1.1 PE-Sports Physiology-Cardiovascular system

What are the 4 valves in the heart?

What are the 4 valves in the heart?

• Tricuspid valve - between right atrium and right ventricle

• bicuspid valve - between left atrium and left ventricle

• 2 semilunar valves - between right ventricle and the pulmonary artery and also between left ventricle and aorta

Describe the cardiac conduction system?

• SA-node generates an impulse which spreads through the arterial walls causing atrial systole

• Impulse is received at AV-node where it is delayed for 0.1 to allow for atrial systole to finish

• Impulse is then sent down the bundle of HIS to the purkinje fibers where ventricle systole occurs

What do Chemoreceptors, Baroceptors and proprioceptors measure

• Chemoreceptors-CO2 levels

• Baroreceptors - blood pressure

• proprioceptors - muscle movement

What is Starling’s law of the heart?

Increased venous return → Greater diastolic filling of the heart → cardiac muscle stretched → more force of contraction → increased ejection fraction

What is stroke volume?

The volume of blood pumped out by the heart ventricles in each contraction

What is venous return?

Amount of blood which returns to the heart through the veins

What are the venous return mechanisms?

• Smooth muscle

• respiratory pump

• Skeletal pump

• Valves

• Gravity (above heart)

What is the equation for cardiac output?

Cardiac Output=Stroke Volume X Heart rate

What is Cardiac Hypertrophy?

Cardiac muscle tears and is then repaired and built back stronger and bigger

What is cardiovascular drift?

Cardiovascular drift occurs after a period of steady state exercise --> Heart rate increases --> stroke volume decreases --> because fluid is lost as sweat --> resulting in a reduced plasma volume --> reduced venous return --> cardiac output also increases due to more energy needed to cool body/ sweat

What causes the Bohr shift?

• Increase in blood temperature

• Decrease in blood pH

• pCO2 increases

What is the vascular shunt mechanism?

The redirecting of blood flow towards the places it is needed the most

What is vasodilation?

The widening of the blood vessels around the working muscles during exercise to increase the amount of O2reaching the working muscles

What is vasoconstriction?

The tightening of the blood vessels during exercise to decrease the amount of O2 reaching the involuntary muscles. like the liver and stomach

What is A-VO2 difference?

The amount of O2 which is taken in by the muscles for aerobic respiration.