Exam Two - endocrine one Flashcards
endocrinology
study of hormones
Which long term functions is the endocrine system responsible for?
metabolism
reg of internal environment
reproduction
growth
development
What are the 3 mechanisms of action of the endocrine system?
- rates of enzymatic reactions
- transport of ions or molecule across cell membranes
- gene expression and protein synthesis
steroid hormones act where?
inside cell
nonsteroid hormones act where?
on cell membrane
(peptide and amine)
What are the organs of the endocrine system?
hypothalamus
pituitary
pineal
parathyroid
thyroid
adrenal
pancreas
What are tropic hormones?
hormones that tell other stuff what to do
hypothalamus makes what (tropic) hormones?
TRH
CRH
GHRH
SS
GnRH
What hormones does the posterior pituitary make?
oxytocin
vasopressin (ADH)
What hormones does the anterior pituitary make?
polactin (PRL)
growth hormone
adrenocorticotropin (ACTH)
thyrotropin (TSH)
follicle-stimulating hormone
lutinizing hormone
pineal makes…
melatonin
parathyroid makes…
PTH
thyroid makes…
- triiodothyronine (T3)
- thyroxine (T4)
- calcitonin
adrenal makes…
aldosterone
cortisol
androgens
pancreas makes…
insulin and glucagon
pancreatic polypeptide and somatostatin
describe the peptide hormone production process
- mRNA makes preprohormone
- preprohormone chain is directed to ER by a signal sequence
- signal sequence is chopped off in the ER which leaves a prohormone
- prohormone goes from ER to golgi
- golgi chop off peptides and make active hormone
- leave golgi in scretory vessicles
- upon release signal, vessicle enters blood and seeks target tissues
peptide hormones are transported where?
the blood
the half life of peptide hormones are?
short
cellular mechanism of peptide hormones are…
- bind to surface membrane receptors
- cellular response through signal transduction system
Where are steroid hormones made generally?
- adrenal cortex of adrenal glands
- gonads
Are steroid hormones stored in the body?
no, they are synthesized as needed, not stored
how are steroid hormones transported?
through the blood with carrier proteins bound to it
half life of steroid hormones are?
long
cellular mechanism of action of steroid hormones
- cytoplasmic or nuclear receptors stimulate genomic effects
- cell membrane receptors stimulate nongenomic responses
melatonin from pineal gland is derived from?
tryptophan
Amine hormones are derived from?
tyrosine
one tyrosine makes…
catecholamines
What are examples of catecholamines?
- epinephrine
- noreponephrine
- dopamine
(they behave like peptide hormones)
two tyrosine molecules make?
thyroid hormones
(behave like steroid hormones)
The ____ pituitary is an extension of nervous tissue
posterior
the _____ pituitary is a true endocrine gland of epithelial origin
anterior
The portal system connect ________ and __________ pituitary
hypothalamus, anterior
two gonadotropins
- FSH
- LH
controls hormones in the ovaries and testes
sex hormones = steroids
thyroid stimulating hormone
thyrotropin - other name
controls hormone synthesis and secretion in the thyroid
thyroid hormones are amines
adrenocorticotrophic hormone
also called adrenocorticotropin
controls hormone synthesis and secretion in the adrenal cortex
cortisol (steroid)
prolactin
(PRL)
controls milk production in the female breast
has a hypothalamic release-inhibiting hormone
growth hormone
also called somatotropin
affects metabolism
stimulates hormone production in the liver
has a hypothalamic release-inhibiting hormone
vasopressin
(antidiuretic hormone ADH)
controls water balance (kidney reabsorption of water)
vasocontriction at high levels
oxytocin
uterine constriction
milk production
emotions
synergism
the effect of interacting hormones is more than additive
permissive hormones
when one hormone has no effect, one hormone has little effect, but together the two hormones have a large effect
antagonistic hormones
hormones have opposite effects that work together to maintain homeostasis
example of antagonistic hormones
parathyroid hormone and calcitonin regulate Ca homeostasis
hypersecretion
- exaggerates a hormones effect
- excess hormone often caused by tumors or exogenous iatrogenic treatment
- negative feedback may lead to atrophy of gland
examples of hyper-secretion diseases
- graves disease
- acromegaly
hyposecretion
- diminishes or eliminates a hormones effect
- deficient hormone: caused by decreases synthesis of materials or atrophy
- absence of negative feedback leads to overproduction of hormones
example of hyposecretion disease
addisons disease
primary pathology
- due to last endocrine gland in the pathway
secondary pathology
due to pituitary gland
tertiary pathology
due to hypothalamus
downregulation
- decreased number of receptors in response to abnormally high hormone levels
- target cell is attempting to diminish its responsiveness to the excess hormone
- hyperinsulinemia
What are some receptor and signal transduction abnormalities
- missing or nonfunctional receptors
- cells fail to respond or respond inappropriately to hormone signals
