Quantcast Defense Mechanisms of the Body - Infection Control and Drugs in the Dental Clinic

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
c. Direct Personal Contact. Infections may be transmitted via direct personal
contact. Examples include hepatitis and syphilis.
d. Opportunistic Microorganisms. Normal flora microbes may become
opportunistic pathogens under certain circumstances. Examples include the bacteria
causing dental caries and periodontal disease.
1-7.
DEFENSE MECHANISMS OF THE BODY
The body has developed defense mechanisms to control and to cope with the
constant attack of microorganisms.
a. The Skin and the Respiratory Tract. The skin acts as the first line of
defense by being bactericidal and fungicidal through sebaceous secretion of fatty acids
and by the presence of native bacteria. The respiratory tract acts as an efficient air
filter. The tortuous passage of air through the nasal turbinate effectively filters objects
heavier than air (for example, dust). Cilia in the bronchi act in a flagellating (sweeping)
manner to expel foreign material and to bring it to the throat where it is swallowed or
expectorated.
b. White Blood Cells. Another defense mechanism is the phagocytic action of
white blood cells and macrophages in the reticuloendothelial system (RES). While
white blood cells circulate throughout the body, they concentrate at sites of serious
infection and inflammation. Fixed phagocytic cells (which line vascular and lymph
channels), as well as wandering phagocytic cells, ingest invading agents in tissues.
c. The Immune System. The immune system is a complex phenomenon
involving antigens and antibodies. Antigens are foreign proteins that elicit immune
reactions in the body. Antibodies are substances manufactured by the body in
response to an antigen. The antibody combines with the antigen to remove or
deactivate it. Active and passive are two types of immunities. Active immunity is
achieved when a person manufactures his own antibodies in response to an antigen.
Passive immunity is achieved when preformed antibodies are administered. These
preformed antibodies are manufactured by another person or an animal that was
previously actively immunized against a specific antigen.
d. The Alimentary Canal. The alimentary canal is a defense mechanism that
destroys harmful bacteria in the stomach by gastric acids (pH 1.0 to 3.5). In addition,
the abundant population of microorganisms existing in the lower colon produces
essential vitamins (such as vitamin K, biotin, and pyrodoxine), indirectly supplementing
other defense mechanisms.
e. The Eye. The mucous membrane of the eye is still another defense
mechanism. It resists infection by lacrimal secretions (tearing) containing wandering
phagocytes and lysozyme (an enzyme which destroys bacteria).
MD0509
1-5



Medical News
Fluorescent dyes 'light up' brain cancer cells
Two new fluorescent dyes attracted to cancer cells may help...
medicalxpress.com
'Vast majority' of neurosurgeons practice defensive medicine
More than three-fourths US neurosurgeons practice some form of defensive...
medicalxpress.com
Colon cancer rates rising among Americans under 50
(HealthDay)—Although the overall rate of colon cancer has fallen in...
medicalxpress.com
Teens, young adults most likely to go to ER after car accidents: report
(HealthDay)—In a finding that won't surprise many parents, a new...
medicalxpress.com
New software analyzes human genomes faster than other available technologies
Investigators at Nationwide Children's Hospital have developed an analysis "pipeline"...
medicalxpress.com
Mobile and interactive media use by young children: The good, the bad and the unknown
Mobile devices are everywhere and children are using them more...
medicalxpress.com
More measles cases seen in january than in typical year: CDC
(HealthDay)—The United States has seen more cases of measles in...
medicalxpress.com
Team discovers key to preventing blindness and stroke devastation
Research led by Nicolas Bazan, MD, PhD, Boyd Professor, Ernest...
medicalxpress.com
Tweeting about sexism may improve a woman's wellbeing
This is one of the findings of a study by...
medicalxpress.com
Altered dopamine signaling a clue to autism
Newly discovered genetic variations linked to autism spectrum disorder (ASD)...
medicalxpress.com
What exactly is coronavirus?
The conflicts in Syria and Iraq are straining public health...
medicalxpress.com
Can Lean Management improve hospitals?
Waiting times in hospital emergency departments could be cut with...
medicalxpress.com
DNA clock helps to get measure of people's lifespans
Scientists have identified a biological clock that provides vital clues...
medicalxpress.com
Scientists home in on reasons behind cancer drug trial disappointment
Scientists based at the University of Helsinki, Finland, have discovered...
medicalxpress.com
Sickle-cell disease patient cured after bone marrow transplant
A Rochester woman who was born with sickle-cell anemia has...
medicalxpress.com
AbbVie reports better-than-expected 4Q on Humira sales
Drugmaker Abbvie posted better-than-expected adjusted results for the fourth quarter...
medicalxpress.com
First Infants Born Following Novel Genetic Screen
(MedPage Today) -- Karyomapping detects genetic disease in embryos before...
medpagetoday.com
Research finds 90 percent of home chefs contaminate food
If you're gearing up for a big Super Bowl bash,...
medicalxpress.com
Scientists find Ebola virus is mutating
(Medical Xpress)—Researchers working at Institut Pasteur in France have found...
medicalxpress.com
New Model Better Predicts Breast Cancer Risk in African American Women
Researchers from Boston University’s Slone Epidemiology Center have developed a...
bumc.bu.edu
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +