cardio Flashcards
which vasculature carry blood away from the heart? which carry blood back to the heart?
arteries=away
veins=back to
what are the 5 factors that regulate the process of diffusion?
1- distance
2-the solvent characteristics
3-the molecule’s characteristics
4-the temperature
5-the barrier
true/false: a heavy molecule diffuse more easily than a. less heavy one
false, the heavier the molecule the harder it diffuses
Do insects have blood? if not, whats their fluid called?
no blood. hemolymph
what are the differences between our circulation and insects’?
-they dont transport oxygen (bcs no Hb)
-open circulation
-no blood
-their heart is made up of chambers
true/false: fish have a single heart and not a double like us and it contains only deoxygenated blood
true
what are the differences between our circulation and the reptilians’?
-they have 3 chambers (2 atria and 1 ventricle)
-their heart contains mixed blood
true/false: the crocodile have only 1 aorta like us
false, they have two
how can the crocodile go into water without breathing?
The valve in the pulmonary aorta (right, deoxygenated) closes and so the deoxygenated blood passes through the left aorta (systemic)
which one is the most compliant? Veins or Arteries? What does it means?
veins are more compliant as they change size according to the volume of blood
which one is the most resistant veins or arteries? and what does it means?
arteries are more resistant since when blood volume increase; their R increases too
HR x SV = ?
CO (cardiac output)
true/false: both arteries and veins have inner valves
false, only veins have them
How can the flow stay the same in arteries and in capillaries?
in arteries the crossectional area is low but the velocity is high. in capillaries the crossectional area is high and the velocity is low (better exchange)
true/false: the Pressure is higher in the capillaries than in the arteries
false, higher in arteries (lower crossectional area, higher velocity)
pressure diastole > pressure systole
false, systole>diastole
why do we assume perfusion P= arterial P?
because arterial pressure»_space; veinous pressure
what does perfusion pressure represent?
the difference between P in and P out
If a vessel with a length of 4 cm have a R=3 and flow=1. What is the R and the flow of a same type of vessel that have a length of 8 cm?
Rx2 so R=6. Flow/2 so flow=0.5
1/R=1/R1 + 1/R2 is from which type: series or parallel?
parallel
what are the two mechanisms that help to maintain the flow of blood with gravity?
1- valves
2- muscles contractions
the tricuspid valve is situed between the ______ _______ and the ______ ventricle
between the right atrium and the right ventricle
the bicuspid (mitral) valve is between the _______ _______ and the ______ ventricle
between the right atria and the right ventricle
Who am I? I am a chamber of the heart with thick muscular wall because of the high pressure of systemic circ
the left ventricle
what is the job of the two coronary veins?
they empty the deoxygenated blood into the right atria
which layer of the heart doesnt contract and which one is the muscle?
epicardium
endocardium
myocardium
pericardium
the pericardium doesnt contract and the myocardium is made out of muscles
which node gets activated first?
sinoatrial or atrioventricular
sinoatrial
if no AV node, what happens to the signal?
it only propagate to the atria and not to the ventricles
Why is the propagation of the signal left to right?
because the right bundle of His is isolated from the septum
what does interstitial current and cytoplasmic current means?
interstitial is the outside of the cell movement of Na and cytoplasmic is the inside of the cell movement of K.
the purkinje fibers can fire an impulse of their own?
yes, if SN doesnt work
what wave in the ECG represent the atrial contraction, when the sinus node fire?
the p-wave
the P-R segment starts from what and end with what?
start with the end of P and end with the start of Q
Start of P until the beginning of Q, who am i?
P-R interval
what is the equation to determine wheter the deflection is + or -?
ext of + (left) - ext of - (right)
when a cell is depolarized, that means the exterior is ___?
negative
why is the Q wave a negative deflection?
because it represent the depolarization of the septum and it is done from left to right in contrast to the right to left of the atria
how are the pacemaker cell characterized in a graph of their membrane potentials?
they dont have a resting potential
what does S-T segment represent?
it represent the time between depolarization and repolarization of the ventricles
when the rythm is slow the person have ______
bradychardia
Calcium binds to what in the muscles?
troponine
what happens during 1/3 of the cardiac cycle?
the ventricle contracts
what are the two phases of the systole?
isovolumetric ventricular contract and ventricular ejection
explain the diastole?
isovolumetric relaxation: ventricles stop contracting and pressure drop below the P of aorta (valves close). Atria has been filling
ventricular filling: P in ventricle is lower than the P in atria so the mitral and tricuspid valves open to fill up the ventricle
what happens when arterial pressure drops?
the arterioles dilate to restore blood flow
where are the ganglion of the parasympathetic and the sympathetic pathway ?
para= cardiac fat pads
sympa= near the spinal cord
where are situed the baroreceptors?
in the carotid arteries
what effect has the low baroreceptor firing (they fire a lot when the BP is high)?
it increase HR,SV and TPR
what effect has chemoreceptors
they increase HR
MAP = ?
= SV x HR x TPR
