Cardiovascular centre is detected by baroreceptors in the aortic sinuses or carotid sinuses, the cardiovascular centre affects changes to the heart rate by sending a nerve impulse to the cardiac pacemaker (or SA node) via sympathetic fibres (to cause faster and stronger cardiac muscle contraction) and the vagus nerve (to cause slower and less strong cardiac muscle contraction). The cardiovascular centre also increases the stroke volume of the heart (that is, the amount of blood it pumps). These two changes help to regulate the cardiac output, so that a sufficient amount of blood reaches tissue. Hormones like epinephrine and norepinephrine can affect
Cardiac glycoside the heart does not have to exert as much force to pump the blood, or directly increasing the heart's contractile force, so that the heart can overcome the higher blood pressure. Cardiac glycosides, such as the commonly used digoxin and digitoxin, deal with the latter, due to their positive inotropic activity. On the other hand, cardiac arrhythmia are changes in heart rate, whether faster (tachycardia) or slower (bradycardia). Medicinal treatments for this condition work primarily to counteract tachycardia or atrial fibrillation by slowing down heart rate, as done by cardiac glycosides. Nevertheless, due to questions of toxicity and dosage, cardiac