Exam 1 (Chapter 7) Flashcards
what do hormones act on?
target cels
what (3) things do hormones do?
-alter rates of enzymatic rxns
-alter transport of ions/molecules across cell membrane
-alter gene expression & protein synthesis
what is goiter?
swelling of the thyroid gland
-due to an excess of the thyroid hormones
what are (3) steps on how to identify the gland & hormone?
1) remove suspect gland
2) replace the hormone (gland extract)
3) create hormone excess
what is different about pheromones in relation to being a hormone?
they are secreted into the external environment
-not by blood like a normal hormone
what is different about cytokines in relation to being a hormone?
they are made on demand
-not stored
what are candidate hormones?
hormones that appear to look/act like a hormone but are a little bit different
-end in “factor”
what are (3) ways you can terminate a hormone?
-limit secretion of hormone
-remove / inactive hormone (enzymes)
-terminate action at the cell (remove receptor, alter pathway)
what does half-life indicate when referring to a hormone? what does it mean to have a short half life?
indicates length of activity and time it takes do reduce conc.
-short 1/2 life = short activity time, quick removal of hormone
what are (3) ways hormones are classified?
-source of hormone
-if release controlled by brain or not
-receptor type they bind to
what are the (3) main chemical classes of hormones?
-peptide/protein hormone
-steroid hormone
-amine hormone
what is required for peptide/protein hormone synthesis?
ribosomes, rough ER, golgi
-preprohormone, prohormone
how is a preprohormone made into prohormone? how is it made into an active hormone?
-preprohormone is shuttled to the rough ER
-sequence is trimmed to make the prohormone
-prohormone is sent to the golgi to be stored in a vesicle
-enzyme inside vesicle cuts & processes it to make the active hormone
how is a peptide/protein hormone released?
-signal is sent to vesicle
-vesicle moves & fuses with plasma membrane
-exocytosis of vesicle to release hormone
how are peptide/protein hormones transported in the blood? (philic or phobic?)
hydroPHILIC / lipoPHOBIC
-can dissolve in plasma
-NO transport protein needed
what type of receptor do peptide/protein hormones use? what mechanism of action is it?
surface receptors
-2nd messenger systems (G-protein, receptor kinases)
do peptide/protein hormones have a fast or slow response? is the half life short or long?
fast response
short 1/2 life
what is required for steroid hormone synthesis? where is it made?
cholesterol
-made in smooth ER
how are steroid hormones stored and released?
NOT STORED
-made on demand
-released through simple diffusion
are steroid hormones hydrophilic or hydrophobic?
hydroPHOBIC / lipoPHILIC
how are steroid hormones transported in the blood?
they require a transport protein
-plasma proteins (makes it water soluble)
what type of receptors do steroid hormones use?
intracellular receptors
-on the cytoplasm or nucleus
what is the mechanism of action of steroid hormones?
alter gene expression
do steroid hormones have a fast or slow response? is the half life short or long?
slow response
-long 1/2 life
what are the (5) steroid hormones?
testosterone
estrogen
aldosterone
cortisol
progesterone
what are the two types of amine hormones?
catecholamines
thyroid hormones
what is required for catecholamine synthesis?
tyrosine (mainly)
tryptophan
are catecholamines hydrophilic or hydrophobic?
hydroPHILIC / lipoPHOBIC
what type of receptor do catecholamines use? what is their mechanism of action?
surface receptors
-2nd messenger systems
how are catecholamines stored and released?
-stored in vesicles
-released by exocytosis
NOT MADE ON DEMAND
how are catecholamines transported in the blood?
no transport protein
-dissolve in plasma
do catecholamines have a fast or slow response? is the half life short or long?
FAST response
SHORT 1/2 life
what are the four common catecholamines?
norepinephrine (tyr)
epinephrine (tyr)
dopamine (tyr)
melatonin (trp)
what is required for thyroid hormone synthesis?
tyrosine and iodine
are thyroid hormones hydrophilic or hydrophobic?
hydroPHOBIC / lipoPHILIC
what types of receptors do thyroid hormones use? what is their mechanism of action?
intracellular receptors
-alters gene expression
how are thyroid hormones stored? are they made on demand?
stored in the colloid
-NOT made on demand
how are thyroid hormones transported in the blood?
use transport proteins
-plasma proteins (makes it water soluble)
do thyroid hormones have a fast or slow response? is the half life short or long?
SLOW response
LONG 1/2 life
what is the (1) thyroid hormone?
T3 & T4
what are the three types of neurohormones?
-adrenal medulla neurohormone that releases catecholamines
-hypothalamic neurohormone released by post pit.
-hypothalamic neurohormone that controls release by ant. pit.
what two glands make up the pituitary gland?
anterior pituitary
posterior pituitary
is the ant. pit. made out of endocrine or nervous tissue?
true endocrine tissue
what (6) hormones does the ant. pit. secrete? which one isn’t trophic?
TSH, ACTH, FSH, LH, Prolactin, GH
-prolactin is NOT trophic
what is a trophic hormone?
a hormone that controls secretion of other hormones
is the post. pit. made out of endocrine or nervous tissue?
nervous tissue
what (2) hormones does the post. pit. secrete?
vasopressin/ADH
oxytocin
what is the main effect of vasopressin / ADH?
regulates water balance in kidneys
-decreases urine output
what are the main effects of oxytocin?
milk ejection
contraction of uterine muscle
are the two post. pit. hormones trophic?
NO, not trophic
what is the portal system? why is it needed?
connects the hypothalamus to the ant. pit.
-allows hormones to travel w/o going thru general circulation
-allows for quick delivery and can be released in small amounts
capillary bed 1 -> portal vein -> capillary bed 2
what are the two types of feedback pathways in hormones?
long loop feedback
short loop feedback
what is long loop feedback?
terminal hormone inhibits hypothalamus and ant. pit.
-MAJORITY!
what is short loop feedback?
ant. pit. hormone inhibits hypothalamus
-GH, ACTH, prolactin
which hormone pathway (of the ones we need to know for the exam) doesn’t have short-loop feedback?
thyroid gland hormone pathway
cortisol pathway
CRH -> ACTH -> cortisol (adrenal cortex)
thyroid gland pathway
TRH -> TSH -> T3 & Tr (thyroid gland)
growth hormone pathway
GHRH (GHIH/somatostatin) -> GH -> IGFs (liver & other)
what is synergism?
2 or more hormones interact and yield a result greater than the sum
EX: glucagon, Epi, cortisol
-all increase blood glucose
-together the increase glucose more than expected value
what is permissiveness?
one hormone unable to exert its full effects unless a second hormone is present
EX: thyroid hormone is permissive to reproduction hormones
-TH & no reproductive hormones = no reproductive system
-no TH & reproductive hormones = no reproductive system
what is antagonism hormone interaction?
two hormones oppose each other’s effects
EX: glucagon & insulin
-glucagon increases blood glucose
-insulin decreases blood glucose
what is hypersecretion?
too much hormone
-creates an exaggeration of hormone effects
-due to exogenous substances
what are exogenous substances?
substance that comes from outside the body
-commonly from medical treatments
EX: cortisol pathway
-acts as (-) feedback & shuts off CRH & ACTH production
-leads to no natural cortisol production
-overtime, it causes the cell to atrophy (cell shrinkage)
what is hyposecretion?
too little hormone
-diminishes or removes hormone effects
EX: cortisol pathway
-low cortisol = no negative feedback
-leads to high CRH & ACTH
what happens when the hormone receptor is defective? what (2) things can cause this?
hormone can’t bind and creates a low cell response
-due to down regulated receptors or missing / nonfunctional receptors (mutation)
-acts like hyposecretion patterns
what happens when the hormone signal transduction pathway is defective? what is the common example?
hormone binds, but doesn’t generate the response
EX: pseudohypothyroidism
-impacts parathyroid hormone
-G-protein doesn’t work
-appears as a hormone deficiency
what are the three diagnosis (pathologies) for endocrine defects?
primary pathology
secondary pathology
tertiary pathology
what is primary pathology? what are the hormone levels (high / low) in the thyroid gland for a primary hypo AND hyper secretion defect?
last gland is defective
-HYPO: high TRH & TSH, low T3 T4
-HYPER: low TRH & TSH, high T3 T4
what is secondary pathology? what are the hormone levels (high / low) in the thyroid gland for a secondary hypo AND hyper secretion defect?
second gland (ant. pit) is defective
-HYPO: high TRH, low TSH & T3 T4
-HYPER: low TRH, high TSH & T3 T4
what is tertiary pathology? why is it hard to diagnose?
first gland is defective (hypothalamus)
-all hormones will be either high (hyper) or low (hypo)
-hard to detect b/c it goes through the portal system, not the general bloodstream
what is evolutionary conservation?
human hormones similar in structure & function being the same in animals
-similar function across vertebrates
EX: insulin in cow, pig, sheep fully function in humans
is Calcitonin conserved in humans?
NO
-fish calcitonin: Ca2+ regulation
-human calcitonin: no role in Ca2+ regulation, has a bigger role in the brain as a NT
what does the word vestigial mean?
a structure that has a function in some organisms, but in other organisms it is present but has NO function
EX: Melanocyte-stimulating hormone
-Reptiles: from pineal gland & uses MSH in lg. amounts
-Humans: has a sm. structure for MSH, does not produce MSH
what is comparative endocringology?
looking at hormones in animals to make discovery of hormones in humans
-comparing hormones in other organisms
EX: melatonin discovery in humans
-melatonin was first discovered in tadpoles
-compared it to humans and made the discovery in humans
