A standing person lies down. Which of the following occurs?
Increase in cerebral blood flow
Immediately increase in venous return to heart
Decreased blood flow to the apex of lung
Increase in heart rate
Ans. b. Immediately increase in venous return to heart (Ref: Ganong23/e p515)Factors Affecting End Diastolic VolumeFactors Decreasing EDVFactors Increasing EDV* Increased intra-pericardial pressureQ (as a result of infection of pressure from a tumor):- Limits the extent to which ventricle can fill* Decrease in ventricular complianceQ:- Increase in ventricular stiffness produced by Ml, infiltrative disease.* Standing decreases venous returnQ* Increased total blood volume increases venous returnQ:- Constriction of vein reduces the size of venous reservoir, decreasing venous pooling and thus increasing venous return* Increased negative intrathoracic pressureQ:- Increases the pressure gradient along which blood flows to the heart* Muscle activityQ: Increases venous return as a result of pumping action
Circulation: Cardiac Output, Venous Return