1.2 - Cardiovascular And Respiratory Systems Flashcards
What does the pulmonary circuit do?
Carries deoxygenated blood back to the lungs and oxygenated blood back to the heart.
What does the systemic system do?
Carry oxygenated blood to the body and deoxygenated blood back to the heart.
Describe the conduction system. (5)
Sino atrial node generates an electrical impulse and fires it across the atria walls.
This is collected by the AV node which delays it by 0.1 seconds to allow the atria to finish contracting.
The bundle of HIS then collects the impulse and carry’s it to the base of the ventricles via the bundle branches.
The punkijne fibres are found at the bottom of the ventricles.
They distribute the impulse around the ventricle walls to cause contraction.
Describe the atrial systole phase of the cardiac cycle.
Lasts 0.1 seconds
Atria contract to force the remaining blood into the ventricles.
Describe the ventricular systole phase of the cardiac cycle.
Lasts 0.3 seconds
AV valves close, semi lunar valves open, allows blood to leave heart.
Ventricles contract, increasing pressure to close AV valves to prevent back flow into atria.
Semi lunar valves forced open as blood is ejected from ventricles into aorta and pulmonary artery.
What happens in the diastole phase of the cardiac cycle. (5)
Lasts 0.4 seconds
AV valves open, semi lunar valves close in order for chambers to fill.
Pressure in atria increase, opening AV valves.
Blood passively enters the ventricles
Semi lunar valves are closed to prevent blood from leaving the heart.
What is stroke volume
The volume of blood ejected from then left ventricle per beat
What is the average resting heart rate
72bpm
What is venous return
The return of blood to the right atria through the veins
What are the 2 factors that stroke volume is dependant on
Venous return
Ventricular elasticity
What is sub-maximal exercise
Exercise which is a low to moderate intensity within a performers aerobic capacity ie below the anaerobic threshold. Associated aerobically.
What is maximal exercise
Exercise which is at a high intensity above a performers aerobic capacity which will take a performer to exhaustion. It is associated with anaerobic work and fatigue.
Explain the frank starling mechanism
Increased Venous return leads to an increased stroke volume, due to an increased stretch on the ventricle walls and therefore the force of contraction
What are the 3 control mechanisms
Neural control
Intrinsic control
Hormonal control
What is neural control
Chemoreceptors - located in aorta, carotid arteries and muscles - inform CCC of chemical changes eg CO2
Propioreceptors - located in the muscles, tendons and joints inform the CCC of movement or motor activity
Baroreceptors - located in blood vessel walls - inform CCC of change in blood pressure
What is intrinsic control
Increased temperature
Increased venous return