Question

Write the full form of SAN. What is its other name?

Answer 1

Hint: The heart is a muscular organ the size of a fist that is made up of cardiac muscles. The cardiovascular system is made up of the heart, blood, and a network of arteries, veins, and other blood vessels. Because it is the motor or pumping organ that helps circulate blood throughout the body as needed, the heart is the most important structure of the circulatory system.
The heart is protected by a thick wall called the pericardium and is placed in the thoracic cavity between the lungs. It has four chambers: right and left atria, as well as left and right ventricles. Atria are the upper chambers, and ventricles are the lower chambers.

Complete answer:
Full form of SAN is a Sino-atrial node. It is also known as a pacemaker.
The two nodal tissues present in the human heart are the Sino-atrial node (SA node) and atrioventricular node (AV node), which are primarily involved in assisting the heart in producing its own action potential (impulses). The contraction of cardiac muscles (heart muscles) and the pumping of blood are caused by this action potential. SA nodes produce around 70-75 impulses each minute, which keep the heart pumping in time. As a result, SA nodes are referred to as pacemakers.
The sinoatrial node is a collection of cells found in the heart's right atrium wall. These cells have the ability to produce an electrical impulse on their own, which passes via the electrical conduction system and causes the heart to contract. The SA node, also known as the heart's natural pacemaker, continuously produces action potentials in a healthy heart, setting the heart's rhythm. Nerves that supply it regulate the rate at which action potentials are produced.
The SA node is found in the right atrium's wall, laterally to the superior vena cava's entry, in a location known as the sinus venarum. It is roughly halfway between a groove on the inside surface of the heart called the crista terminalis and the corresponding sulcus terminalis on the external surface.

Note:

SA NODE	AV NODE
It is present in the right atrium near the opening of the superior vena cava.	It is present in the right atrium at the base of interatrial septum.
Larger in size	Smaller in size
It has maximum rhythmicity.	It has less rhythmicity than the SA node.
Also known as pacemaker.	Also known as pacesetters.
Function regulated by cardiac centre.	Function stipulated by cardiac impulses.