Purkinje fibres were first described by a Czech physiologist, Jan Evangelista Purkinje in 1839, noting that they had a different structure compared to the working muscle. They are work myocardial fibres, which extend from the Bundle of His to the inner ventricular walls, full beneath the endocardium. Rows of Purkinje cells are connected to make up individually Purkinje fibre, which run along the septum of the heart, separating the right and left ventricles. Their main unravel is to distribute the action potentials originating in the pacemaker to the ventricular cardiac muscle cells causing the ventricles to contract, rather than actually producing the contractile force. They take away action potentials approximately eight times faster than modal(a) cardiac cells.
During the cardiac cycle, an electrical impulse is created at the sinoatrial lymph gland (SAN), located in the right atrium, under the influence of the beneficent branch of the autonomic nervous system. This impulse is propagated across the atria to bear them to contract simultaneously (atrial systole) and is represented on an electrocardiogram (ECG) as the P wave. Next, the impulse travels to the atrioventricular node (AV node), located surrounded by the atria and ventricles.
Once the impulse vexes the AV node, it is delayed there onward being conducted through the fast conduction network of the bunch together of His (located in the septum), down the left and right bundle branches and in conclusion arriving at the Purkinje fibres to the myocardium of the ventricles. The time taken for an impulse from the SA node to reach the Purkinje fibres is represented as the P-R interval on the ECG. This enables the ventricles to contract (ventricular systole) from the bill to the base of the heart in a coordinated mood and allow the blood to exit the ventricles via the aorta and pulmonary artery, which is represented as the QRS complex on an ECG. The T wave of an ECG represents ventricular diastole i.e. the...If you want to get a full essay, order it on our website: Orderessay
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