Blood and heart

- Transport oxygen around the body 

- lagre surface area 

- don't have a nucleus what allow more room for oxygen to be carried

- biconcave disc shape 

- Cell immune system 

- produce antibodies agasint mircoorgansims 

- white blood cells mulitply to fight off infections

- clot blood 

- straw coloured liquid 

- carries 

• carbon dioxide to the lungs 
• urea from the liver to the kidenys 
• hormones 
• proteins 
• antibodies and antitoxins produced by white blood cells
• glucose 
• water 

Arteries

• moves fast , carries blood away 
• lumen size = narrow 
• muscle wall = thick 
• blood pressure = high 
• no valves 

Veins

Atra

Ventrilcles

Arterys 

Callpilliars 

• goes in and out, not fast , transferes 
• Lumen size = 1 cell wall thick 
• Muscle wall = none
• Blood pressure = very low 
• no vavles 

veins

•  slow , stops blood from bringing it back 
• Lumen size = wide 
• muscle wall = thin 
• blood pressure = thin 
• has valves