Lecture by Dr. Amin. Jinnah Medical College Peshawar. Prepared by Danyal Hassan (Student).

1. Dr. Amin Lecture by:-
Danyal Hassan
 Immunity
Def:-
 “ The ability of the body to kill or destroy the micro-organisms or toxins,
which tends to damage the body”.
Classification of Immunity:-
1) Natural/Innate/Inborn Immunity:-
Def:-
 “ Natural or Inborn ability of the body which transfers from parents to
offsprings”.
Eg; Destruction of Micro-organisms by WBC’s.
Resistance of skin to micro-organisms.
Various GI- Secretions.
Immunity
Natural Immunity
Acccuired
Immunity

2. 2) Accquired Immunity:-
Def:-
 “ The Immunity which is produced by the body against the micro-
organisms”.
 This Immunity is not transferred geniticallly.
 Produced in our bodies by us.
Eg; Vaccination.
Types f Accquired Immunity
i) Humoral Immunity:-
Def:-
 “ That type of Acq. Immunity which is produced by antibodies against
micro-organisms”.
 Also called as Anti-Body mediated Immunity.
ii) Cell Mediated Immunity:-
Def:-
 “ That type of Acq. Immunity which is produced by T-Lymphocytes”.
Accquired
Immunity
Humoral
Immunity
Cell Mediated
Immunity

3. Cells ( Responsible for Immunity)
a) B-Lymphocytes:-
Formation: Bone Marrow
Maturation: Bone Marrow (that’s why they are called B-Lymphocytes).
Functions: Produces Anti-Bodies (Plasma cells also produces Anti-Bodies).
 Anti-Body functions in Humoral Immunity.
b) T-Lymphocytes:-
Formation: Bone Marrow
Maturation: Thymus (that’s why they are called T-Lymphocytes).
Functions: Responsible for Cell Mediated Immunity.
Inflammation
Def:-
 “The secondry changes occurring in the tissues due to the substances
released as a result of tissue injury”.
 The released substances are Inflammtory Mediators (Histamine,
Prostaglandine, Seritonin, Bradykinin etc.
Cells ( Involved in Inflammation)
WBC’s  All types ( Granulocytes+ Agranulocytes).
Effects of Inflammation
i) Increase in Vascular Permeability ( Swelling).
ii) Vasodilatation  Redness, Warmness, Pain, Loss of Function.
Lymphocytes
B-Lymphocytes T-Lymphocytes

4. Walling Off Effect
Def:-
 “ The blocking of the tissue spaces in the inflamed area by Fibrinogen and
Clotts”.
 It is an important process which prevents the spreading of inflammation.
Anti-Body
Def:-
 “ The Immuno-globulin protein which is produced by the body against an
antigen”.
 It is only produced whenever there is an inflammation in the body.
Sources:-
 B-Lymphocytes
 Plasma Cells
As discussed earlier.
Classification Of Anti-Bodies
There are 5 classes of Anti-Bodies, we have to study:-
i) IgG ( Immuno-Globulin G)
ii) IgM
iii) IgA
iv) IgD
v) IgE
 (Mnemonic: G,MADE)
 None of the Anti-Bodies can pass through the placenta but “IgG” can cross
the placenta.
 IgA is present in the body’s secretions eg; Bile juice, Saliva etc.
 IgE is used in allergic reactions.
 IgM is the very 1st
anti body produced on inflammation.

5. Components of Anti-Bodies
i) Variable Portion  Antigen Binding Site.
ii) Constant Portion  Identification site of Anti-Body.
iii) Heavy Chains  Two
iv) Light Chains  Two
v) Disulphide Bonds.