Section 5: Vascular Physiology

Question 1

Blood flow equation

Answer 1

Flow = Change in pressure over resistance

Question 2

resistance equation

Answer 2

R = 8ηL/πr^4

where η is vicosity
L is length
r is radius

Question 3

Viscosity of blood is determined by

Answer 3

amount of RBC by volume

Regulated by haemocrit

Question 4

Pulse pressure

Answer 4

difference between systolic and diastolic

Question 5

Mean arterial pressure

Answer 5

diastolic pressure + pulse pressure/3

Closer to diastolic b/c heart spends more time relaxing

Question 6

Cardiac output (flow) in relation to pressure

Answer 6

F=MAP/R

where MAP is mean arterial pressure

Question 7

factors that influence vasodilation

Answer 7

myogenic activity
oxygen
carbon dioxide
pH
endothelin
sympathetic influence
vasopressin
angiotensenII
temperature
histamine 
NO

Question 8

Baroreceptor reflex

Answer 8

autonomic mediation of heart veins and arterioles to adjust in the short term

Adjusts blood volume through urine and salt over long period

Question 9

Primary hypertension

Answer 9

catch-all term for high BP associated with specific disease

Question 10

secondary hypertension

Answer 10

occurs due to a known problem (10% of cases)

Question 11

causes of secondary hypertension

Answer 11

renal, endocrine, neruogenic

Question 12

4 types of shock

Answer 12

hypovolemic
cardiogenic
vasogenic (sepsis or anaphylaxis)
neurogenic