Human Health and Disease

Notes

Introduction

Health is a state of complete physical, mental, and social well-being, not merely the absence of disease.

Good Health Depends Upon:

Balanced diet

Personal hygiene

Clean drinking water

Regular exercise

Vaccination

Healthy environment

Mental well-being

Disease

A disease is any condition that disturbs the normal functioning of the body.

Types of Diseases

A. Infectious (Communicable) Diseases

Spread from one person to another through pathogens.

Examples:

Malaria

Typhoid

Pneumonia

Common Cold

Amoebiasis

Ascariasis

AIDS

B. Non-Infectious Diseases

Examples:

Cancer

Diabetes

Hypertension

Allergy

Autoimmune diseases

Pathogens

Disease-causing organisms are called pathogens.

Types:

Pathogen Example

Virus HIV, Rhinovirus

Bacteria Salmonella typhi

Protozoa Plasmodium

Helminths Ascaris

Fungi Candida

Common Human Diseases

1. Typhoid

Causative Organism

Salmonella typhi

Transmission

Contaminated food and water

Symptoms

High fever

Weakness

Abdominal pain

Constipation

Headache

Diagnosis

Widal Test

Prevention

Clean drinking water

Proper sanitation

Vaccination

2. Pneumonia

Causative Organisms

Streptococcus pneumoniae

Haemophilus influenzae

Symptoms

Fever

Chills

Cough

Difficulty in breathing

Affected Organ

Alveoli of lungs become filled with fluid.

Spread

Droplet infection

3. Common Cold

Causative Organism

Rhinovirus

Symptoms

Running nose

Sneezing

Mild fever

Sore throat

Prevention

Hand washing

Avoid close contact

4. Amoebiasis

Causative Organism

Entamoeba histolytica

Symptoms

Dysentery

Abdominal pain

Blood and mucus in stool

Transmission

Contaminated food and water

5. Ascariasis

Causative Organism

Ascaris lumbricoides

Symptoms

Internal bleeding

Fever

Anaemia

Intestinal blockage

Transmission

Contaminated food, vegetables and water

6. Malaria

Causative Organism

Plasmodium species

Important Species:

P. vivax

P. malariae

P. falciparum (Most dangerous)

Vector

Female Anopheles mosquito

Symptoms

High fever

Chills

Sweating

Headache

Life Cycle (Board Diagram)

Human

↓

Liver Cells

↓

RBC Infection

↓

Mosquito Bite

↓

Sexual Reproduction in Mosquito

↓

New Infection

Prevention

Mosquito nets

Drain stagnant water

Insecticides

Immunity

Immunity is the body's ability to resist diseases.

Types of Immunity

1. Innate Immunity

Present from birth.

Characteristics:

Non-specific

Immediate response

Components:

Skin

Mucus

Saliva

Tears

Phagocytes

NK cells

Types

Physical Barriers

Skin

Mucous membrane

Physiological Barriers

HCl in stomach

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