Biology Forums - Study Force

Hi,

I need some help with some of the questions on the review sheet (they're in bold).  I'm going to write out the whole thing with the answers that I already have, which might need correcting or might be helpful to other people.

1.  Identify the following variables in Poiseuille's equation:
     [Delta] P:  the pressure difference between the two ends of the vessel (also known as pressure the gradient)
     r4:  the radius of the blood vessel
     [eta]:  viscosity
     l:  vessel length

2.  Explain how each of the following variables affects blood flow:
     [Delta] P:  flow rate is directly proportional to the pressure gradient.
      r4:  the smaller the radius, the greater the resistance.  The greater the resistance, the slower the flow.
     [eta]:  the higher the hematocrit, the greater the viscosity.  The greater the viscosity, the slower the flow.
      l:  The longer the vessel, the greater the resistance.  The greater the resistance, the slower the flow.

3.  What would cause an increase in the peripheral resistance in a blood vessel?
 
4.  Describe the cardiac cycle.
     The right side of the heart pumps blood to the lungs so that blood can take up oxygen.  This blood is returned to the heart, pumped by the left side of the heart to the rest of the body, and then returned to the right side of the heart again.

5.  ventricular contraction:  systole
     the amount of blood each ventricle pumps per minute:  cardiac output
     the amount of blood pumped to the body per contraction per ventricle:  stroke volume
     the volume of blood in the heart at the end of ventricular contraction:  ESV
     ventricular relaxation:  diastole
     contraction that occurs when the volume of blood in the ventricles... :  isovolumetric contraction
     the ejection of blood near the end of systole... :  ventricular ejection
     the volume of blood in the heart at the end of ventricular relaxation:  EDV

6.  Define Starling's Law.
     When the rate at which blood returns to the heart changes, the heart will adjust its output to match the change in inflow.

7.  What differences would you expect to see between a diseased heart with high peripheral resistance and the healthy heart of an athlete?

8.  What was the effect of increasing flow tube radius on flow rate and flow volume?

9.  Which variable had the strongest effect on fluid flow?

10.  If the viscosity of blood were to increase, what could you do to keep the rate "normal"?
     Increase vessel radius via vasodilation; increase blood pressure

11.  What would occur if the left side of the heart pumped faster than the right side?

12.  What do the valves in the pump Mechanics screen do?

13.  fluid in the left beaker:  blood coming from the lungs
       middle beaker:  left side of the heart
       fluid in right beaker:  blood going to the rest of the body
       flow tube between left and middle beakers:  vein
       flow tube between middle and right beakers:  artery

THANK YOU!!!

The increased peripheral resistance can be overcome by: (1) increasing the pump’s pressure, (2) decreasing the pressure in the right beaker, and (3) increasing the radius of the left flow tube to decrease the pump’s filling time.

Don't know the rest.

Thanks Duddy.  However, I don't think your response is right... the question is "what would cause an increase in peripheral resistance", not how increased resistance can be overcome.

I know, but I really couldn't find anything practical in the manual. Hopefully someone else can chime in.

Giving this topic a bump because I haven't gotten any bites yet.  I have 6 questions, all in bold, that I need help answering.  Thank you!