LO1

• Arteries - Arteries are highly pressured and do not need valves for one way flow, they transport blood away from the heart e.g. aorta or pulmonary artery.  Arteries have thicker and elastic walls.

   

   
•  

  Veins are not highly pressured therefore they need valves for one way flow, they transport blood to the heart e.g. vena cava or pulmonary vein. Veins have thin walls.

  Vein - Veins
• The Heart - Where is it?

   

  ●Between the two lungs

  ●Enclosed by the

     PERICARDIUM

  ●Pericardial fluid is secreted 

     between the layers to aid movement

  ●The pericardium protects the 

     heart from over expansion

   

   
• The walls of the heart are 

     made of cardiac muscle     

     (MYOCARDIUM)

  ●Only found in heart

  ●Never tires but can’t tolerate 

     lack of O2.

   

   
• Function

  •The heart is the primary muscle in the body

  •Beats continuously

  •Provides the tissues and cells with oxygen and nutrients
• Cardiac Muscle


  One of three major muscle types found only in the heart of vertebrates
• Cardiac Muscle


  • Similar to skeletal muscle in possessing contractile units known as sarcomeres
  • Differs from skeletal muscle in exhibiting rhythmic contractions and not being under voluntary control
  • Rhythmic contraction is regulated by the sinoatrial node of the heart, which serves as the heart's pacemaker
• Cardiac muscle is not under voluntary control
• The sinoatrial node of the heart serves as the heart's pacemaker
• Muscular composition of the heart

  •Heart – Cardiac muscle tissue

  •Thick outside tissue – pericardium

  •Thick muscular wall of the heart – myocardium 

  •Inner layer of single cells that line the ventricles – endocardium
• The Heart

  The Heart muscle has adaptations;

  •The wall of the left ventricle is very thick. This is because the energy required to pump the blood around the body is high so the muscle needs to be strong.
• The Heart

  The Heart muscle has adaptations;

  •The heart has valves to encourage one way flow and prevent backflow, if this occurs then there could be a heart attack.
• In your pairs or on your own, find the scientific terms for parts of the heart. If you can also note down whether it is oxygenated or deoxygenated.  You should include:

  •4 chambers of the heart

  •4 major blood vessels

  •4 main valves

  Challenge: explain the…

  • The pulmonary circuit

  •The systemic circuit

  Activity 

  The pulmonary circuit takes deoxygenated blood from the heart to the lungs and oxygenated blood back to the heart

  The systemic circuit takes oxygenated blood from the heart, to the body and back to the heart
• The 4 chambers

  •Top two chambers – atria

  •Lower two chambers – ventricles – more muscular than atria as these are the main pumps 

  •Muscular wall in the middle – septum dividing the heart sagitally

   
• Physical

  Hard to get round – home/stairs/ outdoors. Fall/trip/bang into things. Physically draining. Not able to drive
• Other

  Career options limited – low income?

  Technology – touch screens.

  May not live independently.