mass transport

• affinity


  how easily harmoglobin binds with oxygen and how tightly it holds onto oxygen
• saturation


  how many haem groups are associated with oxygen
• partial pressure


  a measure of the concentration of a gas
• loading


  haemoglobin associating with oxygen
• unloading 


  haemoglobin disassociating with oxygen
• oxyhaemoglobin dissociation curve

  • first oxygen molecule binding difficult due to haemoglobin's condensed structure
  • second and third oxygen binds easier as haemoglobin structure is relaxed, exposing haem groups
  • more difficult for last oxygen molecule to associate as it needs to find last available haem group

  
• the Bohr effect

  1. (higher PP) CO2 is released during respiration, CO2 dissolves in blood plasma making blood more acidic. this causes haemoglobin to denature, relaxes the structure, lowers affinity for O2 so O2 is unloaded and released in tissues
  2. (lower PP) gas exchange removes CO2 from blood, reducing blood acidity. haemoglobin shape changes back. increases affinity for O2 so it takes O2 from air in lungs and holds onto it

  
• what happens at high altitudes


  lower atmospheric concentration of oxygen at higher altitudes, so the body releases erythroppeitin hormone which causes bone marrow to produce more red blood cells
• heart

  .

  A) pulmonary artery

  B) vena cava

  C) right atrium

  D) semi-lunar valve

  E) right ventricle

  F) aorta

  G) pulmonary vein

  H) left atrium

  I) atrioventricular valve

  J) left ventricle

  K) septum

  
• how does the atrias structure reflect its function


  it is has thin and elastic walls, so can stretch as blood is collected
• ventricle function


  pump blood away from the heart
• how does the ventricles structure reflect its function


  they have muscular walls which contract and relax to pump blood
• why does the left ventricle have thicker walls than the right


  right only pumps blood to the lungs, whereas the left pumps blood to the whole body so needs to create enough pressure to pump blood
• aorta function


  carries oxygenated blood to all parts of the body except the lungs
• how is the structure of the aorta related to its function


  it is connected to the left ventricle which pumps oxygenated blood

  thick and elastic walls to withstand high pressure of blood
• vena cava function


  brings deoxygenated blood back from the tissues of the body
• pulmonary artery function


  brings deoxygenated blood to the lungs
• pulmonary vein function

  
  

  brings deoxygenated blood back from the lungs
• atrioventricular valve function 


  allow blood to be pumped forward into the arteries, but prevents the backflow of blood
• double circulatory system

  • one part carries blood between the heart and the lungs (pulmonary loop)
  • one part carries blood between the heart and the body (systematic loop)
• what type of blood to veins carry


  deoxygenated
• what type of blood do arteries carry 


  oxygenated
• red blood cell journey in the cardiac cycle

  1. right atria
  2. antrioventricular valve
  3. right ventricle
  4. right semi-lunar valve
  5. pulmonary artery
  6. lungs
  7. pulmonary vein
  8. left atrium
  9. left atrioventricular valve
  10. left ventricle
  11. left semi-lunar valve
  12. aorta
  13. body
  14. vena cava
  15. right atria
• how is the heart muscle supplied with oxygenated blood


  throught the coronary arteries
• what happens when the coronary arteries are blocked


  blockages can cause heart attacks as heart becomes deprived of oxygen and cannot carry out aerobic respiration. cells die in area of heart
• systole 


  contraction of the heart
• diastole


  relaxation of the heart
• cardiac output


  heart rate x stroke volume
• the cardiac cyle

  1. diastole
  2. atrial systole
  3. ventricular systole
  4. aorta
• diastole (stage 1 cardiac cycle)

  • heart muscle relaxed
  • atria fill with blood
  • increases atrial pressure
  • when atrial pressure becomes higher than the ventricular pressure, the atrioventricular valve opens
  • some blood goes frim the atrium to the ventricle, slightly reducing atrial pressure
• atrial systole (stage 2 cardiac cycle)

  • atrium contract, increasing atrial pressure
  • blood moves into the ventricle increasing ventricular pressure
  • atrium relaxes decreasing atrial pressure
  • short delay
• ventricular systole (stage 3 cardiac cycle)

  • ventricles contract
  • ventricle pressure increases
  • when ventricle pressure is higher than atrial pressure the atrioventricular valve closes
  • when the ventricle pressure is higher than aortic pressure the semi-lunar valve opens
  • blood flows from the ventricle into the aorta
  • as blood leaves the ventricle, the ventricle pressure starts to decreases
• aorta (stage 4 cariac cycle)

  • blood flows into the aorta at high pressure, increasing aortic pressure
  • walls of the aorta stretch, decreasing aortic pressure
  • aorta wall recoils, increasing pressure quickly
  • aortic pressure is now higher than ventricle pressure, so semi-lunar valve closes
  • ventricle relaxes reducing ventricle pressure
  • blood moves along aorta, decreasing aortic pressure
• cardiac output


  the volume of blood ejected from the ventricles per minute
• stroke volume


  the volume of blood ejected from the ventricles each beat
• function of the arteries


  carry oxygenated blood away from the heart. this filters into arterioles, which lead to the rest of the body
• structure of arteries

  • thick muscular layer in wall to withstand high pressure of blood
  • thick elastic layer in wall allowing them to stretch and recoil, allowing them to manage the flow of blood
  • smooth muscle lined with smooth endothelium reduces friction so that blood can easily flow through
  • no valves as blood is always at high pressure, so no backflow of blood
• function of aterioles 


  carries blood from the arteries to the capillaries
• structure of aterioles

  • thicker muscular layer than arteries to control the flow of blood into capillaries
  • thinner elastic layer than arteries as pressure is lower
  • smaller lumen than in arteries
• function of veins 


  carries deoxygenated blood from the body back to the heart