Circulatory System II

Question 1

What is a Leucocyte?

Answer 1

• defense cells
• largest of all blood cells
• 1% of the blood volume

Question 2

What are the 3 main types of leucocytes?

Answer 2

• granulocytes
• lymphocytes
• monocytes

Question 3

What is margination?

Answer 3

Leucocytes form a layer against the inner surface of capillary walls then migrate

Question 4

What is migration?

Answer 4

• The cell pass through the capillary wall to reach and engulf infected tissue (i.e neutrophil)
• process occurs as chemical mediators are released by injured tissue to attract new WBC (chemotaxis)

Question 5

What is chemotaxis?

Answer 5

Movement if a cell as a result of chemical stimulus

Question 6

What percentage of leucocytes are granulocytes?

Answer 6

70%

Question 7

What percentage of leucocytes are Agranulocytes?

Answer 7

30%

Question 8

What cells fall under granulocytes?

Answer 8

• neutrophils
• eosinophils
• basophils

Question 9

What cells fall under agranulocytes?

Answer 9

• moncytes
• lymphocytes

Question 10

What is the general structure of granulocytes?

Answer 10

All contain multi lobular nucleus and have granules in their cytoplasm which help digest invading microbes

Question 11

What is the function of neutrophils?

Answer 11

Majority of the cells phagocytose by surrounding and destroying bacteria/ fungus
- main function is to protect against foreign material entering the body

Question 12

What is the function of eosinophils?

Answer 12

Responds if parasites enter the body, slightly phagocytose
- main function is to migrate out of blood to external environment, tissues form general immune and inflammatory response

Question 13

What is the main function of a basophil?

Answer 13

Inc. in number after an allergic reaction, produce substances which aid inflammatory action

Question 14

Describe the characteristics of a neutrophil?

Answer 14

• named after the natural dyes they take up when stained (purple colour)
• 65% total cell count
• engulf and kill microbes

Question 15

Describe the characteristics of eosinophils?

Answer 15

• 2-5% of cell count
• stain red with eosin dye

Question 16

Describe the characteristics of a basophil?

Answer 16

• 1% of total cell count, take up a blue stain

Question 17

What is the difference between granulocytes and Agranulocytes?

Answer 17

Agranulocytes lack specific granules in their cytoplasm, unlike granulocytes

Question 18

Where do monocytes originate from?

Answer 18

bone marrow

Question 19

Describe the characteristics of a monocyte?

Answer 19

• 2-8% of the total leucocytes
• motile and phagocytic
• become macrophages in tissue

Question 20

What is the function of a monocyte?

Answer 20

when they encounter large amounts of foreign material, they multiply at the site and ‘wall off’ microbes

Question 21

Where do lymphocytes originate from?

Answer 21

bone marrow and the thymus

Question 22

Where are lymphocytes found?

Answer 22

lymph nodes and in the blood stream

Question 23

Describe the characteristics of a lymphocyte

Answer 23

• 25% of leucocytes
• have large nuclei
• large numbers in lymphatic tissue

Question 24

What are the 2 types of lymphocytes?

Answer 24

T and B lymphocytes