Immunity is exemption of Disease and different from Resistance
Immunity in Hindi is known as Pratirodhak shamta whereas Resistance is Rodhak shamta. Difference is clear from name. Find out details in ppt
Naturally occurring protective mechanism against disease eg. mother sent child to the home where small pox has occurred
Control of disease by immune system is not always successful
–System become ineffective & result in Immunodeficiency disease
–While in some others system may over-react and cause Hypersensitivity (allergy)
Immune system get more clear with blood groups A, B, AB & O in 1902 by Karl Land Steiner
Immunity has three important characterstics
it is Specific, Recognizable and Memorizable
Specificity
- Can detect remarkably small chemical differences in foreign materials
e g. strains of influenza virus; CoVid-19
Exception: The Cow and Smallpox Viruses share important antigens (Success behind Edward Jenner experiment)
Memory
The ability to respond more rapidly and to a greater degree when confronted with same antigen on a second occasion
Recognition
- Three Skin graft in guinea pig
- Eight days after grafting two appear healthy & one become discolored
- At 16 days the former healed well whereas other rejected and slough off.
- Why? Because rejected one was recognised as foreign so sloughed off
