# 3B Hemodynamics Flashcards

1
Q

What 3 places receive 75% of the arterial blood flow go from the heart?

A

1.Renal (25%) 2.GastroIntestinal (25%) 3. Skeletal Muscle (25%)

2
Q

What are the two major variables for measuring blood flow? What is the equation relating all of the variables?

A

Pressure and Resistance….Blood Flow (Q)=Change in Pressure/Resistance

3
Q

What is blood pressure?

A

The FORCE with which blood is PUSHED against the walls of the blood vessels

4
Q

What is systolic pressure?

A

the HIGHEST amount of pressure reached DURING ventricular ejection of blood

5
Q

What is diastolic pressure?

A

the MINIMUM amount of pressure just BEFORE ventricular ejection begins

6
Q

What is the name of the sounds when measuring BP? When is systolic BP measured? Diastolic?

A

Korotkoff sounds.. First sound is systolic…NO sound is diastolic

7
Q

What devices use an electronic pressure sensor with a numerical readout of blood pressure?

A

Oscillometric devices

8
Q

What are the two formulas for MAP?

A

MAP=2/3DP+1/3SP…..OR…..MAP=DP+1/3PP (PP=SP-DP)

9
Q

What are the 3 sources for resistance within a SINGLE vessel but can accumulate to alter TPR (total peripheral resistance)? WHICH source does NOT change in vivo?

A

1.Blood Viscosity 2.Vessel Length 3.Vessel diameter/radius….2.Vessel Length is the only one that does not change in vivo

10
Q

Which law is the relationship between resistance, viscosity, vessel length, and vessel radius? What is the formula relating these variables?

A

Poiseuille’s Law….R=8 V L / pi r^4

11
Q

Anemia: Viscosity? Vascular Resistance? Blood Flow?

A

Anemia: low viscosity, low vascular resistance, high blood flow

12
Q

PolyCythEmia: Viscosity? Vascular Resistance? Blood Flow?

A

Increased viscosity, Increased Vascular resistance, Decreased blood flow

13
Q

What is a stack of RBCs? What is the result?

A

Rouleaux stacks…Ischemia

14
Q

What does a 2 fold increase in vessel radius do to blood flow?

A

Increases 16 fold!

15
Q

What does a 4 fold increase in vessel radius do to blood flow?

A

Increases 256 fold!!!

16
Q

What happens to ARTERIAL blood flow when vasoconstriction takes place?

A

Blood flow DECREASES (Q=P/R…R increases MORE then pressure)

17
Q

What happens to VENOUS blood flow when vasoconstriction occurs?

A

Venous return INCREASES (Q=P/R…P increases MORE then resistance) (has to do with normally low p in veins and it makes a BIG effect with a little constriction…arteries already deal with high pressure so constriction contributes more there)