The Blood and Immunity
Chapter 10
Chapter Preview
Red blood cells deliver oxygen and nutrients and carry waste away.
White blood cells search and destroy foreign invaders.
Key words: AIDS, antibodies, antigen, immune response, immunity, platelets, red blood cells and white blood cells.
Blood – A Multipurpose Fluid
Transportation: Transports materials to and from all the cells of the body
Nutrients and oxygen are supplied to cells to meet their needs.
Wastes are carried away to organs that remove wastes
Chemical messengers produced and released in one part of the body are carried in the blood to other areas for cell activity
Blood – A Multipurpose Fluid
Regulation: Absorbs heat from warm areas of the body and release heat in cooler areas. Maintains a constant Ph and water balance.
Protection: Carries specialized cells and chemicals that defend the body against disease and it has the ability to clot protecting the body from injury.
Components of Blood
Plasma- Clear, straw colored liquid part of the blood (55% of the total blood volume). 90% is water, 10% salts, glucose, amino acids, fatty acids vitamins, enzymes, hormones, waste and proteins
3 types of proteins:
Albumin- keeps water from leaving blood.
Fibrinogen- helps clotting
Globulins- transport proteins and fight infection (antibodies)
Components of Blood
Red Blood Cells (erythrocytes): Red in color and carry oxygen from the lungs to the body and carry carbon dioxide from the body to the lungs. There are 30 trillion red cells in the human body and they are filled with Hemoglobin an iron protein. Red cells are made by the bone marrow and live about 120 days. As they die, they are broken down and removed by the liver and the spleen.
Anemia is a vitamin deficiency where there are too few red blood cells.
Sickle cell anemia is a hereditary disease caused by an abnormal form of hemoglobin not a vitamin deficiency
Components of Blood
White Blood Cells (leukocytes)- defenders of the body. Protect from bacteria and viruses. 60 billion in the mature adult. Normally there are 7,000-10,000/cubic millimeter but when infection is present, they can increase to >30,000. There are five kinds of white blood cells:
Neutrophils-phagocytosis (engulf bacteria)
Monocytes- phagocytosis
Eosinophils- clotting and allergy control
Basophiles- release heparin (anticoagulant) and histamine (inflammatory)
Lymphocytes- immunity
Components of Blood
Platelets- cell fragments involved in blood clotting.
Bits of cytoplasm from large cells in bone marrow
1.5 trillion in adult
200 billion per day, live for 7 days
Blood Clotting
Solidification of blood at the site of an injured blood vessel = clotting
Clotting process
Ruptured platelets and the wall of the injured vessel release enzyme- Thromboplastin
Thromboplastin initiates enzyme controlled reactions that converts prothrombin (protein) into thrombin.
Thrombin converts plasma fibrinogen into strands of fibrin
These strands trap RBC and platelets to form a clot
Clot stops the bleeding and cells re-grow to replace damaged cells
When healing is complete, a plasma enzyme- Plasmin dissolves the fibrin clot
Blood Clotting
Factors that prevent clot formation
Smoothness of the inner wall of the vessel prevents platelets from being activated.
Substances in the blood act as anticoagulants and prevent clot formation e.g. heparin (drug used after surgery to prevent clots)
Blood Clotting Problems
Not enough platelets
Vitamin K deficiency
Hemophilia- hereditary disease where one of the clotting factors is missing.
Clotting without injury- clots form and travel through the circulatory system
Block heart artery- heart attack
Block brain artery- stroke
Block lung artery- reduces oxygen to lungs
Section Review
Name the liquid part of the blood.
What is the function of RBC?
What is the function of WBC?
What plasma protein forms the strands in a blood clot?
The Immune System
Carries out a major part of the protective function of the blood.
Cells on constant patrol
Attacks foreign substances that get past other body defense systems
Defenses Against Infection
Pathogens- viruses, bacteria and organisms that cause disease. Found in:
Food
Water
Air
First-Line Defenses
Physical and Chemical Barriers
Skin
Sweat
Tears
Saliva
Membranes lining the body
Mucus
Stomach Acid
Urine
Second-Line Defenses
Inflammatory Response- When a pathogen gets past the first-line defenses
Swelling
Redness
Warmth and pain
Damaged cells release certain chemicals that increase blood flow to the area that causes increased puffiness and warmth that attract phagocytes (neutrophils and macrophages)
Second-Line Defenses cont.
Macrophages- giant WBC that can ingest large numbers of bacteria.
As the inflammation proceeds, phagocytes ingest the pathogens and any damaged tissue. Pus (mixture of phagocytes, dead cells, bacteria and body fluid) collects in the wound and either drains or absorbs into the body.
Viruses produce and enzyme called Interferon that causes uninfected cells to produce enzymes that block the virus.
Third-Line Defenses
Immune System- recognizes, attacks, destroys and remembers each kind of pathogen and produces antibodies that bind to and inactivate pathogens.
Bone Marrow, WBC, lymph nodes, tonsils, thymus and spleen make up the immune system.
Immunity- ability to fight infection through the production of antibodies or cells that inactivate foreign substances or cells. This is call the immune response.
Antigens- substances that can trigger an immune response.
Lymphocytes
Cells of the immune system that recognize specific antigens and either produce antibodies or kill foreign cells directly
B lymphocytes or B cells- produce antibodies
T lymphocytes or T cells- attach foreign cells directly
Capable of recognizing different antigens
Primary Immune Response- when and antigen enters the body for the first time antibodies are formed (10-15 days.
Secondary Immune Response- when the same antigen enters the body again the antibodies activate faster
B cells and Antibodies
Insert photo explanation here
T Cells and Immunity
Insert picture here
Types of Immunity
Active- the body produces it’s own antibodies or killer T cells to attach a particular antigen.
Example: chickenpox
Passive- A person is given antibodies obtained from the blood of either another person or an animal. "Borrowed immunity"
Vaccination
Blood Groups
ABO Blood Groups- A persons blood type depends on the antigen that is present on the surface of a RBC:
A = A antigen
B = B antigen
AB = A and B antigen
O = Neither A or B antigen
Blood Groups
Rh Factors- Group of antigens first found on the RBC’s of rhesus monkeys.
85 % humans have Rh antigen = Rh+
15 % have no Rh antigen = Rh-
Transfusions – Person receiving blood must not have antibodies that will react with any A, B or Rh antigens in the donors blood
Transfusions
Recipient
A
B
AB
O
Donor
A, O
B, O
A, B, O
O
Transplants
When an organ is transplanted from one person (donor) to another person (recipient), the transplant is recognized by the recipients immune system as foreign and activates antibodies to reject the organ. This process can be lessened if the donor and recipient are closely related or by the use of immune suppressing drugs.
Section Review
What are the two types of Lymphocytes?
Define the term antigen
What happens to an antigen-antibody complex?
What antibodies are in the plasma of a person with type B blood?
AIDS
AIDS
Acquired – picked up from other people
Immune Deficiency - breakdown of the bodies immune system
Syndrome – Group of symptoms that indicate disease.
AIDS
HIV- Human immunodeficiency virus is the cause of AIDS.
HIV attacks the helper T cells of the immune system.
Swollen Lymph glands, fever, weakness and weight loss
Pneumocystis carinii- pneumonia
Kaposi’s sarcoma
AIDS
How AIDS is spread
Sexually transmitted
Blood to Blood contact
Blood transfusions
IV drug users who share needles
AIDS
Prevention
Sexual Abstinence
Protected Sex- Latex condoms
Avoid drug use
Treatment
No cure however drugs have been developed to treat the disease and prolong life
Immune Disorders
Allergies- Rapid overreaction to and antigen that is not normally harmful. Trigger the release of histamine that induces an inflammatory response. Antihistamines are used to control the reaction
Pollen, hair, dust mites, insect stings, foods
Immune Disorders
Autoimmune Disease- Immune system fails to recognize some of the person’s body cells as "self" and produces antibodies against them.
Juvenile diabetes, rheumatoid arthritis, multiple sclerosis, lupus.
Cancer is a variety of diseases in which cells of the body multiply without control
Section Review
What is the pathogen that causes AIDS?
How can a person infected with AIDS not show any symptoms of the disease?
Name three ways AIDS can be transmitted.
What is histamine?