Transcript Maintaining Healthy Systems

Maintaining Healthy Systems
The 10 leading causes of death (WHO, 2008)
World
Deaths in
millions
% of deaths
Ischaemic heart disease
7.25
12.8%
Stroke and other cerebrovascular disease
6.15
10.8%
Lower respiratory infections
3.46
6.1%
Chronic obstructive pulmonary disease
3.28
5.8%
Diarrhoeal diseases
HIV/AIDS
2.46
1.78
4.3%
3.1%
Trachea, bronchus, lung cancers
1.39
2.4%
Tuberculosis
Diabetes mellitus
Road traffic accidents
1.34
1.26
1.21
2.4%
2.2%
2.1%
Preventive Health Care
 The best way to stay healthy is to prevent disease
in the first place.
 HOW?
 Eat well.
 Avoid unhealthy foods.
 Exercise.
 Make smart choices.
 Prevent illnesses.
How does your immune system work?
# 1 – Your Skin
 Skin is a barrier to protect your body against
pathogens.
 Pathogens are disease-causing agents (e.g. bacteria,
viruses, fungi, etc.).
 Enzymes in tears, mucous, perspiration and saliva
can destroy microbes.
# 2 – In the Respiratory System
 Mucous and cilia trap debris and pathogens.
# 3. White blood cells
 White blood cells engulf microbes, then destroy
them with enzymes.
 Some white blood cells produce pus at the site
of an infection when they die.
http://www.youtube.com/watch?v=JnlULOjUhSQ
# 4. The Inflammatory Response
 Swelling, heat and redness due to increased blood
flow to the infected area.
 Fever - increased temperature prevents bacteria
from reproducing as fast.
# 5. The Immune Response
 Pathogens have proteins on their surface called
antigens.
 Some white blood cells make proteins called
antibodies that attach to antigens to help
destroy the pathogens.
Allergies
Allergic reactions occur when your body recognizes the
antigens on allergens as dangerous, and tries to fight
them.
An overly sensitive immune system recognizes such harmless substances
as foreign invaders, and then stimulates the production of antibodies to
destroy them. This in turn induces the release of chemicals like histamine,
which is responsible for triggering the inflammatory response of the body.
The blood vessels are dilated during an allergic reaction so that the white
blood cells can get access to the foreign invaders. Immune cells recognize
proteins on allergens as dangerous (e.g. proteins on pollen).
Antibodies are produced. Histamine is released by cells (causes capillaries to
be more permeable) so white blood cells squeeze into extracellular fluid.
http://www.youtube.com/watch?v=TTcL7u05aUU
Histamine is an immune system mediator or, more simply, a chemical
messenger that helps direct your body's response to a foreign
invader. Histamine tells your body's natural defense mechanisms how
to react to something it perceives as foreign.
A hypersensitive immune system recognizes such harmless substances
as foreign invaders, and then stimulates the production of antibodies to
destroy them. This in turn induces the release of chemicals like histamine,
which is responsible for triggering the inflammatory response of the body.
The blood vessels are dilated during an allergic reaction so that the white
blood cells can get access to the foreign invaders.
What are vaccines?
 antigen-containing substances obtained from
weakened or dead microbes
smallpox
Jenner, 1796
rabies
Pasteur, 1885
Salk, 1955
polio
What are antibiotics?
 chemical agents that are toxic to bacteria
Fleming, 1928
 Colds and flu are caused by viruses, so antibiotics
are useless against them.
Organ Transplantation
 What organs and tissues can be donated?
 How many people in Ontario are waiting for organ
transplants?
 How is living donation different from organ donation
after cardiac death (DCD)?