Cardiovascular centre the cardiovascular centre and cause it to increase the rate of impulses sent to the sinoatrial node, or pacemaker, resulting in faster and stronger cardiac muscle contraction and thus increasing the heart rate. Cardiovascular centre The cardiovascular centre is a part of the human brain responsible for the regulation of the rate at which the heart beats through the nervous and endocrine systems. It is found in the medulla oblongata. Normally, the heart beats without nervous control, but in some situations (e.g., exercise, body trauma), the cardiovascular centre is responsible for altering the rate at which the heart beats. It
Cardiac action potential membrane potential Ionic pumps as discussed above, like the sodium-calcium exchanger and the sodium-potassium pump restore ion concentrations back to balanced states pre-action potential. This means that the intracellular calcium is pumped out, which was responsible for cardiac myocyte contraction. Once this is lost the contraction stops and myocytic cells relax, which in turn relaxes the heart muscle. During this phase, the action potential fatefully commits to repolarisation. This begins with the closing of the L-type Cachannels, while the K channels (from phase 2) remain open. The main potassium channels involved in repolarization are the delayed rectifiers (I) and (I)