Blood

The Two main functions of blood are to transport nutrients and oxygen to the cells and carry carbon dioxide and waste materials away from the cells. 

Blood also transfers heat to the body surface and plays a role in defending the body against disease.

1. Blood is composed of a Liquid and Blood Solids.  The liquid makes up about 55 percent of the blood, and blood solids make up the remaining 45 percent.

2. Our Bodies contains 4 to 5 liters of Blood.

BLOOD PLASMA 1. Approximately 55 percent of Blood in

made up of a Fluid Portion called PLASMA. 2. Plasma is the Straw-Colored Liquid portion

of Blood and is 90 Percent Water and 10 percent dissolved fats, salts, sugars, and Proteins called PLASMA PROTEINS.

3. THE PLASMA PROTEINS ARE DIVIDED INTO THREE TYPES:

    A.  ALBUMINS - HELP REGULATE OSMOTIC PRESSURE (MAINTAIN NORMAL BLOOD VOLUME AND BLOOD PRESSURE). THIS IS THE MOST ABUNDANT PLASMA PROTEIN.

    B.  GLOBULINS OR ANTIBODIES - INCLUDE ANTIBODIES THAT HELP FIGHT OFF INFECTION.  ANTIBODIES INITIATE THE DESTRUCTION OF PATHOGENS AND PROVIDE US WITH IMMUNITY.

    C.  FIBRINOGEN - RESPONSIBLE FOR THE ABILITY OF BLOOD TO CLOT.

BLOOD CELLS OR SOLIDS THE CELLULAR PORTION OF BLOOD

MAKE UP THE OTHER 45 PERCENT AND  INCLUDES SEVERAL TYPES OF HIGHLY SPECIALIZED CELLS AND CELL FRAGMENTS.  THEY ARE RED BLOOD CELLS (RBC), WHITE BLOOD CELLS (WBC), AND PLATELETS.

RED BLOOD CELLS (RBC) ERYTHROCYTES 1. RBC are the most

numerous of the Blood Cells. One mm3 of blood contains approx. 5 million RBCs. 

2. RBC are BICONCAVE, or shaped so that they are narrower in the center than along the edges.

3. RBC are produced from cells in the Bone Marrow, they are gradually filled with HEMOGLOBIN which forces out the nucleus and other organelles.

4. Mature RBC do not have a Cell Nucleus and Organelles.  The Mature RBC becomes little more than a membrane sac containing Hemoglobin.

5. Hemoglobin is the iron-containing protein that gives RBC the ability to carry Oxygen.  Hemoglobin gives the RBC their color.

6. RBC stay in circulation for about 120 days before they are destroyed by special WBC in the liver and spleen.  RBC in your body are dying and being replace at a rate of about 2 million per second.

WHITE BLOOD CELLS (WBC) LEUKOCYTES 1. Outnumbered by RBC 5,000-10,000 per mm3

2. WBC are produced in the Red Bone Marrow, The Lymph Nodes, and the Spleen.  They are larger than RBC, almost Colorless, and do NOT Contain Hemoglobin. (Figure 47-12)

3. WBC have a Nucleus and can live for many months or years.

4. THE MAIN FUNCTION OF WBC IS TO PROTECT THE BODY AGAINST INVASION BY FOREIGN CELLS OR SUBSTANCES.

5. WBC called PHAGOCYTES can destroy bacteria and foreign cells by Phagocytosis (engulfed and digested), some produce special proteins called ANTIBODIES, and some release special chemicals that help the body fight off disease and resist infection.

5. WBC called PHAGOCYTES can destroy bacteria and foreign cells by Phagocytosis (engulfed and digested), some produce special proteins called ANTIBODIES, and some release special chemicals that help the body fight off disease and resist infection.

6. Doctors are able to detect the presence of infection by counting the number of WBC in the blood.  When a person has an infection, the number of WBC can Double.

WBC types Neutrophils 54-62% Phagocytize bacteria,

fungi, viruses Lobed nucleus (up to 5)

Eosinophils 1-3% Moderate allergic reactions Fight parasitic worms 2 lobed nucleus

Basophil Less than 1% Release histamine to

promote inflammation Release heparin to prevent

clotting

Monocyte Largest WBC 3-9% Phagocytize bacteria, dead

cells or debris Nucleus spherical or lobed

Lymphocyte 25-33% Smaller than other WBC Large spherical nucleus T-cells attack

microorganisms & tumors B-cells produce antibodies

PLATELETS AND BLOOD CLOTTING 1. Platelets are NOT

Cells; they are tiny Fragments of other Cells that were formed in the bone marrow.

130,000-360,000 per mm3

2. Platelets are formed when small pieces of Cytoplasm are pinched off the large cells in the Red Bone Marrow called MEGAKARYOCYTES, which are found in the Bone Marrow.  Platelets lack a nucleus and their life span is about 7 to 11 days.

3. Platelets play an important role in Blood Clotting.

4. Platelets help the Clotting process by Clumping together and forming a Plug at the site of a wound and then releasing proteins called CLOTTING FACTORS.

5. Clotting Factors start a series of Chemical Reactions that ends with a sticky meshwork of Fibrin Filaments that stop bleeding by producing a clot. (Figure 47-14)

6. A genetic disorder of Clotting Factors is called HEMOPHILIA, suffers may bleed uncontrollably from even a small cut or scrape.

7. Clotting of blood in Vessels can block the flow of blood, if this happens in the brain, brain cells may die, causing a STROKE.

BLOOD TYPES 1. Blood type is

determined by the Type of ANTIGEN present on the Surface of RBC.

2. An ANTIGEN is a protein or carbohydrate that acts as a signal, enabling the body to recognize foreign substances in the body.

3. Blood from Humans is Classified into FOUR GROUPS, based on the Antigens on the Surface of RBC. (Table 47-1)

4. BLOOD TYPING involves identifying the Antigens in a Sample.

5. THREE of the most important human antigens are called A, B, and Rh.

6. The A-B-O System is based on the A and B Antigen. It is a means of classifying blood by the Antigens located on the surface of RBC and the Antibodies circulating in the Plasma.

7. An Individual's RBC may carry an A ANTIGEN, a B ANTIGEN, both A and B ANTIGENS, OR NO ANTIGEN AT ALL. These Antigen patterns are called BLOOD TYPES A, B, AB, O RESPECTIVELY.  (Table 47-1)

8. Type AB is known as a Universal Receiver, meaning that they can receive any type blood.

9. Type O is known as a Universal Donor, meaning they can donate blood to anyone.  

Rh SYSTEM 1. An antigen that is sometimes on the surface

of RBC is the Rh FACTOR, named after the rhesus monkey in which it was first discovered.

2. Eighty-five percent of the U.S. population is Rh-positive (Rh+), meaning that Rh Antigens are present.

3. People who do not have Rh Antigens are called Rh-negative (Rh-).

4. If an Rh- person receives a transfusion of blood that has Rh+ antigens, Rh- antibodies will react with the Antigen and Agglutination (clumping) will occur.

5. The Rh Factor is the reason there are blood test before marriage.  The most serious problem with Rh incompatibility occurs during pregnancy.

6. If the mother is Rh- and the father is Rh+, the child may inherit the Dominant Rh+ allele (gene) from the father.

7. If the babies Rh+ blood gets into the mother during delivery, the mother will develop Antibodies to the Rh Factor.

8. If a second Rh+ child is conceived later, the mother's antibodies can cross the placenta and attack the blood of the fetus.

9. This condition is called ERYTHROBLASTOSIS FETALIS.

10.  To prevent this condition, an Rh- mother of an Rh+ child can by given Antibodies to destroy and Rh+ cells that have entered her bloodstream from the fetus.

11. The antibodies, a substance called RHOGAM, must be administered to the mother within Three Days after the birth of her first Rh+ child to remove from her bloodstream any Rh+ antibodies.

12.  By destroying any Rh+ cells in her bloodstream, any danger to a second child is prevented because the mother will not make any Antibodies against the blood cells of the Rh+ fetus.

Important Vocabulary Aneurysm- bulge in the weakened wall of a

blood vessel Arteriosclerosis-thickening & toughening of

arterial walls Hypertension- Abnormally high blood

pressure > 150/90 Hypotension- low blood pressure that may

impair circulation to vital organs

Varicose Veins- sagging swollen veins distorted by gravity & failure of venous valves

Hemorrhoids- varicose veins in the walls of the rectum/anus

Congestive heart failure- left ventricle can’t keep up with right ventricle, blood backs up into the pulmonary circuit causing pulmonary edema

Myocardial infarction (MI)- coronary circulation is blocked and cardiac muscle cells die from oxygen starvation. (heart attack)

Angina pectoris- exertion or stress produces severe chest pain-caused by insufficiency

Angioplasty- a technique used to reduce plaque built up in arteries—a catheter with an inflatable baloon.