Explanations if anyone needs it:
Path the blood takes through the heart - deoxygenated blood enters the right atria via the vena cava, it then passes through into the right ventricle where it goes to the lungs via the pulmonary artery, in the lungs oxygen diffuses into the blood stream and carbon dioxide diffuses out, the oxygenated blood then travels via the pulmonary vein to the left atria, then into the left ventricle, where it flows out to the rest of the body via the aorta.
Pacemakers/artificial pace makers - the heart has a group of cells in the right atria called pace maker cells which generate small electrical impulses to stimulate the heart muscles to contract and beat. Artificial pacemakers are small electrical devices that are put into the heart via surgery that do the same role as the pacemaker cells.
Mechanical and biological valves -
why people need replacements: leaky valve allowing back flow of blood, stiff valves not allowing enough flow of blood
mechanical valves: made of strong materials, patient needs to take blood thinners to prevent blood clotting on it so they may have other health issues such as easy bruising or excessive bleeding when cut
biological valves: usually taken from an animal e.g a pig so has religious and ethical concerns, they may wear out
Coronary heart disease -
what it is: caused by a build up of fatty materials in the coronary arteries which lead to restricted flow of blood to the heart muscles
treatments: statins which lower the amount of bad cholesterol in the blood stream to prevent build up of fatty materials and also increase levels of good cholesterol, eating a healthier diet e.g low in fats
Blood vessels -
arteries: take oxygenated blood from the heart around the body, have thick walls with elastic fibres and a smaller lumen than veins to help them deal with the high pressure that blood is pumped out of the heart at
veins: thinner walls than arteries as the blood is at a lower pressure, has a wide lumen
capillaries: very thin (one cell thick) to allow efficient exchange of substances e.g oxygen and carbon dioxide
components of the blood -
plasma: a straw coloured liquid that holds the other components and has dissolved substances such as urea, digested food molecules, urea, and carbon dioxide in it.
red blood cells: large surface area and no nucleus to maximise space for haemoglobin(red pigment), haemoglobin reacts with oxygen to form oxygen oxyhemoglobin and transports it around the body
white blood cells: part of the immune system, produce antibodies and antigens, do phagocytosis
platelets: small fragments of broken cells that help clot blood at the site of an injury