what are purkinje fibres and bundle of his
Answers
The AV node tapers down into the bundle of His, which passes into the ventricular septum and divides into two bundle branches, the left and right bundles. Sometimes the 'left and right bundles of His' are called Purkyně or Purkinje fibers.
Purkinje fibers are a unique cardiac end-organ. Further histologic examination reveals that these fibers are split in ventricles walls. The electrical origin of atrial Purkinje fibers arrives from the sinoatrial node.
The bundle of His and its Branches Conduct the Impulse to the Apex of the Heart
The bundle of His and its Branches Conduct the Impulse to the Apex of the HeartThe bundle of His consists of wide, fast-conducting muscle fibers that carry the cardiac impulse through the insulating annulus fibrosus into the fibrous upper part of the ventricular septum. There, it becomes the left bundle branch and the right bundle branch. The right bundle branch travels along the right side of the septum and supplies excitation to the right ventricle. The left bundle branch is really two sets of fibers, one anterior and another posterior. These course down the left side of the septum and supply the left ventricle. The bundle fibers terminate in an extensive network of large fibers called Purkinje fibers. These fibers conduct the impulse at high velocity, 3–5 m s−1. They distribute the impulse to the subendocardium, the layer of cells beneath the endocardium. The endocardium lines the cavities of the heart.