6. Blood

Question 1

What is plasma?

Answer 1

Blood minus the cells

Question 2

What does plasma comprise?

Answer 2

• Water
• Salts and minerals
• Plasma proteins
• Hormones (signal molecules)
• Other clotting factors

Question 3

What is serum?

Answer 3

Plasma minus clotting factors

Question 4

Erythrocytes have a lifespan of how long?

Answer 4

120 days

Question 5

Where are erythrocytes produced?

Answer 5

In the liver in the foetus and bone marrow in adults

Question 6

What is the major erythrocyte protein?

Answer 6

Haemoglobin

Question 7

Where are erythrocytes destoryed?

Answer 7

In the liver and spleen

Question 8

What is the erythrocyte cell membrane major protein?

Answer 8

Spectrin

Question 9

What are the 2 different types of leukocytes?

Answer 9

Granulocytes and agranulocytes

Question 10

What are the 3 different types of granulocytes?

Answer 10

• Neutrophils
• Eosinophils
• Basophils

Question 11

What are the 2 different types of agranulocytes?

Answer 11

• Lymphocytes
• Monocytes

Question 12

Describe neutrophils.

Answer 12

• Commonest white blood cell
• Multi-lobed nucleus
• Granular cytoplasm
• 12-14 um diameter

Question 13

What is the function of neutrophils?

Answer 13

Phagocytic- engulf and destroy bacteria and other foreign macromolecules

Question 14

What are the 3 types of cytoplasmic granule in neutrophils?

Answer 14

• Primary granules
• Secondary granules
• Tertiary granules

Question 15

Name 2 examples of primary granules.

Answer 15

Lyzosomes- myeloperoxidase and acid hydrolases

Question 16

What are secondary granules?

Answer 16

Specific granules that secrete substances that mobilise inflammatory factors

Question 17

What are tertiary granules?

Answer 17

Gelatinases and adhesion molecules

Question 18

Describe eosinophils?

Answer 18

• 1% total white blood cells
• 12-17 um diameter
• Bi-lobed nucleus
• Distinctive large red cytoplasmic granules with crystalline inclusions

Question 19

What is the action of eosinophils? (5)

Answer 19

• Antagonistic in action to basophils
• Phacocytic with particular affinity for antigen/antibody complexes
• Receptors for IgE
• Inhibit mast cell secretion
• Neutralise histamine and restricts the inflammatory response

Question 20

Describe basophils.

Answer 20

• 0.5% white blood cells
• 14-16 um diameter
• Bi-lobed nucleus and prominent dark blue-staining cytoplasmic granules containing histamine

Question 21

What are the functions of basophils? (4)

Answer 21

• Involved in inflammatory reactions and prevent coagulation and afflutination
• Circulating form of tissue mast cells
• Receptors for IgE
• Release histamine and other vasoreactivve agents in response to allergens
• Results in immediate hypersensitivity reaction

Question 22

What are the 2 functional subtypes of lymphocytes?

Answer 22

B cells and T cells

Question 23

What do B cells become?

Answer 23

Plasma cells which secrete antibodies

Question 24

What are T cells involved in?

Answer 24

Cell-mediated immunity

Question 25

What do T helper cells do?

Answer 25

Help B cells and activate macrophages

Question 26

What do T cytotoxic cells do?

Answer 26

Kill previously marked target cells

Question 27

What do T suppressor cells do?

Answer 27

Suppress TH cells and supress the immune response

Question 28

What do natural killer cells do?

Answer 28

Kill virus infected cells

Question 29

Describe monocytes.

Answer 29

- Characteristic reniform nucleus - 15-20 um diameter

Question 30

What are the functions of monocytes? (3)

Answer 30

- Differentiate into several cell types within tissue - Major phagocytic and defensive role - Some become antigen presenting cells, passing antigen fragments to lymphocytes

Question 31

What do monocytes differentiate into?

Answer 31

- Tissue macrophages - Kupffer cells - Osteoclasts - Antigen presenting cells - Alveolar macrophages

Question 32

What are platelets?

Answer 32

Fragments of cells derived from large multi-nucleated megakaryocytes in the bone marrow

Question 33

Describe platelets.

Answer 33

- 1-3 um diameter - Surrounded by cell membrane - Contain vesicles with coagulation factors

Question 34

What are platelets responsible for?

Answer 34

Clotting of blood especially when the endothelium lining of blood vessels is breached

Question 35

Where do all blood cells form in adults?

Answer 35

In the haematopoeitic bone marrow

Question 36

What does the myelon series give rise to?

Answer 36

White blood cells

Question 37

What does the erythron series give rise to?

Answer 37

Erythrocytes

Question 38

What do megakaryocytes give rise to?

Answer 38

Platelets

Question 39

What happens in erythropoeisis?

Answer 39

- Reducing cell size - Haemoglobin production - Reduction and loss of organelles - Basophilia in early precurosrs change to eosinophilia in late prescursors - Loss of nucleus

Question 40

What is erythropoeisis mediated by?

Answer 40

Erythropoeitin (EPO)

Question 41

What happens in granulopoeisis?

Answer 41

- Increasing number of granules - Increasingly complex shape of the nucleus - Large pool of stored mature neutrophils in marrow