Cardiovascular Physiology Flashcards
where is the major site for control of blood pressure?
arterioles
what’s another name for arteries?
resistance vessels?
what’s another name for capacitance vessels?
veins!
which has lower pressure?pulmonoic or systemic?
pulmonic!
what is the primary regulator of ristance
fourth power of ristance
Cardiac output increasses
if MAP increases or TPR decreases
the blood flowing into capillaries is controlled where?
in the arterioles
Precapillary sphincters
are innervated or not?
these are at the origin of capillaries, and aren’t innervated
are there smooth muscle cells at exchange sites in capillaries
NO!!!!
filtration
the net hyrostatic driving force for fluid leaving the capilary
equation for net hydrostatic driving force
pressure of the hydrostatic which is pushing lfuid out =pressure in the interstilal fluid hydrostatic
osmotic formula
interstial fluid - oncotic pressure in the vesssels
filtration is positive,
fitration is negative
positive, we’re pushing fluid out
negative wer’re pushing lfuid in
if the sum of these factors is zero,
no net fluid movement.
the net fluid flux
kf, * (Pc iPi = pii -pic)`
parasymapthetics affect ventricular contractility or vascular smooth muscle contraction
NO!!!ZZ
Why do membranes have a large resistance
it’s due to lipids in the membrane
g and I relationship
increase in conductance, increases the current,
the magnitude of the resting potential is due to
distribution of ions across the cell
selective conductance of the ion
what are glia
supporting cells
oligondendrocytes
form myelin and insulate neurons in the CNS`
schwann cells
glia that form myelin and insualte neurons in the PNS
astroglia
glia that regulate the composition of the extracellular fluid in the CNS
microglia,
macrophage like cell that helps with immune functions in the CNS
true or false action potentials have a constant amplitude
true
absolute refractory period
a period of time after the generation of an action potential during which a second action potential cannot be generated no matter how large the stimulus.
The transition of the sodium channel from the inactivated state to the closed state? requires what???
repolarization of the membrane potential.
relative refractory period
during this period of time a second action potential can be generated but it takes a greater stimulus than normal.
some sodium channels are in the closed state, but some potassium channels still remain open. thus any sodium entering the cell to depolarize will be counteracted by potassium leaving the cell.
myelin
insulates neurons,
nodes of ranvier,
spaces in myelin where action potentials occur. Voltage gated Na + channels K+ channels
Saltatory conduction
action potentials in myelinated neurons occur at the nodes of ranvier
large myelianted fibers - how fast
vs slow unmyelinated fibers
small diameter is slower thanlarge diameter
molecules with high lipid bilaryer permeability
gases, o2 co2 n2 liphophilic moecuesl fatty acids, steroids, ethanol
low lipid bilayer permeability
water
very low lipid bilayer permaeability
glucose ions large charged moleecules
pores characteristics
integral membranes provide a passage ofr solutes,
always opens,
bidirectional, down the concentration gradient.
channels,
gated,
membrane proteins that allow passage of molecuels
gap junctions
allow large molecuels to apss through
where are gap junctions found in abundance
cardiac muscle, certain smooth muscles,
carrier proteins are for `
facilitated transport and active transport systems
facilitated transport
carrier protein for size like glucose into RBC adipose tissue skeletal muscle, heart
urea transport in kidneys
carrier protein
no energy, down concentration gradient
what kind of molecuels for facilitated transport?
large nonpolar molecules
order pores channels and carriers from slow to fast
carriers slowest only 1-2 percycle,
channels, wait for stsimuli to open gate,
and passage through selectivity filter
pores cause its always open and solutes can freely pass through the water filled pore.
Na potassium pump
3 sodium out, 2 potasssium in via 1 atp
Ca2+ atpase function
responsible for maintianing low concentration of calcium in the cytosol. function kick calcium out
H+ atpase,
pumps H_ into organelle
sodium/glucose cotransporter
found in the epithelial cells of the GI tract and proximal tubule of the kidneu!
cotransporter
solute and driving ion are transported in the same direction
sodium organic transporters
transport aa, or neurotransmitters
contertransport
sodium calcium
for maintaining low calcium concentrations in cardiac muscle
h+/neurotransmitter u.
transceullar transport
transport across a cell
paracellular
transport between cells
function of tight junctions
structures found between epithelial cells that prevent the passage of molecules and ions between cells
how is sodium transported into epithelial cells?
across the luminal membrane via secondary active transport and channels
how is sodium transported out of the cell across the basolateral embrane?
Na+/K+ATPase
how is glucose transproted across the membrane??
via Na/glucose cotransport…
glucose is trasnported across the basolateral membrane by facilitated diffusion.
excitatory neurotransmitters
glutamate and aspartate
inhibitory neurotransmitters
glycine and GABA
neurotransmitters
primary chemical messengers usually smal molecules
neuromodualtors
secondary chemical messenger, co released with neurotransmitter.
usually peptides,
high frequency stimulation os often required for the release of neuromodualtors.
