Human Health And Disease
Health may be defined as a state of complete physical, mental and social well-being. When people are healthy, they are more efficient at work.
Health is affected by Genetic disorders – Infections and Lifestyle including food and water, inheritable defects of parents to offspring, we take rest and exercise we give to our bodies, habits that we want etc.
Diseases can be broadly grouped into infectious and non-infectious.
Diseases which are easily transmitted from one person to another, are called infectious diseases.
Among non-infectious diseases, cancer is the major cause of death.
• Bacterium: Salmonella typhi.
• Warnings: Stomach pain, constipation, high fever, weakness, headache and loss of appetite, intestinal perforation and death may occur in severe cases. Typhoid fever could be confirmed by a Widal test.
• Mode of transmission: These swarm spread through contaminated food and water and migrate to other organs through blood.
• Bacterium: Streptococcus pneumonia and Haemophilus influenza.
• Warnings: the alveoli get filled with fluid leading to severe problems in respiration, in severe cases, the lips and fingernails may turn gray to bluish in color. Symptoms include fever, chills, cough, and headache.
• Mode of transmission: transmitted through droplets of infected persons.
• Bacterium: Rhinoviruses.
• Warnings: a Sore throat, hoarseness, nasal congestion and discharge, cough, headache, tiredness.
• Mode of transmission: through droplets of infected persons.
Types of Diseases
The diseases may be classified into two types: Congenital and Acquired.
1 Congenital Diseases: These Diseases are basically physiological abnormalities present from birth.
They may be caused by
(i) a single gene mutation
(ii) chromosomal aberrations
(iii) environmental factors. Unlike the gene-and chromosome-induced congenital defects, environmentally caused abnormalities are not transmitted to the children.
2 Acquired Diseases: These diseases develop after birth.
They are further of two types: Communicable and Non-communicable.
(a) Communicable (Infectious) Diseases: These diseases are caused by bacteria, fungi, protozoans, viruses, rickettsias, and worms.
(b) Noncommunicable (Noninfectious) Diseases: These diseases remain confined to the person who develops them and does not spread to others.
The non-communicable diseases are of four kinds –
(1) Organic Diseases: These diseases are due to malfunctioning of some of the important organs, e.g, epilepsy, heart diseases.
(2) Deficiency Diseases: These diseases are produced by a deficiency of nutrients, minerals, vitamins, and hormones, e.g., kwashiorkor, beriberi, goiter, diabetes are just a few from a long list.
(3) Allergies: When the body, which has become hypersensitive to certain foreign substance, comes in contact with that substance then this type of diseases may be generated.
(4) Cancer: This is caused by a uncontrolled growth of certain tissues in the body.
DISEASE CAUSED BY HELMINTHES WORM.
• Bacterium. A roundworm Ascaris lumbricoides.
• Indications: This parasite is found in the small intestine of man and is of worldwide distribution. It causes nausea, a lot of stomach ache, and cough.
• Mode of transmission: Through food, when soil consists of cyst and eggs, it will be transmitted through vegetables growing on it or through dirty hands or by ingestion of soil.
• Prevention: The disposal of human garbage by underground sewer canals is an effective measure to prevent the spread. Washing of vegetables and fruits before eating help of keep away the eggs of the worm.
• Bacterium. Wuchereria bancrofti.
• Vector. Culex mosquito.
• Indications. The worm lives in the lymph vessels and blocks them, this causes swelling of the body parts like legs scrotum, foot, etc.
• Prevention. Eradication of vector.
DISEASE CAUSED BY FUNGI
• Bacterium: Trichophyton and Epidermophyton
• Indications: the appearance of dry, scaly lesions on various parts of the body such as skin, nails, and scalp with intense itching.
Prevention – Personal hygiene: It includes drinking of clean water, cleanliness of body etc. Public hygiene: It includes proper disposal of sewage,cleaning of water reservoirs, etc.
It is an ability of the body that how much to fight infectious agents
On the basis of the immunity possessed by the body.
Immunity can be Innate immunity and Acquired immunity.
1. Innate immunity is a non-specific type of defense mechanism.
It has four types of barriers –
• Physical barrier: Skin covering of the body, secretion of mucus in the respiratory tract.
• Physiological barrier: Acid in the stomach, tears from the eyes
• Cellular barrier: Lymphocytes in blood and Monocytes.
• Cytokine barrier: Interferon
2. Acquired immunity: It shows two types of responses: primary response and secondary response. It involves two types of lymphocytes –
• B lymphocytes: Show humoral immune response (HI)
• T lymphocytes: Show cell-mediated immunity (CMI)
Structure of an Antibody:
• The antibodies are protein molecules called immunoglobulins and are of various types like IgA, IgM, IgE, IgG.
• Every antibody molecule consists of four polypeptide chains, two are long called heavy chains and other two are short called light chains. Both are arranged in the shape of ‘Y’, hence an antibody is represented as H2L2.
On the basis of production of antibodies, immunity can be further categorized as –
• Active immunity: Body produces its own antibodies against antigens
• Passive immunity: Readymade antibody is transferred from one individual to another
• Colostrum is an example of passive immunity provided by the mother to her child.
Hypersensitivity to a particular allergen is termed as an allergy. IgE is an antibody responsible for allergy.
The indication may be include, sneezing, watery eyes, running nose and difficulty in breathing. Allergy is due to secretion of histamine and serotonin by mast cells. Allergy is treated with anti-histamine, adrenaline, and steroids.
Drugs and Alcohol
Drugs and alcohol demolition includes –
• Opioids: Morphine is concerned with Poppy plant. It is a depressant and painkiller. Heroin is chemically diacetylmorphine. It slows down body functions.
• Cannabinoids: It is concerned with Cannabis sativa. These are taken by oral ingestion and inhalation, they affect the cardiovascular system of the body. Drugs name:- hashish, charas, ganja
• Coca alkaloids / Cocaine: it is concerned with Erythroxylon coca. It is taken by smoking. It is a stimulant and activates the central nervous system.
• Hallucinogens: It is obtained from Atropa belladonna and Datura sp. LSD (Lysergic acid Diethylamide) is obtained from fungus.
• Tobacco: it contains nicotine, which is stimulant. It stimulates adrenaline and increases the secretion of adrenaline. Smoking of tobacco leads to lung cancer, bronchitis, emphysema, coronary heart illnesses.
Adolescence and Drug abuse
Adolescence is the period during which the child becomes matured, It is between 12 – 18 years of age.
Causes of drug abuse – ExperimentationCuriosity, Adventure, Excitement,, Stress or pressure to excel in examination
Effects of drug/alcohol abuse –Depression, isolation, aggressiveness, Malicious mischief, Reckless behavior, Violence, Drop-in academic performance, etc.
Prevention and control – Avoid peer pressure, Counseling and education, take help from teachers, parents, and peers, Take professional and medical help
It was almost eliminated a few years in the human body as per bacterium name Mosquito.
Indications: The attack of malaria is introduced by tiredness, Muscular pain. and headache. During the fever, the patient feels chilly and shivers and has an acute headache, nausea and high temperature. Then few hours after our body perspires freely and the temperature becomes normal. The cycle is repeated if no medicine is taken.
Blood smear made during fever shows the malarial parasites. No parasites are seen at other times.
Cause: Malaria is caused by the toxins produced in the human body by the malarial parasites, Plasmodium.
Transmission: The malarial parasites are carried from the infected to the healthy persons by the female Anopheles mosquito. The mosquito picks up the parasites with the blood when it bites an infected person. When this infected mosquito bites a healthy person, parasites migrate into his blood with the saliva, which the mosquito injects before sucking up blood to prevent its clotting.
Types: There are four types of Plasmodium, which cause different kinds of human malaria –
(1) P. Vivax: It causes harmless tertian malaria, which attacks every third day, The fever is mild and seldom fatal. This species is widespread in the tropical and temperate regions.
(2) P. Ovale: It recurs every 48 hours which is infected by benign tertian malaria.
(3) P. malariae: It causes quartan malaria, which recurs every fourth day may be time taken after 72 hours. This species is found in both tropical and temperate regions, but it is not very common.
(4) P. falciparum: It occurs every 48 hours. It alone is capable of causing three types of malaria, quotidian malaria, which attacks almost daily, malignant tertian malaria, but is very severe and often fatal; and irregular malaria. This species is found only in the tropical region.
Incubation Period: The incubation period for malaria caused by Plasmodium vivax is about 10 days.
Life-history: Plasmodium completes its life cycle in two phases and two hosts: asexual phase in the human host and sexual phase in the female Anopheles mosquito host.
Prevention of malaria means protecting yourself against mosquito bites and taking antimalarial medicines.
Cancer is an uncontrolled and abnormal division of cells, known as
cancer cells that overrun and destroy the surrounding tissues. Generally
Cancer is defined as uncontrolled reproduction of cells without any
(i) Neoplasms or Tumours: A neoplasm is a mass of tissue that grows in excess of normal in an uncoordinated manner and continues to grow after the initial stimulus has ceased. Tumours are classified as benign or malignant.
(ii) Oncology: It is the field of biomedicine devoted to the study and treatment of tumors.
(a) Types of Tumors: There are two types of tumors: benign and malignant.
(1) A benign Tumour is also called Nonmalignant Tumour :
It remains confined to the site of its origin and does not spread to other parts of the body. It causes limited damage to the body. It is non-cancerous.
(2) Malignant Tumour is basically called Cancerous Tumour:
Only malignant tumors are properly designated as cancer. It first grows slowly.
No symptoms are noticed. This stage is called the latent stage. The tumor later grows quickly. The cancer cells go beyond adjacent tissue and enter the blood and lymph. Once this happens, they migrate to many other sites in the body where the cancer cells continue to divide. It is a metastasis.
b) Types of Cancer (Types of Malignant Tumours):
Malignant tumors are generally classified into three main types on the basis of the cell type from which they arise.
This type is mainly derived from epithelial cells. They include cervical
(cervix is part of uterus) cancer, breast cancer, skin cancer, brain cancer, lung cancers, stomach cancer, etc.
(2) Sarcomas: These cancers are located in connective and muscular tissues derived from mesoderm. Thus, they include the cancers of bones, cartilages, tendons, lymphoid tissue, muscles, adipose tissue, Cancer of bones is called osteoma. Cancers of adipose tissue are known as lipomas and cancers of lymphatic tissue are termed as lymphomas.
(c) Causes of Cancer:
The causes of such type of cancer are not fully understood. However, many factors are known to favor cancer development. These factors are called carcinogenic agents or Carcinogens.
Treatment of cancer:
1. Immunotherapy – patients are given with alpha-interferon which activate their immune system and help in destroying the tumor.
2. Surgical – cancerous tissues are surgically removed.
3. Chemotherapy – drugs are used to kill cancerous cells but show side effects of hair loss, anemia, etc.
4. Radiotherapy – tumor cells are irradiated lethally by radiation.