Endocrine Flashcards
(35 cards)
differences between endocrine and nervous system
1. time scale nervous -ms endocrine-hours/days 2. mechanism of communication nervous- action potentials/ neurotransmitters endocrine-hormones 3. strength of signal frequency- nervous amount of signal- endocrine
autocrine signals
locally affect same cell type
paracrine signals
locally affect nearby cells
pheremones
secreted into environment to modify behavior and physio of other
How is secretion rate of hormones controlled
Negative feedback
- action of a substance other than hormone on endocrine gland
- neural control of endocrine gland
- control of secretory activity of one endocrine gland by hormone or neurohormone secreted by another endocrine gland
mechanisms of hormone release
- humoral - in response to changing levels of ions or nutrients
- neural: stimulation by nerves
- hormonal: stimulation received from other hormones
neoplastic hormone production
when nonendocrine tissue produces hormones
syndromes caused by this is called paraneoplastic syndromes
down-regulation
decrease in number of receptors due to prolonged exposure to high concentration of hormone
up-regulation
increase in number of receptors due to prolonged exposure to a low concentration of hormone
permisiveness
presence of hormone increase (or decreases) number of receptors for another hormone
(cooperative hormones)
Functions of endocrine system
- metabolism and tissue maturation
- ion regulation
- water balance
- immune system regulation
- heart rate and blood pressure regulation
- control of blood glucose and other nutrients
- control of reproductive functions
- uterine contractions and milk release
vasopressin function
acts on blood vessels: vasoconstriction
acts on kidneys: decrease urine volume, increase blood volume
osmoreceptors
specialized neurons of hypothalamus that monitor changes in intercellular osmolarity
baroreceptors
specialized neurons that sense change in blood pressure
when is vasopressin released
electrolytes increase
concentration of water decreases
blood pressure decreases
oxytocin
acts on uterus to stimulate contraction
somatostatin
growth hormone-inhibiting hormone
epinephrine
adrenaline
where are catecholamine hormones secreted
medulla
cortisol
regulate glucose metabolism and the immune system
aldosterone
regulate salt and water balance
cushing’s disease
chronically high levels of glucocorticoids like cortisol
unctontrolled catabolism of bone, muscle, skin and other organs
Addison’s disease
loss of adrenal cortical function due to deficit in glucocorticoids
tyrosine/iodide
primary ingredients for synthesis of thyroid hormones
