ICSE 8 Biology Diseases Short

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Table of Contents

    ⚡ Quick Revision: Diseases and Their Classification

    What is a Disease?

    A disease is a departure from a state of health, a condition where the normal functioning of the body is disturbed.

    • Communicable (Infectious): Spread from person to person (e.g., Malaria, COVID-19).
    • Non-Communicable (Deficiency/Degenerative): Not spreadable (e.g., Scurvy, Diabetes).
    Term Card

    Pathogen: A disease-causing microorganism such as bacteria, virus, fungi, or protozoa.

    Disease Category Cause Example
    Bacterial Bacteria Tuberculosis, Cholera
    Viral Virus Polio, Measles, AIDS
    Protozoan Protozoa Malaria, Amoebic Dysentery
    ❌ Don't Confuse:

    Vector vs Pathogen. A pathogen causes the disease (e.g., Plasmodium), while a vector carries it (e.g., Female Anopheles mosquito).

    ⚡ Quick Revision: Communicable Diseases & Vectors

    Common Communicable Diseases

    These are spread through air, water, food, or physical contact. Key exam favorites include:

    • Tuberculosis (TB): Caused by Mycobacterium tuberculosis; spreads through droplets in the air.
    • Cholera: Caused by Vibrio cholerae; spreads through contaminated food and water.
    • Malaria: Caused by the protozoan Plasmodium; transmitted by the Female Anopheles mosquito.
    Vector Disease Carried Prevention Tip
    Anopheles Mosquito Malaria Use mosquito nets; remove stagnant water.
    Aedes Mosquito Dengue / Chikungunya Wear long sleeves; use repellents.
    Housefly Typhoid / Cholera Keep food covered; maintain sanitation.
    Term Card

    Vaccination: The process of introducing a weakened or killed pathogen into the body to stimulate the immune system to produce antibodies.

    ❌ Don't Confuse:

    Antibiotics with Vaccines. Antibiotics treat existing bacterial infections; Vaccines prevent diseases by building immunity beforehand.

    ⚡ Quick Revision: Non-Communicable Diseases

    Deficiency Diseases

    These are caused by a lack of specific nutrients (vitamins or minerals) in the diet over a long period.

    :
    Nutrient Disease Main Symptoms
    Vitamin A Night Blindness Poor vision in dim light.
    Vitamin C Scurvy Bleeding gums; swelling of joints.
    Vitamin D Rickets Soft, weak, or "bowed" bones.
    Iron Anaemia Fatigue; pale skin.
    Iodine Goitre Swelling in the neck region.
    Other Categories
    • Metabolic Diseases: Caused by faulty functioning of organs (e.g., Diabetes).
    • Allergies: Hyper-reaction of the immune system to common substances (e.g., Asthma).
    ❌ Don't Confuse:

    Kwashiorkor with Marasmus. Kwashiorkor is specifically a protein deficiency (swollen belly), while Marasmus is a deficiency of total calories (proteins, fats, and carbs), leading to extreme thinness.

    ⚡ Quick Revision: First Aid Basics

    Term Card

    First Aid: The immediate help or medical assistance given to an injured or sick person before professional medical help arrives.

    Emergency Protocols
    • 1 Burns: Wash with cold running water immediately. Apply an antiseptic cream. Do not prick blisters.
    • 2 Bleeding: Apply firm pressure with a clean cloth. Elevate the wounded part if possible to reduce blood flow.
    • 3 Fractures: Do not move the injured part. Use a splint (stiff support) or sling to keep the bone immobilized.
    • 4 Snake Bite: Keep the patient still. Tie a tight bandage (tourniquet) above the bite to slow the spread of venom. Seek anti-venom immediately.
    ⚠️ The ABC of First Aid

    Airway | Breathing | Circulation

    ❌ Don't Confuse:

    Splint with Sling. A splint is a rigid object used to keep a limb from moving; a sling is a bandage or cloth hung from the neck to support an injured arm.

    ⚡ Quick Revision: Summary & Health Hygiene

    Chapter Master-List
    • Categories: Communicable (Pathogen-led) vs. Non-communicable (Deficiency/Lifestyle).
    • Prevention: Vaccination, proper sanitation, and vector control (mosquito/fly management).
    • First Aid: Immediate action using ABC (Airway, Breathing, Circulation) to stabilize the patient.
    Exam Strategy

    Scientific Names: Memorize the specific pathogens for TB (Mycobacterium tuberculosis) and Cholera (Vibrio cholerae) as they are frequently asked in "Give one word" questions.