Question

Question 3 The following statement regarding hypersensitive reactions is correct It is caused by the first exposure to an antigen OA it involves cellular immunity only ОВ. C. It involves antibodies only OD it can be triggered by exposure to antibodies OE. All of the above statements are false

Answer 1

Ans3)E)All of the above statements are false.

Explaination:Hypersensitivity is exaggregated,abnormal immune response that result in tissue damage and is manifested in the individual on a second or subsequent exposure or contact to an antigen.

Hypersensitivity can result from an abnormality of both humoral and cellular immune responses.

Type 1 ,2 and 3 hypersensitivity are due to inappropriate humoral immune response type 4 hypersensitivity is because of an abnormal cell mediated immune response.

Hypersensitivity is triggered by an secondary exposure of body to an antigen not on antibody exposure.

Ans5)A) All of the statements are incorrect.

Explaination:Complement proteins bind to the Fc part on antibody not on TH cell.

Most of proteins are T dependent antigens while bacterial polysaccharide, lipopolysaccharides and few polymorphic proteins are T independent antigens.

T cells cannot become active when they attach to soluble antigens.For T cell activation antigens must be processed and antigen-MHC complex presented to them by antigen presentating cells(APCs).

MHCII glycoproteins are present only on the surfaces of professional antigen presenting cells that are macrophages,B cells and dendritic cells.