Hemodynamics

Question 1

Adequate blood flow is essential for________

Answer 1

1- Transport of nutrients & waste products.
2- Regulation of body temperature
3- Defensive mechanism

Question 2

What are the functions seen in the left side of the heart?

Answer 2

•High pressure pump
•Blood moves from high
pressure to low pressure

Question 3

What are the functions seen in the Arteries?

Answer 3

•Elastic fibers for compliance and recoil

Question 4

What are the functions seen in the Arterioles

Answer 4

•Thick layer of smooth

muscle

Question 5

What happens to the arterioles if they are sympathetic?

Answer 5

•Sympathetic = vasoconstriction= increased peripheral resistance

Question 6

What are the functions seen in the capillaries?

Answer 6

•Exchange water and dissolved substances

between blood and interstitial fluid.

Question 7

What are the forces seen in the capillary fluid exchange?

Answer 7

1- Capillary hydrostatic pressure (HPc)
2- Capillary oncotic pressure (πc)
3- Interstitial fluid hydrostatic pressure (HPISF)
4- Interstitial fluid oncotic pressure (πISF)

Question 8

What are the functions seen in the veins?

Answer 8

• Accommodate large volume of blood

* Can contract and mobilize blood to the circulation.

Question 9

What are the functions seen in the right side of the heart?

Answer 9

Receives the venous return and then pumps the blood to the pulmonary circulation.

Question 10

What are the functions seen in the pulmonary capillaries?

Answer 10

•Gas exchange.

Question 11

What are the functions seen in the Lymphatic Vessels?

Answer 11

•Drainage system preventing collection of

fluids in the interstitial tissue spaces.

Question 12

What is the formula for the blood flowing through a blood vessel?

Answer 12

•Blood flow through a blood vessel (F) =
Pressure gradient (∆ P)
/Resistance to blood flow (R)

Question 13

What is the formula for the blood flow?

Answer 13

Blood flow (F)= ∆ P/R

Question 14

What is the formula for the resistance?

Answer 14

R= 8ɳL/Πr^4

Question 15

What happens in the diameter of the arterioles?

Answer 15

•Arteriolar vasodilation decreases the resistance and increases blood flow and vise versa.

Question 16

What happens in the blood viscosity?

Answer 16

•It is 3 times greater than water viscosity

Question 17

What is Laminar blood flow?

Answer 17

• The blood flow in the vessel is laminar (in layers).
• In small vessels most of the layers are near the wall
• Laminar blood flow is silent

Question 18

What is turbulent blood flow?

Answer 18

• At and above a critical velocity the blood flow becomes disturbed & turbulent.
• The turbulent flow causes a sound
• Turbulence occurs when a Reynolds number (Re) is exceeded.

Question 19

What is the relation between velocity and cross sectional area?

Answer 19

•The velocity of blood flow is inversely
proportional to the cross sectional area of
the blood vessel.