Basic Sciences - Cardiovascular Physiology Flashcards
Definition of flow
Quantity of fluid being moved passed a point in a given time
Not velocity
Cardiac output equation
CO = SV x HR
Approximate CO in average person
5 L/min
Approximate SV in average person
70 ml
Requirement to generate flow of a fluid
Pressure gradient
Main types of receptor present in the heart
Muscarinic cholinergic receptors - parasympathetic
Beta 1 adrenergic - sympathetic
Main types of receptor present in peripheral blood vessels
Alpha 1 adrenergic - sympathetic
Factors which impact flow of fluid
Most efficient type of flow
Laminar flow
Correlation between pressure, flow and resistance
Pressure = Flow x Resistance
Correlation of pressure, flow and resistance in human circulation
MAP = CO x SVR
Mean arterial pressure
Cardiac output
Systemic vascular resistance
How to calculate flow under laminar flow conditions
Poiseuille’s law
Poiseuille’s law
Which factor has greatest influence on flow
Radius of vessel / pipe (according to Poiseuille’s law)
Calculations for MAP
MAP = CO x SVR
MAP = 2/3 Diastolic BP + 1/3 (Systolic - Diastolic BP)
Reason for MAP representing 2/3 Diastole and 1/3 Systole
Cardiac cycle is 2/3 in diastole
Arterial BP waveform
Dicrotic notch - the change in wave form on the descent
Dicrotic notch on arterial waveform representation
Elastic recoil of aortic wall immediately after aortic valve closure
Normal pressures of right atrium
Systole 5 mmHg
Diastole 2 mmHg
Normal pressures of right ventricle
Systole 25 mmHg
Diastole 0 mmHg
Normal pressures of left atrium
Systole 6 mmHg
Diastole 3 mmHg
Normal pressures of left atrium
Systole 120 mmHg
Diastole 0 mmHg