Download Chapter 21: Infectious Diseases - Holy Trinity Diocesan High School

Chapter 21: Infectious Diseases
A. Physical and Chemical Defenses
a. Skin: physical barrier because no gaps, chemical because sweat contains acids
that kill pathogens
b. Mucous Membranes: trap and wash pathogens away, chemicals that attack
pathogens
c. Cilia: hair-like structures that move mucus and pathogens out of the body
d. Saliva and Tears: contain chemicals to attack pathogens and trap and wash away
e. Digestive System: contain acids, normal movement moves pathogens, contain
normal bacteria that attack pathogens
f. Inflammation: damaged cells release a chemical that enlarges blood vessels
allowing phagocytes (WBC) to attack pathogens; area become red, swollen, and
inflamed; phagocytes release chemicals that form pus
g. Immune System
i. WBC – T cells, B cells: produce antibodies and attack and destroy
pathogens
ii. Antibodies: proteins that tag a pathogen for destruction by T cells
B. Disease Agencies
1. CDC (Center for Disease Control): US governmental agency that
helps safeguard the public from infectious disease and provide
information on healthy decision making
2. NIH (National Institute of Health): US governmental agency that
performs biomedical research
3. Safeguarding the Public
a. Health and Safety Codes (FDA) (Ch 24 PH)
 FDA: inspects, tests, and assess the safety of food,
drugs, and a variety of consumer goods
 OSHA: Occupational Safety and Health
Administration; identifies occupational hazards and
enforces laws requiring minimum safety standards in
the workplace
 EPA: protects the public from environmental hazards;
laws that regulate pollution and sets standards for safe
levels of exposure to toxic substances and radiation
 Local Government: health codes regarding water
quality, sanitation in restaurants, and sewage
treatment facilities
C. Causes of Disease
a. Pathogens: microorganisms that cause disease
 Ex. Bacteria, virus, protozoan, fungus
 Once inside the body they multiply
D. Mode of Transmission
 Pathogens can enter through breaks in the skin or through the moist linings of
the eyes, ears, nose, mouth, or other openings
a. Infected People
 Direct Contact: shaking hands, kissing, STI
 Indirect Contact: coughs or sneezes, contact with blood
b. Infected Animals
 Animal bites can spread rabies, Lyme disease, malaria
c. Contaminated Objects
 Doorknobs, utensils, towels, needles, cups, money, desktops
d. Contaminated Food, Soil, Water
 Salmonella (poultry), botulism (dented cans, improperly stored canned foods),
tetanus (from rusty objects or soil), cholera (drinking water contaminated by
human sewage)
E. Diseases
a. Bacterial
i. Types:
o Strep Throat: bacterial infection of nose and throat
o Lyme Disease: tick bites carrying LD cause red rash, fever, chills
o Meningitis: infection of spinal cord and fluid resulting in high fever,
headache, vomiting, and stiff neck
o MRSA: open wounds, attack lungs
o Tuberculosis: infection of the lungs transmitted from coughing or
sneezing resulting in weight loss, mild fever, constant cough
ii. Treatment: antibiotics
b. Viral
i. Types:
o Common Cold: combination of several viruses; airborne
o Influenza: upper respiratory infections; airborne; 30,000 die/yr
o Pneumonia: serious infection of the lungs
o Mono: fatigue, sore throat, infection of lymph nodes
o Hepatitis: fever, nausea, pain in abdomen, jaundice
A (through waste, contaminated food/water; vaccine)
B (blood, sex, tattoos; vaccine)
C (blood, sex, tattoo; liver transplant, no vaccine)
ii. Treatment: OTC, plenty of fluids, healthy diet
c. Tattoos and Body Piercing: can cause viral or bacterial infections
F. Epidemic Diseases
o An unusually high occurrence of a disease in a certain place during a certain
period of time
o Occur because of contact with infected animals, drug resistance, lack of
immunization, international travel, global foods
a.
b.
c.
d.
West Nile: mosquito bites
SARS (Severe Acute Respiratory Syndrome): contact with cough or sneeze
Avian/Bird Flu: contact with infected bird, person-to-person; sever flu
Malaria: mosquito bite; parasite that affects RBC, can lead to encephalitis
(swelling and infection of the brain)
e. Swine Flu (H1N1)
G. Passive and Active Immunity
Passive: babies receive temporary immunity from the mother before birth and
then through breast milk after birth
Active: receive vaccines (weakened or dead form of the pathogen that results in
an immune response to increase the number of antibodies before exposure to a
stronger pathogen)
H. Prevention
1.
2.
3.
4.
5.
Wash your hands with soap and water (minimum of 20 seconds)
Cough or sneeze into your arm or tissue
Avoid cross-contamination
Cook food fully
Don’t share cups, utensils, Chapsticks, makeup