Blood has four main functions: carrying oxygen and carbon dioxide, removing waste, transporting nutrients, and fighting infections. It contains red blood cells, which carry oxygen and carbon dioxide using hemoglobin, an iron-rich protein. White blood cells help fight infection as part of the immune system. Platelets help blood clot to prevent excessive bleeding from injuries. Blood type is determined by antigens, and certain types cannot be mixed in transfusions. Diseases of the blood include anemias like sickle cell anemia and leukemias, in which too many white blood cells are produced. The lymphatic system carries lymph containing white blood cells and filters it through lymph nodes to fight infection. AIDS weakens this system by infect

1. BLOOD

2. • Blood has four important functions:
1. Carrying oxygen from lungs to all body cells, and
carbon dioxide to the lungs to be exhaled
2. Carrying waste products from the cells to the
kidneys for removal
3. Transporting nutrients to body cells
4. Fighting infections and healing wounds

4. • The liquid part of blood is called plasma, which
makes up most of the blood’s volume.
• Hemoglobin is the chemical in red blood cells that
carries oxygen and carbon dioxide

5. • Hemoglobin is made of an iron compound that
gives blood its red color
• In addition to red blood cells, blood also contains
white blood cells
• White blood cells play a vital role in your immune
system. These cells fight bacteria, viruses, and
other pathogens

7. • Platelets are irregularly shaped cell fragments that
help blood to clot.
• Clotting keeps you from losing too much blood
when you get an injury
• A blood clot acts like a bandage, plugging the
wound
• People with the genetic disorder hemophilia do not
have this clotting factor. A minor cut can be life
threatening for these people

9. • People inherit one of four blood types
• Blood type is determined based on the kind of
antigen present
• Antigens induce the production of antibodies for
immune response

10. • The four
blood types are:
- A
- B
- AB
- O

12. • Certain blood types cannot be mixed during a
blood transfusion
• People with type O blood
are called universal donors
because type O can be
received safely by all other
blood types

13. • Most people also contain an antigen in red blood
cells called the Rh factor. Most people are Rh
positive.
• O positive = the most common type of blood
• AB negative = the least common

15. DISEASES OF THE BLOOD
• Anemia – a condition in which there is a deficiency of
red blood cells. This can be caused by blood loss or
iron deficiency
• Sickle-cell anemia is an inherited form of anemia and is
caused by abnormal structure of red blood cells
• Leukemia is a disease in which white blood cells are
made in excess numbers. These cells are
underdeveloped and do not fight infection well.
- These cells fill bone marrow and crowd out normal cells

16. THE LYMPHATIC SYSTEM
- Lymph is a fluid that contains white blood cells
called lymphocytes
- The lymphatic system carries lymph through
contractions of smooth muscles
- Before lymph enters the blood, it passes through
lymph nodes, bean-shaped organs found
throughout the body

18. • Lymph nodes filter out foreign materials and
lymphocytes, which are important for fighting
infection.
• Other lymphatic organs include tonsils, thymus,
and spleen
• One disease of the lymphatic system is AIDS,
caused by a virus called HIV (human
immunodeficiency virus)
• A person infected with this virus cannot fight off
diseases