Intro to blood structure and function

Question 1

Structure of erythrocytes [4 marks]

Answer 1

• Biconcave discs
• No nucleus
• No DNA/RNA
• No mitochondria

Question 2

Types of granulocytes [3 marks]

Answer 2

• Polymorphonuclear
  neutrophils (weakly staining granules)
• Polymorphonuclear eosinophil (red staining of granules with eosin)
• Polymorphonuclear basophil (blue/purple staining with basic dyes)

Question 3

Examples of mononuclear cells [2 marks]

Answer 3

• Monocytes/Macrophages

- Lymphocytes

Question 4

Structure of thrombocytes/platelets [4 marks]

Answer 4

• Cytoplasmic fragments
• No nucleus
• Membrane bound
• Contain granules

Question 5

What does plasma contain? [4 marks]

Answer 5

• Water
• Salts
• Proteins
• Organic molecules (e.g. metabolites, carbohydrates)

Question 6

What is the most common cation in plasma? [1 mark]

Answer 6

Sodium ions

Question 7

What is the most common cation in cells? [1 mark]

Answer 7

Potassium ions

Question 8

What is the difference between plasma and serum? [2 marks]

Answer 8

• Plasma is the fluid of whole blood

- Serum is the fluid of clotted blood

Question 9

What is an example of an anticoagulant used and how does it prevent clotting? [2 marks]

Answer 9

• EDTA

- It chelates calcium ions (a clotting factor)

Question 10

What is ~90% of the protein aspect of plasma made out of? [1 mark]

Answer 10

Human serum albumin

Question 11

What are the functions of blood? [3 marks]

Answer 11

• Transport
• Defence
• Homeostasis

Question 12

How do erythrocytes carry carbon dioxide? [1 mark]

Answer 12

Via the carbonic acid-bicarbonate buffer system

Question 13

What is the average life span of erythrocytes? [1 mark]

Answer 13

120 days

Question 14

What is the average diameter of erythrocytes? [1 mark]

Answer 14

8μm

Question 15

What is the average thickness of erythrocytes? [1 marks]

Answer 15

2μm

Question 16

What is the structure of haemoglobin? [4 marks]

Answer 16

• It is a tetramer
• Has 2 alpha globin chains and 2 beta globin chains
• Each globin chain carries a haem molecule (binds 1 O2 each)
• Haem holds ferrous iron (Fe2+)

Question 17

What is pulse oximetry and what is it used for? [2 marks]

Answer 17

• Shining a light on a patient’s finger and measuring the light absorption of Hb
• Measures the oxygen saturation

Question 18

What carries insoluble materials in the plasma? [1 mark]

Answer 18

Plasma proteins (e.g. albumin, transferrin)

Question 19

What leukocyte is involved in innate immunity? [1 mark]

Answer 19

Neutrophils

Question 20

What leukocyte is involved in adaptive immunity? [1 mark]

Answer 20

Lymphocytes

Question 21

Which leukocytes are involved in allergic responses? [2 marks]

Answer 21

• Eosinophild

- Basophils

Question 22

Which leukocytes phagocytose pathogens? [2 marks]

Answer 22

• Neutrophils

- Monocytes/macrophages

Question 23

Where do immunoglobins (Ig) come from and what is their function? [2 marks]

Answer 23

• Made by B-lymphocytes

- Act as antibodies

Question 24

What do complement proteins do for immunity? [3 marks]

Answer 24

• Kill pathogens
• Binds to bacterial cell membrane and bore holes
• Cooperate with Ig and WBCs

Question 25

What is haemostasis? [1 mark]

Answer 25

Stopping of a flow of blood

Question 26

How is clotting done? [2 marks]

Answer 26

• Platelet plug forms

- Fibrin clot reinforces platelet plug

Question 27

What does testing the levels of urea and electrolytes do? [1 mark]

Answer 27

Determines whether the kidney is functioning properly or not

Question 28

What is the average total blood volume in a 70kg male? [1 mark]

Answer 28

5 litre

Question 29

What is the average plasma volume in a 70kg male? [1 mark]

Answer 29

2.5 to 3 litres

Question 30

What is the haemocrit/packed cell volume? [1 mark]

Answer 30

Proportion of cells in blood

Question 31

What is the normal range for haemocrit? [1 mark]

Answer 31

0.4 to 0.5