Presentation on theme: "The Body’s Defenses California Standards 10.a., b. & c."— Presentation transcript:
1The Body’s DefensesCalifornia Standards 10.a., b. & c.
2Pathogens Pathogens are disease causing agents such as: 1. bacteria 2. viruses3. prions and4. single cell organisms
3First Line of DefenseSkin: prevents pathogens from entering the body
4Skin = the first line of defense The skin is the organ which defends the body from infection by blocking the entry of pathogens.
52. Mucous Membranes: found in your nose and throat and stop the entry of pathogens into your body.
6Second Line of Defense Inflammatory Response Temperature Response ProteinsWhite Blood Cells
71.Inflammatory Response A series of events that suppress infection and speed recoveryHistamine: increase blood flow by dilating blood vessels.White blood cells invade infected areaSwelling and redness occurs
8When the skin is punctured pathogens are allowed to enter the body. capillary
9Injured or damaged cells release the chemical histamine which causes the blood vessels to dilate increasing blood flow to the area. This blood flow causes swelling and redness to the area.
10Increased blood flow bring white blood cells that attack and destroy pathogens. The presence of ‘puss’ at a wound is the presence of white blood cells.
112. Temperature Response 1. Higher temperature called a fever 2. Bacteria do not grow well at high temperatures3. Enzymes are destroyed or denatured
12Temperature ResponseBasically, the temperature is a response that is helpful in fighting pathogens because bacteria do not grow well at high temperatures.
13Bacteria and Antibiotics Antibiotics are specifically used to kill bacterial infections. They do nothing for viral, or virus caused, infections.
143. Proteins 1. Complementary System made up of 20 different proteins. 2. Punctures cell membrane of bacteria3. Interferon released to fight viruses
154. White Blood CellsNeutrophilsMacrophagesNatural Killer Cells
16Neutrophils Engulf and destroy pathogens Release chemicals that kill bacteria and themselves
17Macrophages Kill and ingest pathogens Clear dead cells and other debrisFound in spleen and lungs
18Natural Killer Cells Attacks cells infected with pathogens Puncture cell membraneDetect and kill cancer cells
21Specific Defense Against Disease The last type of defense against invading organisms is the specific line of defense. This defense by your body attacks specific pathogens and in the process produces antibodies that in the future can attack that specific pathogen if it occurs again.
22Third Line of DefenseImmune Response: consists of an army of cells that combat specific pathogensAntigen: a substance that triggers an immune responseAntibody: a ‘Y-shaped molecule that is produced by plasma cells when exposed to an antigen.
23Non-functioning immune response A person’s immune response is not functioning well if it is unable to fight pathogens. This is because their body cannot produce the specific antibody for that pathogen. AIDS is just such a disease because a patient’s body inability to defend itself against invading organisms.
24Antibodies and Antigens An antibody is produced by your body in response to a specific antigen.An antigen is a foreign substance which causes the body to produce a specific antibody.
25Antibodies attacking an antigen ‘Y’ shaped antibody
26AntibodiesAntibodies are substances formed by the human body in response to foreign proteins entering the body.
27Resistance to Disease Immunity – resistance to a particular disease. Vaccination – a medical procedure used to produce immunity.Vaccine – a solution of dead or modified pathogens that can no longer cause disease.
28Vaccines and Infection Vaccines are effective in preventing disease because they are dead or modified pathogens with antibodies directed against a specific pathogen.