Leucocytes

Question 1

What are the categories of leukocytes?

Answer 1

Granulocytes - NEB

Agranulocytosis - Monocytes and Lymphocytes

Question 2

Granulocytes

Answer 2

They contain specialized membrane-bound cytoplasmic granules

Question 3

Average number of leukocytes

Answer 3

4,000 - 11,000 per microlitre

Question 4

Function of Leukocytes

Answer 4

Defense against diseases

Leukocytes form a mobile army that helps protect the body from damage by bacteria, viruses, parasites, toxins and tumor cells

Question 5

Lifespan of leucocytes

Answer 5

It varies from one type to the other
- Several hours to several days for the majority
- Many years for a few memory cells

Question 6

How do leucocytes work?

Answer 6

By phagocytosis and formation of antibodies and sensitized lymphocytes that destroy or inactivate the invader

Question 7

Neutrophils

Answer 7

40%-70% WBCs

• Nucleus multilobed
• Duration of development: 6-9 days
• Life Span: 6 hours to a few days
• Function: Phagocytize bacteria

Question 8

Eosinophils

Answer 8

• 1%-4% WBCs
• Nucleus bilobed
• Development:6-9 days
• Life Span: 8-12 days
  Function:
  1) Kill parasitic worms
  2) destroy antigen-antibody complexes
  3) inactivate some inflammatory chemical of allergy

Question 9

Basophils

Answer 9

• 0.5% WBCs
• Nucleus lobed
• Development: 3-7 days
• Life Span: a few hours to a few days
• Function:
  1) Release histamine and other mediators of inflammation
  2) contain heparin, an

Question 10

Monocytes

Answer 10

• 4%-8% WBCs
• Nucleus U-shaped
• Development: 2-3 days
• Life Span: months

Function:
Phagocytosis
Develops into macrophages in tissues

Question 11

Types of lymphocytes

Answer 11

T cells
B cells
NK cells

Question 12

Lymphocytes

Answer 12

20%-45% WBCs
Nucleus spherical or indented
- Development: days to weeks
- Life Span: hours to years
Function
Mount immune response by direct cell attack (T cells) or via antibodies (B cells)

Question 13

Which lymphocytes are responsible for adaptive immunity?

Answer 13

T and B cells

Question 14

Which lymphocytes protect the host from tumors and virus infected cells?

Answer 14

NK cells

Question 15

How do NK cells work?

Answer 15

By releasing cytotoxin granules to lyse cell membranes and kill abnormal cells

Question 16

Which lymphocytes are responsible for cell-mediated immunity?

Answer 16

T cells

Question 17

Which lymphocytes are responsible for humoural immunity?

Answer 17

B cells

Question 18

Types of T cells

Answer 18

Cytotoxic killer T cells
Helper T cells
Memory T cells
Suppressor T cells

Question 19

Types of B cells

Answer 19

IgA
IgE
IgD
IgG
IgM

Question 20

Which lymphocytes are responsible for phagocytosis of bacteria?

Answer 20

Neutrophils

Question 21

Which lymphocytes are responsible for killing parasitic worms?

Answer 21

Eosinophils

Question 22

Which lymphocytes are responsible for releasing mediators of inflammation?

Answer 22

Basophils

Question 23

Which lymphocytes are responsible for destroying antigen-antibody complexes?

Answer 23

Eosinophils

Question 24

Which lymphocytes contain an anticoagulant? And which anticoagulant?

Answer 24

Basophils, Heparin

Question 25

Which lymphocytes are responsible for inactivating some inflammatory chemicals of allergy?

Answer 25

Eosinophils

Question 26

Leukocytes are deployed in the infected areas outside blood vessels via 3 steps:

Answer 26

Margination Diapedesis Chemotaxis

Question 27

Margination

Answer 27

Cells slow down because of cell adhesion molecules secreted by endothelial cells

Question 28

Diapedesis

Answer 28

Here, leukocytes slip out of the capillary blood vessels.

Question 29

Chemotaxis

Answer 29

Here, leucocytes gather in large numbers at areas of tissue damage and infection by following the chemical trail of molecules released by damaged cells or other leukocytes

Question 30

Leukocyte disorders

Answer 30

Leucopenia Leucocytosis Leukemia

Question 31

Leucopenia

Answer 31

Less than 4000 leucocytes per microlitre present in blood. It is a major side effect of chemo

Question 32

Leucocytosis

Answer 32

More than 11,000 leucocytes per microlitre present in blood

Question 33

Leukemia

Answer 33

WBCs become cancerous since descendants of stem cell remain unspecialized , become motor ic and impair bone marrow function.

Question 34

Which leucocyte disorder is usually a side effect of chemo?

Answer 34

Leucopenia