Cardiorespiratory System Flashcards
Systole
Term used to describe the contraction phase of the cardiac cycle. The ventricles contract and pump blood to the arteries
Diastole
The relaxation phase of the cardiac cycle
Stroke volume
The volume of blood that leaves the heart during each contraction
Cardiac output
The amount of blood the heart pumps out. Measured in Litres per minute
Q = SV x HR
Anticipatory rise
Slight increase in heart rate usually before activity starts due to the expectation of exercise
How does exercise improve physical health
Cardiac muscle surrounds heart making it stronger More red blood cells Lungs get stronger Reduce risk of disease Higher metabolism
What is the pathway of blood in order
Vena cava Right atrium Tricuspid valve Right ventricle Pulmonary semilunar valve Pulmonary artery Lungs Pulmonary vein Left atrium Bicuspid valve Left ventricle Aortic semilunar valve Aorta Body
Trained person
High red blood cell concentration Cardiac hypertrophy increases heart size Increased stroke volume Increased haemoglobin so more oxygen can attach Low resting heart rate Fast return to resting heart rate
Untrained person
Higher resting heart rate
Takes longer to return to resting heart rate after exercise
More prone to disease and health issues
Lower stroke volume
Order of cardiac conduction system
SAN Atrial systole AVN Ventricle systole Bundle branches Bundle of his ..
Venous return
The return of blood to the right side of the heart via the vena cava
Starling’s law
The more blood that is returned to the heart, the more blood that is ejected. Higher venous return leads to greater diastolic filling meaning the cardiac muscle is stretched leading to a greater force of contraction, resulting in bigger stroke volume.
The 6 venous return mechanisms
Skeletal muscle pump Respiratory pump Pocket valves Smooth muscle in vein walls Gravity Suction pump action of the heart
Skeletal pump
Muscles contract and change shape which puts means muscles put pressure on veins causing and pump/squeeze effect
Respiratory pump
Muscles contract and relax as we breathe in and out meaning pressure changes in stomach and chest puts pressure on veins to pump blood
