Introduction to Blood

Question 1

What is the normal distribution of blood in the body?

Answer 1

• Lungs: 1L
• Systemic venous circulation: 3L
• Heart and arterial circulation: 1L

Question 2

What are 6 functions of blood?

Answer 2

• Carriage of physiologically active compounds
• Clotting
• Defence
• Carriage of gas
• Thermoregulation
• Maintenance of ECF pH

Question 3

What does blood consist of?

Answer 3

• Plasma
• RBCs
• WBCs
• Platelets

Question 4

What does plasma do??

Answer 4

Circulates biologically active molecules and compounds

Question 5

What are the 3 categories of plasma proteins?

Answer 5

• Albumin
• Globulin (a,B, y)
• Fibrinogen (and other clotting factors)

Question 6

Where do plasma proteins perform their functions?

Answer 6

In the circulation

Question 7

What do plasma proteins generate?

Answer 7

Colloid oncotic pressure

Question 8

What is the result of colloid oncotic pressure?

Answer 8

• Concentration of fluid remains unchanged

- Volume of plasma and interstitial fluid alters

Question 9

What does ISF act as?

Answer 9

Fluid reservoir

Question 10

What 2 forces is movement of fluid between capillary and interstitial space subject to?

Answer 10

• Hydrostatic pressure

- Colloid oncotic pressure

Question 11

What does the net movement of fluid depend on?

Answer 11

• Capillary hydrostatic pressure
• Interstitial hydrostatic pressure
• Interstitial fluid protein concentration
• Plasma protein concentration

Question 12

What is hypoproteinaemia?

Answer 12

Abnormally low levels of circulating plasma protein.

Question 13

What does hypoproteinaemia cause?

Answer 13

• Prolonged starvation
• Liver disease
• Intestinal diseases
• Nephrosis

Question 14

What is a common characteristic of hypoproteinaemia?

Answer 14

Oedema due to loss of oncotic pressure

Question 15

What are erythrocytes?

Answer 15

RBC

Question 16

What cells are myeloid cells?

Answer 16

• Erythrocytes
• Platelets
• Neutrophils
• Monocytes
• Basophils
• Eosinophils

Question 17

What cells are lymphoid cells?

Answer 17

• Neutrophils
• Monocytes
• Basophils
• Eosinophils
• Lymphocytes

Question 18

Describe erythrocytes.

Answer 18

• Most abundant blood cell
• 120 day lifespan
• Highly flexible, biconcave, non-nucleated
• Densely packed with haemoglobin

Question 19

What are the 2 colours of blood?

Answer 19

• Oxyhaemoglobin: bright red found in arteries

- Deoxyhaemoglobin: cherry red found in veins

Question 20

What is erythropoiesis?

Answer 20

RBC formation

Question 21

What is erythropoiesis controlled and accelerated by?

Answer 21

Erythropoietin

Question 22

Describe leukocytes.

Answer 22

• Nucleated

- Larger than RBCs

Question 23

What are leukocytes involve in?

Answer 23

Defence against pathogens

Question 24

Describe neutrophils.

Answer 24

• Most abundant WBC
• Constantly producing them
• Phagocytic

Question 25

Describe eosinophils.

Answer 25

- Increase in number rapidly during allergy | - Attack pathogens too large for neutrophils and other defence cells

Question 26

What do basophils do?

Answer 26

- Release histamine and heparin | - Trigger inflammation

Question 27

Describe monocytes.

Answer 27

- Largest WBC - Migrate to spleen, liver, lungs and lymph nodes - Become macrophages once they have reached their destination

Question 28

Describe macrophages.

Answer 28

- Mature monocytes that has migrated from the blood to the connective tissue - Mya reside in tissue for up to 3 months - Phagocytic

Question 29

Describe lymphocytes.

Answer 29

- Key constituent of adaptive immune system | - B cells and T cells

Question 30

What is leucopoiesis?

Answer 30

WBC formation

Question 31

What is leucopoiesis controlled by?

Answer 31

A cocktail of cytokines including colony stimulating factors and interleukins

Question 32

Where are cytokines released from?

Answer 32

- Endothelial cells - Fibroblasts - Mature WBC

Question 33

What do cytokines do?

Answer 33

Stimulate mitosis and maturation of leukocytes

Question 34

What happens when someone has a bacterial infection?

Answer 34

Increase in neutrophils

Question 35

What happens when someone has a viral infection?

Answer 35

Increase in lymphocytes

Question 36

What does the differential white cell count allow us to do?

Answer 36

Differentiate between infection types

Question 37

What are platelets?

Answer 37

- Membrane bound cell fragments (from megakaryocytes) - Rarely nucleated - Formation governed by thrombopoietin - 10 day lifespan

Question 38

What do platelets do?

Answer 38

Adhere to damages vessel walls and exposed connective tissue to mediate clotting

Question 39

What do platelets not do?

Answer 39

Adhere to healthy intact endothelium

Question 40

What is haematocrit?

Answer 40

Measurement of the proportion of blood that is made up of cells

Question 41

Viscosity

Answer 41

How thick/sticky blood is compared to water

Question 42

What is viscosity dependent on?

Answer 42

- Haematocrit: 50% increase increases viscosity by 100% - Temperature: Increase in temp decreases viscosity - Flow rate: decreased flow rate increases viscosity