Nodalvävnaden

Nodalvävnaden, also known as nodal tissue, refers to specialized cardiac muscle cells in the heart responsible for initiating and conducting electrical impulses. These impulses regulate the heart's rhythmic contractions, ensuring efficient blood circulation. The primary components of the nodal system are the sinoatrial (SA) node and the atrioventricular (AV) node.

The SA node, often called the heart's natural pacemaker, is located in the upper wall of the right atrium. It spontaneously generates electrical impulses at a regular rate, typically between 60 and 100 beats per minute in a healthy adult at rest. These impulses then spread across the atria, causing them to contract and pump blood into the ventricles.

Following atrial contraction, the impulse reaches the AV node, situated in the interatrial septum near the junction of the atria and ventricles. The AV node briefly delays the impulse before transmitting it to the ventricles. This delay is crucial as it allows the atria to completely empty their blood into the ventricles before the ventricles contract.

From the AV node, the electrical signal travels through the bundle of His, which branches into the left and right bundle branches. These branches further divide into Purkinje fibers that extend throughout the ventricular walls. This intricate network ensures that the ventricles contract in a coordinated manner, efficiently propelling blood to the lungs and the rest of the body. Any disruption to the nodalvävnaden can lead to arrhythmias, or irregular heartbeats.