Blood Cells - Functions Of Leucocytes

Question 1

Where are blood cells produced?

Answer 1

In haematopoietic tissues such as bone marrow

Question 2

What percentage of the world have iron deficiency anaemia?

Answer 2

30%

Question 3

What are newly formed erythrocytes called?

Answer 3

Reticulocytes

Question 4

Why can reticulocytes be stained by specific dyes, and what are these dyes called?

Answer 4

They can be stained because they contain small amounts of RNA.

Cresyl violet
Methylene blue

Question 5

Describe the clinical significance of the reticulocyte count?

Answer 5

The lifespan of a reticulocyte is short and therefore it gives information on the activity of the bone marrow.

Increased reticulocyte count indicates that erythrocytes production has increased.

Question 6

Name different types of leucocytes.

Answer 6

\+ Granulocytes
\+ Monocytes
\+ Lymphocytes 
\+ Neutrophils
\+ Eosinophils 
\+ Basophils

Question 7

What are the features of the bacterium Streptococcus pneumoniae?

Answer 7

+ It’s one cause of pneumonia

+ 5% mortality rate

+ In 20% patients, the bacterium spreads to the blood

+ If it spreads then mortality is 20%

Question 8

How do you restrict infection to the lungs?

Answer 8

+ Induce chemotaxis of neutrophils - confines pathogen to local site

Question 9

What is released in order to prevent clotting?

Answer 9

Heparin

Question 10

What is released during an allergic reaction?

Answer 10

Histamine

Question 11

What is the average life span of a red blood cell?

Answer 11

120 days

Question 12

What is the role of mast cells and basophils in the immune system?

Answer 12

Bind onto antibodies in bloodstream via Fc receptors on their surface - IgE is the antibody involved in allergic responses.

Question 13

What 3 active agents are typically released in basophil and mast cells?

Answer 13

+ Histamine

+ ECF-A: an eosinophil chemotactic factor for anaphylaxis

+ SRS-A: a slow reactive substance of anaphylaxis

Question 14

What are features of monocytes?

Answer 14

+ Monocytes/macrophages are produced in the bone marrow

+ In the bloodstream they are called monocytes

+ Migrate into the blood then local tissue, where they become fixed tissue phagocytes

+ Highly phagocytic

Question 15

What are the two different types of Monocytes?

Answer 15

+ M1 macrophage: involved in disruptive processes. Pro-inflammatory

+ M2 macrophage: pro-resolution

Question 16

Describe features of a lymphocyte.

Answer 16

+ Small when circulating in the bloodstream;resting stage

+ Immune response initiated; gets much bigger; transforms to a lymphoblast and proliferates

Question 17

What are the two main types of lymphocytes?

Answer 17

+ B-cell: produces plasma cells (humoral response). Antibody producing cells.

+ T-cells: cytotoxic killer cells (cell-mediated response). Can kill other cells if infected with a virus. Involved in graft rejection.

Question 18

What is the role of a lymphocyte?

Answer 18

To eliminate the antigen, either by releasing antibodies (B cells), cytotoxic granules (T cells) or by signaling to other cells of the immune system (helper T cells)

Question 19

What is the role of a monocyte?

Answer 19

+ Phagocytosis
+ Antigen presentation (capturing antigens)
+ Cytokine production