Cardiovascular System

Question 1

Give an average value for cardiac output for a performer at rest and during maximal exercise. (2)

Answer 1

At Rest
4—6l/min
During Exercise
20—40 l/min

Question 2

Describe how the conduction system of the heart controls the systolic phase of the cardiac cycle. (5)

Answer 2

SANinitiatesan impulse
this causesatrialsystole
blood forced from the atria to the ventricles through AV valves
impulse is received by the AV node
impulse continues down the bundle of Hisandto the Purkinje fibres
Causingventricularsystole
blood is ejected from the ventricles via the semi luna valves

Question 3

Explain the cardiac cycle of the heart (3)

Answer 3

Atrial systole is when the atria contractwhichforces blood into the ventricles
Ventricular systole is when the ventricles contractwhichpumps blood out of the heart to the body and the lungs
Diastole is when the atria and ventricles relaxwhichallows blood to enter heart.

Question 4

Describe how the conduction system of the heart controls the systolic phase of the cardiac cycle. (5)

Answer 4

SA node sendsan impulse
this causesatrialsystole
blood forced from the atria to the ventricles through AV valves
impulse is received by the AV node
impulse continues down the bundle of Hisand thento the Purkinje fibres
Causingventricularsystole
blood is ejected from the ventricles via the semi luna valves