Cardiac Cycle

Question 1

Cardiac myocytes

Answer 1

Striated muscle cells
Spontaneous depolarisation
Depolarisation spreads via inter calculated discs

Question 2

What does depolarisation of cardiac myocytes do?

Answer 2

Allows calcium ions to enter and cause contraction
Depolarisation spreads via conduction system so is in coordinated manner

Question 3

Diastole

Answer 3

Ventricle relaxing

Question 4

Systole

Answer 4

Ventricle contracting

Question 5

Blood flow route

Answer 5

1) vena cava bring D.O blood to R.A then to R.V then to lungs via P.A
2) P.V returns O.B to L.A then to L.V
3) aorta takes blood around the whole body

Question 6

Electrical system

Answer 6

1) SAN depolarises which spreads to AVN
2) depolarisation spreads throughout the bundle of hiss
3) up through the purkinjie fibres and surrounds the left ventricle causing ventricular systole

Question 7

What does parasympathetic activity do?

Answer 7

Decreases heart rate through release of acetylecholine

Question 8

What does sympathetic activity do?

Answer 8

Increases heart rate through release of noradrenaline