L16 Active Learning Flashcards
Which organ has the most constant supply of blood and why?
Brain - Cause it needs continuous supply of oxygen and nutrients to function properly, it is very sensitive to O2 deprivation.
In aorta vs capillaries, what are the ratios of aggregate cross sectional area?
Why is there proportionally more smooth muscles in the walls of the arterioles than the aorta?
Because arterioles control blood flow to capillary beds
what are the three types of capilaries?
continuous, fenestrated and discontinuous( sinosoidal).
At same pressure which of the three types of capillary will have the highest Jv(Fluid movement)?
In a capillary with a Kf of 1, what is the direction of fluid movement across the capillary wall and the net driving force if:
Pc is 28 mmHg
Pi is 4 mmHg
πcis 24 mmHg
πiis 3 mmHg
Jv is 3 ml/min.
Explain the role of the lymphatic system in relation to the circulatory system?
drain excess interstitial fluid and return into cardiovasular system via subclavian vein and ,maintain fluid volume.
If Jv is positive, what does that mean with the direction of fluid movement in capillaries?
Explain the role of the lymphatic system in relation to the circulatory system
Drain excess interstitial fluid
Subclavian vein allows interstitial fluid to drain back into the blood to maintain blood volume
What features of cardiac cells enable the heart to beat in a synchronous and coordinated way with maximal force?
- Intercalated disks
- desmosomes
- electrical coupling forms syncitium
- Gap junctions
What causes the heart sounds S1 and S2?
S1 - Atrioventricular valves closing.
S2 - Semilunar valves closing.
Why is the T wave larger than the P wave ?
Reflects the movement of ions in the ventricles vs the atria - which is a bigger muscle.
Why are the QRS wave and T wave both positive deflections if one is ventricular depolarisation and the other is repolarisation?
Reflects the direction of the depolarising and repolarising event between two electrodes.
If each small square on the diagram is 0.04 seconds, what is the heart rate (BPM)? There are 25 squares.
25*0.04 = 1 Second so there is 60 beats per minute.
If resistance increases 4 fold, what would happen to the flow?
Reduce to 1/4
