transport in animals

• fish have two chambered hearts and a single circulation, this mean that for one circuit of the body,

  the blood passes once through the heart
• arteries carry oxygenated blood away from the heart, except the pulmonary artery. veins carry de-oxygenated blood.
• there are 4 chambers of the heart; right atrium, right ventricle, left atrium, left ventricle
• deoxygenated blood from the body enters the right atrium, this blood is under low pressure
• blood passes through the right ventricle, which contracts to pump blood to the lungs, where the blood is deoxygenated
• oxygenated blood from the lungs enters the left atrium, thsi blood is still under low pressure
• oxygenated blood enters the left ventricle, which contracts very hard to pump the blood into the aorta artery. the left ventricle is very thick and guarantees high a pressure to pump blood around the whole body
• pathway of blood flow: the blood passes through the vena cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta
• the ventricles have thicker muscle walls then the atria as they have to pump blood out of the heart and so need to generate a higher pressure
• the left ventricle has a thicker muscle wall than, the right ventricle as it is pumping blood at a high pressure through out the body, where as the right ventricle is pumping blood at a lower temp to the lungs
• the septum seperates the two sides of the heart and so prevents mixing of oxygenated and deoxygenated blood
• the basic function of all valves is to prevent blood flowing backwards.

  • the atrioventricular valves separate the atria from the ventricles.
  • the valve in the right side of the heart is the tricuspid, and the valve in the left side of the heart is the bicuspid
  • these valves are pushed open when the atria contracts, and are pushed shut to prevent blood flowing back into the atria when the ventricles contract
• • the semilunar valves are in the two blood arteries that come out of the top of the heart. these arteries are unusual - only 2 that have valves in them
  • this valves open when the ventricles contract, to squeeze the blood past them out of the heart. but contract to avoid blood flowing back into the heart
• an ECG looks at the electrical activity of the heart which is what controls heart activity. sensors attached to the body are coupled with a machine that gives an ECG reading, normal and abnormal activity can be identified.
• an electrocardiogram is device which tracks heart activity, can measure pulse rates via the opening and closing of heart valves
• can check ECG using a stethoscope... can listen to the lub-dub sounds of the heart made my valves opening and closing, this can help identify abnormal sounds