Question

which of the followinf regarding nk cells is false?

a.nk cells are a type of neutrophil

b.nk cells attack cancer cells and virus infected body cells,

c.nk cells are present in the bl, sppleen, lymph nodes, and red bone marrow.

d. nk cells attack cells that display abnormal mhc antigens.

innate imune system defense include

a.b cells

b. t cells

c.phagocytes

d.plasma cells

which of the following is not a function of the lymphatic system?

a.carrying out immune repsonse

b. transporting respiratory gases

c.transporting diertary fats

d.drainig excess interstitual fluid

which of the statements below does not describe antigens?

a. antigens can include prteins, nucleic acids, lipoproteins,glycoproteins, and certain large polysaccharides

b. the parts of antigen molecules that initiate immune responses are called epitopes or antigenic determinants

c.antigens only come from microbes

d.antigens exhibit immunogenicity and reactivity

Lymph capillaries are absent in all but which of the following?

a.digestiev organs

b.cns

c.bones and teeth

d. bone marrow

Answer 1

1) Answer : a

Nk ( Natural killer cells) are a type of lymphocytes which are cytotoxic. They are known to differentiate and mature in the bone marrow, lymph nodes, spleen, tonsils, and thymus, where they then enter into the circulation. They attack virus infected cells and tumour cells. They can attack cells with abnormal mhc( major histocompatabilty complex) antigens. They kill cells by apoptosis.

2) Answer : C

Innate immune system defence includes phagocytic cells (PMN or polymorphonuclear leucocytes or Neutrophils ) dendritic cells, natural killer cells, plasma proteins. T cells, B cells, plasma cells, lymphocytes comes under adaptive immunity which is stimulated by microbes,

3) Answer : b

Lymphatic system does not play any role for exchange of respiratory gases.

4) Answer : d

Antigens does not exhibit immunogenicity and reactivity because they can not elicit immune response on their own. They too have small sizes which are not sufficient to generate immune response like peptides.

5)Answer : b

lymph capillaries are tiny, thin-walled microvessels located in the spaces between cells (except in the central nervous system and non-vascular tissues) which serve to drain and process extracellular fluid. The thymus and the bone marrow constitute the primary lymphoid organs involve in the production and maturation of b and T cells .The secondary or periphery lymphoid organs which include lymph nodes and the spleen, maintain mature naive lymphocytes and initiate an adaptive immune response.