Download body defenses

BODY DEFENSES
Methods of Transmission
• Direct Contact
• Airborne Transmission
• Bodily fluids
• Oral Transmission
DIRECT CONTACT
• IN THE OR ONLY STERILE SUPPLIES AND
STERILE INSTRUMENTS ARE USED!
• Sterile- Completely free of ALL
microorganisms
• Contaminated- These items can then become
a FOMITE
AIRBORN TRANSMISSION
• Water droplets carry organisms from one
surface to another. Then can enter the body
directly through the respiratory tract or
another entry site.
• Aerosol droplets (droplet nuclei) are dried
remnants of previously moist secretions.
Aerosol droplets can remain suspended in the
air because of their size.
TRANSMISSION OF BODILY FLUIDS
• Blood-borne pathogens are a high risk to
hospital personnel and may acquire a disease
through contact with blood and bodily fluids.
• Strict protocols for handling/isolating medical
waste, body fluids, specimens and soiled
equipment
ORAL TRANSMISSION
• Pathogens ingested in food or through fecaloral transmission.
• Poor hygiene among patients and hospital
staff contributes to the spread of pathogens in
this way.
FREQUENT HANDWASHING!!
PORTAL OF ENTRY; COMMON MEANS
OF ENTRY
• Urogenital infection
• Skin penetration
• Sexually Transmitted Diseases (mucous
membrane)
• Mother to infant transmission
IMMUNITY
• This is the body’s ability to accept substances
that are part of the body (“self”) and eliminate
those that are not!
GENERAL TYPES OF IMMUNITY
– Exists from time of birth
– Conferred through exposure to a
specific substance or microbe, called an
antigen.
•
When exposure occurs the immune system
develops antibodies, which are specific
proteins that trigger the immune system to
launch its defenses
Chemical and Mechanical Body
Defenses………
• Intact skin
• Respiratory system
Bacteriostatic chemicals in saliva, low
PH in the stomach and resident Flora
In the intestine prevent infection
• NORMAL FLORA…….(RESIDENT) Bacterial
colonies that live in symbiosis
INFLAMMATORY RESPONSE
•
•
•
•
•
Inate immune response to injury
Heat
Redness
Swelling
Pain
Cellular response – Microorganisms invade the body. Specialized
Leukocytes rush to the site; surround and engulf them
• PHAGOCYTOSIS – Immune response triggered
by the process of inflammation
ACTIVE IMMUNITY…….
• Develops when the body is stimulated to form
its own antibodies against specific disease
antigens…….Examples:
• 1. By getting the disease
• 2. By Vaccination (small amount of disease in
vaccination, just enough to formulate
antibodies).
PASSIVE IMMUNITY……..
• Develops when the body receives the specific
disease antibodies from an outside source…..
Fetus receives
antibodies in utero
from moms immune
system, or breast milk
Receives a specific antigen,
i.e.; tetanus antitoxin
VACCINES
• PROVIDE A FORM OF ACQUIRED IMMUNITY
HYPERSENSITIVITY
• IMMUNE RESPONSE TO A SUBSTANCE….
• Occurs in individuals who have previous
exposure and sensitivity to the substance
ANAPHYLACTIC SHOCK
Severe immediate reaction
Can lead to death
ALLERGY
• Hypersensitivity to a substance in the
environment, is a process mediated by the
immune system……
Immediate and Delayed Reactions….
• TYPE I – Release of Histamine, difficulty breathing,
(Anaphylactic Shock)
• TYPE II – Cytotoxic Reaction, Mismatched blood
transfusions and hemolytic disease in newborns
• TYPE III – Antigen/Antibody complexes, tissue damage,
itching, rash, severe tissue swelling
• TYPE IV- Cell-mediated (not related to antibodies) occur
after 24-72 hours after exposure….example, positive
reaction to the tuberculin skin test
AUTOIMMUNITY
• Rheumatoid Arthritis
• Systemic Lupus
• Ulcerative Colitis