thing that all humans have in common is
blood. Blood flows through the veins and
arteries of all humans. Today we will specifically
discuss the makeup of blood. I want to discuss
the flow of blood through the body, the
types of blood cells, and transfusions.
Blood is carried through the body by two
types of blood vessels, arteries and veins.
carried by the arteries has received oxygen
from the lungs. Arteries take this oxygen-rich
blood to all parts of the body. After delivering
oxygen around the body, blood travels through
the veins back to the heart and lungs for
more oxygen. So arteries carry blood with
oxygen away from the heart. Veins carry
blood without oxygen back to the heart.
let's look at blood itself in more detail.
Whole blood is made up of three types of
blood cells. They are red blood cells, white
blood cells, and platelets. Each type of
cell has a different function in the body.
Red blood cells contain hemoglobin (pronounced
hee-muh-glow-bun). Hemoglobin is what picks
up oxygen in the lungs, and then releases
the oxygen to other parts of the body.
gives blood its distinctive bright red color.
The second type of blood cells are leukocytes
(pronounced loo-kuh-sytes), or more commonly
known as white blood cells. There are fewer
white blood cells than red blood cells.
So there's more hemoglobin in blood than
leukocytes. The job of the leukocytes is
to help the body fight against infection.
blood cells clean up or eat bad things that
get into our blood. Lastly, are the platelets.
They are necessary in the blood clotting
process. For example, when you cut your
finger, it is the platelets that go to work
to stop the bleeding. If the cut is large,
the platelets will need some help to stop
the bleeding. You may have to get stitches
or use a bandage.
if the cut is small, the platelets will
collect to block blood from coming out of
the wound. Remember they are like plates.
So they make a stack. That is what forms
scabs over wounds. Let's quickly review
the three types of blood cells and what
they do before we move on to talk about
or red blood cells, carry oxygen throughout
the body. Leukocytes, or white blood cells,
fight infection. And platelets work in the
blood clotting process. All three are crucial
to a healthy working body. OK, so now let's
talk about blood transfusions and blood