Cardiac Conduction System and Vitamin B12

Running head: BIOSCIENCE ASSIGNMENT
BIOSCIENCE ASSIGNMENT
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BIOSCIENCE ASSIGNMENT
Question 2:
A. The important components that form of the cardiac conduction system include the SA
node, AV node, bundle of His, bundle branches, and Purkinje fibers. Studies state that
the SA node is the collection of the specialized cells called the pacemaker cells and is
mainly located in the upper wall of the right atrium at the junction region where the
superior vena cava is found to enter (Rigo, 2017). The atrioventricular node is mainly
seen to be located within the atrioventricular septum and is located near the opening of
the coronary sinus. The atrioventricular bundle is mainly the continuation of the
specialized tissue of the AV node. It mainly helps by serving and transmitting the
electrical impulse from that of the Av node to that of the Purkinje fibers of the ventricular
region. The Purkinje fibers are the network of the specialized cells that are abundant with
that of glycogen and have extensive gap junctions. The SA node also called the
anatomical pacemaker mainly begins the sequence by making the atrial muscles to
contract. From this region, the signals are seen to travel to the AV node and it takes its
pathway through the bundle of His and then moves down the bundle branches. The
signals are then seen to move through the Purkinje fibers and this makes the ventricle to
undergo contraction.
B. At first, the excitation signal also called an action potential is created by SA node. Then,
the wave of excitation spreads across the atria and thereby it causes them to contract. The
Sa node is located in the upper wall of the right atrium and is composed of nodal tissue
that has characteristics of both nervous tissue and muscles. The signal upon reaching to
the atrio-ventricular node gets delayed for about a tenth of a second. This delay is seen to
allow the atria in contracting and emptying their contents into the ventricular region prior