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Larger lumens of veins with valves, Skeleton muscle activity and Respiratory pump
Three factors that are important in promoting venous return are:
1. Intact system
2. Good pump - valves - size of vessels - PR
3. Breathing - respiratory pump
Wiki User
∙ 11y ago
Wiki User
∙ 10y agoRepiratory pump, veins with valves, and skeletal muscles acting as pumps.
("Watch pocket" valves and skeletal muscle pumps.)
Wiki User
∙ 14y agoThree factors that are important in promoting venous return are:
1. Intact system
2. Good pump - valves - size of vessels - PR
3. Breathing - respiratory pump
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What will the venous return be if the cardiac output is 7.5 liters?
Venous return must always match cardiac output. So a CO of 7.5 l/m mill mean a VR od 7.5 l/m
What is the functional nature of a portal system and how does it differ from normal venous return flow?
In a portal system, blood flows from a capillary bed through veins to another capillary bed. It differs from normal venous return because it is not taken straight to the heart.
What increases venous return?
According to Starling's law, an increase in venous return (i.e. increase in preload on the ventricles) results in a more effective contraction, hence augmenting cardiac output, as long as the actin and myosin fibrils in the muscle fibers are not overstretched. In the most simple terms, the more blood the heart collects blood from venous return, the more it is able to distribute through cardiac output. If venous return is poor, cardiac output will be poor- basically like a water pump that is connected to an insufficient supply of water.
How does venous return impact the quality of performance?
venous return is the blood returning to the heart. Which means that the more blood is pumped out, the more returns. Starling's Law states that stroke volume is dependent upon venous return, therefore, if VR increases, SV increases, or, if VR decreases, SV decreases as well. So, the healthier the heart is, it pumps more blood providing the oxygen needed in the body for muscles to work. The faster the blood provides the oxygen, your body would have more oxgyen, this means that there would be less oxygen debt at the end of the event or game.
What Venous system that carries digested materials?
The Portal Venous System
What is the most important factor is helping blood return to the heart through the venous system?
Skeletal muscle pump
What is the function of venous valves?
Valves aid in venous return by preventing the back flow of blood.
Tip the bed head down for venous return?
No, lift legs for venous return. Make sure legs are above heart. You do this for shock or bleeding.
How does the venous return mechanism work?
pressure gradient , gravity , skeletal muscle pump, thoracic pump and cardiac suction would be the mechanisms for venous return.
What is a normal venous return of blood flow?
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.
What increases stroke volume?
increase venous return
Why the jugular venous pressure falls during inspiration?
because the endothoracic pressure is decreased and the venous return to the heart is increased.
What are 3 important factors affecting stroke volume?
Venous return controls EDV (end diastolic volume) and thus stroke volume and cardiac output. Venous return is dependent on: - blood volume and venous pressure - vasoconstriction caused by the sympathetic nervous system - skeletal muscle pumps - pressure drop during inhalation
What is return blood?
Return blood, most likely, refers to the venous blood that is returned to the heart.
What two things aide venous return within the body?
wht?
What factor affecting stroke volume is determine by venous return?
contractility
What does the venous return depend on?
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.
