Blood

Question 1

What does red bone marrow do?

Answer 1

form blood cells

Question 2

What is blood?

Answer 2

a specialised fluid connective tissue

Question 3

What are the functions of blood?

Answer 3

• gaseous exchange
• transport of nutrients, hormones, antibodies, water and metabolic wastes

Question 4

What are the 3 components of blood?

Answer 4

• plasma (55%)
• buffy coat (1%)
• RBCs (45%)

Question 5

What are the 4 components of plasma?

Answer 5

• water
• proteins
• electrolytes
• dissolved gases

Question 6

What are the 2 components of the buffy coat?

Answer 6

• platelets
• WBCs

Question 7

What are RBCs also known as?

Answer 7

erythrocytes

Question 8

What is the main function of RBCs?

Answer 8

gaseous exchange

Question 9

What does the biconcave shape of RBCs facilitate?

Answer 9

gaseous exchange and allows more haemoglobin closer to the plasma membrane

Question 10

What does haemoglobin consist of?

Answer 10

4 polypeptide chains complexed with iron-containing haeme groups

Question 11

What are the 6 stages of the RBC lifecycle?

Answer 11

1. erythropoiesis starts in the bone marrow
2. erythrocytes are released into vesicles and circulate for 120 days
3. spleen (and liver) macrophages break down old erythrocytes intro bilirubin, iron and amino acids
4. liver processes bilirubin into bile
5. small intestine excretes bile in faeces
6. kidney excretes bile in urine and releases erythroprotien (EPO) to stimulate erythropoiesis

Question 12

Which ABO blood group has no antibodies present in the plasma?

Answer 12

AB

Question 13

How can the blood group be determined using clumping?

Answer 13

• if clumping occurs with anti-A, the blood type is A
• if clumping occurs with anti-B, the blood type is B
• if clumping occurs with both, the blood type is AB
• if no clumping occurs with either the blood type is O
• if clumping occurs with anti-Rh, the blood is Rh positive; if not, it’s Rh negative

Question 14

What is Rh factor?

Answer 14

a protein found on the surface of RBCs

Question 15

What are WBCs also known as?

Answer 15

leukocytes

Question 16

What are the 2 groups of WBCs?

Answer 16

• granulocytes
• agranulocytes

Question 17

What are the 3 types of granulocyte and what % of WBCs do they make up?

Answer 17

• neutrophil (40-75%)
• eosinophil (1-6%)
• basophil (1%)

Question 18

Describe the nucleus of the 3 types of granulocyte

Answer 18

• neutrophil - highly lobulated
• eosinophil - bilobed
• basophil - bilobed

Question 19

What are neutrophils involved in?

Answer 19

the acute inflammatory response to tissue; they kill bacteria, fungi and foreign debris

Question 20

What are signs of acute inflammation?

Answer 20

heat, redness, swelling, pain and loss of function

Question 21

What do the granules of eosinophils contain?

Answer 21

peroxidase, histaminase, arylsulfatase and other hydrolytic enzymes

Question 22

How do eosinophils provide defence against parasites?

Answer 22

by engaging in the phagocytosis of antigen-antibody complexes

Question 23

What do the granules of basophils contain?

Answer 23

hydrolytic enzymes, histamine, heparin sulphate and slow-reacting substance (SRS) of anaphylaxis

Question 24

What do SRS and histamine do?

Answer 24

cause small blood vessel dilation associated with allergic and inflammatory reactions

Question 25

What is the action of histamine in endothelial cells?

Answer 25

binds to H1 receptors which produce nitric oxide (potent vasodilator) within the cells

Question 26

What is the action of histamine in smooth muscle cells?

Answer 26

nitric oxide diffuses in and causes relaxation

Question 27

What does histamine do to blood vessels?

Answer 27

increase the permeability of the blood vessel walls, allowing more immune cells and other factors to pass through to the site of injury or infection

Question 28

What are the 2 types of agranulocytes and what is their size?

Answer 28

- lymphocytes (largest WBC) - monocytes (smallest WBC)

Question 29

Describe the lymphocyte nucleus

Answer 29

round and densely stained with a small amount of pale non-granular cytoplasm

Question 30

Where are most lymphocytes present?

Answer 30

both the blood and lymph

Question 31

What are the 3 functional types of lymphocyte and what are their lifespans?

Answer 31

- T-lymphocytes (long) - B-lymphocytes (variable) - natural killer cells (short)

Question 32

What are T-lymphocytes involved in?

Answer 32

cell-mediated immunity

Question 33

What are the 3 types of T-lymphocytes and what are their functions?

Answer 33

- cytotoxic T-lymphocytes – recognise and kill the cells with foreign antibodies - helper T-lymhocytes – release factor to activate B-lymphocytes, CTLs and macrophages to participate in immune reaction - suppressor T cells – suppress the activity of B-lymphocytes and the immune response

Question 34

What do B-lymphocytes do?

Answer 34

contribute to humoral immunity by differentiating into plasma cells and producing circulating antibodies

Question 35

What do natural killer cells do?

Answer 35

attack cancer cells, foreign cells and virus-infected cells (innate immunity)

Question 36

What is the shape of a monocyte nucleus?

Answer 36

horseshoe

Question 37

What do monocytes do?

Answer 37

play a chief role in phagocytosis during infections by entering tissues and differentiating to form macrophages which contribute to both homeostasis and disease

Question 38

Describe innate immunity (specificity, line of defence, response time, memory and components)

Answer 38

- non-specific - first - short - no memory - skin, mucous membranes, epithelial cells, phagocytes

Question 39

Describe adaptive immunity (specificity, line of defence, response time, memory and components)

Answer 39

- specific - second - longer than innate - memory via memory cells - T- and B-lymphocytes

Question 40

What is adaptive immunity?

Answer 40

immunity developed upon exposure to a specific pathogen that includes humoral and cell-mediated immunity

Question 41

What are platelets?

Answer 41

small, round biconvex, non-nucleated cells

Question 42

What are megakaryocytes?

Answer 42

large cells with a lobulated nucleus found in bone marrow

Question 43

How are megakaryocytes formed?

Answer 43

using endomitosis (mitosis without cytokinesis)

Question 44

How are platelets formed?

Answer 44

from the cytoplasm of megakaryocytes (thrombocytosis)

Question 45

What is the major role of platelets?

Answer 45

blood clotting

Question 46

What are the 3 steps of blood clotting?

Answer 46

1. platelets adhere to the site of injury by binding with collagen fibres 2. activated platelets attract more platelets to the site of the clot 3. thrombin induces the formation of fibrin which stabilises the blood clot

Question 47

What is plasma?

Answer 47

an aqueous solution of inorganic salts

Question 48

What are the main plasma proteins and what are their functions?

Answer 48

- albumins – bulk of plasma proteins; transport protein for fatty acids - globulins – antibodies of the immune system; transport protein for lipids and heavy metal ions - fibrinogen – soluble protein that polymerises to form insoluble fibrin during blood clotting

Question 49

What do plasma lipoproteins do?

Answer 49

deliver insoluble lipids from the tissues where they are synthesised to those that utilise, degrade or store them

Question 50

What are the 2 type of lipoproteins that carry cholesterol?

Answer 50

- high density lipoprotein - carries good cholesterol back to liver - low density lipoprotein - carries bad cholesterol to tissues for excretion

Question 51

What is haematopoiesis?

Answer 51

formation of blood cellular components from haematopoietic stem cells by the red bone marrow

Question 52

What is erythropoiesis?

Answer 52

formation of RBCs

Question 53

What is thrombocytopoiesis?

Answer 53

formation of platelets

Question 54

What is granulocytopoiesis?

Answer 54

formation of granulocytes

Question 55

What is monocytopoiesis?

Answer 55

formation of monocytes

Question 56

What is lymphocytopoiesis?

Answer 56

formation of lymphocytes