The document discusses immunity and the immune system. It defines immunity as the resistance exhibited by the host against microorganisms and their products. The immune system includes cells, tissues, and molecules that mediate resistance to infection. The main roles of the immune system are to defend against microbes and tumor cells. There are two main types of immunity - innate immunity which is genetic and provides initial resistance, and acquired immunity which develops from exposure and results in stronger resistance upon future exposures. The mechanism of immunity involves epithelial surfaces, mucous membranes, and other defenses that act as barriers against pathogens.

1. IMMUNITY
PRESENTED BY
BHANENDRA SAHU, DHANESHWAR, ABHAY GAUTAM
B.OPTOMETRY 2ND SEM
MENTORED BY
MISHEL SEPTHY , PUSHMILA JAIN
B.OPTOMETRY 4TH SEM

2. INTRODUCTION:-
Immunity is referred to the resistance exhibited by the host
towards injury caused by micro-organism and their products
Study of structure and function of the immune system known as
“Immunology”
Cells, tissues and molecules that mediate resistance to infection
known as “Immune System”
Resistance of a host to pathogens and their toxic effects are
known as “IMMUNITY”

3. ROLE OF THE IMMUNE SYSTEM:-
Defense against microbes
Defense against the growth of tumor cells
Kills the growth of tumor cells
HOMEOSTASIS:-
Destruction of abnormal or dead cells
Eg:- dead red or white blood cell antigen and antibody complex

6. The main two type’s of immunity:-
Innate Immunity
• The resistance to infections which an individual posses by virtue of
his genetic and constitutional makeup
Acquired Immunity
• Resistance that an individual acquires during his lifetime, which
may be week or absent on first exposure but that increase
dramatically with subsequent exposures to same specific pathogen

7. The Innate immunity is of three types:-
• Species Immunity-
• Total relative refractoriness to a pathogen show by all members of
a species
Eg: All human beings are not susceptible to plant pathogens
• Racial Immunity-
• Within species different races may show differences in susceptibility
to infections
Eg: Negros are resistant to yellow fever and malaria

8. •Individual Immunity-
• Exhibited by different individuals in a race
Eg: Homozygous twins exhibit similar degree of resistance to leprosy
and tuberculosis. Such correlations are not seen in heterozygous
twins
•The Acquired immunity is of two types:-
Active Immunity-
• Also known as adaptive immunity
• Resistance developed by an individual as a result of an antigenic
stimulus
• Used for prophylaxis to increases body resistance

9. • 2 types :-
• Natural active immunity
• Artificial active immunity
Passive Immunity:-
• Resistance transmitted passively to a recipient in a readymade
from.( recipients immune system plays no active role )
• Used for treatment of acute infection
• 2 types :-
• Natural passive immunity
• Artificial passive immunity

10. The Immune system :-

11. MECHANISM OF IMMUNITY :-
Epithelial Surface:-
• Skin and epithelial surfaces cover the body and protects the
individuals
• Healthy skin poses bactericidal influence, salt ,drying sweat
,long fatty acids
• Wet hand predisposes to mycotic and pyogenic infections

12. Mucous membranes:-
• Respiratory tract shape of nose , nasal orifice

13. Respiratory tract barrier to prevent infection :-
• Cilia in Respiratory tract
• Propel the foreign particles
• Respiratory secretion contain

14. Oral Cavity :-
• Saliva
• Stomach HCL
• Large intestine large number
of bacteria

15. Conjunctiva :-
• Contain lacrimal secretions
• Tears contain antibacterial substances
• Lysozyme present except in CSF, sweat, Urine

16. ANTIGEN :-
• Any substance which when introduced parentally into the body
stimulates the production of antibody specifically
• This is a traditional definition since it had got some exception
- Polio vaccine – oral administration
- Some antigen may not produce antibodies
• Specificity is the hallmark of all immunological reactions

17. FUNCTION OF ANTIGEN :-
Immunogenicity :-
• Induction of immune response
Immunological Reactivity :-
• Specific reaction with antibodies or sensitized cells
• Based on this function antigen is classified as
- Complete antigen :
Induce antibody formation and specific immune response

18. ANTIBODIES :-
• A antibody is an immunoglobulin (glycoprotein) molecule
formed by the immune system in response to an antigen
stimulus
• Immunoglobulin provides a structural and chemical concepts
• “Antibody” is a biological and functional concept
• All antibodies are immunoglobulin but all immunoglobulin are
not antibodies
• Constitute the gamma globulin portion of blood protein 20-
25% of total serum protein

20. CLASSES OF ANTIBODIE’S :-
• Based on physiochemical and antigenic difference antibodies
are classified as :-
- IgG : IgG1 , IgG2 , IgG3 , IgG4
- IgM : Serum IgA or secretory IgA and IgA1 or IgA2
- IgA
- IgD
- IgE
***Decreasing order of their concentration

22. IgG:- Immunoglobulin G or IgG works efficiently to coat microbes,
speeding their uptake by other cells in the immune system
IgM:- IgM is very effective at killing bacteria
IgA:- Concentrates in body fluids- Tears saliva, the secretions of the
respiratory tract and the digestive-guarding the entrances to the body
IgE:- whose natural job probably is to protect against parasitic
infections, is villain responsible for the symptoms of allergy
IgD:- Remains attached to B cells and plays a key role in initiating
early B cell response.

23. REFERENCE
https://www.slideshare.net/antigen and antibody
https://www.slideshare.net/immunity
Images from google image
https://www.google.com/images/immunity