excitable cell + endocrine Flashcards
simple diffusion vs channel-mediated diffusion vs facilliated diffusion vs active transport
simple diffusion: directly cross the plasma membrane w/o use of membrane protein
c.m diffusion: w/ protein **channels **
faciliated diffusion: undergoes a conformational change w/ protein carrier; mole binds & shift to other side
active transport: require **ATP, **only 1 to go against the c. grad
endocytosis vs exocytosis
endocytosis: absorb molec by forming a pocket w/ cell membrane; gets pinched off as a vesicle
exocytosis: vesicle fuse to plasma membrane, release content
describe the water mvmnt in isotonic vs hypertonic vs hypotonic ? why
isotonic: no net mvmnt of water ‘ oSM same as body fluid
hypertonic: water leaves the cell ‘ lower than body fluid
hyPOtonic: water enters the cell ‘ higher oSM
list 3 types of gates
- mechanically gated i.c: requries mechanical manipulation
- chemically gated i.c: w/ chmical binding, open
- voltage gated i.c: w/ voltage change, open
depol: cell becomes more ____ than RMP (when ___/__ opens)
repol: cell returns to _____
hyperpol: cell becomes more ____ than RMP (when __/___ enters)
threshold: min ____ o trigger ____
(+) when Na+ / Ca++
RMP
(-) / when K+ leaves / Cl+ enters
voltage / AP
looses strength over time and travels a short distance
graded potential (e.g in eye)
when Na+ VG channels open, it travels from ____ (high/low) to ____(high/low) concentration gradient
=> electrical potential accumulates more (+/-) change
high to low
more
how to trigger an AP in graded potential?
- stimulus creates depol: Na+ enters via mech/chem channels
- as it travels down to the axon hillock., K+ leaks out
- graded potential hits threshold => triggers AP
- signal sent to the brain
describe the action potential
- due to graded potential, depol occurs
=> Na+ VG channels open - since they’re quick to close, Na+ stops
- since K + VG channesl slower to open, repol occurs (back to RMP)
- since they’re** slower to close**, hyperpol occurs
how AP propagates down an axon
- graded potential occurs
Na+ VG channels open => depol occurs - these Na+ is attracted to next section, still @ RMP (+ to -)
=> AP fires in next section - meanwhile repol & hyperpol occurs in the 1st
name a myelin-related disease
multiple sclerosis: myelin damaged adn starts to dissapear
=> AP can’t properly propagate down an axon
describe the (-) fdbk loop at thyroid gland
hypothalamus releases Thyrotropin R.H (TRH)
=> stimulates the release of thyroid stimulating hmn (TSH)
make T3 / T4 at the thyroid gland
if high lvl of T3/ T4, create a (-) fdbk loop
supresses TRH & TSH
lwoer T3 & T4
compare hyperthyroidism vs hypothyroidism
describe the (-) fdbk loop of corticol
how would a doctor diagnos a Cushing’s disease?
what happens in a chemical synapse
hint think of NMJ for skeletal muscle
- AP arrives @ axon terminal, depol area
2.** Ca2+ VG **channels open - vesicle fuse to the plasma membrane, release content to the synpatic cleft
- binds to receptor on post-snypatic membrane
- LIGAND gated channels open
- GRADED POTENTIAL occurs in post-synaptic neuron
if depol__ occurs in the post-synpatic neuron, this is called ______ (EPSP)
if _____ occurs in the post-synpatic neuron, this is called ______ (IPSP)
excitatory post-synpatic potential
hyperpol / inhibitory post-synpatic potential
how hmn travel in ant pituitary
neurons from hyothalamus travels down the hypothalamus- hyposeal portal system towards ant. p
bounds to membrane bound receptor there
triggers premade peptide
towards target tissue
why is A FLAT PIG relevant?
adreno-corticotropic hmn (ACTH) acts on corticotropin r.h towards adrenal glands
Thyroid Stimulating hmn acts on Thyrotropin R.H for thyroid glands
prolactin acts on Prolactin R.H =? breast tissue
Growth Hmn acts on Growth Hmn R.H => various
hyperthyroidism vs hypothyroidism
hyper– vs hypo–
increase in T3 & T4 vs decrease
high basal metabolic rate
sensitive to warm room temp vs senstive to room temp
increased heart rate + hyperactive vs snow reflex, lethargy, apathy
describe the (-) fdbk loop of in zonna fasciculata
hypothalamus releases corticotropin R.H (CRH)
=> stimulates the release of adrenocorticotropic hmn (ACTH)
releases cortisol in adrenal glands
creates a (-) fdbk loop
=> supresses CRH, ACTH
=> lowers cortisol lvl
composition of T3 & T4
triiodothyronine (T3) & thyrosine (T4)
tyrosine precursor + iodine = T3 & R4
T/F: ADH is made in posterior pituitary
F ‘ posterior pituitary doens make hmn
ADH & oxytocin travels down from hypothalamus to pos. p
describe a peptide/protein hmn
in in -in or -hmn
w/ membrane bound receptor, dissolve in blood and hydrophilic
precursor: amino acid
describe a steroid hmn
ends in -ol or -one
w/ intracellular receptor, transported in bnlood and bound to protein
lipophilic
precursor: cholesterol
distinct amino hmn: hydrophilic and hydrophobic
(+): precursor both tyrosine
hydrophobic: w/ intracellular receptor, transported in blood and bound to protein; lipophilic
hydrophilic: w/ membrane bound receptor, disoolved in bnlood and hydrophilic
T/F: propagation is faster in myelinated neurons (w/ saltatory conduction0 than unmyelinated one (continuous conduction)
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