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The normal venous return of blood flow refers to the amount of blood that is returned to the heart from the veins per unit of time. In a resting individual, the average venous return is approximately 5 liters of blood per minute. This value can fluctuate depending on factors such as physical activity or medical conditions.
Elevation of any edematous (swollen) body part, especially an appendage, decreases inflammation by using gravity to aid venous return of blood back to the heart. In damaged tissue, blood will flow to the area for healing. When the damaged part is elevated, it promotes venous return. For elevation as a purpose of edema reduction to be truly effective, the elevated body part must be higher than the heart. In other words, if you are sitting on a couch with your ankle on a coffee table, that is not true elevation.
Skeletal muscle contractions which pulls the blood back and valves which close after blood has passed through it.
The venous duct connects the umbilical arteries to the liver.
Syndromes related to venous insufficiency are caused by valve incompetence. Venous insufficiency is a chronic (long term) condition
The veins act as a blood reservoir, because of the ease of distending them. 55-60% of blood is in systemic veins which is important for blood pressure. The volume of blood returned to the right atrium of the heart per minute is called the venous return. Generally venous return is equal to cardiac output, due to the closed system of the circulation, except for minor transient periods. A number of factors affecting the venous return are: Smooth muscle: Due to presence of smooth muscle, the diameter of the veins can be altered by sympathetic discharge(normally vasoconstrictive), adrenaline and angiotensin II (cause venoconstriction). But because the diameters of veins are large, venoconstriction has little effect on peripheral resistance. Elasticity of the heart: If the elasticity decreases, then the ability to fill the heart is reduced. valves: one way valves in the veins (not in large veins) ease blood flow to heart. Muscle pump: When muscles, particularly leg muscles contract, the thin walled veins are squeezed and the blood is forced towards heart, when muscles relax, blood enters the veins, but only from the arterial side. This is an important mechanism for facilitating venous return. Respiratory pump: Breathing in causes negative pressure in thorax causing a suction effect, i.e. the pressure gradient pushing blood towards the right atrium is increased, thus more blood returns to the heart, which means that inspiration leads to an increase in venous return. The opposite occurs with expiration, and venous return is decreased. Gravity: Opposes return of blood from the periphery during sitting or standing. The effect is lost when we lie down. Blood pressure at venous end of capillary: An increased pressure at the venule end of the capillary reduces venous return, because the pressure difference between the right atrium and the peripheral veins is reduced. Similarly a decrease in pressure at the venule end would increase venous return. Right atrial pressure: Is the inflow pressure for the heart. It is a function of the amount of blood returned to the heart and the pumping ability of the heart. Its value at rest is normally close to zero but can also become negative (between -4 to 5 mmHg). Its value is increased by blood volume, a weak heart, rapid increase in venous return. Its value is decreased by lower blood volume and a strong heart. The lower the pressure the greater the venous return (due to suction effect), but there is a limit to the increase in venous return because veins are collapsible.
Valves aid in venous return by preventing the back flow of blood.
No, lift legs for venous return. Make sure legs are above heart. You do this for shock or bleeding.
pressure gradient , gravity , skeletal muscle pump, thoracic pump and cardiac suction would be the mechanisms for venous return.
increase venous return
because the endothoracic pressure is decreased and the venous return to the heart is increased.
Return blood, most likely, refers to the venous blood that is returned to the heart.
wht?
contractility
SV = EDV - ESV Therefore, stroke volume is greatest when venous return is increased. By 1st year paramedic science student.
venous insufficiency
The Valsalva maneuver to increase thoracic pressure illustrates the effect of external factors on venous pressure.