CARDIOVASCULAR Flashcards
What is anticipatory rise?
An increase in heart rate before exercise caused by adrenaline.
What is possible risk of having high cholesteral?
Stroke/ cardiovascular disease/ heart attack
Process of the cadiac conduction system:
-Electrical signal sent to SA node
-Causes walls of atria to contract and forces blood into ventricles
-0.1 second delay at AV node for full diastolic filling
-Bundle of HIS
-Purkinje fibres
-Ventricles contract
What are the stages of the sympathetic nervous system?
-Information from receptors sent to cardiac control centre in medualla oblongata
-Down sympathetic nervous system
-SA node, AV node
-Increase heart rate
-Increase in venous return
-Increase in ejection fraction
What is systole?
When the heart contracts and empties
What is disatole?
When the heart relaxes and fills
What do chemoreceptors detect?
-Increase in C02
-Increase in lactic acid
-Decrease pH
What do proprioreceptors detect?
Increase in movement
What do barroreceptors detect?
Decrease in blood pressure
Which two factors affect stroke volume?
-Venous return
-Elasticity of cardiac fibres
What is starling’s law?
-Increased venous return
-Greater diastolic filling phase
-Cardiac muscle stretched
-More force of contraction
-Increased ejection fraction
Cardiac output=
stroke volume x heart rate
What happens to stroke volume during exercise?
-Increases as intensity of exercise increases
-Continues for up to 40-60% of max effort then plateaus
-Increase in HR increases diastolic fillling phase
-Ventricles dont have enough time to fill
What are the stages of cardiovascular drift?
-Occurs after 10 mins of prolonged exercise in warm environment
-Sweat causes water loss in blood cuasing it to go viscous
-Decrease in venous return
-HR increases to maintain cardiac output
Name 4 mechanisms of venous return:
-Skeletal muscle pump
-Pocket valves
-Respiriatory pump
-Cardiac suction pump