NEET BIOLOGY

Detailed explanation-1: -The sinus node continuously generates electrical impulses, thereby setting the normal rhythm and rate in a healthy heart. Hence, the SA node is referred to as the natural pacemaker of the heart.

Detailed explanation-2: -The SA (sinoatrial) node generates an electrical signal that causes the upper heart chambers (atria) to contract. The signal then passes through the AV (atrioventricular) node to the lower heart chambers (ventricles), causing them to contract, or pump. The SA node is considered the pacemaker of the heart.

Detailed explanation-3: -The sinus node, the natural pacemaker of the heart, is located in the heart’s upper chamber, called the atrium. It is responsible for initiating the electrical impulse that travels through the heart, causing it to beat in a regular rhythm and heart rate.

Detailed explanation-4: -The heart is made up of four chambers-two upper (atria) and two lower (ventricles). The rhythm of the heart is typically controlled by the sinus node, an area of specialized cells in the right upper heart chamber (right atrium). This natural pacemaker produces electrical signals that trigger each heartbeat.

Detailed explanation-5: -The sinus node generates an electrical stimulus regularly, 60 to 100 times per minute under normal conditions. The atria are then activated. The electrical stimulus travels down through the conduction pathways and causes the heart’s ventricles to contract and pump out blood.