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level: The circulatory system

Questions and Answers List

level questions: The circulatory system

QuestionAnswer
why do animals have a heart and circulatory system?to pump blood around the body so that oxygen can diffuse into cells for respiration
features of a mass transport systemnetwork of blood vessels to move through blood as the medium of movement controlled direction and speed by the heart
why is a mass transport system important?Overcomes the limitation of diffusion in larger organisms transports substances around the body allows the exchange of substances to occur
properties of waterdipolar molecule contains hydrogen bonds high specific heat cohesive good solvent
why is water dipolar?water has a permanent dipole oxygen atom is more electronegative than hydrogen atoms
why is the polarity of water important?allows other polar molecules and ions to dissolve in water
what is specific heat capacity?the amount of heat required to increase the temperature of 1 gram of matter by 1 degree celsius
why is water's high heat capacity important?helps organisms to maintain a constant temperature which is essential for vital process that occur in the body
why is water cohesive and why is it important?strong attraction between water molecules due to its dipolar nature allows it to flow and transport susbstances
why is water a good solvent?water is polar so polar molecules and ions can dissolve in it
what are the blood vessels?arteries, veins, capillaries transport blood around the body
function of arteriescarry oxygenated blood away from the heart and to the body tissues (except the pulmonary artery)
structure of arteriessmall lumen smooth inner endothelial lining thick layer of smooth muscle cells thick layer of elastic fibre lots of collagen
functions of veinscarry deoxygenated blood from the body to the heart (except the pulmonary vein)
structure of veinswide lumen inner endothelium lining thinner layer of smooth muscle cells and elastic fibres less collagen valves
how is the structure of capillaries related to its function?as it is one cell thick it allows for the easy metabolic exchange of substances
what is the function of the endothelium in blood vessels?the smooth passage of blood through arteries and veins short diffusion distance in capillaries
what is the function of the smooth muscle cells?expand and contract to dilate and constrict the lumen which regulates blood pressure
what is the function of elastic fibres in blood vessels?stretch and recoil to maintain blood pressure
what is the function of collagen in blood vessels?to withstand the high blood pressure generated in the blood vessels provides structural support to the vessels
what is the function of valves?prevents the backflow of blood they only open one way if pressure is higher behind the valve it opens and if pressure is higher in front of the valve it is closed
features of the heartvena cava left and right atria left and right atrioventricular valves left and right ventricles left and right semi lunar valves pulmonary artery pulmonary vein aorta coronary arteries septum cardiac muscle (made of cardiac cells)
what processes are involved in the cardiac cycle?atrial systole ventricular systole diastole
what does the heart do?the muscle at the centre of the circulatory system that pumps blood around the body
what happens during atrial systole?the atria contract AV valves are open and SL valves closed pressure in atria increases blood is pushed into the ventricles
what happens during ventricular systole?ventricles contract AV valves closed, SL valves open pressure in ventricles increases blood is pushed up into the pulmonary artery (right) and aorta (left)
what happens during diastole?heart is relaxed AV valves open pressure in atria begins to increase
how many chambers does the heart have?4 2 atria and 2 ventricles
what does each side of the heart do?the right side pumps deoxygenated blood to the lungs the left side pumps oxygenated blood to the body
why does the left side have more cardiac muscle than the right side?on the left side blood has a longer distance to travel therefore needs to generate higher pressure so that the oxygenated blood can reach all the cells
why is the septum important?it divides the left and right sides it prevents the mixing of oxygenated and deoxygenated blood it maintains the concentration gradient of the blood in each side allowing for efficient gas exchange and diffusion