transport systems in animals

• the blood is made from plasma , red blood cells , white blood cells , platelets
• blood transports nutrients , oxygen , co2
• red blood cells contain haemoglobin which attatch's with oxygen to be oxyhaemoglobin
• white blood cells - phagocytes move towards , engluf and digest pathogens
• white blood cells - lymphocytes produce antibodies specific to a pathogen . antibodies attach to pathogens antigens and destroy them
• the heart - unoxygenated blood from the body flows from the vena cava to right atrium to right ventricles and to the lungs from the pulmonary artery collecting oxygen returning through the pulmonary vein to the left atrium into the left ventricle and through the aorta to the body
• the heart is supplied with blood from the coronary artery
• veins have a thin muscular wall and wide central channel at low pressure , they have valves to stop the backflow of blood
• arteries have a thick muscular wall , a narrow central channel , high pressure
• capillaries have thin walls and large surface area allowing maximum gas exchange between blood and cells