Structure of the heart

• Thick muscular wall...


  cardiac muscle
• 2 properties of the cardiac muscle 


  it never fatigues as long as it is getting oxygen and glucose. It is also myogenic this means it can contract and relax without any hormonal or nervous stimulation
• The artia have thin muscular walls...why


  because they don't need to contract much as they just need to transfer the blood into the ventricles which is not that far away
• why do atria have elastic walls

  so that they can stretch back, so enough blood enters
• the ventricles have thick muscular walls...why

  they need to contract more as they need to pass the blood to the arteries which are a further distance away
• why does the right ventricle have thinner muscular walls compared to the left ventricle

  this is because they need to pump blood at a lower pressure. This is so that the capillaries in the lungs don't get damaged. And also so that blood flow is slow, so that there is enough time for gas exchange
• why does the left ventricle have thicker muscular walls compared to the right ventricle

  they need to pump blood at a higher pressure, ensuring that all the cells in the body get oxygen
• 2 types of veins

  VENA CAVA and the PULMONARY VEIN
• VENA CAVA


  it carries deoxygenated blood from the body to the right atrium
• PULMONARY VEIN 


  It carries oxygenated blood from the lungs to the left atrium
• 2 types of arteries

  PULMONARY ARTERIES and AORTA
• PULMONARY ARTERY 


  It carries deoxygenated blood from the right ventricle to the lungs, where it can gain oxygen and become oxygenated
• AORTA


  it carries oxygenated blood from the left ventricle to the rest of the body
• Role of valves 


  it ensures that blood flows in one direction
• How valves work

  when there is a high pressure of blood behind, the valves open. When there is a high pressure of blood in front, the valves close
• 2 types of valves

  atrioventricular valves and semi-lunar valves
• the valve between the right atrium and the right ventricle is called..

  tricuspid valve
• the valve between the left atrium and the left ventricle is called...

  bicuspid valve
• the valve between the left atrium and the left ventricle is called...

  bicuspid valve
• tricuspid valve is made from...

  3 flaps
• the bicuspid valve is made from..

  2 flaps
• the semilunar valve is found between..

  the aorta and the pulmonary artery
• 2 names of the semi-lunar valve

  aortic valve and the pulmonary valve
• Septum

  it separates the oxygenated blood and the deoxygenated blood. This is so that there is high concentration of oxygen in the oxygenated blood, to maintain a concentration gradient so that oxygen can diffuse into the cells.
• why do the right ventricles have thinner muscular walls


  they require smaller contractions to generate a lower blood pressure this is so that the capillaries in the lungs do not get damaged and so that blood flow is slow so that there is enough time for gas exchange