cardiac conduction system

what is pulmonary circulation

the passage of blood from the heart to the lungs and back

what is systemic circulation

the passage of blood around the body to the muscle tissue and back

what is cardiac muscle

also known as myocardium - the muscle that causes the heart to contract

where is the sino atrial node - (SAN) located and what does it do

right atrium and it controls the heartbeat

the heart is myogenic what does this mean

the heart initiating its own heartbeat

what is the atrio - ventricular node located and what does it do

right atrium and it relays the electrical impulse from the SAN and spreads it down the centre of the heart the through the bundle of his

what is the bundle of his

a branch of specialised nerves that spread down the septum of the heart

what are the purkinje fibres

fibres that relay the impulse up around the bottom of the ventricles

what is systole

the contraction of the ventricles

what is diastole

the relaxation of the ventricles

explain what happens during atrial diastole

the atria fill with blood, the atrioventricular valves are closed and the semi lunar valves are open

explain what happens during ventricular diastole

the rising pressure of the atria cause the AV valves to open and the ventricles fill with blood, the AV valves are opened and the semi lunar valves are closed

explain atrial systole

the atria contract which forces the blood into the ventricles, the AV valves are open and the semi lunar valves are closed

explain ventricular systole

ventricles contracting increasing the pressure so the blood is forced into the aorta and pulmonary artery and the AV valves are forced to close

explain the heart conduction

the heartbeat is initiated by the SAN which causes atrial systole, the impulse the passes through the AVN and then the bundle of his - the purkinje fibres then carry the impulse throughout the ventricles causing contraction and ventricular systole