Blood

• Blood is made up of 4 parts: plasma, red blood cells, white blood cells and platelets
• Erythrocytes - biconcave disc, no nucleus [allows maximum transport of oxygen], made in bone marrow of long bones [leg, arm, ribs], short life span [3 months]
• Red blood cells contain hemoglobin, this is where oxygen attatches itself. The reaction between haemoglobin and oxygen is reversible
• The reaction between haemoglobin and carbon monoxide is irriversible
• When oxygen reacts with haemoglobin, the oxygen goes where it is needed
• When carbon monoxide reacts with haemoglobin, there is less oxygen available to transport, causing short breath and tiredness
• White blood cells are for defense
• Phagocytes - lobed nucleus, ingests pathogens
• Lymphocyte - huge nucleus, sprays and kills pathogens with antibodies, produces anti-bodies
• Platelets - fragments or red blood cells, involved in clotting of blood
• Oxygen exposure to platelets cause them to release: prothrombin, thrombin, fibrhogen and ribrin
• Fibrin - fibre like substance forms across open wound, RBC and WBC gets caught, kills pathogens, hardens and forms a scab
• Scab - physical barrier preventing pathogens from entering
• Plasma - liquid part of blood, Transports: water, blood cells, glucose, amino acids, urea, carbon dioxide and hormones
• Iron is an essential mineral for formation of haemoglobin