explain origin and conduction of heart beat 5 marks
Answers
Explanation:
The origin, conduction and regulation of heartbeat involves Sino-Atrial node (SA Node), inter-nodal pathways, atrioventricular node (AV Node), the AV bundle and the bundle of Purkinje fibres. ... It is situated near the opening of superior venacava in right atrium.
Answer:
involves Sino-atrial node ,inter-nodal pathways ,atrioventricular node, the AV bundle and the purkinje fibres.
Explanation:
Sino-atrial node
small muscular flattened mass of neuromuscular .Its situated near the opening of venacava in the right atrium. Sinus nodal fibres connects directly with the atrial muscle fibres so that any action potential that begins in the sinus node transmits immediately into atrial muscle wall. The fibres of SA node has ability of self excitation and control the rate of entire heartbeat.
Atrioventricular node (AV node)
is a small mass of neuromuscular tissue located in the wall of atrial septum near atrio-ventricular valves. The AV node is also capable of initiating impulses of contraction but at slower rate than SA node.
Atrioventricular bundle / AV bundle
is a mass of specialized fibres originating from AV node. AV bundle crosses the fibrous ring that separate atria and ventricle. And divides into right and left branches at upper end of septum. Within the ventricular myocardium these branches breaks down into fine purkinje fibres. Purkinje fibres convey impulses of contraction from AV node to the apex of myocardium where the wave of ventricular contraction begins and sweeps upwards, pumping blood into pulmonary artery and aorta.