Heart

• Components of blood


  plasma, platelets, red blood cells, white blood cells
• Plasma


  Liquid part of blood
• Platelets


  blood clotting
• red blood cells


  carry oxygen
• white blood cells


  fight infection
• Arteries

  carry blood away from the heart to the organs, generally oxygenated blood
• How are arteries adapted to their function?

  the walls stretch and recoil because of their elastic and muscular layer. the blood in the arteries is under high pressure. Narrow lumen helps maintain high pressure
• Veins


  carry blood from the organs back to wards the heart,generally deoxygenated
• How are veins adapted to their function?

  they have 'watch pocket' valves to prevent back flow
• Capillaries


  carry blood through the organism bringing the blood close to every cell in the organ
• How are capillaries adapted to their function?

  they are permeable, so substances are transferred between the blood and cell. their walls are only one cell thick
• what substances are transported in the blood?

  Oxygen, carbon dioxide, glucose, urea
• where do the substances in the blood diffuse in and out?

  cells
• factors that make coronary heart disease more likely

  obesity, lack of exercise, smoking and vaping, age, high blood pressure, stress
• systole


  Contraction of the heart
• Diastole


  Relaxation of the heart
• Receptor


  detect an increase in CO2 depending on how much you respire
• sinonatrial node


  pacemaker of the heart
• largest artery in the body

  aorta- it carries oxegenated blood to the whole body from the heart
• Why is the left ventricle thicker than the right?

  The left ventricle must pump blood throughout the entire body, so there is more pressure whereas the right only has to go to the lungs.
• which way do the ventricles contract


  bottom to top
• What is heart rate controlled by?

  controlled by the nervous system, and can be increased by things like caffeine and stress
• Adaptations of red blood cells

  biconcave shape for a large surface area, no nucleus so there is more space for more haemoglobin, small and flexible so they can fit through narrow blood capillaries, thin so there is a short distance for the oxygen to diffuse to reach the center of the cell
• Haemoglobin


  the red pigment that carries oxygen around the body in the red blood cells
• Oxyhemoglobin


  Hemoglobin combined with oxygen, when oxygen diffuses into red blood cells at the lungs
• what happens to red blood cells in a capillary bed?

  blood in the capillary bed becomes deoxygenated
• 4 factors that help blood clotting

  platelets, clotting factors, fibrin, other cells
• fibrin

  an insoluble protein formed from fibrinogen, which is soluble during the clotting of blood.
• how is a blood clot formed?

  • when the skin is broken platelets arrive
  • platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin
  • this forms an insoluble mesh across the wound
  • red blood cells become trapped -> clot
  • clot dries and becomes scab
• infections


  a condition that occurs when pathogens enter the body, multiply, and cause harm
• Phagocytes


  White blood cells that attack invading pathogens
• Lymphocytes


  wbc that produces anti bodies
• pulmonary artery


  Carries deoxygentated blood from the heart to the lungs
• pulmonary vein


  carries oxygenated blood from the lungs to the heart
• deoxygenated blood


  contains more CO2, so it is more acidic, because it dissolves in blood plasms
• oxygenated blood


  has less carbon dioxide and more oxygen
• pulmonary circuit


  system of blood vessels that carries blood between the heart and the lungs
• systemic circuit


  Circuit of blood that carries blood between the heart and the rest of the body.
• Aorta


  carries blood from the left ventricle to the body
• vena cava


  the largest vein in the body, it carries blood from the body back to the heart.