Exercise Physiology Flashcards
Which region of the brain controls the cardiovascular system?
The medulla
What does the medulla do in relation to the SA node and how is this node stimulated?
The medulla changes the firing rates of the pacemaker which sends signals to the atria causing them to contract. This is stimulated by sympathetic and parasympathetic nerves.
Describe the route that blood takes through the heart starting with blood leaving the heart, making reference to vena cava, pulmonary arteries and veins, atriums and ventricles.
Blood leaves the heart through the aorta and is transferred around the body. Blood returns via superior and inferior vena cave veins. The blood is transferred into the right atrium. The blood moves through to the right ventricle due to the contraction of the atrium and the opening of the tricuspid valve. From the ventricle the blood is pushed through the pulmonary artery which takes it to the lungs to collect more oxygen. From here the blood is transferred into the left atrium via the pulmonary vein. It then passes the bicuspid valve entering the left atrium which is then contracted pushing blood through the aortic valve into the aorta.
What is myocardium and why does this affect the left ventricle more than any other area of the heart?
Myocardium is the muscular tissue of the heart. This is predominant in the left ventricle due to the requirement for the ventricle to contract with a greater force than the other areas of the heart.
What is the difference between diastole and systole?
Diastole is the relaxation phase of a heartbeat in which chambers fill with blood. Whereas systole is the contraction phase of a heartbeat in which chambers release/pump blood.
In relation to the intrinsic conduction system describe the path taken from a signal beginning at the medulla and ending with the ventricles contracting.
The medulla sends a signal to the SA node, which causes the atria chambers of the heart to contract. When they contract this sends an impulse to the AV node which travels down the bundle of hiss. The signal is then picked up by purkinje fibres which are found in the inner walls of the ventricles causing them the contract thus pushing blood around the body.
What are the 5 different networks blood can take around the body, and give description of their structure?
Arteries - thick with lots of smooth muscle tissue
Arterioles - thinner than arteries
Capillaries - one cell thick to allow materials to be passed through them
Venules - thicker than capillaries
Veins - thicker than venules with small amount of smooth muscle
