The document discusses the blood and immune systems. It describes that blood is made up of red blood cells, white blood cells, and plasma. Red blood cells carry oxygen around the body using hemoglobin, while plasma carries nutrients and waste. White blood cells help fight pathogens as part of the immune system. Together, the blood and immune system work to maintain homeostasis by transporting substances and defending the body.

1. Blood and Immune System
IHS Unit 4

2. Learning Targets
• Identify key elements of the blood and
immune system.
• Discuss functions of these systems as they
relate to homeostasis.

3. Blood!
• An adult person has about 5 liters of blood.
– It is made primarily in the bone marrow.
– It has three components (red blood cells, white blood
cells, and plasma)
– It has the function of carrying all sorts of stuff around
the body.

4. Red Blood Cells
• These are flattish cells that
carry oxygen.
– Oxygen on carried on a
protein called hemoglobin
(has iron).
– Red blood cells have no
nucleus.
– Red blood cells are made in
bone marrow, and are
recycled by the spleen.
– People with two few (or
malformed) red blood cells
have a disease called
anemia.

5. Plasma
• This is the liquid part of the blood.
– It carries water, electrolytes, proteins, nutrients,
hormones, clotting factors and waste products
around the body.
– Plasma sometimes leaks out of capillaries, and is
picked back up by the lymph vessels.
– When blood is put in a test tube, the plasma will
rise the top, and is clear and yellow-tinted.

6. The Immune System
• This is our defense system
against pathogens.
– It is incorporated into every
system of the body.
– Immune cells are present in
most body tissues.
– The immune system also has it’s
own special vessels called
lymph vessels that run through
body.
– White blood cells are one of the
major parts of the immune
system.

7. White Blood Cells
• These are cells that travel in
the blood to kill pathogens.
They are made in bode
marrow or in lymph nodes.
– They increase when infection
is present.
– There are many types of white
blood cell to fight different
kinds of pathogen.
– Cancer of white blood cells is
called leukemia.

8. Lymph Vessels
• These are the slow-flowing vessels that carry lymph.
– Lymph is a fluid made up of plasma leakage, and “mess”
made by immune response around the body.
– Lymph nodes are found along the vessels, which fight
pathogens that may be present and produce white blood
cells and antibodies.

9. Maintaining Homeostasis
Blood
• Blood is the body’s primary
delivery system.
• It carries nutrients, oxygen,
and waste products to their
destination in the body.
• It helps the body function
by moving hormones and
immune cells around.
Immune
• The immune system is our
protection from pathogens.
• Cells that are part of the
immune system are found
in most tissues.
• A primary part of the
immune system travels in
the blood: white blood cells.