Cardiovascular Disease Flashcards
What is heart rate
Amount of blood pumped from the left ventricle per beat (ml)
What is stroke volume
The volume of blood pumped out of the left ventricle per minute
What is cardiac output
The number of heart contractions per minute (bpm)
How do you calculate cardiac output
Heart rate x stroke volume
How do you calculate maximum heart rate
220-age
What is heart rates response to exercise
Continued action of proprioceptors/chemoreceptors
Increase as exercise intensity increases
Increase due to adrenaline acting on SA node
Optimal level where supply of O2 is equal to demand
Further increase/ decrease may occur due to change in workload
Removal of waste
Resting rate
What determines stroke volume
Venous return
Starlings law
What is starlings law
The greater the stretch on the walls of the heart, the greater the force of contraction
Heart walls are stretched by blood returning to heart during diastole phase
Describe starlings law in relation to exercise
I’m exercise more blood is returned therefore more stretch to accommodate the blood so more force of contraction and more blood pumped out, and less blood is left behind at the end of systole, increasing ejection fraction
How do you calculate ejection fraction
Stroke volume/ EDV (amount of blood in ventricles at the end of diastole.
What is cardiovascular drift and what causes it
The slight increase in HR during prolonged exercise.
This is caused after ten mins by:
Sweating causing decrease in blood plasma/ blood becomes more viscous
Venous return decreases so sv decreases
HR increases to maintain cardiac output and cool body
What are the training effects (ABICH)
Athletes heart
Bradycardia
Increased contractility
Capillaridation
Hypertrophy
What is athletes heart
Increase in EDV during rest and exercise caused by repeated stretching of the chamber walls
What’s is bradycardia
RHR of under 60bpm caused by athletes heart and hypertrophy
What is Increased contractility
A more powerful systolic phase
What is cappillarisation
Increase capillary growth within the heart
What is hypertrophy
Cardiac muscle increases in size and strength
Systole and diastole
Systole is heart muscle in contraction
Diastole is heart muscle in relaxation
What happens during systole
- The atria contract pushing remaining blood down into ventricles
- Atrio ventricular valves close
- Ventricles contract pushing blood through semi lunar valves
What happens during diastole
- The atria fill up
- Rising pressure pushes open the av valves and the ventricles start to fill
- Blood is kept in the heart by the semi lunar valves
Conduction of the heart
Sally Anne always Buys Pickled Vegetables (memory tool)
SA node- sends out regular impulses across atria
AV node- receives, delays, then passes on the electrical impulses
Bundle of His- a large insulated nerve carries impulses to bundle branches
Bundle branches- carry impulse around apex of the heart
Purkinje fibres- nerve endings that release the impulse across the ventricles
