulsing?
It will have more FSH than LH
What is the tuberoinfundibulnar system?
Comprises all neurons that send axonal projections to the median eminence. Hormones target the anterior pituitary through the capillary system.
What is the neurohypophysial tract?
Comprises neurons whose axons terminate in the posterior pituitary.
What do the pars distalis, pars tuberalis and pars intermedia make up?
Anterior Pituitary
What do the pars nervosa and infundibulum make up?
Posterior Pituitary
What are the tissues and cells of the adenohypophysis?
The anterior pituitary is made of glandular tissue with cords of epithelial cells.
What are the tissues and cells of the neurohypophysis?
The posterior pituitary is made of neural tissue with axons and glial cells.
Where do magnocellular axons terminate?
Posterior Pituitary
What are the major hormones secreted by the posterior pituitary?
Arginine Vasopressin (AVP) Oxytocin
Histology: What are Herring bodies?
Herring bodies are terminal endings of unmyelinated axons with vesicles of AVP and OXY.
What are the major cell types of the anterior pituitary?
Acidophils
Basophils
Chromophobes
What are the relative abundance of the cell types of the anterior pituitary?
Acidophils - 40%
Basophils - 10%
Chromophobes - 50%
What is the function and composition of acidophils?
Somatotrophs - GH
Lactotrophs - Prolactin
What is the function and composition of basophils?
Corticotrophs - ACTH
Gonadotrophs - LH and FSH
Thyrotrophs - TSH
What is the function and composition of chromophobes?
Paracrine actions
Histology: Appearance of acidophils
Acidophils are light pink
Histology: Appearance of basophils
Basophils are very dark
Histology: Appearance of chromophobes
Chromophores appear clear
