B2: Circulatory System

1. Function

   Annotations:

   • Carries Co2, hormones, glucose etc. 
2. Structure

   Annotations:

   • Straw coloured liquid Contains dissolved substances and suspended cells.

1. Function

   Annotations:

   • Carry oxygen to cells.
2. Structure

   Annotations:

   • Biconcave disc shape - large surface area for absorbing O2 by diffusion.  No nucleus - makes more room for oxygen.  - cells die after 30 days Contain haemoglobin proten (iron) - allows O2 to bing to it, creating oxyhaemoglobin Flexible - can fit through small blood vessels

1. Function

   Annotations:

   • Fight infection/defend against microbes
2. Structure

   Annotations:

   • Lobed nucleus 2 mechanisms: - some engulf microbes - some produce antibodies to stick to microbes.

1. Function

   Annotations:

   • Form clots which become scabs. - stops excess bleeding - prevents microbe infections
2. Structure

   Annotations:

   • No nucleus Cell fragments Form mesh with blood platelets at site of cut.

1. Right Atrium
   1. Valve
      1. Right Ventricle
         1. Pulmonary Artery
            1. Lungs
               1. Pulmonary Vein
                  1. Left Ventricle
                     1. Valve
                        1. Left Atrium
                           1. Aorta

Annotations:

• Carry blood away from heart High pressure Thick wall

Annotations:

• Carry blood to heart Low pressure Valve to prevent backflow

Annotations:

• Site of exchange between cells and blood. Thin walls for diffusion - lots of surface area Tiny holes for tissue fluid to leak