Question

describe the conducting system of heart

Answer 1

The electrical conduction system of the hearttransmits signals generated usually by the sinoatrial node to cause contraction of the heart muscle. The pacemaking signal generated in the sinoatrial node travels through the right atrium to the atrioventricular node, along the Bundle of His and through bundle branches to cause contraction of the heart muscle. This signal stimulates contraction first of the right and left atrium, and then the right and left ventricles. This process allows blood to be pumped throughout the body.


Cardiac muscle has some similarities to neurons and skeletal muscle, as well as important unique properties. Like a neuron, a given myocardial cell has a negative membrane potential when at rest. Stimulation above a threshold value induces the opening of voltage-gated ion channels and a flood of cations into the cell. The positively charged ions entering the cell cause the depolarizationcharacteristic of an action potential. Like skeletal muscle, depolarization causes the opening of voltage-gated calcium channelsand release of Ca2+ from the t-tubules. This influx of calcium causes calcium-induced calcium release from the sarcoplasmic reticulum, and free Ca2+ causes muscle contraction. After a delay, potassium channelsreopen, and the resulting flow of K+ out of the cell causes repolarization to the resting state.[3][4]

There are important physiological differences between nodal cells and ventricular cells; the specific differences in ion channels and mechanisms of polarization give rise to unique properties of SA node cells, most important, the spontaneous depolarizations necessary for the SA node's pacemaker activity.

Answer 2

in human Heartbeat is controlled by conducting system it consists of
1) SAN
2) AVN
3) bundle of his
4) Purkinje fibers

1) SAN : sinoatrial node or pacemaker it is mass of specialised muscle tissue present in the upper part of the right article near the opening of the superior Vena cava it initiatives that Heartbeat and sets the pace hence it is called as a pacemaker
2) AVN : auricular ventricular node it is also specialised muscle tissue present in the lower part of the articular Septum
3) bundle of his this arises from AVN passes into interventricular septum and divides into right and left branches
4) Purkinje fibers : branches of bundle of his divides into number of small branch is called purkinje fibres please fibres penetrate muscle cells of ventricles




$<marquee>hope it may help you be brainly$