B2: Circulatory System

1. Function

   Anotações:

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

   Anotações:

   • Straw coloured liquid Contains dissolved substances and suspended cells.

1. Function

   Anotações:

   • Carry oxygen to cells.
2. Structure

   Anotações:

   • 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

   Anotações:

   • Fight infection/defend against microbes
2. Structure

   Anotações:

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

1. Function

   Anotações:

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

   Anotações:

   • 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

Anotações:

• Carry blood away from heart High pressure Thick wall

Anotações:

• Carry blood to heart Low pressure Valve to prevent backflow

Anotações:

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