Download 7. The Importance of Blood

+
Importance of Blood
+
Functions

Transports oxygen and nutrients to cells.

Carries away metabolic wastes and secretions (including
hormones).

Stabilizes internal pH.

Serves as a highway for white blood cells.

Helps stabilize body temperature in mammals.
+
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.
+
Plasma
•
92% Water
•
8% proteins, ions, nutrients…
•
Accounts for 50-60% of blood volume.
•
Transports lipids and vitamins through
the body.
•
Gives blood the “liquid” texture.
•
Acts as a solvent- sugars, lipids, amino
acids, vitamins, oxygen, carbon
dioxide and nitrogen are all dissolved
into plasma.
+
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.
+
White Blood Cells
•
Made in the bone marrow
and usually clump together
in lymph nodes and the spleen.
•
They continue to divide in the
lymph nodes until needed.
•
There are 5 types of WBCs- neutrophils, eosinophils,
basophils, monocytes, and lymphocytes
•
Neutrophils and monocytes act as phagocytes to
destroy foreign invaders. Lymphocytes are more
specialized.
+
Platelets
•
Cell fragments wrapped
in plasma membrane.
•
Last about 5-9 days
•
Hundreds of thousands
are constantly in the blood
stream.
•
Release substances that
cause clotting- a
necessary part of the
blood.