Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
what are the peak pressure in the atria and ventricles during systole? diastole?
|
- RA & LA: around 5mmHg
- RV: 35 mmHg - LV: 120 mmHg - during diastole the pressure in the ventricles goes to about 0 |
|
|
what is the formula for cardiac output?
|
- total volume of blood through systemic or pulmonary circulation per unit time (ml/min)
- CO = HR (beats/min) X SV (volume/beat) |
|
|
what is the stroke volume?
|
- the volume ejected with each beat
|
|
|
how are velocity (V) and flow (Q) related? what does this do to velocity if area is increased? decreased?
|
- velocity (cm/min) = flow (cm^3/min) / area (cm^2)
- if area is increased the velocity decreases, if area is decreased the velocity increases |
|
|
why does velocity decrease in capillaries? what happens to flow?
|
- velocity decreases b/c there is a great increase in capillary cross sectional area
- flow is constant - the decrease in velocity allows gas exchange in the capillaries |
|
|
what does the ultrasonic doppler flow meter measure? is coronary flow included?
|
- measures cross sectional area of aorta & velocity of flow in order to calculate flow
- A x V = Q - no this technique measures CO minus coronary flow |
|
|
what is the formula for calculating mean arterial pressure?
|
- mean arterial pressure = systole-diastole/3 + diastole
|
|
|
what is the formula for the pressure drop? how does this relate to flow & pressure drop between arterial & venous systems?
|
- pressure drop = Q x R
- if you know flow & pressure difference b/w aorta & venous system (venous system negligible) then you can calculate total peripheral resistance - TPR is increased in diseases like HBP |
|
|
what is poiseuille's law in terms of flow, pressure drop & radius?
|
- Q = deltaP x pi x r^4 / 8hL
- or deltaP = Q 8hL / pi x r^4 - basically radius is really important: if radius is increased a little the pressure drop decreases & flow increases |
|
|
what does a swan-ganz catheter do?
|
- measures right side pressures
- inserts just outside of RA then pulled in with flow of blood - can see RA & RV pressures & go into pulmonary artery to get to pulmonary wedge pressure and see pressure in LA |
|
|
what does the pulmonary wedge pressure tell you?
|
- pressure downstream in pulmonary capillaries - really only way to look at LA pressure
|
|
|
what is the pathway for a LV catheter?
|
- insert into femoral artery, goes opposite of blood flow
- can get pressure in LV & aorta |
|
|
what is the a wave of wiggers diagram? c wave? v wave?
|
- a wave is after p wave on EKG - it is increased pressure in RA
- c wave is the deformation of the mitral valve due to ventricular contraction & deformation into the atria - v wave is increasing pressure in LA from return of pulmonary veins --> when ventricle relaxesthen mitral valve opens |
|
|
what causes the mitral valve to open? closure?
|
- pressure in atria is greater than pressure in the ventricle
- closure when pressure in ventricle becomes bigger than the atria = lub sound |
|
|
what opens the aortic valve? closes?
|
- pressure in LV is greater than that in aorta
- closes when pressure in aorta is greater than that in ventricle = dub |
|
|
what is the dichrotic notch of aorta?
|
- due to recoil of previously stretched aorta - second jump in aortic pressure early in diastole
|
|
|
how do you measure stroke volume?
|
- difference between end diastolic volume & end systolic volume
|
