Hypothalamic-Pituitary Relationships pt1 Flashcards
Where are the cell bodies of the axons in the posterior pituitary located?
Supraoptic nucleus (SON) - ADH Paraventricular nucleus (PVN) - oxytocin
Both part of the Hypothalamus
What are the main hormones secreted by the anterior pituitary?
ACTH, TSH, FSH, LH, GH, prolactin
FLAT PiG
Both Neural and endocrine connections utilizing the Portal system- allows direct delivery in high concentrations to Ant Pituitary w/o the hormones having to enter systemic circulation
What are the hormone families of the anterior pituitary?
ACTH family (Corticotrophs) TSH (Thyrotrophs), FSH, LH (Gonadotrophs) family GH (Somatotrophs), prolactin (Lactotrophs) family
What are primary, secondary, and tertiary endocrine disorders of the HP axis?
Primary - peripheral endocrine gland (ex: thyroid)
Secondary - pituitary
Tertiary - hypothalamus (allll the way back at the beginning)
What is release of FSH and LH in the HPG axis regulated by?
GnRH release in hypothalamus (pulsatile)
What does FSH/LH release promote in males and females?
Males - testosterone production (FSH-Sertoli cells; LH-Leydig cells)
Females - estrogen and progesterone secretion (FSH-Granulosa cell; LH-Theca cell)
What is acromegaly?
Excessive growth of soft tissue, cartilage, and bone in hands, feet, and face due to prolonged/excessive secretion of GH in adult life
Test: includes an oral dose of glucose- if GH is not suppressed, test is positive
What does GH target?
Liver (increase glycogen and fat breakdown for energy and release of IGF) and bone/muscle (increase length and size/volume)
-signaling via JAK-STAT (just recognize if for some reason this pops up on the test) Jak took HGH to impress ladies
What does IGF do?
Stimulates hypertrophy and hyperplasia (proliferation rate)
-Plays negative feedback role with GH once it accumulates
What is gigantism?
High IGF-1 stimulation of long bone growth before closure of bone epiphyses
How does GH work in a fed state?
GH induces liver to produce IGF-1 which stimulates mitogenesis, lypolysis, and differentiation
How does GH work in a high carb, low protein state?
GH inhibited, liver will not produce IGF-1. Causes lipogenesis and carb storage
How does GH work in a low carb, high protein state?
Increased GH levels, liver will produce IGF-1. Causes lipolysis (lipids as energy source), ketogenic metabolism, and diabetogenic effect (decrease glucose uptake)
How is prolactin usually suppressed?
It is usually under tonic inhibition by hypothalamic dopamine
What does prolactin do?
Stimulates and maintains lactation (by inhibiting dopamine secretion by hypothalamus-which normally inhibits it),
also suppresses GnRH (inhibits LH and FSH) which decreases reproductive function and suppresses sexual drive (so female/whatever they/them want to be referred as** cannot get pregnant again)
