CHAPTER 12BLOOD Page 243

12:1 The Role of Blood A. Blood Function

1. Blood is a body tissue part liquid and part cells. 2. Average human adult contains about 5 liters of

blood. 3. Pick up and deliver nutrients and waste.

B. Delivery Jobs of Blood (6 substances)1. Delivers digested nutrients from fats, proteins, and

carbs to all body cells. 2. Delivers oxygen to all body cells. 3. Delivers chemical messengers to SOME body cells. 4. Blood delivers water, minerals, and vitamins to

cells.

12:1 The Role of Blood

C. Pick-up Jobs of the Blood. 1. Picks up carbon dioxide waste from cells

and carries it to the lungs. 2. Picks up chemical wastes from cells and

carries it to the kidneys. 3. Moves excess body heat into the skin. 4. Blood picks up excess body heat and

moves that heat to the skin where the heat leaves the body.

a. Red flush that appears after exercise is due to widening of blood capillaries in the skin

12:1 The Role of Blood

D. Other functions of blood1. Help fight disease and help stop bleeding.

E. Animals without Blood1. Sponges, jellyfish, and flatworms have no

blood or blood vessels. 2. Animals without blood live in water and

the water serves as their blood. a. It brings oxygen and food to cells, and

carries any wastes chemicals from the body.

Review Questions

1. What are the six substances blood delivers to the body cells?

2. What three substances are picked up by the blood?

3. How do animals without blood get oxygen and food?

4. How does blood help a person maintain normal body temperature?

HUMAN BLOOD

12:2 Parts of Human Blood

A. Plasma1. Nonliving yellow liquid part of blood. 2. Blood plasma is 92% water. 3. Remaining 8% includes blood proteins,

nutrients, salts, and waste chemicals. 4. Most of the pickup and delivery jobs of

blood are carried out by plasma.

• Plasma is a pale yellow fluid that consists of about 92% water and 8% other substances, such as proteins, ions, nutrients, gases, and waste products.

Plasma is a colloidal solution, which is a liquid containing suspended substances that do not settle out of solution. Most of the suspended substances are plasma proteins, which include albumins, globulins, and fibrinogen.

Plasma volume remains relatively constant. Normally, water intake through the digestive tract closely matches water loss through the kidneys, lungs, digestive tract, and skin.

PLASMA

B. Red Blood Cells

1. Cells in the blood that carry oxygen to the body tissues.

2. Make up most of the blood. 3. About 5 million red blood cells in ONE

drop of blood. 4. Part of the living portion of blood, give

blood its red color.

B. Red Blood Cells (continued)

5. RBC are round. 6. Red Blood Cells have a lifespan of about

120 days. 7. Body must constantly make new red

blood cells. 8. Red blood cells are made in the Bone

Marrow.a. Bone Marrow is the soft center part of the

bone.

C. Role of Red Blood Cells

1. Main part of blood that helps with pickup and delivery.

2. Deliver oxygen to cells3. Oxygen coming into lungs picked up by

red blood cells, plasma carries blood to all body parts and oxygen is given to the cells.

C. Role Red Blood Cells (cont’d)4. The protein HEMOGLOBIN is found in red

blood cells. 5. Hemoglobin combines with oxygen to give

blood its red color. 6. Hemoglobin contains the mineral iron. 7. If a person’s diet is low in iron they may

have a condition called Anemia. 8. Anemia is a condition in which there are too

few red blood cells in the blood. a. A person with anemia will usually feel week,

tired, and short of breath.

Red Blood Cells

D. White Blood Cells(Leukocytes)1. Destroy harmful microbes. 2. Remove dead cells3. Make proteins that help prevent disease. 4. Part of the living portion of the blood.

D. White Blood Cells (cont’d)

5. WBC has a nucleus. 6. Larger than Red Blood Cells7. Average life span of WBC is 10 days. 8. Healthy person has 8,000 in one drop of

blood. 9. Made in Bone Marrow like Red Blood

Cells. 10. Also made in spleen, thymus gland, and

tonsils.

E. Role of White Blood Cells

1. White Blood Cells do three things too help us defend ourselves and fight disease:

a. They can ingest the pathogens, this means that they digest and destroy them

b. They produce Antibodies which neutralize pathogens and destroy the disease.

c. They produce Antitoxins which counteract the toxins released by pathogens

DO NOT COPY

•Pathogen: An agent of disease. A disease producer. The term pathogen most commonly is used to refer to infectious organisms. These include bacteria (such as staph), viruses (such as HIV), and fungi (such as yeast). Less commonly, pathogen refers to a noninfectious agent of disease such as a chemical.

E. Role of White Blood Cells

2. Number of White Blood Cells increase during an infection.

a. # decreases after infection is over. 3. Remove (Eat) dead cells throughout the

body.

White Blood Cells

F. Leukemia

1. Blood cancer in which # of WBC’s increase at an abnormally fast rate.

2. Three differences between normal rise and leukemia.

Comparison: Leukemia vs. Infection

Leukemia Infection

1. WBC count may reach 100,000 or more in one drop of blood.

2. WBC does not return to normal.

3. Not normal cells, can’t do the job by normal WBC.

1. WBC count rarely goes above 30,000.

2. WBC returns to normal after infection.

3. WBC are normal and perform job.

G. Platelets

1. Cell PARTS that aid in forming blood clots.

2. Not complete cells, but a living part of the blood.

3. When injury occurs, platelets break apart and release a chemical. a. Chemical starts the formation of the clot.

4. 250,000 platelets in one drop of blood.5. Life span of platelet 5 days. 6. Platelets made in bone marrow.

H. Hemophilia

1. Disease in which a person’s blood won’t clot.

2. Minor cut or bruise could become life threatening.

3. Hemophilia is a Genetic disease. a. Can be passed from his or her parents.

Platelets