Defense Systems and Medical Treatments

This page focuses on the body's defense systems against pathogens and various medical treatments for infectious diseases.

Non-specific Defense Systems

The body has several non-specific defense mechanisms that prevent pathogens from entering:

1. Skin: Provides a protective layer with dead cells and sebum, which kills bacteria.
2. Nose: Contains hair and mucus to trap pathogens.
3. Lungs: The trachea and bronchi are covered with cilia and mucus to trap and remove pathogens.
4. Stomach: Contains hydrochloric acid that kills pathogens.

Specific Defense System: The Immune System

The immune system protects and destroys pathogens and toxins through three main mechanisms:

1. Phagocytosis: White blood cells ingest and destroy pathogens.
2. Antibody production: Protein molecules that stick to pathogens and trigger their destruction.
3. Antitoxin production: Molecules that neutralize toxic substances produced by pathogens.

Vocabulary: Phagocytosis is the process by which white blood cells engulf and destroy pathogens.

Vaccinations

Vaccinations work by introducing a dead or inactive form of a pathogen into the body, stimulating the immune system to produce antibodies.

Definition: Herd immunity occurs when a large portion of a population becomes immune to a disease, making the spread of the disease from person to person unlikely.

Antibiotics

Highlight: Antibiotics were first developed in the 1940s and are effective against bacterial infections.

Example: Penicillin is a common antibiotic used to treat various bacterial infections.

Types of Diseases and Pathogens

This page provides an overview of different types of diseases and pathogens, their characteristics, and examples of specific diseases.

Diseases

Diseases are categorized into two main types: communicable and non-communicable.

Definition: Communicable diseases are those that can spread from one person to another, while non-communicable diseases cannot be transmitted between individuals.

Examples of communicable diseases include measles, while non-communicable diseases include heart disease.

Highlight: Health is defined as a state of physical and mental well-being. Causes of ill-health include diseases, poor diet, stress, and other life situations such as working with harmful chemicals.

Pathogens

Pathogens are microorganisms that cause infectious diseases. There are four main types of pathogens:

1. Bacteria
2. Viruses
3. Protists
4. Fungi

Example: The Human Papilloma Virus (HPV) is an extremely common virus that can cause cervical cancer. About 3,000 women are diagnosed with cervical cancer every year in the UK.

Viral Diseases

Vocabulary: Viruses are pathogens that cannot be killed by antibiotics.

Examples of viral diseases include:

1. Measles: Highly infectious, with symptoms including fever and a red skin rash.
2. HIV (Human Immunodeficiency Virus): Initially presents with flu-like symptoms, but eventually severely damages the immune system, leading to AIDS.

Highlight: Antiretroviral drugs can stop the HIV virus from multiplying, allowing infected individuals to have a normal life expectancy, although this is not a cure.

Bacterial Diseases

Bacterial diseases can be treated with antibiotics. Examples include:

1. Salmonella (food poisoning): Spread through ingesting infected food, causing symptoms like fever, abdominal cramps, and diarrhea.
2. Gonorrhea: A sexually transmitted disease with symptoms including yellow/green discharge and pain when urinating.

Highlight: Many strains of gonorrhea have become resistant to penicillin antibiotics.

Protist Diseases

Example: Malaria is a protist disease spread by mosquitoes, causing symptoms such as fever and potentially fatal complications.