blood physiology

Question 1

Haematocrit

Answer 1

• Everything that isn’t plasma

- Buffy coat and red plot cells

Question 2

plasma made up of

Answer 2

• Water
  
  • Plasma proteins (7% by mass)
  • Salts (mainly Na, Cl, buffers HCO3-
  • Nutrients (eg. Glucose, amino acids
  • Wastes eg. Urea, uric acid, bilirubin
  • Dissolved gases (eg. Oxygen, cardon dioxide

Question 3

plasma does

Answer 3

○ Maintenance of the internal environment

○ Rapid transport system: nutrients, wastes, hormones, heat

Question 4

plasma protein functions

Answer 4

§ Colloidal osmotic pressure (especially albumin)
§ pH buffering
§ Transport eg. Lipid binding proteins, hormone binding proteins
§ Immunity eg. Antibodies
§ Blood coagulation - fibrinogen -> fibrin

Question 5

• Granulocytes

Answer 5

○ Neutrophils
○ Eosinophils
○ Basophils

Question 6

• Agranulocytes

Answer 6

○ Lymphocytes

○ Monocytes

Question 7

○ Neutrophils

Answer 7

§ Anti bacterial cells - eat bacteria

§ Rapid to infection site to form pus

Question 8

○ Eosinophils

Answer 8

§ Destroy parasites extracellularly - release enzymes, oxidants
§ Also weaking phagocytes (of allergens)

Question 9

○ Basophils

Answer 9

§ Activate other WBCs during inflammation and allergic reactions - release histamine

Question 10

○ Monocytes

Answer 10

§ Become macrophages - powerful phagocytes

Question 11

Lymphocytes

Answer 11

• respond to foreign substances/cells

B and T cells

Question 12

§ B lymphocytes

Answer 12

□ 20% of circulating lymphocytes

□ Proliferate and become plasma cells that produce antibodies (humeral immunity)

Question 13

§ T lymphocytes

Answer 13

□ 80% of circulating lymphocytes

□ Proliferate and become activated t cells(cell-mediated immunity) that kill foreign invading cells or altered cells

Question 14

erythrocytes consist of membrane enclosing

Answer 14

○ Water
○ Electrolytes
○ Haemoglobin
○ Metabolic enzymes

Question 15

haemoglobin consists of

Answer 15

§ Globin (polypeptide chains
§ HbA: 2x a-globin and 2x B globin
§ Haem unit: (1x Fe and 1x protoporphyrin molecule)

Question 16

• O2 disassociation curve

Answer 16

○ Local conditions alter how tightly Hb binds O2
○ Hb dumps more O2 in metabolically active tissues
§ Acidosis, high temp, high PCO2 (Bohr effect)

Question 17

• CO2

Answer 17

○ More soluble - 22x in plasma/cytoplasm than O2

○ Can increase transport efficiency if loaded into RBCs

Question 18

carbon dioxide transport 3 ways

Answer 18

§ Carbonic anhydrase in RBC catalyses the reaction CO2 +H2O H2CO3 H+ + HCO3-
§ Hb in RBC (and proteins in plasma) bind CO2 forming carbamino compounds
- dissolves in blood

Question 19

RBC destruction

Answer 19

• no nucleus therefore cant repair
  
  • Life span 120 days
  • Old cells removed by spleen, liver and bone marrow

Question 20

red blood cells are removed due to

Answer 20

○ Reduced flexibility

○ Rupture

Question 21

RBC being phagocytosed by macrophages

Answer 21

○ Fe recycles

○ Rest disposed of - bilirubin

Question 22

causes of hypoxia

Answer 22

§ Haemorrhage/increased RBC destruction
§ Insufficient haemoglobin eg. Iron deficiency
§ Reduced O2 availability eg. High altitudes
§ Insufficient B vitamins (B12 and folic acid)

Question 23

red cell count

Answer 23

5. 0 x 10^12 cells/L (males)

4. 8 x 10^12 cells/L (females)

Question 24

haemoglobin

Answer 24

150 g/L (M)

135 g/L (f)

Question 25

haematocrit / packed cell volume

Answer 25

0. 45 (M)

0. 42 (F)