Hemodynamics

Question 1

Hemodynamics

Answer 1

The study of blood moving through the circulatory system

Question 2

Flow

Answer 2

• Also called volume flow rate
• Indicates the volume of blood moving during a particular time
• units: L/min

Question 3

Arteries

Answer 3

Tubes that carry blood away from the heart

Question 4

Veins

Answer 4

Tubes that return blood to the heart

Question 5

Capillaries

Answer 5

Connect arteries and veins. Tiny to sell exchange food oxygen and weighs between blood and body cells

Question 6

Circulatory System

Answer 6

Consist of the heart, arteries, arterioles, capillaries, venules, and veins

Question 7

Heart

Answer 7

The pump that produces flow through the circulatory system

Question 8

Layers of blood vessel walls

Answer 8

• Tunica intima-inner layer
• Tunica Media-middle
• Tunica adventitia
• Arteries typically have a much thicker Tunica media compare with veins

Question 9

The three basic forms of blood flow

Answer 9

• Pulsatile flow
• Phasic flow
• Steady flow

Question 10

Pulsatile flow

Answer 10

-Occurs when blood moves with the variable velocity
-Cardiac contraction
Commonly appears in the arterial circulation

Question 11

Phasic flow

Answer 11

Occurs when blood moves with the variable velocity. Respiration. Often appears in the Venous circulation

Question 12

Steady flow

Answer 12

Occurs when the fluid moves at a constant speed of velocity. Present in the venous circulation one individual stop breathing for a brief moment.

Question 13

Laminar flow

Answer 13

A flow condition in which streamlines are aligned and parallel. Characterized by layers of blood that travel individual speeds. The highest velocity’s are in the center of the vessel.

Question 14

Plug flow

Answer 14

Occurs in all of the layers and blood cells travel at the same velocity. Also known as blunted flow.

Question 15

Parabolic flow

Answer 15

Bullet shaped profile. Velocity is highest in the center of the lumen and is gradually decreases to it’s minimum at the vessel wall.

Question 16

Stenosis

Answer 16

A narrowing in the lumen of a vessel

Question 17

Pre-stenosis

Answer 17

-Velocity decreases
Pressure increases
Dampened blood flow/ slows down

Question 18

At stenosis

Answer 18

Velocity increases

Pressure decreases

Question 19

Post-stenosis

Answer 19

Velocity decreases
Because of turbulent blood flow
Pressure increases

Question 20

Reynolds number

Answer 20

Predicts whether flow is laminar or turbulent.
Greater than 2000 is true turbulence
Less than 1500 is laminar flow

Question 21

How is energy imparted to blood?

Answer 21

By the contraction of the heart during Systole

Question 22

Forms of energy associated with blood

Answer 22

• Pressure energy
• Kinetic energy
• Gravitational energy

Question 23

The continuity equation

Answer 23

Ties together the relationship between the vessel area, the velocity of blood, in the volume of blood flow
Q=VA
Diameter and velocity are inverse

Question 24

Bernoulli effect

Answer 24

Describes the relationship between velocity and pressure in a moving fluid
Derive from the principle of conservation of energy, which states that with steady flow the sum of all forms of energy is the same everywhere
P1-P2(change in P)=4V^2

Question 25

Poiseuille’s Law

Answer 25

Describes the relationship between volume flow, pressure, and resistance.
-The radius of a vessel is directly proportional to the volume flow. Slow resistance most strongly depend on the vessel radius because the radius in the equation is with power 4(r^4).So that a small changes in radius may result in large changes in flow.

Question 26

Venous hemodynamics

Answer 26

-Veins are thin walled and collapsible
During normal function, veins have a low pressure, or only partially filled with blood and therefore, only partially expand
The cross-sectional shape of a vein during normal function is flattened or hourglass shaped
The greatest portion of circulating blood is located in the venous system