Zusammenfassung der Ressource
B2: Circulatory System
- Components of
Blood
- Plasma (55%)
- Function
Anmerkungen:
- Carries Co2, hormones, glucose etc.
- Structure
Anmerkungen:
- Straw coloured liquid
Contains dissolved substances and suspended cells.
- Red Blood Cells
- Function
Anmerkungen:
- Structure
Anmerkungen:
- 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
- White Blood Cells
- Function
Anmerkungen:
- Fight infection/defend against microbes
- Structure
Anmerkungen:
- Lobed nucleus
2 mechanisms:
- some engulf microbes
- some produce antibodies to stick to microbes.
- Platelets
- Function
Anmerkungen:
- Form clots which become scabs.
- stops excess bleeding
- prevents microbe infections
- Structure
Anmerkungen:
- No nucleus
Cell fragments
Form mesh with blood platelets at site of cut.
- Heart
- Vena Cava
- Right Atrium
- Valve
- Right Ventricle
- Pulmonary Artery
- Lungs
- Pulmonary Vein
- Left Ventricle
- Valve
- Left Atrium
- Aorta
- Transportation
- Arteries
Anmerkungen:
- Carry blood away from heart
High pressure
Thick wall
- Veins
Anmerkungen:
- Carry blood to heart
Low pressure
Valve to prevent backflow
- Capilliaries
Anmerkungen:
- Site of exchange between cells and blood.
Thin walls for diffusion
- lots of surface area
Tiny holes for tissue fluid to leak