Circulation

Question 1

Parts of circulatory system

Answer 1

Cardiovascular - closed - blood
Lymphatic system - open - collects fluid from lymph nodes

Question 2

Arteries, arterioles, microcirculation and venules/veins

Answer 2

Arteries - transport blood
Arterioles - last arteries with muscular walls

Question 3

Physical determinants

Answer 3

Ohm’s law
I = V/R
Current = flow of blood
Voltage = pressure difference
R = resistance to flow

Darcy’s law of flow = Q = ^P/R

Question 4

Blood flow

Answer 4

Laminar flow - smaller vessels
Turbulent flow - large vessels

Question 5

Speed of flow

Answer 5

v = Q/A
velocity = flow/cross sectional area

Question 6

Viscosity of blood

Answer 6

Hematocrit ratio
Erythrocyte volume/whole blood volume

Question 7

Sum of determinants of blood flow

Answer 7

Poiseuille’s law

Q = k ^P r4/nL

k - constant
L- length
^P - pressure difference
r - radius
n - viscoxity

Question 8

Total peripheral resitance

Answer 8

Q = ^P/R

Question 9

Vessel radius / diameter

Answer 9

Resistance is reversely proportional to r4.
So r is super important to flow.

Question 10

Microcirculation

Answer 10

Net filtration = hydrostatic pressure - oncotic pressure.
filtrated fluid = reabsorbed fluid + lymph
High hydrostatic pressure or low oncotic pressure = edema.

Question 11

3 main parameters of cvs

Answer 11

tissue blood flow
cardiac output
arterial blod pressure