Video Transcript
Which component of blood is
primarily responsible for causing it to clot? (A) Plasma, (B) white blood cells,
(C) hemoglobin, (D) red blood cells, or (E) platelets.
The flow of blood throughout our
body is essential to the normal functioning of all our organs, as it provides them
with oxygen and with nutrients. The body cannot afford to lose
large volumes of blood, as this would cause the failure of our essential organs as
they’re not supplied with the oxygen or nutrients they require, which will
eventually lead to death. Therefore, when blood vessels
carrying blood are damaged due to an injury, the blood coagulates at the site of
injury into a thickened mass of blood tissue called a blood clot. Blood clots plug the damaged vessel
and prevent excessive bleeding.
Blood consists of several different
components. So, let’s look at the different
components listed in the question and see if we can identify which one of them is
responsible for initiating the formation of blood clots. Plasma is the fluid medium of
blood. All the components of blood are
suspended in the plasma, which is responsible for transporting them throughout the
body. Therefore, this option has nothing
to do with clotting, so it’s incorrect. White blood cells are the
infection-fighting cells. White blood cells are responsible
for identifying pathogens in the body and generating immune responses against
them. Since these cells play no role in
forming blood clots, this option isn’t correct either.
Hemoglobin is found in cells called
red blood cells. Hemoglobin is a pigment in these
red blood cells that’s responsible for carrying oxygen towards the tissues that need
them and carbon dioxide away from them. Hemoglobin is not responsible for
forming blood clots however, so this option is also incorrect. Although blood clots do contain
some red blood cells as we can see here, these cells are not actually responsible
for forming the clots themselves, which is what the question is asking us for. So, this option is also
incorrect.
Platelets are fragments of larger
cells called megakaryocytes that are found in bone marrow. The platelets work with other
clotting factors in the blood to initiate blood coagulation. When the endothelial lining of a
blood vessel is damaged, platelets are attracted to the sites of injury and form a
structure called a platelet plug. They become activated and trigger
cascade of biochemical reactions that leads to the formation of a blood clot. The correct answer to the question
is, therefore, platelets.
