Pacemaker (sinoatrial node)
The heart is divided into four chambers, the left atrium, the left ventricle, the right atrium, and the right ventricle. The two chambers in the upper portions of the heart are the atrium, and the two at the lower portions are the ventricles.
The Perch, like all gilled fish, has a two-chambered heart consisting of a single Atrium and ventricle. De-oxygenated blood is pumped through the heart into the gills, where it becomes oxygenated and then flows to the perch's body tissue through arteries. Atrium-->Ventricle-->gills-->arteries-->body tissue-->veins-->repeat
The largest part of the heart is the left ventricle.
One separating the atrium and ventricle is called atrial septum and ventricular septum respectively.
Probably less than when you got it new!The scar tissue is dead tissue,meaning the nerve endings are no so sensitive as they were when you first did your piercing.
Bundle of His .
sinoartial
The sino-atrial node (SA node) and, specifically the tissue of Bachmann's Bundle located within the SA node.
Buchman's Bundle
Sino-atrial node(SA node), it's also called natural Pacemaker.
Photo-sensitive tissue.
It ia a specialized bit of heart tissue that controls the heartbeat.
The structure of the right atrium is to send blood through an atrioventricular valve to the right ventricle and it's structure is mostly muscle and tissue.
vulva
You may be asking about the sinoatrial node and the atrioventricular node, two nerve bundles that work together to regulate the heartbeat.
No, nervous is an adjective meaning sensitive or excitable.
toilet bowl effect