Our topic for this week: Blood

In studying blood, the major topics are the formed elements within blood (the blood cells), blood plasma, and how blood clots. Therefore, we will examine each of these major topics in turn, as we begin our own study of blood. By the way, the study of blood is called hematology.

A more specific outline for this unit is shown below. As I describe each of the three major topics, you will see that there are many subtopics within them. For example, you already know that "formed elements" include red blood cells, white blood cells, and platelets. In addition, you saw in lab that one's blood type depends on proteins expressed on the cell membrane of the red blood cell. All of that (and more) will have to be included in the formed elements section of this unit.

Keep in mind as you go through this unit that blood is a tissue. It is a type of connective tissue, and it is also a fluid tissue. Basically, as a connective tissue it has to be composed of cells and extracellular matrix-- it is made up of cells, and plasma is the extracellular matrix. Can you picture that?

Outline:

Formed elements

Development of formed elements

Function of formed elements

Red blood cells (erythrocytes)

antigens on RBC surface determine blood type

White blood cells (leukocytes)

Platelets

Plasma

	General plasma contents
	Maintaining plasma osmotic balance
	Maintaining plasma pH

Damage control: both clotting and the inflammatory response