Human Health and Diseases Class 12 | Biology NCERT Chapter 7 One Shot | CBSE NEET

LearnoHub - Class 11, 122 minutes read

Health encompasses physical, mental, and social well-being, achieved through yoga, exercise, and a balanced diet. Diseases like typhoid, malaria, pneumonia, and ringworm require specific diagnosis and treatment, emphasizing the importance of maintaining good health to prevent illnesses.

Insights

  • Health encompasses physical, mental, and social well-being, achieved through yoga, exercise, and a balanced diet.
  • Diseases are categorized as infectious or non-infectious, with common examples like typhoid, malaria, and pneumonia having distinct causes, symptoms, and treatments.
  • The immune system plays a vital role in protecting against diseases, with lymphocytes producing antibodies to combat pathogens through humoral and cell-mediated immunity.
  • AIDS and cancer are severe health conditions with distinct causes, symptoms, and treatments, emphasizing the importance of prevention and early diagnosis for effective management.

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Recent questions

  • What is the definition of health?

    Health is complete physical, mental, and social well-being.

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Summary

00:00

"Complete Health: Physical, Mental, Social Well-being"

  • Health is defined as complete physical, mental, and social well-being.
  • Physical well-being involves being disease-free and physically fit.
  • Mental well-being requires peace of mind, absence of stress, anxiety, and depression.
  • Social well-being entails good relationships with friends and neighbors.
  • Maintaining good health involves yoga, physical exercise, and a balanced diet.
  • Yoga is both a physical and spiritual discipline that enhances mental and physical well-being.
  • Physical exercise, like walking, jogging, or sports, boosts energy and flexibility.
  • A balanced diet includes fruits, vegetables, dairy, protein-rich foods, and whole grains in appropriate amounts.
  • Diseases disrupt the body's normal functioning, leading to symptoms and signs.
  • Diseases are categorized as infectious (communicable) or non-infectious (non-communicable), based on their ability to spread from person to person.

15:37

Mosquitoes transmit diseases like typhoid and malaria.

  • Mosquitoes transmit diseases by sucking blood and injecting pathogens into the body.
  • Common diseases affecting humans include typhoid, malaria, pneumonia, scarious, and ringworm.
  • Typhoid is caused by Salmonella typhi, leading to symptoms like high fever, headache, weakness, and loss of appetite.
  • Typhoid is diagnosed through blood or urine culture tests, including the Widal test.
  • Antibiotics are used to treat bacterial infections like typhoid, not viral infections.
  • Pneumonia is caused by Streptococci pneumonia and Haemoflagellates, affecting the lungs and leading to symptoms like cough, fever, chills, weakness, and shortness of breath.
  • Pneumonia is diagnosed through chest X-rays, urine tests, and mucus tests, and treated with antibiotics.
  • The common cold is a viral infection spread through contaminated air and objects, affecting the nasal passages and causing symptoms like runny nose, sore throat, cough, and hoarse voice.
  • Treatment for the common cold includes nasal sprays, nasal drops, and painkillers, as antibiotics are ineffective against viral infections.
  • Malaria is caused by Plasmodium parasites transmitted through mosquito bites, leading to symptoms like fever.

30:46

"Malaria: Transmission, Symptoms, Diagnosis, Treatment, Prevention"

  • Female Anopheles Mosquitoes are the only ones capable of transmitting malaria parasites into the human body.
  • Malaria symptoms include high fever, chills, headaches, body aches, nausea, and vomiting.
  • Malaria diagnosis involves blood tests and liver function tests to detect the presence of the parasite.
  • Antimalarial drugs are available in the market for treating malaria effectively.
  • The life cycle of a malarial parasite involves transmission from mosquitoes to humans, leading to the spread of the disease.
  • The malarial parasite enters the human body through mosquito bites, transmitting gametocytes and spores.
  • Spores released by the parasite multiply in the human body, affecting red blood cells and causing symptoms of malaria.
  • The malarial parasite uses both humans and mosquitoes as hosts in its life cycle.
  • A similar transmission process is explained for amoebic dysentery, where contaminated food and water spread the infection through house flies.
  • Prevention of amoebic dysentery involves maintaining cleanliness and hygiene in food and water consumption.

46:20

Preventing Disease: Steroids, Antibiotics, and Hygiene

  • Steroids are given to everyone for treatment.
  • Antibiotics can be used for worms that are bacteria.
  • Antibiotics are effective against bacteria only.
  • Ringworm is caused by a fungus called Phyton.
  • Ringworm symptoms include dry, itchy skin with red patches.
  • Anti-fungal drugs like creams can treat ringworm.
  • Personal cleanliness and not sharing personal items can prevent infectious diseases.
  • Proper disposal of excreta and clean drinking water are crucial for disease prevention.
  • Washing fruits and vegetables before consumption helps prevent infections.
  • Using mosquito repellents and insecticides in drainage areas can prevent disease spread.

01:02:24

Understanding Immune System: Memory, Cells, Antibodies

  • The body's immunity system protects against disease-causing organisms by storing memory of past attacks.
  • Acquired immunity involves primary and secondary responses to pathogen attacks.
  • Primary response is low intensity, while secondary response is high intensity due to memory of past attacks.
  • Lymphocytes, including B and T cells, play a crucial role in immune responses.
  • B lymphocytes produce antibodies to neutralize pathogens, while T lymphocytes stimulate B cells.
  • Antibodies are Y-shaped proteins that recognize and neutralize antigens, preventing their harmful effects.
  • Antigens are foreign substances that trigger the production of antibodies by B lymphocytes.
  • B cells include plasma B cells that produce antibodies and memory B cells that respond quickly to subsequent attacks.
  • T cells, like helper T cells, assist in stimulating B cells to produce antibodies in cell-mediated immunity.
  • Humoral immunity involves antibodies in the blood, while cell-mediated immunity relies on cells to combat pathogens without antibody production.

01:18:18

"Immune System, Transplantation, Vaccination: Key Concepts"

  • The immune system of the body is crucial for distinguishing between self and non-self, leading to rejection of foreign organs like kidneys.
  • Blood group and tissue matching are essential before transplantation to prevent rejection by the body.
  • Immunosuppressants are given to transplant patients to boost their immune response and prevent rejection.
  • Active immunity involves the production of antibodies inside the body, as seen in cases like chickenpox or hepatitis A.
  • Vaccination introduces a weakened or dead form of a microbe into the body to trigger an immune response and build immunity.
  • Natural active immunity occurs when a person naturally contracts a disease and develops antibodies against it.
  • Artificial active immunity is achieved through vaccines, where the body produces antibodies without contracting the disease.
  • Natural passive immunity happens when antibodies are passed from mother to child, while artificial passive immunity involves injecting antibodies directly into the body.
  • Vaccination schedules are crucial to ensure the effectiveness of vaccines, especially for children.
  • Vaccination has been instrumental in eradicating diseases like smallpox and reducing the prevalence of others like measles, showcasing its effectiveness in disease prevention.

01:33:32

Understanding Allergies: Causes, Symptoms, and Treatments

  • Allergens cause agitation in the body, leading to allergic reactions.
  • Mast cells release chemicals like histamine and serotonin during an allergic response.
  • Mast cells are immune cells found in tissues and along blood vessels.
  • The immune system produces antibodies, like immunoglobulin, in response to allergens.
  • When allergens interact with mast cells, granules are released, causing allergic symptoms.
  • Allergic reactions occur when the body encounters allergens like dust, pollen, or perfume.
  • Symptoms of allergies include watery eyes, runny nose, breathing difficulties, and sneezing.
  • Anti-allergen drugs can be used to alleviate severe allergy symptoms.
  • The human immune system consists of lymphocytes, which produce antibodies to fight antigens.
  • Lymphoid organs like the bone marrow, thymus, spleen, lymph nodes, tonsils, and Peyer's patches play crucial roles in the immune response.

01:49:13

Understanding AIDS: Causes, Symptoms, and Prevention

  • AIDS is caused by the human immunodeficiency virus (HIV), targeting the immune system, making even a mild cold fatal.
  • Transmission of AIDS occurs through sexual contact, contaminated blood transfusion, and from an affected mother to her child.
  • The virus spreads through blood transfusion, affected needles, and from an affected mother to her child via the placenta.
  • HIV is a retrovirus that enters host cells, undergoes reverse transcription, and replicates, leading to a decrease in T cells and macrophages.
  • Symptoms of AIDS include diarrhea, fever, weight loss, and minor infections turning fatal due to the immune system being targeted.
  • AIDS can be diagnosed through an Elisa test, and treatment involves anti-retroviral drugs to reduce the number of viruses in the body.
  • Prevention of AIDS transmission includes using condoms, avoiding multiple sex partners, ensuring partners are HIV tested, and using disposable needles.
  • Cancer is abnormal cell growth and division leading to the formation of tumors that disrupt normal body functioning.
  • Tumors can be benign, limited to one area, or malignant, spreading to other parts of the body through blood or lymphatic system.
  • Benign tumors grow locally, while malignant tumors spread rapidly to other body parts, impacting normal body functions.

02:04:31

Understanding Cancer: Growth, Spread, and Treatment

  • Lymph spreads throughout the body, connecting different parts and can spread from one place to another.
  • Malinators are lymph cells that continue to grow without limits, causing traffic problems in the body.
  • Malinators are harmful as they grow and spread, damaging healthy tissues and causing tumors.
  • Metastatic cancers are cancers that grow and spread to other body parts, damaging healthy tissues.
  • Carcinogens are agents that turn normal cells into cancerous cells, such as ultraviolet radiation and oncogenic viruses.
  • Cancer can have genetic links, increasing the risk of cancer but not guaranteeing its occurrence.
  • Cancer diagnosis involves techniques like biopsies and scans like MRI, CT, and PET scans to detect cancer cells.
  • Cancer treatment includes surgery to remove cancerous cells, chemotherapy to destroy cancer cells, and radiotherapy to kill cancer cells with radiation.
  • The type of cancer treatment depends on the stage and type of cancer, sometimes involving a combination of surgery, chemotherapy, and radiotherapy.
  • Chemotherapy has side effects but with advancements, treatments are improving, and early diagnosis through regular check-ups is crucial for effective treatment.

02:20:15

Dangers of Drugs, Tobacco, and Alcohol

  • Heroin is a chemical compound extracted from the latex of the poppy plant, acting as a depressant that slows down bodily functions.
  • Cannabinoids, obtained from the cannabis plant, impact the brain by binding to receptors, affecting memory, thinking capabilities, and coordination.
  • Cocaine, an alkaloid from the cocoa plant, is a strong CNS stimulant that increases dopamine levels, providing extra energy but leading to negative long-term effects.
  • Tobacco, containing nicotine, is harmful when smoked, chewed, or snuffed, impacting the lungs, respiratory system, blood pressure, adrenal glands, and potentially causing cancer and heart disease.
  • Peer pressure, trendiness, and curiosity are common reasons why youth turn to drugs, alcohol, or tobacco, leading to addiction due to the effects on the central nervous system.
  • Social gatherings often involve the consumption of harmful substances like drugs, tobacco, or alcohol, causing long-term harm to the body.
  • It is crucial to be cautious of adopting harmful habits from others and to understand the severe adverse effects of substances like drugs, tobacco, and alcohol on health.
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