Health and disease class 12. NCERT Solutions for Class 12 Biology Chapter 8 Human Health and Disease 2019-01-10
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NCERT Solutions for Class 12 Biology Chapter 8 Human Health and Disease
Life cycle of plasmodium : Plasmodium enters the human body as small sporozoites through the bite of infected female anopheles mosquito and multiplies within the lever cells. You might have heard about malaria, a disease man has been fighting since many years. Lymphoid organs are the organs where origin and maturation and proliferation of lymphocytes occur. Infections- caused due to pathogens. Ringworms are generally acquired from soil or by using towels, clothes or even the comb of infected individuals.
Drinking water and food contaminated by the faecal matter are the main source of infection. They infect the nose and respiratory passage but not the lungs. Health can be defined as a state of complete physical, mental and social well-being. Cancer detection and diagnosis-cancer detection is based on biopsy and histopathological study of the tissues, blood and bone marrow test for increased cell counts. Lymphatic vessels of lower limbs get blocked. A large number of other infectious diseases like polio, diphtheria, pneumonia and tetanus have been controlled to a large extent by the use of vaccines. When the functioning of one or more organs or systems of the body is adversely affected, characterised by various signs and symptoms, we say that we are not healthy, i.
It protects the individuals from pathogens present on other members of the same species. Concept of health There are four major concepts of health 1. Cancer cells lost this property. It could lead to heavy drinking in adulthood. As you have read, immune system is unique in the sense that it recognises foreign antigens, responds to these and remembers them. Cancer cells lose the molecules that keep cells bonded together.
Human Health and Disease for Class 12 Chapter 8 Biology Notes
When People are healthy they are more efficient to work which increases productivity and brings economic prosperity. The exaggerated response of the immune system to certain antigens present in the environment is called allergy. The secondary lymphoid organs provide the sites for interaction of lymphocytes with the antigen, which then proliferate to become effector cells. Primary lymphoid organs include bone marrow and thymus. Psychosocial concept- This concept states about social cultural and economic as well as psychological factors in defining health and disease. This means deficiency of immune system, acquired during the lifetime of an individual indicating that it is not a congenital disease.
NCERT Class XII Biology Chapter 8 : Human Health and Disease
It constitute 50% of lymphoid tissues in human body. The pathogens can enter our body by various means, multiply and interfere with normal vital activities, resulting in morphological and functional damage. Symptoms of these disease include internal bleeding, muscular pain, fever, anemia and blockage of the intestinal passage. . In later years, biology stated that mind influences, through neural system and endocrine system, our immune system and that our immune system maintains our health.
Signal Recognition Normal cells recognize signals. Such precautions have become all the more important especially in the light of recent widespread incidences of the vector-borne Aedes mosquitoes diseases like dengue and chikungunya in many parts of India. Drug and alcohol abuse also affect our health adversely. A cartoon of an antibody is given in Figure 8. Even friends, if they find someone using drugs or alcohol, should not hesitate to bring this to the notice of parents or teacher in the best interests of the person concerned.
Important Questions class 12 Biology Human Health and Disease
As these cells actively divide and grow they also starve the normal cells by competing for vital nutrients. Generally taken by snorting and injection, heroin is a depressant and slows down body functions. The eggs of the parasite are excreted along with the faeces of infected persons which contaminate soil, water, plants, etc. Human immune system can distinguish between self and foreign molecules or foreign bodies. Explain in brief about the types, diagnosis and treatment available for cancer? Elephantiasis or filariasis Wuchereria W. This is one of the two types of our acquired immune response — antibody mediated. Flowchart to show lifecycle of Plasmodium Immunity — the ability of host cells to fight the disease causing microorganism due to immune system is called immunity.
Human Health and Disease for Class 12 Chapter 8 Biology Notes
Ascaris, the common round worm and Wuchereria, the filarial worm, are some of the helminths which are known to be pathogenic to man. Cancer cells do not communicate with each other Adhesion and Invasion These cells have external membranes that allow them to bond with other cells. Two, sometimes, due to genetic and other unknown reasons, the body attacks self-cells. Some are obtained from fungi. No Innate Immunity Acquired Adaptive Immunity 1 Present from birth itself Develops during life time 2 The immunity remains throughout life. Coca alkaloid or cocaine is obtained from coca plant Erythroxylum coca, native to South America.
