Chapter 39

Chapter 39 Immunity from Disease
Section 1 The Nature of Disease
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A. What is and Infectious Disease?
1. ____________________ – disease producing organisms
a. Ex: Bacteria, Protozoa, Fungi, Virus
b. Main source of pathogens are soil, contaminated water and infected organisms
2. ___________________ – any disease caused by the presence of pathogens in the body
B. What Causes Disease?
1. Not all diseases are caused by a pathogen some may be genetic and others are
breakdowns of a system
2. First Pathogen
a. Robert Koch (1876) found Anthrax
b. Cultured the bacteria and injected it into healthy organisms
c. Determined a way to find a pathogen
i. Pathogen must be found in host in every case.
ii. Pathogen must be isolated and cultured
iii. When pathogen is placed in a healthy host it will case the disease
iv. Pathogen must be able to be isolated from organism and cultured again
v. Exceptions:
1. Some pathogens are not able to be cultured
2. Viruses will only grow within a host
C. Spread of Infections
1. Must be continuous source of diseased organism or a contaminated object the pathogen
has come into contact with and can live on.
2. Main source of pathogens are human – used as carriers
3. Humans can spread pathogens without knowing it
4. Animals can pass on the pathogen also
5. Soil harbors fungi and bacteria
6. Water can be contaminated by feces

D. Transmission of Disease
1. Direct Contact
a. ___________
b. ___________
2. Through the Air
a. ___________
3. Intermediate Organism (Vector)
a. ___________
b. ___________
c. Ex: Bubonic Plague
c. ___________
d. ___________
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E. What causes the Symptoms of Disease?
1. Pathogen runs into your immune system. If it beats your immune system it continues into
the rest of your body
2. Pathogens produce toxins, which are poisonous to the body. Pathogens can interrupt
protein synthesis or destroy cells.
a. Ex: ______ – destroys nerve cells and causes an increase in muscle contractions
F. Patterns of Disease
1. Disease can spread rapidly
a. _________________
b. _________________
c. _________________
2. CDC
a. Tries to keep up with diseases and trends
3. Outbreaks
a. Occurs periodically and usually due to someone traveling to a foreign city
4. Endemic Disease
a. Many people in one are affected in a short period of time
i. Ex: Flu

G. Treating Diseases
1. Antibiotics work by inhibiting the growth and development of micro-organisms
2. Viruses are immune to antibiotics – virus must run its course
3. Antibiotic Resistance occurs when bacteria mutates
4. Body’s built in immune system
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Chapter 39 Immunity from Disease
Section 2 Defense Against Infectious Disease
A. ____________________________
• Your skin is the line of defense your body has against pathogens
o Maintains homeostasis
o Absorbs fats from the digestive system
o Helps the body defend itself
1. _________________ – Physical Barrier to Micro-organisms
2. _________________ – Trap Micro-organisms
a. Mucus
b. Sweat
c. Tears
d. Saliva
3. _________________ – type of WBC’s that eat pathogens by engulfing them
4. _________________
a. Redness
b. Swelling
c. Pain
d. Heat
5. _________________ – group of proteins that attach themselves to the pathogen and
help destroy them by attracting phagocytes
6. _________________ – host specific defense and helps to make antiviral proteins
B. Acquired Immunity
1. When your body is invaded your immune system immediately starts to react.
2. When you become ill, your body “remembers” and recognizes other diseases.
3. This may take days or weeks but this is why you may be sick only a few days or a few
weeks.

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C. Lymphatic System
1. Cells of the body are bathed in fluid. The liquid picks up wastes and takes it to the
lymphatic vessels to be disposed of through the veins.
2. The lymph vessels pass through the lymph nodes and lymphocytes. The white blood
cells defend against disease
3. _________________ – large groups of lymph nodes on the back of the throat
4. _________________ – filters and cleans the blood
5. _______ – lymph organ – lymphocytes mature and differentiate into specific fighting cells
D. Antibody Immunity
1. Immune system recognize substances as self or non-self
2. When the body recognizes a foreign substance it produces specific lymphocytes when
then produces specific antibodies
3. Antigens are found on surfaces of proteins. When a foreign antigen appears. When a
foreign antigen appears antibodies are produced to fight them.
a. __________ – cell produces in bone marrow and processed in the thymus gland
b. __________ – lymphocyte that produces antibodies when activated by one of the
t-cells
E. Cellular Immunity
1. T-cells binds to antigens
a. Helper T-cell stimulates killer T cell
b. Killer T-cell produces memory T-cells to react next time
F. Immunity from Disease
1. ________________________
a. Develops as a result of acquiring antibodies
b. Natural Immunity - Mom gives antibodies to the child through milk or the placenta
c. Artificial Immunity – inject antibodies in from someone or something immune to the
pathogens (Vaccine)
2. ________________________
a. Develops as a result of exposure to the antigen
b. Memory cells are then produced to react to pathogen next time
G. AIDS and the Immune System
1. _______________ – Human Immunodeficiency Virus
2. _______________ – Acquired Immunodeficiency Syndrome