Human Health and Diseases Class 12 Notes Biology Chapter 8 - CBSE
What are Human Health and Diseases?
Health is the state of complete physical, mental, and social well-being.
A condition of the living body or plant or one of its parts that impairs normal functioning and is typically manifested by distinguishing signs and symptoms : like sickness, malady etc.
Pathogens also known as infectious agents are the parasites that enter the human body through various means, then multiply, and interfere with normal metabolic activities of the host. They are organisms that can cause disease. There are five main types of Pathogens :
Controlling The Spread Of Pathogenic Disease
Vaccination is the term used for giving a vaccine i.e., the process of introducing a substance to a host.
Immunisation is the term used for the process of both getting the vaccine and becoming immune to the disease as a result of the vaccine.
Organs Of Human Immune System
|➥ Primary Lymphoid Organ
|➥ Secondary Lymphoid Organ
|➥ It consist of bone marrow and thymus.
|➥ Lymphocytes migrate here after attaining maturity.
Aids (Acquired Immuno Deficiency Syndrome)
It is caused by HIV (Human Immunodeficiency Virus) [HIV is a retrovirus (RNA virus)].
Transmission of HIV occurs through:
Sexual contact with infected person, Sharing infected needles, Transfusion of contaminated Infected blood from mother to child through placenta.
Diagnosis of AIDS
By ELISA (Enzyme Linked Immuno Sorbent Assay)
No permanent cure; antiretroviral therapies can prolong the life of patient.
Prevention of AIDS
Types Of Tumor
Remain confined to their original location and do not spread.
These exhibit metastasis i.e., the cells sloughed from such tumors reach distant sites and wherever they reach, new tumor is formed.