Overview of cardiovascular system Flashcards
What determines cardiac output?
Stroke volume and heart rate (SV*HR)
What is the typical CO for a 70kg person?
5 l/min
How much can CO increase in elite athletes during exercise?
Can increase 6 fold
What is the typical total blood volume for a 70kg person?
5 l; entire blood volume passes through the heart each minute
What are the functions of the cardiovascular system?
Transport of oxygen, nutrients, and metabolites to tissues; removal of metabolic waste products; distribution of hormones to tissues; secretion of hormones; regulation of body temperature; involvement in homeostasis mechanisms
What is hydrostatic pressure?
Pressure exerted on the walls of the container by the fluid within the container; is proportional to the height of the column
How does pressure change through the CV system?
Pressure decreases with distance as energy is lost due to friction; CSA and vessel compliance also affect pressure
Where is the pressure of the CV system generated?
The contractions of ventricles generates pressure which is transferred to the blood
What property of fluids allows pressure to be the driving force of movement in the CV system?
Fluids are incompressible
What is the equation for flow?
Pressure difference between two points/resistance
Why is length not relevant to resistance in regards to the CV system?
Length of veins doesn’t change acutely
What is resistance directly proportional?
Resistance is directly proportional to radius of vessels; radius elevated to power of 4, causing big changes to flow
What is the equation for flow (using equation for resistance also)?
Pressure difference((3.14radius^4)/8Ln); where n = viscosity of blood
What is the equation for flow rate?
Volume/unit of time; l/min
What is the equation of velocity of flow?
Measures speed of flowing blood; flow rate/CSA; cm/s
