lecture 31 - immune cells of blood

Question 1

What are the two overall components of blood, and at what ratios?

Answer 1

55% plasma, 45% formed elements

Question 2

What are the components of plasma?

Answer 2

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

Question 3

What are the 3 key formed elements of blood?

Answer 3

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

Question 4

What is the general term for white blood cells?

Answer 4

Leukocytes

Question 5

What process allows bone marrow stem cells to produce blood cells?

Answer 5

Hematopoiesis.

Question 6

What are the 3 blood cell lineages?

Answer 6

Erythoid, myeloid, lymphoid

Question 7

What type of cell are in the Erythroid lineage?

Answer 7

Red blood cells (erythrocytes)

Question 8

What types of blood cells are in the myeloid lineage? (4)

Answer 8

Granulocytes, monocytes, dendritic cells, platelets

Question 9

Are blood cells of the myeloid lineage innate or adaptive in nature?

Answer 9

Innate

Question 10

What types of cells are in the lymphoid lineage?

Answer 10

B and T lymphocytes (B/T cells)

Question 11

Are cells in the Lymphoid blood cell lineage adaptive or innate in nature?

Answer 11

Adaptive

Question 12

What two blood cell lineages are white blood cells?

Answer 12

Myeloid and lymphoid

Question 13

What is the name for granulocytes found in blood?

Answer 13

Neutrophils

Question 14

What proportion of leukocytes are represented by neutrophils?

Answer 14

75%

Question 15

What is the structure of a neutrophil?

Answer 15

Has a multi lobed nucleus and contains granules

Question 16

What is the function of neutrophils?

Answer 16

They highly phagocytic - can ‘eat and kill’ pathogens.

Question 17

When do neutrophil levels in the blood increase?

Answer 17

When there is infection or inflammation

Question 18

When can neutrophils move out of blood and into tissue?

Answer 18

When there is inflammation

Question 19

What is the name for granulocytes found in tissue?

Answer 19

Mast cells

Question 20

What are mast cells?

Answer 20

Cells that line mucosal surfaces and release granules that attract other white blood cells to areas of tissue damage/infection.

Question 21

What are monocytes?

Answer 21

Cells present in the blood that have a low level of phagocytosis until they leave the blood and develop into macrophages in tissues.

Question 22

What are macrophages derived from?

Answer 22

Monocytes

Question 23

Where are macrophages found?

Answer 23

In tissue - not in blood

Question 24

Do macrophages have a high or low rate of phagocytosis?

Answer 24

High

Question 25

What are the possible ways that a macrophage can sit in tissue?

Answer 25

Can become resident/sessile, or move though it (migratory)

Question 26

What are the 3 functions of macrophages?

Answer 26

Phagocytosis, release of chemical messengers, show info about pathogenic microbes to T cells.

Question 27

What is phagocytosis?

Answer 27

Ingestion of bacteria by cells such as macrophages

Question 28

What is the purpose of chemical messaging by macrophages?

Answer 28

Signals to other cells to aid in clearing infection

Question 29

How do macrophages share information about pathogens?

Answer 29

They break up viruses and attach a piece to a receptor on its surface, where it can be recognised by the adaptive immune system.

Question 30

How do macrophages link the innate and adaptive immune systems?

Answer 30

They share information about viruses with T cells, activating the adaptive immune system.

Question 31

What is the function of dendritic cells?

Answer 31

Link innate and adaptive immune systems - they are phagocytic and can present antigens to adaptive immune cells.

Question 32

Where are dendritic cells found, and in what numbers?

Answer 32

In low numbers in blood and tissues in contact with the environment.

Question 33

How are immune cells carried around the body?

Answer 33

In blood and in lymph

Question 34

Where does lymph in tissues collect?

Answer 34

Lymphatic vessels

Question 35

Where does lymph drain to, from the lymphatic vessels?

Answer 35

Lymph nodes

Question 36

Where do dendritic cells meet T cells?

Answer 36

Lymph nodes

Question 37

What does PAMP stand for?

Answer 37

Pathogen associated molecular pattern

Question 38

What is a PAMP?

Answer 38

A small molecular motif conserved within a class of microbes and are a common ‘building block’.

Question 39

What are common PAMPS in viruses?

Answer 39

nucleic acids - ssRNA and dsRNA

Question 40

What are the common nucleic acid PAMPS of viruses?

Answer 40

single stranded RNA and double stranded RNA

Question 41

What are the locations/types of common bacterial PAMPs?

Answer 41

Cell wall, flagella, nucleic acid

Question 42

What are the common PAMPs found in bacterial cell walls?

Answer 42

Lipopolysaccharide (LPS), endotoxins, lipoteichoic acid

Question 43

What are the common PAMPs found in bacterial flagella?

Answer 43

Flagellin

Question 44

What is the common PAMP found in bacterial nucleic acids?

Answer 44

unmethylated CpG DNA

Question 45

How do toll-like receptors activate innate immune responses?

Answer 45

Toll-like receptors in the cell membrane recognise PAMPs and can then signal to the nucleus to transcript genes and translate to form proteins that aid in cellular defence.

Question 46

What intracellular component allows cells to defend against pathogens that have come inside it?

Answer 46

Phagolysosomes

Question 47

How do phagolysosomes defend cells?

Answer 47

They recognise the nucleic acid PAMPs of invading bacteria/viruses and engulf and decoat them, preventing them from colonising the inside of the cell.

Question 48

What is the clinical name for fever?

Answer 48

Pyrexia

Question 49

What is pyrexia?

Answer 49

Fever - an abnormally high body temperature (usually >37 degrees celsius)

Question 50

What does the fever do to the body’s ‘thermostat’?

Answer 50

Resets the temperature regulation, controlled by the hypothalamus

Question 51

What substances produce a fever?

Answer 51

Pyrogens

Question 52

What are pyrogens released by?

Answer 52

Bacteria and immune cells

Question 53

What chemical messenger and pyrogen is produced by phagocytes?

Answer 53

interleukin-1

Question 54

What is interleukin-1?

Answer 54

A pyrogen and cytokine

Question 55

What is the purpose of fever?

Answer 55

Stop pathogen growth and enhance immune function

Question 56

How does changing phagocytic activity decrease a fever and restore the biological thermostat?

Answer 56

Decreasing phagocytosis leads to a decrease in interleukin-1 release and therefore less pyrogen, so the fever comes down.

Question 57

What is the difference between lymphocytes and leukocytes?

Answer 57

Leukocytes are all the white blood cells in the blood, while lymphocytes are a specific type of leukocyte that are found in lymph

Question 58

Are mast cells phagocytic?

Answer 58

Yes