Question

John lacerates his radial artery while cutting a bagel. He loses approximately one-fourth of his blood volume before arriving at the hospital. What physiological responses do you expect in response to this blood loss?

Answer 1

The blood loss will be detected as drop of the blood pressure in the aryerioles and venules. The Baroreceptors there sense the the pressure difference drop and sends signal make sympathetic system active making the blood vessels constricted. The flow of the blood is reduced in certain areas bconstruction of venous capacitance vessels and the cutaneous and splanchnic arterial beds. This will make the skin pale coloured. This decrease the preload. In order to increase the blood supply to different regions the heart rate increases. The blood pressure is increased by increasing the diastolic pressure. The systemic resistance is increased by constricting blood vessels. The vasopressin is increased and the blood reabsorption is done as much as possible to maintain the fluid in the body. In kidneys the renin angiotensin Aldosterone system activates and the aldosterone later produced will make the water retention in the body and thus maintain the blood volume