Definitions [5]
Define health.
Health is defined as the state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.
Definition: Immunity
The overall ability of the host to fight the disease-causing organisms conferred by the immune system is called immunity.
Definition: Immunology
The study of the immune system and immune responses is called immunology.
Define antibiotic.
- Carbon compounds obtained from some bacteria and fungi for destroying or preventing the growth of harmful micro-organisms are called ‘Antibiotics’.
- Examples of antibiotics: Penicillin, ampicillin,
Definition: Antibiotics
Carbon compounds obtained from certain bacteria and fungi that destroy or inhibit the growth of harmful microorganisms and are used in the treatment of infectious diseases is called antibiotics.
Key Points
Key Points: Immunity
- Immunology studies the immune system, while immunity is the host's ability to fight disease-causing organisms.
- Body defence works at two levels: external local barriers that prevent entry, and the internal immune system that fights invading germs.
- The immune system can accurately distinguish between the body's own cells (self) and foreign invaders (non-self).
- Foreign substances that trigger an immune response are antigens, and the protective chemicals produced against them are antibodies.
- Stimulated lymphocytes divide into active effector cells (to fight the immediate infection) and dormant memory cells.
- Memory cells stay in the lymph nodes to mount a much faster and stronger immune response upon subsequent encounters with the same antigen.
