Mechanisms of Hormonal Regulation Flashcards
what is endocrinology
study of intracellular and extracellular communication by hormones
how does the endocrine system maintain homeostasis
regulate metabolism, growth/development, and reproduction
what are the main messengers in the endocrine system
hormones
where are receptors of target organs located in the endocrine system
on cells surface or intracellular
where are endocrine hormones secreted?
into the blood
where are exocrine hormones secreted?
through ducts opening onto an epithelium
what are juxtacrine hormones?
target and effector in direct contact
what do neurocrine hormones influence
on or by nerves
what are paracrine hormones?
target and effector are near each other
what are autocrine hormones?
target cell is the effector cell
what are neuroendocrine hormones?
involve both nervous stimulation and endocrine secretion
what is the hypothalamus
brain region/center where activity of the ANS and endocrine glands are integrated with input from other brain centers
how are endocrine and CNS responses linked
pituitary
the hypothalamus contains cells that produce hormones…
TRH, GRH, GHRH, CRH, somatostatin, dopamine, vasopressin/ADH, oxytocin
where are hormones of the hypothalamus released
blood
what do hormones of the hypothalamus target
mainly the pituitary
where do releasing hormones/factors and inhibiting hormones/factors act on?
anterior pituitary
what are trophic hormones
hormones that stimulate a particular target organ or cell
what does gonadotropin do?
stimulates gonads (testes and ovaries)
wht does thyrotropin/TSH do?
stimulates thyroid gland
what does ACTH do?
stimulates adrenal cortex
how do tropic hormones interact with their target cell
membrane bound or cytoplasmic receptors
where are membrane bound receptors located? who do they interact with?
cellular membrane and interact with protein type hormones
where are cytoplasmic receptors located? who do they interact with?
cytoplasm of cell; interact with steroid hormones
what forms the anterior pituitary lobe / adenohypophysis
pars tuberalis, distalis, and intermedia
what forms the posterior pituitary lobe / neurohypophysis
infundibulum and pars nervosa
what are the regulatory functions of hormones
electrolyte and water balance + storage and metabolism of nutrients
what hormones are responsible for electrolyte and water balance
aldosterone and vasopressin
what hormones are responsible for storage and metabolism of nutrients
insulin and cortisol
what are the morphogenic functions of hormones
synthesis of cellular components, growth and development, sexual maturation and reproduction
what hormones synthesize cellular components
thyroid hormone, catecholamines, and steroid hormones
what hormones are responsible for growth and dev?
GH, thyroid hormones, and steroid hormones
what hormones are responsible for sex maturation and reproduction
gonadotropins, estrogen, testosterone, and HCG
do water soluble proteins require a carrier protein to be transported through plasma? Are they biologically active?
no carrier protein; biologically active
do water insoluble proteins require a carrier protein to be transported through plasma? Are they biologically active?
carrier protein needed; biologically inactive
what type of hormones are anterior pituitary hormones?
protein type
tell me about protein type hormones
made of aa/peptides and are water soluble, short half life, polar molecules
can protein type hormones diffuse across the phospholipid bilayer?
no; they need membrane bound receptors
what are steriod hormones derived from
cholesterol
tell me about steroid type hormones
not water soluble, physiologically active
can steroid type hormones diffuse across the phospholipid bilayer?
yes
where is estradiol made
ovary
where is estriol made
placenta
what are the aromatic amine hormones?
T3, T4, and catecholamines (EPI, NE, and DA)
where are aromatic amine hormones derived from
tyrosine
tell me about EPI
made in adrenal medulla, water soluble,action is immediate
tell me about T3 and T4
made in thyroid, NOT water soluble, action is quick when released in target tissue
how do membrane bound receptors regulate transcrpition?
intracellular signaling cascades
how do intracellularreceptors regulate transcrpition?
bind response elements
main regulators in endocrine sys?
hypothalamus and pituitary
what happens as glucose increases in the plasma?
pancreas makes and secretes insulin
what is the primary hormone control mechanism in the endocrine system?
negative feedback
what 3 endocrine organs does neg feedback use
hypothalamus, pituitary, and organ/target cell
where are hormones metabolized? excreted?
metabolized in liver and kidney; excreted in urine and feces
how is the hypothalamus connected to the posterior pituitary?
neural system
how is the hypothalamus connected to the anterior pituitary?
portal veins
what does the hypothalamus produce and control the release of?
ADH, oxytocin, inhibiting and releasing hormones
what controls the ANS
hypothalamus
what does the posterior pituitary do
stores and releases ADH and oxytocin
what does the anterior pituitary do
produces and secretes stimulating hormones
How are hormone abnormalities classified
Degree of hormone stimulation and where the disorder originates
