Blood

Question 1

What is the average circulating volume of an adult male

Answer 1

5L of blood
1L in lungs
3L in systemic venous circulation
1L in heart and arterial circulation

Question 2

What is the function of blood

Answer 2

1. Carriage of physiologically active compounds (plasma)
2. Clotting (platelets)
3. Defence (WBC)
4. Carriage of gas (RBC)
5. Thermoregulation
6. Maintenance of ECM pH

Question 3

What is the composition of plasma

Answer 3

1. Is 4% of body weight
2. Is 95% water
3. Makes up 50% of blood

Question 4

What are the plasma proteins

Answer 4

1. Albumin
2. Globulin - alpha, beta, gamma globulins
3. Fibrinogen and other clotting factors

Question 5

What is colloid oncotic pressure

Answer 5

1. Plasma proteins in vessel cause low water concentraion
2. Water from ICF diffuse into plasma
3. Capillary hydrostatic pressure favours movement out of capillary

Result - concentration of fluid is unchanged volumes are altered, ICF has 3x-4x volume

Question 6

What is the normal lifespan of RBC and platelets

Answer 6

RBC - 120 days
Platelets - 10 days

Question 7

What is the funtion of RBC

Answer 7

Densely packed with haemoglobin
Highly flexible
Bioconcave
No nucleus
7-8 micrometer

Question 8

What is erythropoiesis

Answer 8

RBC formation
Controlled and accelerated by hormone erythropoietin

Question 9

What does erythropoietin do

Answer 9

Stimulates maturation process of pluripotent stem cells to erythroblasts (immature RBC)

Question 10

Describe secretion of erythroproteins

Answer 10

Secretion - kidney (85%), liver (15%)
Secretion increased when O2 delivery to kidneys is low

Question 11

What are the 5 main types of WBC

Answer 11

Granulocytes - Neutrophils, Eosinophils, Basophils
Argranulocytes - Monocytes, Lymphocytes

Question 12

What is the differences between monocytes and macrophages

Answer 12

Monocytes - Circulate in body up to 72hrs
Macrophages - Myocytes that migrated to CT and live for 3 months

Question 13

What controls WBC formation

Answer 13

Controlled by cytokines
Colony stimulation factors - Granulocyte CSF
Interlukeukins

Question 14

Describe cytokines

Answer 14

Released from mature WBC
Stimulates mitosis and maturation of leukocytes

Question 15

What stimulates leukopoiesis

Answer 15

Bacterial infection - increase neutrophils
Viral infection - increase lymphocytes

Question 16

What are platelets

Answer 16

Membrane bound cell fragments
Rarely nucleated
2-4 micrometers

Question 17

What is the role of thrombopoientin

Answer 17

Governs formation of platelets

Question 18

What is the function of platelets

Answer 18

Adhere to damaged vessel walls and exposed CT to mediate blood clotting

Question 19

What is Haematocrit

Answer 19

The % of RBC to whole blood
Normal range 40-50% , changes (hydration and elevation)

Question 20

What is blood viscosity

Answer 20

How thick/sticky blood is compared to water

Question 21

How does viscosity change

Answer 21

Haematocrit - 50% increase, increases viscosity by approx 100%
Temperature - Increase in temp decreases viscosity, vise versa. 1oC changes viscosity by around 2%
Flow rate - descrease flow rate increase viscosity and vise versa