Others

Question 1

Macrophage

Answer 1

It is derived from bone marrow
Migrates as monocyte and settles in various tissues as mature macrophages

Question 2

Macrophage differs from monocyte

Answer 2

5-10 folds larger than monocyte
Contains more lysosomes and organelles
More phagocytic activity
Produces more lytic enzymesand cytokines
Longer life in tissues

Question 3

Func of macrophage

Answer 3

1. Phagocytosis: ingests bacteria ,viruses and other fp and destroys themby formation of phagosome
2. Antigen presentation. Serve as APC. Foreign material is ingested, degraded and fragment of it is presented on cell surface along with mhc antigens to lymphocytes
3. Synthesis and release of cytokines
   IL 1, 6, 8, 12 and TNF a

Question 4

Macrophage in peripheral blood

Answer 4

Monocyte

Question 5

Mq in liver

Answer 5

Kupffer cell

Question 6

Brain Mq

Answer 6

Microglial cell

Question 7

Lung

Answer 7

Alveolar mq

Question 8

Bone

Answer 8

Osteoclast

Question 9

Connective tissue

Answer 9

Histiocyte

Question 10

Kidney

Answer 10

Mesenglial cell

Question 11

Natural killer cell

Answer 11

Can kill target cell without activation
Originates from bone marrow stem cells
Large granular lymphocytes
Part of innate immune system
Lack cd3,tcr, surface igm and igd
Produce IFNv and TNFa that stimulates maturation of dendritic cell
Deficiency of nk cell causes herpes and HPV infections, cancer

Question 12

Function of nk cell

Answer 12

1. Recognises virus infected cells by detecting lack of class 1 mhc proteins on surface of infected cells
2. Kill virus infected cell and tumor cells using cytotoxins
3. Non specific killing
4. Produce v IFN that activates macrophages to kill bacteriaa
5. Nk cells express cd16 for specific region of Ab molecule, can attach Ab and subsequently destroy target cells (ADCC)

Question 13

Antigen presenting cells

Answer 13

Monocytes- peripheral blood
Mq- tissues
Dendritic cells- lymphoid tissue
Langerhans cells- epidermis
B cells - lymphoid tissue, blood