hypothalamic and pituitary function Flashcards
how does hypothalamus communicate with AP and PP
AP- release regulating factors delivered through blood
PP- neuronal
Negative feedback
- few exception.. but pituitary hormones regulated by negative feedback
Growth hormone GH
large polypeptide hormone produced in AP
-regulates growth
excessive Gh results in
giantism
- too much GH before puberty)
Acromegaly
- too much GH after pubery
pediatric GH deficiency
short stature (but normal proportion)
treatment: GH replacement
adult GH deficiency
reduced muscle mass and increased mortality from CV issues, and impaired psychosocial function
Treatment of GH disorder
giantism: surgical removal of pituitary
acromegaly:
1) surgery
2) radiation
3) drugs- reserved for patients with large tumors or residual disease despite radiation and/or surgery
Therapeutic uses pediatric GH deficiency
treat early and stop before epiphyseal plate closes
treatment efficacy decline as pt grows older
high cost
therapeutic uses of pediatric Non-GH deficient short stature
normal GH levels but very short
-must be 2.25 std deviations below mean
= shortest 1.2% of their peers
high cost
Pediatric Short Stature Associated with Prader Willi Syndrome
genetic disorder/ shortstature, metntal impairment, incomplete sexual development and urge to eat constantly
Gh is indicated to increase height
GH most be avoided in severly obese pts due to risk of death
GH deficiency in adults therapeutic uses
can increase lean body mass, increase lumbar spine density
neg effects: increased systolic pressure and fasting blood glucose
note: GH increases muscle mass but not strength
Somatropin
GH available as recombinant DNA technology
structure/ function identical to GH
administration: IM or subQ
Prolactin
polypeptide hormone produced by the anterior pituitary
deficiency: without symptoms except distubances in lactation
overproduction: multiple adverse effects
regulation of release of Prolactin
predominantly inhibitory
- hypothalamus release of dopamine
= suppression of prolactin release
hypersecretion
female: amenorrhea, galactorrhea, infertility
male: libido and potency reduced
suppressing with dopamine agonists
cabergoline and bromocriptine
bind with dopamine receptors in pit exerting same effect as dopamine
Antidiuretic Hormone (vasopressin)
acts on kidneys
-reabsorpiton of water
deficiency produces diabetes insipidus (produces large columes of urine)
ahd physiology
increases water reabsorption from nephron
= urine concentrated
stimulates contraction of GI tract vascular smooth muscle
