1. Health and Disease
Health
- Defined by the World Health Organization (WHO) as a
state of complete physical, mental, and social well-being, not merely the
absence of disease or infirmity.
- Factors influencing health include genetics,
environment, lifestyle, and access to healthcare.
Disease
- A pathological condition resulting from various factors
such as infections, genetic defects, or environmental influences.
- Diseases can be classified into:
- Infectious Diseases: Caused by pathogens (bacteria, viruses, fungi, parasites).
- Non-infectious Diseases: Result from genetic, environmental, or lifestyle
factors (e.g., diabetes, heart disease).
2.
Pathogens and Human Diseases
Pathogens
- Microorganisms that cause disease in hosts. Major types
include:
- Bacteria:
Single-celled organisms that can be pathogenic.
- Viruses:
Acellular entities that require a host to replicate.
- Fungi:
Can cause infections in humans (e.g., athlete's foot).
- Parasites:
Organisms that live on or in a host and benefit at the host's expense.
Common
Human Diseases Caused by Pathogens
- Malaria:
- Caused by Plasmodium species (protozoan).
- Transmitted by Anopheles mosquitoes.
- Symptoms include fever, chills, and flu-like illness.
- Filariasis:
- Caused by filarial worms (Wuchereria bancrofti).
- Transmitted by mosquito bites.
- Leads to lymphatic obstruction and elephantiasis.
- Ascariasis:
- Caused by Ascaris lumbricoides (roundworm).
- Transmitted through contaminated food/water.
- Symptoms include abdominal pain and malnutrition.
- Typhoid:
- Caused by Salmonella typhi (bacterium).
- Transmitted through contaminated food/water.
- Symptoms include prolonged fever, weakness, and
abdominal pain.
- Pneumonia:
- Caused by bacteria (e.g., Streptococcus pneumoniae)
or viruses.
- Symptoms include cough, fever, chills, and difficulty
breathing.
- Common Cold:
- Primarily caused by rhinoviruses.
- Symptoms include sneezing, runny nose, sore throat.
- Amoebiasis:
- Caused by Entamoeba histolytica (protozoan).
- Transmitted through contaminated food/water.
- Symptoms include diarrhea and abdominal pain.
- Ringworm:
- A fungal infection caused by dermatophytes.
- Symptoms include circular rashes on the skin.
- Dengue:
- Caused by the dengue virus.
- Transmitted by Aedes mosquitoes.
- Symptoms include high fever, severe headache, pain
behind the eyes.
- Chikungunya:
- Caused by chikungunya virus.
- Transmitted by Aedes mosquitoes.
- Symptoms include fever and severe joint pain.
3.
Basic Concepts of Immunology
Immunology
- The study of the immune system and its responses to
pathogens.
Vaccines
- Biological preparations that provide acquired immunity
to a particular infectious disease.
- Types of vaccines:
- Live attenuated vaccines (weakened pathogens).
- Inactivated vaccines (killed pathogens).
- Subunit vaccines (pieces of pathogens).
- mRNA vaccines (genetic material encoding antigens).
Cancer
- Uncontrolled growth of abnormal cells in the body.
- Types include carcinomas (epithelial tissue), sarcomas
(connective tissue), leukemias (blood), and lymphomas (lymphatic system).
HIV
and AIDS
- HIV (Human Immunodeficiency Virus) attacks the immune
system, specifically CD4+ T cells.
- AIDS (Acquired Immunodeficiency Syndrome) is the
advanced stage of HIV infection characterized by opportunistic infections
and cancers.
Adolescence
and Substance Abuse
- Adolescence is a critical developmental period
characterized by physical and psychological changes.
- Drug abuse can lead to addiction, affecting mental
health and social relationships.
- Alcohol abuse can result in liver damage and other
health issues.
- Tobacco abuse is linked to respiratory diseases and
cancers.
4.
Microbes in Human Welfare
Microorganisms play essential roles
in various sectors:
Household
Food Processing
- Fermentation processes involve microbes to produce
yogurt, cheese, bread, sauerkraut, etc.
Industrial
Production
- Microbes are used in the production of antibiotics
(e.g., penicillin), enzymes (e.g., amylase), and biofuels (e.g., ethanol).
Sewage
Treatment
- Microbial processes break down organic matter in sewage
treatment plants to reduce pollution before discharge into water bodies.
Energy
Generation
- Certain microbes can produce biogas from organic waste
through anaerobic digestion.
Biocontrol
Agents
- Beneficial microbes are used to control pests and
diseases in agriculture without harming the environment.
Biofertilizers
- Microbes like nitrogen-fixing bacteria enhance soil fertility
by converting atmospheric nitrogen into forms usable by plants.
Key
Diagrams
- Structure of a flower showing male and female
reproductive parts.
- Diagram illustrating the life cycle of malaria-causing
parasite (Plasmodium).
- Flowchart of the immune response upon vaccination.
Summary
This unit emphasizes the
significance of understanding human health and diseases caused by various
pathogens while highlighting the role of microbes in improving human welfare
through food processing, industrial applications, sewage treatment, energy
generation, biocontrol agents, and biofertilizers. Understanding these concepts
is crucial for addressing public health challenges and leveraging microbial
applications for sustainable practices!