Lecture 31

Question 1

What is blood composed of?

Answer 1

Plasma and cells

Question 2

How much of the blood does plasma make up?

Answer 2

55%

Question 3

How much blood does the formed elements make up?

Answer 3

45%

Question 4

What is found in the plasma?

Answer 4

Proteins (including antibodies/ immunoglobulin), other solutes and water.

Question 5

What is found in the formed elements?

Answer 5

Platelets, white blood cells (leukocytes) and red blood cells

Question 6

Where is the source of blood?

Answer 6

Bone marrow stem cells

Question 7

What are the three blood cell lineages?

Answer 7

Erythroid, Myeloid and lymphoid

Question 8

What is erythroid cell lineages?

Answer 8

Red blood cells (erythrocytes)

Question 9

What is myeloid cell lineages?

Answer 9

Granulocytes, monocytes, dendritic cells and platelets (innate immune cells)

Question 10

What is lymphoid cell lineages?

Answer 10

B and T lymphocytes (Adaptive immune cells)

Question 11

Neutrophils are 75% of all leukocytes, true or false?

Answer 11

True

Question 12

Are neutrophils highly phagocytic?

Answer 12

Yes

Question 13

When do the numbers of neutrophils increase?

Answer 13

When there is an infection.

Question 14

What is neutrophils job?

Answer 14

To “eat and kill” bad bacteria

Question 15

What can neutrophils do to trap microbes?

Answer 15

They can eat them or spit out DNA net traps

Question 16

Where do mast cells line?

Answer 16

Mucosal surfaces, they are not found in blood

Question 17

What do mast cells release to attract white blood cells?

Answer 17

Granules? fix

Question 18

Are monocytes present in blood?

Answer 18

Yes

Question 19

What happens when a monocyte leaves the blood?

Answer 19

It forms a macrophage, as it gains cytoplasm and nucleus increase, it also becomes high in phagocytosis

Question 20

What are the 3 important functions of the macrophage?

Answer 20

1. phagocytosis (professional eaters)
2. Release of chemical messengers
3. Show information about pathogenic microbes to T cells

Question 21

What are dendritic cells most important for?

Answer 21

To help trigger adaptive immune responses

Question 22

Where are dendritic cells found?

Answer 22

Found in all tissues in contact with the environment and in small amounts in the blood.

Question 23

How do cells of the immune system move around the body?

Answer 23

Cells are carried in the blood and in the lymph

Question 24

What are pathogens?

Answer 24

Disease-causing microbes

Question 25

What are some of the common building blocks of viruses?

Answer 25

Nucleic acids: ssRNA, dsRNA

Question 26

What is some common building blocks of bacteria?

Answer 26

Cell wall: lipopolysaccharides (LPS)/ endotoxins, lipoteichoic acid Flagella: Flagellin Nucleic acid: Unmethylated CpG DNA

Question 27

How do you recognise patterns in bacteria and viruses?

Answer 27

Toll-like receptors

Question 28

How do toll-like receptors allow the cell to identify bacteria and viruses?

Answer 28

Cell signalling to regulate gene transcription

Question 29

Why do you find phagolysosomes inside the cell?

Answer 29

Intact molecules are swallowed in the cell whole, so the phagolysosomes engulf the virus/bacteria to digest it/ break it down.

Question 30

What occurs when you get a fever?

Answer 30

- Abnormally high temperature - Re-setting of the thermostat (in the hypothalamus) - Pyrogens- released by cells of the immune system - Phagocytes produce the chemical messenger and pyrogen interleukin-1 (IL-1) after ingesting bacteria - Decreasing phagocytosis decreases IL-1, therefore, decreases your temperature.

Question 31

What do granulocytes do?

Answer 31

Circulate in the blood and can move into the tissue during inflammation

Question 32

Why does a dendritic cell have such a large surface area?

Answer 32

Increases the chance that it will come in contact with a bacteria or invading organism

Question 33

Why are dendritic cells in very low numbers?

Answer 33

Because they are very potent and they are found in all tissues that are in contact with the environment.

Question 34

Can cells leave blood to enter tissues?

Answer 34

Yes

Question 35

What do lymphs in tissues do?

Answer 35

They collect into lymphatic vessels. These drain lymph into lymph nodes

Question 36

How do you recognise pamps?

Answer 36

Through PRR or pattern recognition receptors.

Question 37

Where are the PRR on innate cells and platelets and what do they do?

Answer 37

On the surface, which allows them to recognise common bacterial cell wall components or yeast cell wall components.

Question 38

Where are the toll like receptors?

Answer 38

In the lipid bilayer there are toll like receptors, although a little bit sticks out the edge of the cell to recognise the common molecular patters.

Question 39

Why are there toll-like receptors in the cell and what does it do?

Answer 39

For signalling within the cell, once it binds to one of those particular cell wall components, it can send signals through a bunch of enzymes that send a cascade of signalling through to the nucleus, then regulate or alter gene transcription.

Question 40

Can the phagolysosome also send out messages to the nucleus to alter gene transcription?

Answer 40

Yes