Health, Disease and Defence

Economic Costs of Diseases

  • Costs to Society:

    • Both communicable and non-communicable diseases impose significant economic costs on society.

    • These costs include:

    • Treatment expenses covered by the National Health Service (NHS).

    • Long-term hospital stays for chronic conditions.

    • Expenses for specialist staff and medications.

    • Reduced productivity and impact on families where caregivers may take time off work.

Types of Communicable Diseases

  • Microorganisms and Types of Diseases:

    • Bacteria: Chlamydia, Salmonella, Tuberculosis

    • Viruses: HIV (leading to AIDS), common cold, flu, HPV

    • Fungi: Athlete's foot, Potato blight

  • Transmission and Prevention:

    • Spread through contact, air, food, and bodily fluids.

    • Prevention through vaccinations, proper food handling, and aseptic techniques.

Aseptic Techniques for Growing Bacteria

  • Procedure Overview:

    • Sterilization:

    • Use autoclaving, flaming, and alcohol to sterilize equipment (Petri dishes, loops, culture media).

    • Inoculation:

    • Keep Petri dishes partially covered to minimize contamination.

    • Work near a Bunsen burner.

    • Incubation:

    • Incubate cultures at a maximum of 25°C to avoid pathogen growth.

    • Safety:

    • Clean work surfaces and properly dispose of bacterial cultures.

Body's Defence Mechanisms

  • Key Components of Defence:

    • Physical Barriers:

    • Skin, mucous membranes, blood clotting

    • Immune Response:

    • Antibodies produced by lymphocytes in response to antigens.

    • Phagocytes engulf and digest microorganisms (phagocytosis).

    • Memory Lymphocytes:

    • Provide rapid response upon re-exposure to the same pathogen.

  • Types of Immunity:

    • Active Immunity: Production of antibodies by the body.

    • Passive Immunity: Temporary immunity acquired from another source, e.g., injections.

Antibiotics and Bacterial Resistance

  • Role of Antibiotics:

    • Antibiotics (e.g., Penicillin) are produced by fungi to kill bacteria or inhibit growth.

  • Superbugs:

    • Overuse of antibiotics leads to bacterial resistance (e.g., MRSA).

    • Superbugs continue to survive and reproduce despite treatments, complicating eradication efforts.

  • Preventive Measures:

    • Limit antibiotic use, improve hygiene, isolate infected patients.

Vaccination and Immunity

  • Vaccination Process:

    • Use dead or modified pathogens to raise antibody levels and form memory lymphocytes.

    • Booster shots may be required for sustained immunity.

  • Interpreting Vaccine Efficacy:

    • Understanding antibody levels post-vaccination is crucial for assessing immunity.

Interactions Causing Non-Communicable Diseases

  • Contributory Factors:

    • Inherited genetic predispositions (e.g., certain cancers).

    • Lifestyle choices, such as:

    • Poor diet (high in sugar and fat) leading to obesity.

    • Lack of exercise.

    • UV exposure leading to skin cancer.

    • Substance abuse (alcohol and tobacco).

  • Heart Disease Connection:

    • Obesity can lead to cardiovascular diseases and Type 2 diabetes.

Blockages in Blood Vessels and Cardiovascular Health

  • Mechanism of Blockage:

    • Cholesterol buildup can lead to clots, restricting oxygen and glucose flow to cells, resulting in cell death (heart attack or stroke).

  • Treatment Options:

    • Angioplasty, stenting, statins, and aspirin are common treatments.

Cancer Overview

  • Cell Division and Tumour Types:

    • Uncontrolled cell division (mitosis) leads to cancer; two types of tumours:

    • Benign Tumours: Encapsulated and non-invasive.

    • Malignant Tumours: Capable of spreading (metastasis).

  • Lifestyle Impact on Cancer Risk:

    • Certain cancers linked to lifestyle choices (e.g., cervical cancer and HPV virus, lung cancer and smoking, skin cancer and UV light).

Common Lifestyle Factors and Risks

  • Alcohol Consumption:

    • Binge drinking leads to liver damage and foetal alcohol syndrome; societal impacts include crime and impaired health.

  • Smoking Hazards:

    • Cigarette components such as Tar, Nicotine and Carbon Monoxide lead to serious respiratory diseases (bronchitis, emphysema, lung cancer), and affect oxygen transport in the blood.

Summary of Microbes and Their Impacts

  • Microbes:

    • Bacteria, viruses, and fungi are responsible for many diseases; prevention and control methods are crucial to public health.

  • Healthcare Costs:

    • The treatment of both communicable and non-communicable diseases places a significant burden on health resources.