Adrenaline, secreted into the blood, accelerates the heart rate, increasing oxygen supply to muscles. It also causes the contraction of muscles around small arteries in the digestive system and skin, redirecting blood flow to skeletal muscles.
How does adrenaline influence the heart, and what are the physiological effects on blood circulation during a stressful situation?
Share
Adrenaline influences the heart by binding to beta-adrenergic receptors on cardiac cells. This binding increases the heart rate (chronotropy), the force of contractions (inotropy), and accelerates electrical conduction (dromotropy). These effects collectively enhance cardiac output. Simultaneously, adrenaline causes vasoconstriction in certain blood vessels, directing blood towards vital organs and muscles. This, combined with increased cardiac output, elevates blood pressure. Consequently, during a stressful situation, adrenaline optimizes blood circulation by improving oxygen delivery to essential tissues, enhancing alertness, and preparing the body for physical exertion, all essential elements of the fight-or-flight response.