Question

The action potential is conducted from the atria to ventricles by:
A. Purkinje fibre
B. SA node and AVN
C. Bundle of his and SAN
D. All of the above

Answer 1

The heart is a muscular organ that circulates a large amount of blood in animals throughout its lifespan. It is made up of auricles and ventricles. It consists of a cluster of cells situated in the upper part of the wall of the right atrium that performs the action potential in the heart.

Complete answer: In the right upper corner of the right atrium is situated the sino-atrial node (SA node), and AVN (AV node) is located near the atrioventricular septum in the lower-left corner of the right atrium. The SAN can produce the full amount of energy for intervention, i.e. 70-75 per min, and is responsible for activating and sustaining the heart's rhythmic contractile function. Thus, it is called the pacemaker of the heart. From the SA node, AVN conducts the action potential from the atria to the ventricles. Therefore through SA node and AVN, the action potential is conducted from the atria to ventricles. The cardiac cycle is the human heart's performance from the end of one heartbeat to the start of the next. It consists of two periods: one during which, after a duration of robust contraction and pumping of blood, the heart muscle relaxes and refills with blood called diastole, nicknamed systole.
So, the correct answer is option B.

Note: Cardiovascular development occurs between 3 and 6 weeks after ovulation in a human embryo. The first indication of autonomous heart operation that can be investigated using non-invasive methods such as doppler ultrasound is the cardiac function. Fetal hemodynamics are determined by the heart and placenta as the primary organ.