Don't have a nucleus, which means more space for hemoglobin and oxygen
Shaped like a biconcave disc, which gives them a large surface area for absorbing oxygen
White blood cells
Essential part of the immune system, defend against infection
How white blood cells defend against pathogens
Phagocytosis (engulf/consume microorganisms)
Produce antibodies that bind to and help destroy pathogens
Produce antitoxins that neutralize toxins produced by pathogens
White blood cells
Have a nucleus, unlike red blood cells
Platelets
Small fragments of cells that float in the blood and rush to wounds to help clot the blood and stop bleeding
Plasma
Pale straw-colored liquid that makes up over half the blood's volume, carries nutrients, waste products, hormones, proteins, and antibodies
Most adults have about 5 liters of blood flowing through their circulatory system at any one time
Artificial blood
A blood substitute consisting of salt water, adds volume to the circulatory system but doesn't contain red blood cells so can only replace about 1/3 of the blood
Blood transfusion
Giving a person real blood that has been donated, provides red blood cells to survive blood loss
