LeBlanc 2 Flashcards
T/F The RV & LV have the same pressure.
False. The left pressure has much higher pressure than the right side.
You get more elastic & less muscular w/ arteries the larger/smaller you get?
Larger Arteries: more elastic
Smaller Arteries: more muscular
What do endothelial cells do in arteries?
All blood vessels have a layer of endothelial cells.
Thru NO endothelial causes vasodilation.
If undamaged, endothelial cells keep clots from forming.
You need a pressure difference for blood to flow. For this reason RA has low/high BP?
For this reason capillaries have low/high BP?
RA has a low BP so the venous return is possible.
Capillaries also have low BP.
What is responsible for the low BP in capillaries?
Why is this important?
Important b/c need time for exchange of gases & nutrients @ the capillary beds.
LOW BP b/c branching & large cross-sectional area
sorta acting against this is the decreased diameter which increasing peripheral resistance.
What is the relationship b/w cross sectional area & velocity?
Higher cross sectional area
slower velocity…Think A1v1=A2v2
Where is most of the blood held in the vasculature?
2/3 of the blood is held in the veins. Can be constricted out if more cardiac output is needed.
Are the right side & left side of the heart are connected in series or in a parallel circuit?
In series.
The systemic pathway is connected in series or in parallel?
In parallel.
Can veins collapse? When?
Yes, when there is super low pressure, like when there is negative pressure in the chest.
Where does the greatest drop in pressure come in the cardiovascular system?
Once you hit the small arteries & arterioles.
What is the normal pressure of the RA?
0 mmHg
Increased resistance is caused by what change to the blood vessel lumen diameter?
A decrease in the diameter of the lumen of the blood vessel
What is the cardiovascular version of V=IR?
BP=Blood Flow X Peripheral Resistance
What is the difference b/w pulsatile & continuous flow?
Pulsatile: rhythmically intermittent…b/c of nature of the heart.
Continuous: one long stream
Where is there the most pulsatile flow? Continuous Flow?
Most pulsatile flow nearest the heart…nearest the great vessels. Most continuous flow near the capillaries.
What are the factors that contribute to the continuous flow near the cardiovascular system?
The big arteries are elastic. If they were stiff, would be more pulsatile.
The resistance of the smaller arteries, arterioles, & capillaries forces continuity.
T/F The velocity of blood flow in slower in the SVC & IVC than it is in the aorta.
False. a difference in these velocities would for some reason create an imbalance.
Where is the largest reserve of blood in your body?
2/3 of your blood is stored in your veins. If you need more blood in your system…vasoconstriction of the veins & get that stuff moving!
What is so special about the atrial kick?
It is an extra contraction of the atrium. It ejects a little extra blood into the ventricle. Thru the Starling mechanism…it causes more ventricular stretching & therefore a stronger contraction.
In the Wiggers Diagram…what does the P wave correspond to?
Atrial depolarization. Atrial contraction--eventually atrial kick Increased Atrial Pressure Increase in Ventricular Volume Slight Increase in Ventricular Pressure
When do the AV valves close? What heart sound does this correspond to?
When ventricular pressure is higher than the atrial pressure. S1.
What happens after the AV valves close?
Isovolumic contraction.
Ventricular pressure increases dramatically.
Ventricular Volume stays constant.
Atrial pressure increases slightly b/c of transient notch (ventricle pushing up on the atrium)
What happens when isovolumic contraction is finished?
Aortic valve opens b/c ventricular pressure is greater than aortic pressure.
Ejection of blood from the ventricle.
