Human Health and Diseases {Class 12th Biology}

Unit: Microbes in Human Welfare

Chapter: Human Health and Diseases

Class: 12th Biology

Presented By: Dr. Priyanka Patade

"Every Human Being Is The Author Of His Own Health Or Disease"- Buddha

Health

What Is Health?

In simple terms, Health can be defined as free from all diseases and infections.

According to the World Health Organization (WHO), health is not only the absence of disease or illness. It is a state of an active and energetic condition including the physical, mental, and social well being.

A balanced diet and regular exercise play an important role in maintaining a good health of an individual.

Factors influencing health

There are many factors which affect health, such as:

◆ Poorly balanced diet.

◆ Genetic Disorders.

◆ Stress, and anxiety.

◆ Infection from pathogens.

◆ Intake of unhealthy and unhygienic food.

◆ Lack of exercise and other physical activities.

What are Diseases?

A disease is an abnormal condition affecting a healthy living organism.

Any condition which interferes with normal functioning of the body and impairs the health.

Disease Types of Diseases

I. Congenital Disease- inborn disease & genetically inherited.

II. Acquired Disease- after birth & non- inheritable.

I. Congenital Disease

(These diseases are present since birth)

1. Disease due to gene mutation. E.g.- Haemophilia, Colour blindness.

2. Disease due to chromosomal mutation E.g.- Down’s syndrome, Klinefelter’s syndrome.

II. Acquired Disease

1. Communicable or infectious diseases- air, water, food, physical contact or vectors(Bacteria, Virus, Protozoa, Helminth, Fungus etc.)

These diseases are caused by the pathogens, such as bacteria, virus, fungi, parasites.

These can be easily transmitted from one person to another, hence it is also known as a contagious or communicable disease. 

For example: Common Cold, Tuberculosis, flu, ringworm, malaria

2. Non- communicable or non- infectious diseases- Diseases which cannot be transmitted from one person to another are called non-infectious disease, it is also known as a non-communicable disease.

These diseases can be either caused by genetic disorders, unhealthy diets, lack of physical activity, excessive use of tobacco, drugs or alcohol and few environmental factors.

Deficiency disease (Diabetes), Degenerative (Arthritis), Cancerous & Allergic diseases (Asthma)

Some Common Diseases In Humans

🔼A pathogenic bacterium known as Salmonella typhi is known to cause typhoid in humans.

🔼Pneumonia is caused by Streptococcus pneumoniae and Hemophilus influenza.

🔼Rhinovirus, a group of virus, is known to cause one of the most of infectious ailments in humans, Cold.

🔼Plasmodium, a small protozoan causes Malaria.

🔼Entamoeba histolytica causing amoebiasis (amoebic dysentery)

🔼Ascaris (an intestinal parasite) causes ascariasis.

🔼Wuchereria, the filarial worm causes filariasis or elephantiasis.

Example 1

Typhoid 

Causative agent: Salmonella typhi (Bacterium)

Epidemiology: Contaminated food & water, enters small intestine & migrate to other organs through blood.

Symptoms: Sustained high fever (39º to 40ºC), Weakness, Stomach pain, Constipation, Headache, Loss of appetite.

Severe cases: intestinal perforations & death

Did you know?

Mary Mallon nicknamed Typhoid Mary- typhoid carrier & was cook by profession, continued to spread typhoid for several years through food she prepared.

Example 2

Pneumonia

Causative agent: Streptococcus pneumoniae & Haemophilus influnenzae (Bacteria)

Epidemiology: Inhalation of droplets/aerosols released by an infected person by sharing glasses and utensils with an infected person by sharing glasses and utensils with an infected person.

Symptoms: Disease develop by causing infection in respiratory tract, Alveoli due to infection gets filled with fluid.

severe problems in respiration, symptoms includes fever, chills, cough and headache, severe cases the lips and finger nails may turn gray to bluish in colour.

Did you know?

Pneumonia claims the lives of more children under 5 than diarrhea, malaria and HIV combined!

Example 3

Common Cold

Causative agent: Rhino virus

Epidemiology: Inhalation of droplets of cough or sneeze of an infected person, Transmission through contaminated objects.

Symptoms: Infect the nose and respiratory passage but not the lungs, Common cold shows symptoms like nasal congestion and discharge, sore throat, hoarseness, cough, headache, tiredness, etc. Symptoms usually last for 3-7 days.

Did you know?

There are no Antiviral medications for treating the common cold.

Example 4

MALARIA

Pathogen: Plasmodium (P. vivax, P. malariae, P. ovale, P. falciparum)

Malignant malaria caused by P. falciparum is fatal.

Organs affected: liver, RBC.

Method of transmission: By biting of female anopheles mosquito (vector)

Symptoms: high fever and chill, fever occurs on every alternate day, vomiting.

Malaria Life Cycle

🔼Malaria parasite exists in the form of a motile sporozoite.

🔼The vector of malaria i.e. the female Anopheles mosquito transmits the malarial sporozoites into the hosts.

🔼When an infected mosquito bites a human, the sporozoites are injected into the blood through the mosquito’s saliva.

🔼The sporozoites travel into our body and accumulate in the liver. These parasites initially multiply within the liver, by damaging the liver and rupturing the blood cells in the body.

🔼Malaria kills by causing the destruction of the red blood cells in the host. The parasites reproduce asexually in the RBCs, bursting the cells and releasing more parasites to infect more cells.

 🔼The rupture of red blood cells by the malaria parasite releases a toxin called hemozoin which causes the patient to experience a condition known as the chills.

Malaria Life Cycle.

🔼When the female Anopheles mosquito bites an infected human, the parasites enter the mosquito’s body along the human blood it is drinking.

🔼It is inside the mosquito’s body that the actual development and maturing of the parasite happens.

🔼The parasites produced in the human body reach the intestine of the mosquito where the male and females cells fertilize each other to lead to the formation of a sporozoite.

🔼On maturing, the sporozoite breaks out the mosquito’s intestine and migrate to the salivary glands.

🔼Once they reach salivary glands, they wait till the mosquito bites another human and the process of infection and disease begins all over again.

🔼It is prudent however to observe that the complete development of the malaria parasite takes place in two different hosts; humans and mosquitoes.

Prevention of malaria

There are two ways to deal with malaria –Prevent the mosquito bite from happening (i.e preventative steps) or attack the parasites once they have infected the body.

The first method advocates the use of mosquito nets and mosquito repellent such as permethrin to prevent mosquitoes from biting.

The second form of treatment uses a chemical called Quinine present in the bark of a cinchona tree.

A form of drug chloroquine has proven very effective against malaria even though it is not a vaccine.

Example 5

Amoebiasis/ Amoebic dysentery

Causative agent: Entamoeba histolytica (protozoan)

Epidemiology: 1. Transmission of parasite from faeces of infected person to food or food products through Houseflies (mechanical carrier). 2. Drinking water contaminated by the faecal matter are the main source of infection.

Target Organ: Large intestine

Symptoms: Constipation, abdominal pain and cramps, stools with excess mucous and blood clots.

Example 6

Ascariasis

Causative agent: Ascaris lumbricoides (Round worm) - Helminths.

Epidemiology: Consumption of contaminated water, vegetables, fruits etc., contamination takes place through faeces of infected person which have the egg of parasite.

Target organ: Intestine

Symptoms: Internal bleeding of intestine, muscular pain, fever, anaemia blockage of the intestinal passage.

Example 7

Elephantiasis/ Filariasis

Causative organism: Wuchereria bancrofti & W. malayi (Filarial worms)- Helminths.

Epidemiology: Bite of female mosquito vectors- Culex.

Target organ: Lymphatic vessels of lower limbs, genital organs.

Symptoms: 1. Chronic inflammation of organs (many years)- lymphatic vessels which result in appearance of elephant like leg- Elephantiasis. 2. Deformation of genital organ.

Example 8

Ring Worm

Causative agent: Microsporum, Trichophyton & Epidermophyton(fungi)

Epidemiology: 1. Acquired from the soil. 2. Using towel, clothes or even comb of infected individuals. 3. Heat & moisture enhances the growth of organism.

Target organs: Skin, nails, folds of skin in groin & toes.

Symptoms: 1. Appearance of dry, scaly lesions in skin nails and scalp. 2. Lesion accompanied with intense itching.

Questions

1. Explain any three preventive measures to control microbial infections.

2. "Maintenance of personal and public hygiene is necessary for prevention and control of many infectious diseases”. Justify the statement giving suitable examples.

3. Represent schematically and explain the life cycle of a malarial parasite.

4. Explain various types of diseases along with suitable examples.

5. Write the causal organism, epidemiology and symptoms of Pneumonia, Common cold and Amoebiasis.

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Prevention & control of diseases

Infectious diseases can be prevented through maintenance of personal and public hygiene.

Diseases can be grouped as

⏩Food & water borne diseases⏪

⏩Air borne diseases⏪

⏩Vector borne diseases⏪

Food & water borne diseases

Proper personal hygiene include keeping the body clean; Consumption of clean drinking water, food, vegetables, fruits, etc.

Proper public hygiene which includes proper disposal of waste and excreta; Periodic cleaning and disinfection of water reservoirs, pools, cesspools and tanks 

Observing standard practices of hygiene in public catering.

Eg.- typhoid, amoebiasis and ascariasis.

Air borne diseases

Close contact with infected person & their belongings should be avoided.

Personal hygiene is also very important to prevent diseases.

Eg.- Pneumonia and Common cold.

Vector borne diseases

Controlling or eliminating the vectors and their breeding places.

Avoiding stagnation of water in and around residential areas, Regular cleaning of household coolers, use of mosquito nets.

Introducing fishes like Gambusia in ponds that feed on mosquito larvae, spraying of insecticides in ditches, drainage areas and swamps, etc.

Doors and windows- wire mesh to prevent the entry of mosquitoes like Aedes & Culex mosquitoes, houseflies.

Diseases can be now prevented- vaccines and immunisation.

Vaccines - eradicate smallpox, polio, diphtheria, pneumonia and tetanus.

Through Biotechnology we can make available newer and safer vaccines.

Discovery of antibiotics and various other drugs has also enabled us to effectively treat infectious diseases.

Immunity

The overall ability of host to fight against disease causing organisms is called immunity.

The foreign agents could be pathogens or any foreign substance which in turn could cause disease in host.

Types of Immunity

1. Innate Immunity 2. Acquired Immunity

Innate Immunity- which is present from the time of birth & is not pathogen specific.

Acquired Immunity- not from time of birth & is pathogen specific; Immunity is conferred based on memory that immune system have for that pathogen.

Innate Immunity

It is a non- specific type of defence which is present at the time of birth.

Immunity is provided by different barriers which prevent entry of foreign agents in body.

Innate immunity consist of four types of barriers

⏩Physical barrier⏪

⏩Physiological barrier⏪

⏩Cellular barrier⏪

⏩Cytokine barrier⏪

1. Physical Barrier

Barrier which prevents entry of microbes into the body which comes in contact with body.

Skin- main barrier which prevents entry of the micro-organisms.

Mucus coating- present at epithelium lining of the respiratory, gastrointestinal and urogenital tracts-trap microbes

 2. Physiological Barrier

Body secretions of body acts as physiological barrier & prevents microbial growth.

Stomach- acid (HCl), Mouth- saliva, Eyes- tears; contain lysozyme.

3. Cellular Barrier

Certain cells of body- eradicate microbes & provide immunity.

Act by engulfing pathogen & destroys them by secreting certain chemicals against them.

Tissues which mainly act as cellular barrier- leukocytes also called WBC.

Leukocytes (WBC)- polymorpho-nuclear leukocytes (PMNL neutrophils) and monocytes and natural killer (type of lymphocytes) & macrophages in tissues can phagocytose and destroy microbes.

4. Cytokine barriers

Proteins (interferons)- protects healthy cells from invasion of pathogens.

Usually secreted from virus infected cells.

Interferons- protect non-infected cells from further viral infection.

Acquired Immunity

Acquired immunity or adaptive immunity is the immunity that our body acquires or gains over time. Unlike the innate immunity, this is not present by birth.

The ability of the immune system to adapt itself to disease and to generate pathogen-specific immunity is termed as acquired immunity. It is also known as adaptive immunity.

An individual acquires the immunity after the birth, hence is called as the acquired immunity.

It is specific and mediated by antibodies or lymphocytes which make the antigen harmless.

The main function of acquired immunity is to relieve the victim of the infectious disease and also prevent its attack in future.

It mainly consists of an advanced lymphatic defence system which functions by recognizing the own body cells and not reacting to them.

The immune system of our body identifies the pathogens which have encountered in the past. It is mainly caused when a person comes in contact with the pathogen or its antigen.

Our body starts producing antibodies to engulf the pathogen and destroy its antigen.

When it encounters for the first time, it is called a primary response. Once a body gets used to these pathogens, antibodies are ready to attack them for the second time and are known as naturally acquired immunity.

Features of Acquired Immunity

Specificity: Our body has the ability to differentiate between different types of pathogens, whether it is harmful or not, and devise ways to destroy them.

Diversity: Our body can detect vast varieties of pathogens, ranging from protozoa to viruses.

Differentiate between self and non-self: Our body has the unique ability to differentiate between its own cells and foreign cells. It immediately starts rejecting any foreign cell in the body.

Memory: Once our body encounters a pathogen, it activates the immune system to destroy it. It also remembers what antibodies were released in response to that pathogen, so that, the next time it enters, the similar procedure is followed by the body to eliminate it.

Cells Involved in Acquired Immunity

The acquired immunity involves two types of cells:

⏩B-cells and T-cells⏪

B-cells

They develop in the bone marrow.

These cells are activated on their encounter with foreign agents. These foreign particles act as foreign markers.

The B-cells immediately differentiate into plasma cells which produce antibodies specific to that foreign particle or so-called antigen.

These antibodies attach to the surface of the antigen/foreign agent.

These antibodies detect any antigen in the body and destroy it.

The immunity dependent on B-cells is called humoral immunity.

T-cells

They originate in the bone marrow and develop in the thymus.

T-cells differentiate into helper cells, cytotoxic cells, and regulatory cells. These cells are released into the bloodstream.

When these cells are triggered by an antigen, helper T-cells release cytokines that act as messengers.

These cytokines initiate the differentiation of B-cells into plasma cells which release antibodies against the antigens.

Types of Acquired Immune Response

⏩Humoral Immune Response/ humoral immunity⏪

⏩Cell-mediated Immune Response/ CMI⏪

Humoral Immune Response/ humoral immunity

The antibodies produced by B-lymphocytes are present in the blood cells and they are transported all over the body. This is why it is called the humoral immune response as it consists of an antibody produced by the lymphocytes.

It depends upon the action of antibodies circulating in the body. When an antibody on a B-cell binds with an antigen, humoral immunity comes into play.

Cell-mediated Immune Response/ CMI

Cell-mediated immunity is initiated by the T lymphocytes.

T-lymphocytes are capable of recognizing whether tissue or an organ is from our body or foreign bodies.

This is the reason why we cannot transplant and implant the organs into our body even if we find the donor with the same blood group because our body might reject the transplanted organ.

The T-cells quickly recognize that the tissue or an organ as a foreign and do not allow it to become a part of the body. This is why transplant receivers have to take immunosuppressant medication for the rest of their lives. This response is controlled by the T-lymphocytes.

What are Antibodies?

Antibody (Ab) is also known as an immunoglobulin(Ig).

These are large, Y-shaped blood proteins produced by plasma cells.

They bind to foreign particles and invade them.

Antigens are foreign pathogens that invade the body.

Hence, antigens stimulate the production of antibodies by the immune system.

Structure of Antibody

Each antibody molecule has four peptide chains, two long chains and two short chains arranged in a Y shaped structure.

Two long chains are called heavy chains and two short chains are called light chains, hence an antibody is represented as H2L2.

Different types of antibodies are produced in our bodies which are IgA, IgM, IgE, IgG.

Types Of Antibodies

IgM

IgM is the first antibody produced in response to a microbial attack by B cells.

It is the largest antibody.

IgG

Most abundant isotype in the plasma, and comprises 80% of the total antibody content in the serum.

It is transferred to the placenta through the foetus and protects the infant until it’s birth.

IgD

It is involved in the production of the antibody by B cells.

IgE

IgE is present in the least amounts in the serum.

These are present in the linings of the respiratory and intestinal tracts and respond to allergic reactions.

Types of Acquired Immunity

⏩Active Immunity⏪

⏩Passive immunity⏪

Active Immunity

Active immunity involves the direct response to a foreign antigen within the body.

Active immunity occurs when we are in contact with the pathogen or its antigen.

When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body. This type of immunity is called active immunity.

Active immunity is slow and takes time to give its full effective response.

Antigens stand for antibody generator. So what our body does is, it starts producing antibodies to attack the pathogen based on its antigen.

Passive Immunity

Passive immunity involves the immune response by the antibodies attained from outside the body.

The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant. The foetus also receives some antibodies from their mother, through the placenta during pregnancy. It is an example of passive immunity.

These ready-made antibodies protect the body even if the body hasn’t yet experienced a primary response.

While active immunity may protect us from a disease for a lifetime, passive immunity is the more short term.

Questions

1. Write the causal organism, epidemiology and symptoms of Elephantiasis, Ascariasis and Ringworm.

2. Define immunity. Explain the types of immunity.

3. Write a note on barriers of innate immunity.

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Vaccines

The principle of immunisation or vaccination is based on the property of ‘memory’ of the immune system.

In vaccination, a preparation of antigenic proteins of pathogen or inactivated/weakened pathogen (vaccine) are introduced into the body.

The antibodies produced in the body against these antigens would neutralise the pathogenic agents during actual infection.

The vaccines also generate memory – B and T-cells that recognise the pathogen quickly on subsequent exposure and overwhelm the invaders with a massive production of antibodies.

Immunization

Immunization is a process providing resistant to pathogenic microbes and other infectious diseases by the administration of a vaccine into the body.

By immunization, it stimulates the body’s immune system to protect against subsequent infection or disease.

If a person is infected with some deadly microbes to which quick immune response is required as in tetanus, we need to directly inject the preformed antibodies, or antitoxin (a preparation containing antibodies to the toxin).

 Even in cases of snakebites, the injection which is given to the patients, contain preformed antibodies against the snake venom. This type of immunisation is called passive immunisation.

Recombinant DNA technology has allowed the production of antigenic polypeptides of pathogen in bacteria or yeast. e.g., hepatitis B vaccine produced from yeast.

What is an Allergy?

The exaggerated response of the immune system to certain antigens present in the environment is called allergy.

The substances to which such an immune response is produced are called allergens.

An allergy is an immunological hypersensitivity. The antibodies produced to these are of IgE type.

Common examples of allergens are mites in dust, pollens, animal dander, etc.

Symptoms of allergic reactions include sneezing, watery eyes, running nose and difficulty in breathing.

Allergy is due to the release of chemicals like histamine and serotonin from the mast cells.

The use of drugs like anti-histamine, adrenalin and steroids quickly reduce the Symptoms of allergy.

What is Autoimmunity?

Autoimmunity is the system of immune responses of an organism against its healthy cells and tissues. A disease which results due to this kind of response is called an autoimmune disease.

The higher vertebrates are capable of recognising foreign antigens. Due to the memory-based acquired immunity, their immune system could very well distinguish between its cells and the foreign organisms.

However, due to a genetic condition or some other unknown reason, the body attacks its own cells. The resulting diseases are called autoimmune diseases. The most common example of an autoimmune disease is rheumatoid arthritis (RA). Others are Addison’s disease, Graves’ disease, polymyositis (PM), etc.

Lymphoid Organs

The organs of the immune system which are involved in defending the body against invading pathogens causing infections or spread of tumours is termed as Lymphoid organs.

It includes bone marrow, lymph nodes, lymphatic vessels, thymus, spleen, and various other clusters of lymphoid tissue.

Lymphoid organs are the site of origin, maturation, and proliferation of lymphocytes. They exist as primary, secondary or tertiary and these are based on their stage of development and maturation.

Primary lymphoid organs

The primary lymphoid organs produce and allow the maturation of lymphocytes.

Examples of primary lymphoid organs include thymus and the bone marrow.

Secondary lymphoid organs

The secondary lymphoid organs are in promoting the sites for the interaction of lymphocytes with the antigen.

Secondary lymphoid organs are the spleen, lymph nodes, tonsils, Mucous Associated Lymphoid Tissue (MALT), Peyer's patches of the small intestine and appendix.

There is lymphoid tissue also located within the lining of the major tracts (respiratory, digestive and urogenital tracts) called mucosal associated lymphoid tissue (MALT). It constitutes about 50 per cent of the lymphoid tissue in human body.

 The thymus is a lobed organ located near the heart and beneath the breastbone. Both bone-marrow and thymus provide micro-environments for the development and maturation of T-lymphocytes.

The spleen is a large bean shaped organ. The spleen is located under the ribcage and above the stomach in the left upper quadrant of the abdomen. It mainly contains lymphocytes and phagocytes. It acts as a filter of the blood by trapping blood-borne microorganisms. Spleen also has a large reservoir of erythrocytes.

The lymph nodes are small solid structures located at different points along the lymphatic system.

Lymph nodes serve to trap the micro-organisms or other antigens, which happen to get into the lymph and tissue fluid. Antigens trapped in the lymph nodes are responsible for the activation of lymphocytes present there and cause the immune response.

Acquired Immune Deficiency Syndrome (AIDS)

 It is a disorder of cell-mediated immune system of the body. There is a reduction in the number of helper T-cells which stimulate antibody production by B-cells. This results in the loss of natural defence against viral infection.

AIDS is caused by the Human Immuno deficiency Virus (HIV), a member of a group of viruses called retrovirus, which have an envelope enclosing the RNA genome.

AIDS was first noticed in USA in 1981. World AIDS day is celebrated on 1^st December.

Mode of transmission

⏩(a) By sexual intercourse⏪

⏩(b) By infected blood, blood products, donated semen and organs⏪

⏩(c) By contaminated needles used⏪

⤷During the treatment of patients

⤷When drug abusers share needles

⏩(d) From an infected mother to her child⏪

⤷Across the placenta before birth

⤷While the baby is passing through the birth canal

⤷Possibly by breast milk

Symptoms of AIDS

An HIV infection can be divided into 3 stages:

(1) Asymptomatic Carrier: Only 1%-2% of those newly infected have symptoms like fever, chills, aches, swollen lymph glands, and an itchy rash. These symptoms disappear, and there are no other symptoms for 9 months or longer.

(2) AIDS Related Complex (ARC): The most common symptom of ARC is swollen lymph glands in the neck, armpits, or groin that persist for 3 months or more.

(3) Full-Blown AIDS: In this final stage, there is severe weight loss and weakness due to persistent diarrhoea and usually one of several opportunistic infections is present.

After getting into the body of the person, the virus enters into macrophages where RNA genome of the virus replicates to form viral DNA with the help of the enzyme reverse transcriptase.

This viral DNA gets incorporated into host cell’s DNA and directs the infected cells to produce virus particles.

The macrophages continue to produce virus and in this way acts like a HIV factory.

Simultaneously, HIV enters into helper T-lymphocytes (TH), replicates and produce progeny viruses.

The progeny viruses released in the blood attack other helper T-lymphocytes. This is repeated leading to a progressive decrease in the number of helper T-lymphocytes in the body of the infected person.

Diagnostic test for AIDS is ELISA (enzyme-linked Immuno-sorbent assay).

Treatment of AIDS with anti-retroviral drugs is only partially effective. They can only prolong the life of the patient but cannot prevent death, which is inevitable.

Preventions of AIDS

Use of condoms during sex

Avoiding unsafe and multiple sex

Blood should be screened before transfusion

Materials should be sterilized before using

Public awareness

Cancer

Cancer is one of the most dreaded diseases of human beings and is a major cause of death all over the world.

Normal cells show a property called contact inhibition by virtue of which contact with other cells inhibit their uncontrolled growth.

Cancer cells lost this property.

Types of tumour

Cancerous cells continue to divide giving rise to masses of cells called tumors. There are two kinds of tumour-

⏩Benign tumors⏪

⏩Malignant tumors⏪

Benign Tumour

These tumours are localized at a particular location in the body.

Moreover, it does not spread to the other parts of the body and is generally harmless. However, when a benign tumour occurs in areas such as the brain, they can turn fatal.

Treatment often involves surgery and it does not grow back.

Malignant Tumour

These tumours are cancerous – meaning that it will grow quickly and spread to other normal tissues of the body. This ability to spread is called metastasis.

Usually, cancer cells metastasize when it gets into the bloodstream or the lymph nodes and form secondary tumours across various sites in the body.

Types of Cancer

From a medical perspective, cancer types can be classified based on the type of cell it originated from. Therefore cancer can be classified into:

⏩Carcinoma⏪

⏩Sarcoma⏪

⏩Melanoma⏪

⏩Lymphoma & Leukaemia⏪

Carcinoma: The most common form of cancer, it originates from the epithelial cells

Sarcoma: Originates from the connective tissues such as cartilage, fat and bone tissues.

Melanoma: Originates from melanocytes, which are a type of cell that contains pigments.

Lymphoma & Leukaemia: Originates from the cells that comprise blood (such as b lymphocytes or white blood cells)

Causes of Cancer

Many factors are attributed to causing cancer. The most probable factors include:

Physical factors – Ionizing radiation such as X-rays and gamma rays

Chemical factors – Such as tobacco and smoke

Biological factors – Viral oncogenes, proto-oncogenes and cellular oncogenes. Cancer causing viruses called oncogenic virus have gene called viral oncogenes. Several genes called cellular oncogenes (c-onc) or proto oncogenes have been identified in normal cells.

The above factors are called carcinogens.

Diagnosis of Cancer

The following methods are used to detect cancer:

⏩Biopsy⏪

⏩Histopathological studies of tissue⏪

⏩Radiography technique⏪

⏩Computed tomography (C.T.)⏪

⏩Magnetic resonance imaging (M.R.I.)⏪

⏩Molecular biology techniques⏪

Treatment of Cancer

Surgery – Surgically removing localized cancerous mass (Effective for benign tumours)

Radiation therapy – In this therapy, radiation is used to kill the cancer cells.

Chemotherapy – Chemotherapeutic drugs are used to kill cancer cells.

Combination therapy - Most cancers are treated by combination of surgery, radiotherapy and chemotherapy.

Immunotherapy – Patients are given with alpha-interferon which activate their immune system and help in destroying the tumour.

Drug abuse

The intake of drugs for a purpose other than their normal clinical use in an amount and frequency that impairs one’s physical, physiological and psychological function, it constitutes drug abuse .

The drugs which are commonly abused include opioids, cannabinoids, coca-alkaloids, barbiturates, amphetamines, and LSD(lysergic acid diethylamide)

Types of drugs

⏩Opioids⏪

⏩Cannabinoids⏪

⏩Coca- alkaloids⏪

⏩Hallucinogens⏪

1. Opioids: These drugs bind the opioid receptors in central nervous system and gastro-intestinal tract. e.g., morphine and heroin.

Morphine is obtained from the latex of poppy plant .

Heroin (smack) is obtained by acetylation of morphine. It is chemically diacetyl morphine and it is bitter, white, odourless, crystalline compound.

Heroin is a depressant and slows down the body functions and is also known as brown sugar.

It is generally taken by smoking and injection.

2. Cannabinoids: These are a group of chemicals which interact with the cannabinoid receptors present mainly in the brain.

⤷Natural cannabinoids are obtained from the inflorescence of Cannabis sativa .

⤷Marijuana, hashish, ganja and charas are also produced by various combinations of flower tops, leaves and resins of Cannabis plant .

⤷They affect the cardiovascular system of the body and are taken by inhalation and oral ingestion.

⤷They are abused by sports persons in recent times.

3. Coca- alkaloids: It is obtained from Erythroxylum coca.

⤷It interferes with the transport of neurotransmitter, dopamine.

⤷It is usually taken by smoking.

⤷It has a potential stimulating action on the central nervous system and produces a sense of euphoria and increased energy, its excessive dosage causes hallucination.

4. Hallucinogens: They produce the sense of ‘see sound and hear colour’.

⤷Products from plants like Atropa belladona and Datura . are hallucinogenic.

⤷LSD(Lysergic Acid Diethylamide) is obtained from a fungus, Claviceps purpurea

Tobacco

It is usually chewed or smoked or used as snuff.

⤷It mainly contains nicotine, which is a stimulant and toxin.

⤷Adrenal gland is stimulated by nicotine to release adrenaline and non-adrenaline which increases the blood pressure and heartrate.

⤷Chances of lung cancer, bronchitis, coronary heart diseases, cancer of throat, gastric ulcer, cancer of urinary bladder etc. are increased by the smoking of tobacco.

⤷Smoking of tobacco also increases the carbon monoxide content of blood and reduces concentration of haemebound oxygen, thus causing oxygen deficiency in the body.

Alcohol

Alcohol is a depressant and it affects central nervous system.

The chronic use of drugs and alcohol damages nervous system and liver (cirrhosis)

 The use of drugs and alcohol during pregnancy is also known to adversely affect the foetus.

Addiction and Dependence

There are following causes of drugs/alcohol abuse:-

 ⏩Curiosity⏪

⏩Need for adventure⏪

⏩Excitement⏪

⏩Experimentation⏪

⏩To escape from stress⏪

⏩Un supportive family structure⏪

The tolerance level of the receptors in our body increases with repeated use of drugs/alcohols, and consequently they respond to higher doses of drugs/alcohols.

If the regular dose of drugs/alcohol is abruptly discontinued, the body to manifests a characteristic and unpleasant withdrawal symptoms which can anxiety, nausea, sweating etc.

Adolescence and drug abuse

Adolescence is the period during which the child becomes matured.

It is between 12 –18 years of age.

Use of alcohol during adolescence can lead to heavy drinking in adulthood.

Effects of drug abuse

Reckless behaviour, and violence are the immediate effect of drug abuse.

Excess doses may lead to coma and death due to cerebral haemorrhage, respiratory and heart failure.

Death is caused by a combination of drugs or their intake with alcohol.

Infections like AIDS and Hepatitis can be caused if drug is taken intravenously.

Central nervous system and liver is damaged by chronic use of drugs and alcohols.

The side-effects of the use of anabolic steroids

In Females

⤷Masculinisation (features like males)

 ⤷Increased aggressiveness

⤷Mood swings

 ⤷Depression

 ⤷Abnormal menstrual cycles

⤷Excessive hair growth on the face and body

⤷Enlargement of clitoris

⤷Deepening of voice

In Males

⤷Acne, increased aggressiveness, mood swings, depression

⤷Reduction of size of the testicles, decreased sperm production

⤷Potential kidney and liver dysfunction

⤷Breast enlargement

⤷Premature baldness

⤷Enlargement of the prostate gland. 

Warning Signals

i. Drop in Academic performance

ii. Lack of interest in personal hygiene

iii. Withdrawal and isolation from family and friends

iv. Aggressive and rebellious behavior

v. Lack of interest in hobbies

vi. Change in sleeping and eating habits

vii. Fluctuations in weight etc.

Prevention and Control

i. Avoid undue peer pressure

ii. Education and counselling

iii. Seeking help from parents and peers

iv. Looking for danger signs

v. Seeking professional and medical help

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