 Composed of:  Plasma (mostly water)  Red blood cells (carries oxygen)  White blood cells (immune system)  Platelets (blood clotting)

 When you cut yourself:  Platelets stick to edges of broken blood vessels and cluster around wound  Platelets release clotting factors (proteins)  These proteins produce fibrin – long sticky strings  Fibrin sticks to blood vessel walls and forms a web – red blood cells get caught in it

 Four different blood types: A, B, AB, O  Determined by markers (antigen) on RBCs that trigger our immune system  If your body finds a foreign marker, it will attack it with special proteins (antibodies) A We are armed and ready to destroy Type B! Antigen Antibodies

 Type A blood:  A antigens  Produce anti-B antibodies A We are armed and ready to destroy B!

 Type B blood:  B antigens  Produce anti-A antibodies B We are armed and ready to destroy Type A!

 Type AB blood:  A and B antigens  No antibodies produced A Sorry, we have other important places to be! B

 Type O blood:  No antigens  Anti-A and anti-B antibodies produced At your service!

 What type of blood can a Type A person receive? A We are armed and ready to destroy B! A B A B

 What type of blood can a Type B person receive? B A B A B We are armed and ready to destroy Type A!

 What type of blood can a Type AB person receive? A B A B A B

 What type of blood can a Type O person receive? A B A B I am armed and ready to destroy Type B! I am armed and ready to destroy A!

 To whom can a Type A person give blood to?  To whom can a type B person give blood to?  To whom can a type AB person give blood to?  To whom can a type O person give blood to?

 Plasma (and some other cells) moves through capillary walls and into fluid between cells  lymph  Some reabsorbed  The rest goes into system of vessels, nodes, and organs  These “screen” the lymph for microorganisms (germs) before returning it to circulatory system

 White blood cells in lymph nodes destroy “trash” found in lymph  When you’re sick  lots of “trash”  Lymph nodes swell  Lymph vessels also run along intestines  Absorb fat and fat-soluble vitamins  Transports them to blood