This document discusses factors related to human health and illness. It notes that health is defined by the WHO as complete physical, mental and social well-being, not just the absence of illness. Illness occurs when an organism's function is altered, showing symptoms. To maintain good health and avoid illness, one can control their environment, habits, personal characteristics, and access to preventive healthcare. The document also categorizes illnesses based on causes, symptoms, frequency and transmission; and discusses how the body defends against infection through external barriers and the immune system.

1. Topic 2
3˚ ESO
The human being and health
Presentation by Liannette Bellido Cintrón
NOVEMBER 2010

2. • Health (WHO) It is the complete physical, mental and
social well being, and not just the absence of illness.
• Illness: Is a disorder that occurs when a part of an
organism is altered and stops fulfilling its function
correctly, showing characteristic symptoms.
• In order to maintain good health and avoid illness, we
can control the following factors:
1. A healthy environment
•Free from harmful biological elements (microbes and other
dangerous living things)
•Free from harmful physical elements such as radiation and noise
•Free from harmful chemical elements (poison and pollution)
•Also free from elements that are damaging to health such as
violent and aggressive atmospheres
2. Aquiring the habits and styles of a healthy life
3. Certain personal characteristics such as hereditary factors, age
etc.
4. The presence or existence of an efficient health system with
preventative measures or programs

3. • In order to maintain good health and avoid illness, we can control the
following factors:
1. A healthy environment
– Free from harmful biological elements (microbes and other
dangerous living things
– Free from harmful physical elements such as radiation and noise
– Free from harmful chemical elements (poison and pollution)
– Also free from elements that are damaging to health such as
violent and aggressive atmospheres
2. Aquiring the habits and styles of a healthy life.
3. Certain personal characteristics such as hereditary factors, age etc.
4. The presence or existence of an efficient health system with preventive
measures or programs.

4. Types of illness
• Depending on the cause, illnesses can be:
– Infectious: they are caused by pathogenic microbes.
– Non-infectious: they are not caused by micro organisms.
• Depending on its course:
•Acute: they show up quickly and don’t last long
•Chronic: they develop slowly and last a long time.
• Depending on the frequency:
•Sporadic: they are not very common
•Endemic: they are common and exclusive to a certain region (e.g
malaria)
•Depending on the number of people affected:
•Epidemic: the illness attacks many people in a short space of time.
•Pandemic: this is when the epidemic affects many countries or even
the whole planet

5. Infectious Diseases
Microorganisms that cause infectious diseases are:
Bacteria
Virus
Fungi Protozoa

6. Infectious Diseases

7. Illness Main organs and
tissues affected
Measles Skin
Hepatitis Liver
Rabies Nervous Tissue
AIDS Immune system
Tuberculosis Lungs
Cholera Intestines
Diphtheria Upper respiratory
tract
Tetanus Muscles
Athletes’ foot Skin
Candidiasis Skin and mucus
Malaria Blood
Sleeping sickness Nervous Tissue
Microorganisms
Virus
Bacteria
Fungi
Protozoans
Examples of
illnesses
caused by
these microbes

8. How infectious diseases are transmitted
• Infectious disease are contagious
because causing microorganisms are
transmitted from an infected person to a
healthy person through different ways.

9. • By direct contact-
The microorganism
goes directly from the
place where it is to
the receiver, without
any intermediary, as it
happen with measles
or sexually
transmitted diseases.

12. When the pathogens defeat the defenses of the
invaded organism, an infection occurs.
Phases of infectious disease:
• Incubation period- The time between the start of
the infection and the manifestation of the first
symptoms. Its duration depends on the kind of
disease.
The development of an infectious
disease

14. • An ill individual can spread the disease in any
phase of his or her sickness.
• There are also some individuals that do not develop
the symptoms of a disease but can spread it.
The infectious disease

15. The organism fights infection by activating two systems
of defenses:
• External defenses –
This is the first line of defense of the organism. It
includes structural, mechanical, biochemical, and
ecological defenses. These defenses can work
together. Example: the skin
The defense of the organism
against infection

16. Structural defenses,
such as the skin and
mucose membranes.
Biochemical
defenses, such as
saliva, tear drops
and gastrci juices.
Mechanical defenses
that drag foreign
particles from the body
Ecological defenses,
such as E. coli, a
bacteria that humans
have in their stomach.

17. • Internal defenses-
If the external defenses are not enough the immune
system activates the leukocytes and white blood cells.
These defenses are very effective and are divided
between unspecific and specific.