Circulation And Hemodynamics

Front 1

Pressure drop is proportional to _

Back 1

resistance

Front 2

Types of large arteries

Back 2

-Conducting elastic arteries - pulmonary artery, aorta, carotid artery - expand during systole, relax during diastole, lessens fluctuations in BP and flow
- Distributing muscular arteries - distributes blood to specific organs - femoral and splenic - smooth muscle layers constitute 2/3 of wall thickness

Front 3

Types of flow

Back 3

-Ideal
-Laminar
-Turbulent

Front 4

Definition of ideal flow

Back 4

Ideal flow has no interaction with the vessel wall

Front 5

What makes fluid non ideal

Back 5

Viscosity - blood has high viscosity because of RBC mainly and also blood proteins

Front 6

What kind of flow do viscous fluids have

Back 6

Turbulent or laminar

Front 7

What is the relationship between flow and vessel in ideal flow

Back 7

Flow is proportional to vessel area or square of vessel radius

Front 8

Describe laminar flow

Back 8

Flow that is slower near the wall - outside, move faster closer to center

Front 9

Relationship of flow and vessel in laminar flow

Back 9

Laminar flow varies with the fourth power of the radius

Front 10

Most powerful determinant of resistance

Back 10

Radius - inversely proportional to fourth power of the radius

Front 11

What controls radius of the vessel

Back 11

Vasoconstriction and vasodilation

Front 12

Relationship between vessel length and resistance

Back 12

Direct - tortuosities of the veins increase length and resistance of vessels

Front 13

How does viscosity affect resistance

Back 13

-Direct -
-Indirect - causes inverse relationship between resistance and fourth power of radius

Front 14

Viscosity is increased by _
Decreased by _

Back 14

Polycythemia - increased
Anemia and hypoproteinemia - decreased

Front 15

Turbulent flow

Back 15

Fluid flows in irregular fashion

Front 16

What usually causes turbulent flow and how do you test for that

Back 16

Atherosclerotic plaque that usually occurs at branch points
-Test by auscultating for bruits

Front 17

Systolic pressure

Back 17

Peak arterial pressure during systole

Front 18

Diastolic pressure

Back 18

Least arterial pressure during diastole

Front 19

Pulse pressure

Back 19

PP = SP - DP

Front 20

Mean arterial pressure

Back 20

MAP = DP + 1/3 PP

Front 21

Vasoconstriction _ resistance

Back 21

increases

Front 22

Which conditions show increased resistance

Back 22

Capillary rarefaction, obstructions, excess blood volume, atherosclerotic plaque

Front 23

Cardiac output

Back 23

Heart rate * Stroke volume or
Mean arterial pressure - central venous pressure /total peripheral resistance

Front 24

Essential hypertension

Back 24

-When chronic resting pressure is more then 140/90, kidney not regulating blood pressure normally
-Also seen in polycythemia

Front 25

Hypertensive crisis

Back 25

-Acute large increase in BP
-Usually from excessive vasoconstriction due to cold medicine overdose or cocaine

Front 26

Hypotension

Back 26

-Low resting BP
-Blood loss, hypoprotenimea, dehydration, anemia, anaphylaxis

Front 27

_ is required to cause blood flow against systemic resistance

Back 27

Diastolic pressure

Front 28

Isolated systolic hypertension

Back 28

Reduced arterial compliance due to atherosclerosis

Front 29

Isolated diastolic hypotension

Back 29

May be due to aortic valve regurgitation

Front 30

• Why are arteries referred to as ‘resistance vessels’?

Back 30

This term is applied to arteries since their main function is to regulate central blood pressure and also the distribution of blood to individual organs by altering their resistance

Front 31

Hypovolemia - causes

Back 31

Hemorrhage
Diarrhea/vomitting
Extreme sweating
Cutaneous (burns)

Front 32

Effect of hypovolemia

Back 32

Reduced venous return and cardiac output

Front 33

Compensation of hypovolemia

Back 33

-Sympathetic activation causes vasoconstriction to organs that are not vital - GI, kidney
-Autotransfusion - reduction in capillary pressure causes shift from outside of capillary to inside

Front 34

Heart failure causes decrease in _

Back 34

Inotropic state

Front 35

Regulatory mechanisms of BP

Back 35

Neurological mechanism - arterial receptors help regulate arterial pressure, venous and atrial pressure help regulate volume
Hormonal regulation - renin- angiotensin- aldosterone system and ADH help in hemorrhage, atrial naturetic peptide promotes sodium excretion
-Kidney regulation - increased MAP increases salt and water excretion, decreased MAP decreases salt and water excretion