180 likes | 304 Views
Defense against Disease. Physical and Chemical Defenses. Skin- Both a physical and chemical barrier. Sweat contains acids that kill many bacteria. Skin cells shed constantly and pathogens on those skin cells shed with them.
E N D
Physical and Chemical Defenses • Skin- Both a physical and chemical barrier. Sweat contains acids that kill many bacteria. Skin cells shed constantly and pathogens on those skin cells shed with them. • Mucous Membranes- Openings such as mouth, eyes, and nose. Secrete liquid called mucus, which trap pathogens and washes them away. Also contains chemicals that attack pathogens.
Cilia- Tiny hair like projections. Line mucous membranes. Ex. Breathing in dust. • Saliva and tears- Contain chemicals and also wash away pathogens • Digestive system- Chemicals such as acid, the motions of the digestive system, and excretion all help get rid of pathogens
Inflammation • This is your bodies general response to injuries • Phagocytes- White blood cells that leak out of cells when injury occurs • Phagocytes engulf and destroy pathogens while the area is inflamed • Phagocytes also give off substances that promote healing.
The Immune System • White blood cells called Lymphocytes carry out most of the immune system’s functions • Immunity is when the body is already equipped to destroy pathogens that enter the body
Lymphocytes • Killer T cells- Destroy pathogen • Helper T cells- Produce chemicals that stimulate other T cells and B cells to fight off infection • Suppressor T cells- turn off other immune system cells when an infection has been brought under control
B cells produce antibodies. • Antibodies are proteins that attach to the surface of pathogens or to the toxins produced by pathogens.
The Lymphatic System • A network of vessels that collect fluid from your tissues and return it to the blood stream. This fluid is called lymph fluid. • Have hundreds of small stations called lymph nodes • Lymph nodes act as a sort of filter • Phagocytes and lymphocytes are contained in the lymph node and attack pathogens
Passive and Active Immunity • Passive: Immunity acquired by receiving antibodies from a source other then one’s own immune system. This is temporary and not life long. • Ex. Babies receive antibodies from the mother’s milk • Active: Results from having a disease or receiving a vaccine.
Common Infectious Diseases Bacterial Diseases • Strep Throat: Found usually in the nose and throat. Symptoms: Swollen lymph nodes, sore throat, head ache, and fever. Diagnosed by swabbing the throat • Lyme Disease: contracted when bitten by a tick. Symptoms: red rash at bite site, fevers, chills and body aches.
III. Bacterial Meningitis: Infection of the spinal cord and the fluid that surrounds the brain. Symptoms: high fever, headache, vomiting, and stiff neck. IV. Tuberculosis (TB): Transmitted when droplets of an infected persons cough or sneeze are inhaled. Symptoms: Fatigue, mild fever, and a constant cough. The disease may not show up for years after contraction.
Treating Bacterial Infections • Antibiotics are used to treat bacterial infections • Antibiotic resistance can happen when a person does not take all of their prescribed medicine.
Viral Infections • Common cold: Symptoms include sneezing, sore throat, coughing, chest congestion, head aches and muscle aches. Most last three to seven days. Colds spread when a person touches a contaminated object or inhales droplets from a sneeze or a cough. • Influenza: Infection of the upper respiratory system. Symptoms: High fever, sore throat, headache, and a cough. Spread same as cold.
Pneumonia: People who have heart disease or are elderly may experience their flu turn into pneumonia. • Hepatitis: Type A: Transmitted through human wastes or contaminated water. Type B: More severe then type A. Transmitted through blood or sexual contact. Type C: Transmitted through blood or sexual contact. Type C is the number one reason for liver transplants in the U.S
Treatment of Viral Infections • In most cases there are no particular medicine that can cure a viral infection. • Best treatments are : rest, a well-balanced diet, and plenty of fluids. • There are also many medicines that treat viral symptoms • These medicines make a person feel better but do not rid the body of the virus.
When Should I See a Doctor? • Extremely sore throat, earache, vomiting, diarrhea, or temperature of 101 F that lasts for more then two days • Mucus from your nose or throat is thick and yellow • Difficulty breathing, or severe pain anywhere • A cut or scrape that does not heal as it should • An illness that lasts longer then usual
Prevention • Wash Hands • Do not share items that transfer pathogens (towels, eating utensils, cups or hair brushes) • Cook and store food properly • Avoid close contact with infected individuals • Stay home when not feeling well • Learn to manage stress in healthful ways • Sleep at least 8 hours a night • Avoid unhealthful substances. Ex: Drugs