The Heart

Question 1

Layer of Pericardium

Answer 1

outer of fibrous pericardium and inner of serous pericardium (pericardium fluid inbetween)

Question 2

layer of hear

Answer 2

endocardium - smooth, continious with blood vessels, valves
myocardium - muscle, thicker in left ventricle
epicardium - serous , serous fluid

Question 3

sinoatrial node

Answer 3

wall of the right atrium

Question 4

atrioventricular node

Answer 4

top of ventricular septum

Question 5

bundle of his

Answer 5

within the ventricular septum

Question 6

purkinje fibre

Answer 6

specialised cell within the ventricle walls

Question 7

Nerve impulse is initiated by the SA node
Nerve impulse travels across atrial walls and stimulates AV node
Impulse continues down the bundle of His to the Purkinje fibres at the apex of the ventricles
The atria contract – ATRIAL SYSTOLE
Blood is forced into the ventricles
The atria relax – ATRIAL DIASTOLE
The ventricles contract – VENTRICULAR SYSTOLE
Blood is forced upwards , closing the AV valves and opening the aortic and pulmonary valves
Blood is moved from the ventricles into the systemic and pulmonary circulations
The ventricles then relax – VENTRICULAR DIASTOLE
The semilunar valves clos