Transcript 7. The Importance of Blood

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Importance of Blood
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Functions

Transports oxygen and nutrients to cells.

Carries away metabolic wastes and secretions (including
hormones).
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Stabilizes internal pH.
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Serves as a highway for white blood cells.

Helps stabilize body temperature in mammals.
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What is blood made of?
 Plasma-
a straw colored liquid that serves as a
transport medium for blood cells and platelets.
 Red
Blood Cells- aka Erythrocytes- concave disks
that transport oxygen to cells and carry away
carbon dioxide.
 White
Blood Cells- aka Leukocytes-made in the
bone marrow-they engulf dead cells and anything
foreign to the body (bacteria).
 Platelets-cell
fragments that initiate blood clotting.
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Plasma
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92% Water
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8% proteins, ions, nutrients…
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Accounts for 50-60% of blood volume.
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Transports lipids and vitamins through
the body.
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Gives blood the “liquid” texture.
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Acts as a solvent- sugars, lipids, amino
acids, vitamins, oxygen, carbon
dioxide and nitrogen are all dissolved
into plasma.
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Red Blood Cells
• Transport oxygen to cells.
• Carries carbon dioxide
away from cells
• Do not have a nucleus.
• Live for about 120 days.
• Phagocytes remove old
blood cells.
Why are Red Blood Cells red?
 Red
blood cells are made
up of a protein pigment
called hemoglobin.
 Hemoglobin
contains iron
which binds to oxygen.
 Hemoglobin
helps RBCs
to carry oxygen.
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White Blood Cells
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Made in the bone marrow
and usually clump together
in lymph nodes and the spleen.
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They continue to divide in the
lymph nodes until needed.
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There are 5 types of WBCs- neutrophils, eosinophils,
basophils, monocytes, and lymphocytes
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Neutrophils and monocytes act as phagocytes to
destroy foreign invaders. Lymphocytes are more
specialized.
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Platelets
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Cell fragments wrapped
in plasma membrane.
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Last about 5-9 days
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Hundreds of thousands
are constantly in the blood
stream.
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Release substances that
cause clotting- a
necessary part of the
blood.