HPA A&P, Pathophysiology Flashcards
what is part of the diencephalon at the base of the brain
hypothalamus
what is the hypothalamus attached to
pituitary via infundibulum
what does the hypothalamus store
stores and releases hormones that act on pituitary
how is the pituitary attached to the hypothalamus
via hypophysial stalk, sits within the sella turcica
how is the posterior pituitary attached
via neural connection-hypothalamohypophysial tract
aka neurohypophysis
how is the anterior pituitary attached
via portal blood vessels-hypothalamic hypophyseal portal system
aka adenohypophysis
how do hormones affecting the anterior pituitary travel
via hypophysial portal blood from hypothalamus
hormones released from pituitary will act on their target organs
where are the Herring bodies
within posterior pituitary
terminal end of nerves that are extending form hypothalamus
where hormones are stored/released
What does ADH do
increase water reabsorption within the kidney
what stimulates ADH
blood pressure: if low, implies low volume
osmolality will also cause/change release
alcohol inhibits secretion of ADH
What does TRH stimulate
TSH and inhibits prolactin
what does GnRH stimulate
FSH and LH
what is the effect of substance P
inhibits ACTH, stimulated GH, FSH, LH, prolactin
what does the follicle-stimulating homrone target
granulosa cells within the ovaries to stimulate estrogen production and follicular maturation
sertoli cells within the testicles to promote speratogenesis
where is ACTH made
within anterior pituitary
what does ACTH target
cortex of the adrenal gland and will induce steroidogeneiss (primarily cortisol)
where is the pineal gland located
within the central aspect of the brain
what is the pineal gland made of
photoreceptive cells capable of secreting melatonin
regulates circadian rhythm
how are pituitary adenomas characterizedd
microadenomas: typically asymptomatic
macroadenomas: m/c after hormone regulation or impinge on surrounding structures (mass effect)
What is MEN syndrome
autosomal dominant disorders that predispose patients to endocrine tumors
multiple endocrine neoplasia
3 different subtypes based on endocrine tissues affected
what do prolactimonas cause
increase prolactin levels
- breast milk production, gynecomastia
what does GHRH act on
anterior pituitary
what is excessive growth hormone and insulin-like growth factor (IGF-1) during childhood/adolescence
giantism
what is excessive growth hormone during adulthood, after growth plates have closed
acromegaly
what manages how GH affects the tissues
IGF
what is most commonly associated with growth homrones secreting adenoma within the pituitary gland
acromegally
what is most commonly associated with excessive GHRH
giantism
what does acromegaly result in
frontal bossing
enlarged tongue
prognathism
“spade-like” hands, enlarged feet and face
what are gene predispositions for gigantism
alternation in MEN1 gene
AIP (familial)
activation of oncogene gasp
x-linked duplication error
what largely defines tonicity of intracellular and extracellular space
sodium
what increases as sodium levels increase
osmolality
What is SIADH
Syndrome of inappropriate antidiuretic hormone
-water reabsoprtion, retained fluid, increased extracellular fluid
decreased urine output, N/V, AMS, weight gain
what is diabetes insipidus
not enough ADH, or not working appropriately
- volume out, dilute urine - hypernatremia (Dry Inside)
polyuria, polydipsia, weight loss, dehydration
what is the presentation of central diabetes insipidus
polyuria, polydipsia, nocturia, decreased urine osmolality, decreased urine sodium
what is the presentation of SIADH
typically associated with downstream hyponatremia
presentation can range from: thirst, anorexia, fatigue, DOE, vomiting, cramping, weight gain, seizure, neurologic damage
what is hypopituitarism
lack of 1+ hormones typically secreted from anterior pituitary
what is Panhypopituitiarism
no hormones coming from pituitary
what is sheehan syndrome
ischemia (leading to necrosis) of pituitary due to postpartum hemorrhage
what is a pituitary apoplexy
hemorrhage into pituitary
what are the clinical presentations of hypopituitarism
symptoms depend on what hormone is affected
ACTH deficiency: decreased cortisol - N/V, fatigue, weakness, weight loss, can be fatal
TSH deficiency: hypothyroidism
TSH and LH deficiency: amenorrhea, testicular atrophy, decreased libido
GH deficiency: hypopituitary dwarfism, elevated BMI, osteoporosis
what is pituitary dwarfism associated with
growth hormone deficiency
may be congenital or develop at later age
