Introduction to structure and function of blood

Question 1

What is the shape and dimensions of erythrocytes

Answer 1

• Biconcave

- Around 8 micrometers in length, 2.5 micrometers in height

Question 2

What do erythrocytes not have

Answer 2

A nucleus, DNA, RNA or mitochondria

Question 3

What are the two most common leukocytes

Answer 3

Neutrophils and lymphocytes

Question 4

What is a neutrophil

Answer 4

A polymorphonuclear granulocyte

Question 5

What does polymorphonuclear mean

Answer 5

Irregular and multi-lobed nucleus

Question 6

What does a granulocyte mean

Answer 6

Prominent cytoplasmic granules

Question 7

What are the 3 type of granulocytes

Answer 7

Neutrophil
Eosinophil
Basophil

Question 8

What is characteristic about a neutrophil

Answer 8

Weakly staining granules, commonest WBC

Question 9

What is characteristic about an eosinophil

Answer 9

Prominent granules stain red with eosin, make up 1-4% of WBCs

Question 10

What is characteristic about a basophil

Answer 10

Granules stain blue/purple with basic dyes, make up less then 0.5% of WBCs

Question 11

What are the two types of mononuclear cells

Answer 11

Monocytes

Lymphocytes

Question 12

What is characteristic about a mononuclear cell

Answer 12

They lack granules and have large, regular nuclei

Question 13

What are thrombocytes

Answer 13

Cytoplasmic fragments that have no nucleus, are membrane bound and contain granules

Question 14

Where do blood cells come fro

Answer 14

Mature blood cells are produced from stem cells in the bone marrow

Question 15

How are some blood diseases treated

Answer 15

Bone marrow transplantation

Question 16

What is plasma

Answer 16

A fluid containing water, salts, proteins and organic molecules (metabolites, carbohydrates and lipids)

Question 17

What positive ions (cations) exist in blood plasma

Answer 17

Mainly sodium, but also potassium, calcium, magnesium and hydrogen ions

Question 18

What negative ions (anions) exist in blood plasma

Answer 18

Mainly chloride but also bicarbonate, phosphate, sulphate and organic anions

Question 19

What is serum

Answer 19

The fluid left after blood clotting

Question 20

What happens when a blood test requires un-clotted blood

Answer 20

Use an anticoagulant e.g. EDTA

Question 21

How much of the plasma is blood proteins and what do they do

Answer 21

7-9% of plasma is protein
Complex; thousands of different proteins
90% is single protein called albumin
Maintains the osmotic pressure in blood

Question 22

What are the 3 functions of blood

Answer 22

1. Transport
2. Defense
3. Homeostasis

Question 23

How is the blood involved in transport

Answer 23

Carries oxygen/nutrients to tissues
removes CO2/other waste products from tissues
Transport other substances like hormones from sites of production to sites of action

Question 24

How are erythrocytes involved in transport

Answer 24

Transports oxygen from lungs to body tissues

Help in removal of CO2 from body tissues to lungs

Question 25

How is CO2 carried in plasma

Answer 25

Carried as bicarbonate Red cell enzyme carbonic anhydrous helps CO2 o dissolve in plasma in the tissues and to come out of solution in the lungs

Question 26

What is the structure of haemoglobin

Answer 26

Its a tetramer made up of 4 polypeptide chains; 2 alpha and 2 beta chains Each chain has a haem molecule that holds a ferrous Fe2+ ion

Question 27

How does haemoglobin carry oxygen

Answer 27

Oxygen binds reversibly to the iron atom through a co-ordination bond

Question 28

What is oxyhemoglobin

Answer 28

Fully saturated with O2 = bright red

Question 29

What is deoxyhemoglobin

Answer 29

Fully desaturated without O2 = dark red

Question 30

What do plasma proteins do

Answer 30

Carry substances which are poorly soluble in water e.g. Lipids and lipid soluble hormones/vitamins

Question 31

What kind of metal ions do plasma proteins carry and why

Answer 31

calcium, ferrous and copper ion | These ions can be toxic and if you get a bacterial infection, bacteria wont be able to uptake these required ions

Question 32

What does thyroxine binding protein (TBG) do

Answer 32

Somewhat hydrophobic molecule that carries thyroxine

Question 33

What does transferrin do

Answer 33

Carries ferrous ions

Question 34

What does a neutrophil do

Answer 34

Phagocytose and kill bacteria and fungi | The main mediators of innate immunity

Question 35

What does a lymphocyte do

Answer 35

Main mediators of adaptive/acquired immunity Produces antibodies Kills virus infected cells

Question 36

What do eosinophils do

Answer 36

Kills parasites | Involved in allergic responses

Question 37

What do basophils do

Answer 37

Kills parasites Involved in allergic responses Involved in inflammation

Question 38

What do monocytes/macrophages do

Answer 38

Phagocytosis of dead cells and pathogens | Presentation of antigens

Question 39

What does the plasma carry for immune defence

Answer 39

Immunoglobins, complelement proteins and platlets

Question 40

How are immunoglobins made and what do they do

Answer 40

Made by b-lymphocytes | Act as antibodies against pathogens

Question 41

What do complement proteins do

Answer 41

Kill bacteria and other pathogens | Cooperate with Ig and WBC

Question 42

What do platelets do

Answer 42

Its major role is primary haemostasis; stops blood flow Recognises damage at a blood vessel wall Forms a plug that stops bleeding but it insecure and temporary Fibrinogen is a major plasma protein; secondary haemostasis

Question 43

What is homeostasis

Answer 43

Keeping the internal environment of the body constant - Maintaining pH at 7.4 - Controlling distribution of water and solutes - Distributing heat

Question 44

What must be kept within safe limits through homeostasis

Answer 44

Plasma pH Ion concentrations Protein concentrations

Question 45

What does a full blood count include

Answer 45

``` Haemoglobin concentration -Used to diagnose anemia Mean red cell volume -Size of RBCs Mean red cell haemoglobin content -How much Hb in each red cell Haematocrit -These help to diagnose the type of anaemia Total white blood cell count -Important for diagnosing infection ```

Question 46

Liver function tests (LFT's)

Answer 46

Albumin concentration Liver enzymes (released from damaged liver cells) Clotting factors

Question 47

Urea and electrolytes (U&E's)

Answer 47

Test kidney function | Metabolic abnormalities

Question 48

Blood glucose

Answer 48

Test for diabetes

Question 49

Lipid profile

Answer 49

Triglycerides Cholesterol LDL and HDL Risk of cardiovascular disease