Function: defense against the body’s invaders.
keep the body healthy.
Microorganisms that spread and cause disease.
*Early in history- thought to be from
4 ways- person to person, environment, animal bite & contaminated
Pathogens- disease causing organisms. infectious
specific markings on pathogens to say what type it is.
-anything that triggers immune system.
-similar to a barcode
1 cell organisms ie: strep throat, tetanu, t.b., plague
virus- nonliving proteins, need living cell to reproduce.
fungi- molds, yeasts. ie: athlete’s foot
*antiseptic- kills bacteria on living (skin)
*disenfectant- kills bacteria on nonliving
Lines of defense:
*1st Line of defense- Barriers: Non-specific
Skin- oil/sweat-dead skin fluffs off
Digestive- enzymes destroy (stomach)
*2nd Line of Defense - Non specific
Inflammation- infected area red and swollen.
fever helps by slowing growth of disese. Blood goes to area. WBC-(pagocytes) patrol to find disease then engulf and digest
*3rd Line of
Defense - Specific against disease
Immune system: wbc-(lymphocytes) specific cells that conquer specific antigens.
Antibodies match up markings of antigens to prepare for destruction.
Lymphocytes that originate in the bone marrow but mature in the Thymus.
Two types: 1) Helper T cells- detect and identify
presence by reading markings, antigens, of invaders. Alert B cells and killer T cells.
2) Killer T cells- target viruses
and destroy them.
B-cells: Lymphocytes that originate and
mature in the Bone marrow.
Produce antibodies that
bind with the pathogens antigens so the wbc-phagocytes can prey and destroy them. Makes plasma cells that have the antibodies.
makes memory cells to help with immunity for future detection of the pathogen. It takes longer to produce antibodies to new
Passive Immunity: short term. antibodies
prduced by other source, puts antibodies into our bodies.
Active Immunity: long lasting.
body makes own antibodies
to respond to antigen.
begin soon as antigen introduced- quicker 2nd time around against the pathogen.
*Once body has
had the disease, gets immunity so doesn’t get it again. This is due to memory cells.
weakened shot of antigen to begin process of antibody production, so memory cells will be available once the diseased pathogen
arrives into the system.
DISEASES (Non Communicable)
* Person doesn’t contract,
not an infection
Person can’t avoid
* Person’s can’t spread from one to another
* Causes: harmful substances,
irritants, unbalanced diet, failed immune syst. and stress