Immune system

Pathogen

aka: germs- these cause infectious diseases

Antigen

substance that triggers an immune response, a "flag" for the immune system

Antibodies

attach to, and kill, specific pathogens

White blood cell or leucocytes

"eats" and destroys pathogen

Immune system

cells, tissue, and organs that fight to defend our bodies

Epidermis

first line of defense against pathogens

First Line of Defense

Barriers to prevent pathogens getting in the body

Surface membrane barriers (First Line of Defense)

Skin, Stomach Mucosa, Saliva, Mucus, and Cilia & Nasal hairs

Second Line of Defense (innate)

protective cells and fluids; inflammation Natural Killer and phagocytosis - nonspecific response, fever

Third line of Defense (specific)

Adaptive Immune Response (B cells and T cells)

Inflammatory response

redness, swelling, heat, pain

Macrophages (Second Line of Defense)

Engulfs foreign materials into a vacuole (by phagocytosis), enzymes from lysosomes digest material

Monocytes

*An agranular leukocyte that is able to migrate into tissues and transform into a macrophage.

Killer Cells (Second Line of Defense)

Can kill cancer cells, destroy virus-infected cells, Release perforins and granzymes

Interferon (Second Line of Defense)

proteins secreted by virus infected cells, bind to healthy cell surfaces to inhibit virus binding

Inflammatory response (Second Line of Defense)

Triggered when body tissues are injured, injured cells release Histamine and Kinins, "Four Cardinal Signals," Results in a chain of events leading to protection and healing

Inflammatory response (Functions)

Prevents spread of damaging agents, disposes of cell debris and pathogens, sets the stage for repair

Fever (Second Line of Defense)

Abnormally high body temperature
second line of defense

1'st Line of Defense (Summary)

Skin, Stomach lining, Mucus, Saliva (spit), Lacrimal Fluid (Tears), Ear Wax

2'nd Line of Defense (Summary)

Macrophage Cells, Natural Killer Cells, Complement Proteins, Interferon, Inflammatory Response, Fever

Antigen Specific

Recognizes and acts against particular foreign substances

Memory Cells

Recognize and mount stronger attacks in previously encountered pathogens

Lymphocytes (B cells)

Become immunocompetent in the BONE MARROW

Lymphocytes (T cells)

Become immunocompetent in the THYMUS

Cell-mediated immunity (CMI)

type of immunity produced by T cells Lymphocytes, that attack infected or abnormal body cells (all non-self) to protect the body

humoral immunity

Type of immunity produced by B cells produce antibodies after exposure to specific antigens; type of adaptive immunity

Active Immunity

B cells encounter antigens and produce(s) antibodies & memory cells

Naturally acquired (active immunity)

antibodies made due to direct exposure to an antigen
Occurs after first exposure to an antigen

Artificially acquired (active immunity)

-vaccination/
immunization
-can't cause disease but provokes an immune response
-memory; long term

Booster vaccines

increases immune response: antibody and memory cell production
amplifies secondary response

Passive Immunity

Antibodies are obtained from someone else

(Protection provided by "borrowed antibodies")
(No memory cells produced)
(lasts 2-3 weeks)

Naturally acquired (passive immunity)

From a mother-->her fetus

Aquired passive immunity

patient receives ready (preformed) immunoglobulin antibodies (serum) as an injection

Regulatory (suppressor) cells

T cells type that modulate the immune system, maintain tolerance to self-antigens, and prevent autoimmune disease.

T helper cells (CD4)

1. Produce cytokines that stimulate macrophages, NK cells, dendritic cells, and other t cells
2. Some helper T's turn B-Cells on so they can make antibodies-Which circulate and bind to antigens

T Cytotoxic Cells (CD8+ T Cells)

Activated into cytotoxic T lymphocyte (CTL)s recognize and kill self-cells altered by infection
Self-cells carry endogenous antigens on a surface presented with MHC class I molecules
CTL releases perforin and granzymes that induce apoptosis in the infected cell

Allergies (Hypersensitivity)

Undesirable reactions produced by a normal immune system. Requires a pres-sensitized immune state of host: abnormally high immune responses

Hypersensitivity I

ie: hay ever, allergies, or bee stings

Hypersensitivity II

ie: autoimmune hemolytic anemia, Rh hemolytic disease, blood transfusion

hypersensitivity III

ie: lupus erythematosus, rheumatoid arthritis

hypersensitivity IV

ie: TB, fungus and parasitic infection, contact dermatitis

AIDS (acquired immune deficiency syndrome)

-sexually transmitted infection caused by HIV, resulting in damage to the immune system
- the Human Immunodeficiency Virus (HIV) which over a period of years weakens the capacity of the immune system to fight off infection so that weight loss and weakness set in and other afflictions such as cancer or pneumonia may hasten an infected person's demise

HIV (Humain Immunodeficiency Virus)

Virus that destroys the immune system that should protect the body from diseases. The disease is passed from person to person through sexual acts, blood transfusions, used hypodermic needles, or from mother to child during birth.

lupus

when immune system attacks tissues causing redness, pain, swelling, and damage

rhumatoid arthritis (RA)

autoimmune disease causing inflammation (painful swelling) in the affected parts of the body. Also affects other organs

Immunoglobulins (antibodies)

The binding of a specific antibody to its specific target antigen initiates antibody-mediated immunity

Ig (immunoglobulin) structure

2 heavy chains, 2 light chains, disulfide bonds

IgA antibodies

secreted antibodies; found in saliva, tears, and mucous membranes

IgE antibodies

On mast cells, on basophils, and in blood
Allergic reactions; lysis of parasitic worms

IgM antibodies

Pentamer
5-10% of serum antibodies
Fix complement
In blood, in lymph, and on B cells
Agglutinate microbes; first Ab produced in response to infection
Half-life = 5 days

IgD antibodies

Monomer, In blood, in lymph, and on B cells
On B cells, initiate immune response
Half-life = 3 days

IgG antibodies

Most commun
80% of serum antibodies
Fix complement
In blood, lymph, and intestine
Cross placenta
Enhance phagocytosis; neutralize toxins and viruses; protects fetus and newborn
Half-life = 23 days

autoimmune disease

when the body produces antibodies against itself=> destruction of "own" tissue

primary immunity

Occurs in response to 1st encounter with pathogen. Patient lacks memory cells for that pathogen and low levels of IgM & IgG capable of recognizing that pathogen. (slower response)

secondary immune response

Immune response after the body has already been exposed to a specific antigen. Response is faster, of greater magnitude, and more prolonged.

immunosuppression

treatment to repress or interfere with the ability of the immune system to respond to stimulation by antigens, used in transplantation to prevent rejection

anaphylaxis (anaphylactic shock)

An extreme, life-threatening systemic allergic reaction that may include shock and respiratory failure.

Kaposi's sarcoma

Form of skin cancer frequently seen in acquired immunodeficiency syndrome (AIDS) patients. Consists of brownish-purple papules that spread from the skin and metastasize to internal organs.

erythroblastosis fetalis (hemolytic disease of the newborn)

a disorder that results from the incompatibility of a fetus with Rh-positive blood and a mother with Rh-negative blood, causing red blood cell destruction in the fetus, during second or more pregnancy

Ig that Cross placenta

IgG