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Immunity-
Definition –Immunity is defined as Resistance exhibited by the host against any foreign
antigen including, microorganisms and their products.
Classification
2 Types-Innate and Acquired immunity
Innate-native immunity
• It’s the Resistance which individual possesses by birth by virtue of his Genetic and
constitutional make up
Characteristics of innate immunity
• It’s the first line of defense in minutes
• It doesn’t depend on prior contact
• Its non-specific
• There is no memory
• Diversity of innate immunity is limited
Types of innate immunity
1.Species level
• It’s the Resistance shown by all the members of a particular species due to
Physiological and biochemical difference between the tissues of different host species
For example, Frogs are resistant to anthrax, but toads are not
2.Racial immunity
• Within one species different races may exhibit difference in susceptibility to
infections
For example, Resistance to Plasmodium falciparum in Africa and Mediterranean coast
3.Individual level
Resistant to infection varies with different individuals
Factors influencing innate immunity
• Age
• Hormones
• Nutrition
• Stress
Age-Two extremes of life carry higher susceptibility to infection
Immune apparatus in foetus is Immaturee. Pathogens like Rubella, Cytomegalovirus and
Toxoplasma gondii cross placental barrier and lead to congenital malformations
In Old Age-Waning of immune response seen
Hormonal influences - Hormonal disorders -Diabetes mellitus, hypothyroidism,
adrenal dysfunction, Pregnancy (steroid level) enhance susceptibility to infection
Ex: Staphylococcus sepsis common in diabetes
Nutrition-Malnutrition predisposes to infections.
JT
Immunity-
Definition –Immunity is defined as Resistance exhibited by the host against any foreign
antigen including, microorganisms and their products.
Classification
2 Types-Innate and Acquired immunity
Innate-native immunity
• It’s the Resistance which individual possesses by birth by virtue of his Genetic and
constitutional make up
Characteristics of innate immunity
• It’s the first line of defense in minutes
• It doesn’t depend on prior contact
• Its non-specific
• There is no memory
• Diversity of innate immunity is limited
Types of innate immunity
1.Species level
• It’s the Resistance shown by all the members of a particular species due to
Physiological and biochemical difference between the tissues of different host species
For example, Frogs are resistant to anthrax, but toads are not
2.Racial immunity
• Within one species different races may exhibit difference in susceptibility to
infections
For example, Resistance to Plasmodium falciparum in Africa and Mediterranean coast
3.Individual level
Resistant to infection varies with different individuals
Factors influencing innate immunity
• Age
• Hormones
• Nutrition
• Stress
Age-Two extremes of life carry higher susceptibility to infection
Immune apparatus in foetus is Immaturee. Pathogens like Rubella, Cytomegalovirus and
Toxoplasma gondii cross placental barrier and lead to congenital malformations
In Old Age-Waning of immune response seen
Hormonal influences - Hormonal disorders -Diabetes mellitus, hypothyroidism,
adrenal dysfunction, Pregnancy (steroid level) enhance susceptibility to infection
Ex: Staphylococcus sepsis common in diabetes
Nutrition-Malnutrition predisposes to infections.
JT
