3.4.1: Structure of the circulatory system Flashcards
What is mass flow
molecules are carried in the flow of the blood plasma
What are the 3 factors that make up a circulatory system
pump, transport fluid, series of tubes
do mammals have a circulatory system and why? do plants have a circulatory system and why?
mammals: yes circulatory system as heart = pump, transport fluid = blood plasma, tubes = blood vessels
plants = no pump and so no circulatory system
what are the two types of circulatory system
single and double (birds, crocs, mammals)
describe how a single circulatory system works
heart only transports deoxygenated blood, blood passes through heart once per cycle, oxygenated blood goes directly from gas exchange surface to body tissues
describe how a double circulatory system works
left side of heart transports oxygenated blood, right side of heart transports deoxygenated blood. Blood passes through heart twice per cycle. Oxygenated blood from gas exchange surface passes through heart before going to tissues
explain how double circulation works in a mammal
pulmonary veins transport oxygenated blood from lungs to heart, then the systemic arteries transport oxygenated blood from heart to body tissue. Systemic veins transport deoxygenated blood from body tissue to heart, then the pulmonary arteries transport deoxygenated blood from heart to the lungs
describe the external structure of the heart
aorta, coronary artery, pulmonary veins (all transport oxygenated blood). vena cava, coronary vein, pulmonary artery (all transport deoxygenated blood)
describe the full structure of the heart
aorta, semi-lunar valves, left pulmonary artery, pulmonary vein, left atrium, left ventricle, bicuspid atrioventricular valves, superior vena cava, right pulmonary artery, right atrium, inferior vena cava, right ventricle, tricuspid atrioventricular valves, valve tendons
what is the difference in the left side of the heart to the right and the ventricle wall thickness
left ventricle walls are thicker than right ventricle walls, so left side of the heart is bigger than the right
where is the semi lunar valve
valve between ventricles and arteries - only opens one way
where is the atrioventricular valve
valve between atrium and ventricle, left side is called bicuspid, right side is called tricuspid
what is the function of the semilunar and atrioventricular valves and also the valve tendons
to prevent the backflow of blood. Valve tendons prevent the a.v. valves from inverting
what is the role of the coronary arteries and coronary veins
coronary arteries supply oxygenated blood to the cardiac muscle - the heart
coronary veins take deoxygenated blood away from the heart
explain why the bicuspid often ceases to work effectively and has to be replaced and why the tricuspid rarely needs replacing
the bicuspid valve is exposed to higher pressure from the left ventricle as the left ventricle has thicker walls and so can pump blood at a higher concentration
