Download Immunology Phagocytes Killer T-cells Macrophages

Phagocytes

Killer T-cells

Immunology Macrophages

Natural Killer Cells

Immune System 

Group of cells in the body that recognize foreign substances



F(x) = to neutralize or destroy all things “non-self” (pathogens or invaders)

What is a Pathogen?  Any

toxin, living organism, or other agent that can cause disease.

Immune Cells  Immune

cells circulate throughout the body in the blood system and the lymphatic system

Lymphatic System  A network

of vessels that penetrate nearly every tissue of the body, and a collection of tissues & organs that produce immune cells



F(x): Fluid

recovery from tissues

 Lymph

= fluid

Immunity  Lymph

is filtered before returning to blood

Lymph Tissues & Organs 

Lymph Nodes  Clean the lymph & alert the immune system to pathogens



Tonsils  Guard against ingested or inhaled pathogens



Thymus  Produces T-cells



Spleen (largest Lymph Organ)  Monitors blood for foreign objects  Recycles old RBCs

TONSIL

Body Defense - Two Types 1.

Non-Specific

2. Specific

Non-Specific Body Defense  Innate

or inborn, not affected by prior exposures

 NOT

specific for any invader

 Operates

constantly

Non-Specific Body Defense  SKIN

– 1st Line of Defense

Physical

barrier = prevents entry of pathogens Must be unbroken to be effective Acidic, oily, sweat glands– inhibits bacterial growth

Non-Specific Body Defense  MUCUS

MEMBRANES

Respiratory,

Digestive, Urinary, Reproduction tracts F(x):  To trap debris & pathogens

Non-Specific Body Defense  HAIRS Nasal

passage Traps debris & pathogens  CILIA Upper

Respiratory

Tract Traps debris & pathogens

Non-Specific Body Defense  CELLULAR Activated

DEFENSE

when other defenses are

breached Two

Types:  Phagocytes  Leukocytes

Phagocyte eating dying cells.

Phagocytes  Cell’s  F(x):

that recognize “non-self” items

engulf or “eat” foreign debris

 Reside

in lymph organs

 Travel

to the site of infection, via the blood stream Macrophage

– a type of phagocyte

Leukocytes (Natural Killer Cells)  a.k.a.

NK Cells

 WBCs

police the blood & lymph

 F(x): Bind

to membrane of the invader, release chemicals, cause infected cell to lyse

Non-Specific Body Defense  CELLULAR

(TISSUE) DEFENSE

Inflammatory Fever

Response

Inflammation  Local

defensive response to tissue injury of any kind

 Response  Helps

is directly at site of injury

to prevent spread of the damaging agent

Inflammation  The

4 Signs of Inflammation – S.H.A.R.P.

Swelling Heat

↑ All

four of these – due to fluid build-up

↓ Redness Pain

Fever  Abnormal

elevation in body temp.

Response

 Stimulates  Heat

to infection

phagocytes to go to work

kills many pathogens

 Increases

the rate of enzymatic rxns

Non-Specific Body Defense  CHEMICAL Interferons

DEFENSE (antiviral proteins)



Interferons

Secreted by virus-infected cell



Stimulates non-infected cells to make proteins that block viral protein synthesis



Slows infection to allow specific defenses to begin working



Activates macrophages to “eat” (non-self) viral invaders

Specific Body Defense 

Immunity = ability to ward off a specific infection or disease 



Highly specific resistance to disease

Process: 

Particular invader recognized  Switches on immune response  Invader is remembered so that future invasions can be immediately fought

Specific Body Defense 

Specific Body Defense is born out of the Lymphatic System Bone marrow  makes B-cells, which make specific antibodies

i.e.

Antigens  Irritant

or pathogen– molecule that react with antibodies Epitope

= region of antigen recognized by a specific antibody

 Stimulates

formation of antibodies

Antibodies 

Molecules that react with or bind to antigens  Mark

antigens for destruction by macrophages



Form due to the exposure to a specific antigen

Antibodies  Made

by B-cells

 Found  Once

in plasma, & all body secretions

present, allows immediate immune response to pathogens

Antibodies  Structure

(most common)

 Composed

of 2 heavy chains, 2 light chains  Constant & Variable regions  Antigen-binding site Variable region

Constant region

Specific Body Defense  Helper

T-cells

Attract

other T-cells (Killer T-cells) and macrophages to an antigen

 Killer

T-cells

Directly

attack & kill pathogens, release chemicals to lyse cells

Specific Body Defense  Suppressor

T-cells

Stops

immune response when antigen is successfully overcome

Scanning Electron Micrograph of a T-cell

Specific & Non-specific Defenses work together to protect the body from disease-producing pathogens 

B-cells mature in bone tissue



T-cells mature in thymus tissue

Applications of Immune Response Immunization= process that increases an organism’s rxn to antigen & therefore improves its ability to resist or overcome infection.

Vaccine= living or inactivated organism used to induce specific immunity

Vaccines  Attenuated

agents:

Virus/bacteria

that has been modified to be incapable of causing disease

 Inactivated Pieces

agents:

or a whole organism that has been chemically inactivated Can’t reproduce but retains antigenicity

Immunity 3

Types: Active Passive Cell Mediated

Active Immunity 

When an individual responds to an antigen  



Resulting from vaccination against or Recovery from a natural infection

Permanent Immunity

Passive Immunity 

Antibodies produced from another organism injected into the body



Temporary protection against disease

Cell-Mediated Immunity  Killer

T-cells attack any cell not marked with a special protein (i.e. cells that are “non-self”)