When a person changes position from standing to lying down, following change is seen:: (A) Hea rate increases, (B) Venous return to hea increases immediately, (C) Cerebral blood flow increases, (D) Blood flow at apices of lung decreases
Answer is B. B i.e. Venous return to hea increases immediately In standing posture, 300- 500m1 of blood pools in venous capacitance vessels of lower extremities, which is immediately returned towards heaQ on assuming lying down posture. Cardiovascular system Onlying On standing - Stroke volume - Cardiac output - Venous return - Central blood pool Increase Decrease - Central venous pressure - Aerial BP - Abdominal & limb flow - Hea rate - Peripheral venous pooling - Total peripheral resistance Decrease Increase - Abdominal & limb resistance - Small vein pressure