What Are the Factors Promoting Venous Return Flashcards

The muscle pump prevents pooling and edema. It also directs blood back towards the heart. It aids in venous return because venous return is the amount of blood going back to the heart from the venous system, so the muscle pump does that. SV is enhanced by increased venous return during exercise.

Cardiovascular drift during steady state exercise is when the heart rate increases gradually. It is greater in heat because while exercising in the heat your heart rate goes up and stroke volume goes down. Stroke volume goes down because water is leaving blood through sweat.

-Heart rate (HR) increases as exercise intensity increases up to maximal heart rate. -Stroke volume (SV) increases up to 40% to 60% VO2 max in untrained individuals and up to maximal levels in trained individuals. -Increases in HR and SV during exercise cause cardiac output (Q) to increase. -Blood flow and blood pressure increase. -Result in increased blood delivery to metabolically active tissue to: -reduce CO2 -bring in fuel as CHO and FAT -bring in O2 -bring in amino acids to build and repair muscle

Arteries narrow and have thicker muscle in walls. Muscle for vasodilatation (blood flow increase) and vasoconstriction (blood flow decrease) allows to control where blood flow goes. Veins do not do this. When you need blood to muscles during exercise the arteries with vasodialte to the muscles, but vasoconstrict to other parts of the body.

During rest, there is blood going to the brain, organs, muscles, heart and skin. During exercise, the blood to the brain decreases, stays the same in the heart, increases in the muscles, decreases to the skin, and decreases to the organs.

Because they have: -increased vagal tone/decreased sympathetic drive -increased blood volume -increased myocardial contractility -increased left ventricular volume

Pressure= Flow*Resistance BP= Cardiac output * total peripheral resistance -resistance due to friction of blood flowing over vessel walls -resistance increased with: -/\ blood viscosity - /\ vessel length - \/ vessel diameter (to the 4^th power)

SBP increases with increases in aerobic workload. -greater pressure generated by heart=greater flow to working tissues -there is a linear relationship between workload and systolic BP -blood flow and pressure are tied to tissues’ needs for nutrients DBP remains fairly constant: pressure during relaxing heart still relaxing during exercise.

Resistance increased with: -/\ blood viscosity: how thin or thick fluid is (more watery, easier to flow) - /\ vessel length: all lengths of the arteries - \/ vessel diameter (to the 4^th power): most important for determining resistance. Because resistance is greater with bigger and smaller vessels, small changes in vessel diameter have large effects on resistance.

Rest: MAP= DBP + [0.333 (SBP-DBP)] Exercise: MAP= DBP + [0.5 (SBP- DBP)]

Because during resistance exercise straining compresses the vessels, peripheral resistance increases, and blood pressure increases in an attempt to perfuse tissues. Also during resistance exercise blood systolic can go over 200, which is why veins pop out of arms and neck (this is okay). During resistance you exhale to reduce the pressure. It requires large increase in systolic blood pressure to maintain blood flow.

It increases during exercise because myocardial blood flow must increase to meet O2 demand. Flow may increase 4-6 times. Oxygen is delivered to the heart by blood in the coronary arteries.

Because SBP is an indicator of the amount of force the heart must generate. HR is the number of times in a minute it does it. Similar to weight lifting (amount of weight lifted * number of repetitions). There for it is the estimated amount of work the heart is doing (force of contraction with number of times the heart is beating per minute) RPP= SBP * HR ßboth increase during exercise (good indicator of how hard the heart is working)

Atherosclerosis is when fat, cholesterol, and other substances build up in the walls of arteries and form hard structures called plaques. It is bad related to death because it increases resistance, which lowers the blood flow. If that builds up too much eventually it will stop blood flow all together. Related to exercise, it will make it so that your muscles cannot get enough blood and oxygen to them, therefore they cannot perform.

It is a block of blood flow in the coronary artery. It is an area of ischemia (reduced blood flow) due to blocked artery.