Innate immunity: immune cells in the body

Question 1

what are the 2 main components of blood

Answer 1

1. plasma - 55%
2. formed elements - 45%

Question 2

what does the plasma of the blood contain

Answer 2

1. proteins including antibodies (cytokines)/ immunoglobulin
2. other solutes
3. water

Question 3

what are the formed elements in blood

Answer 3

1. platelets
2. white blood cells/leukocytes
3. red blood cells

Question 4

what is hematopoiesis

Answer 4

the process of forming blood cells and other components in the body, primarily within the bone marrow. It involves the differentiation and proliferation of hematopoietic stem cells (HSCs) into various specialized blood cells like red blood cells, white blood cells, and platelets.

Question 5

what are the 2 types of blood cell lineages

Answer 5

1. myeloid
2. lymphoid

Question 6

what are blood cell linages derived from

Answer 6

hematopoietic stem cells in the bone marrow

Question 7

what blood cells are included in the myeloid lineage

Answer 7

erythrocytes - red blood cells
innate immune cells - granulocytes, monocytes, dendritic cells, platelets

Question 8

what blood cells are included in the lymphoid lineage

Answer 8

adaptive immune cells - B and T lymphocytes

Question 9

what are granulocytes

Answer 9

Granulocytes are a type of white blood cell that has small granules inside them

Question 10

what are neutrophils

Answer 10

• makes up 75% of all leukocytes
• are highly phagocytic therefore they engulf pathogens to kill them
• attracts other cells to the site of infection or injury

Question 11

when does granulocytes enter the tissue after circulating the blood

Answer 11

they enter the tissue during inflammation to attract other cells

Question 12

what is NETosis

Answer 12

when the neutrophil bursts in order to spread its DNA contents on the pathogen, killing it

Question 13

where are mast cells found

Answer 13

mast cells line mucosal surfaces, they are not found in the bloodstream

Question 14

what are mast cells

Answer 14

Mast cells are specialized immune cells found in various tissues throughout the body, acting as the body’s “alarm system”

Question 15

what do mast cells do when there is a site of infection or injury

Answer 15

they release granules, that are very densely packed, that attract white blood cells to the areas of tissue damage

Question 16

what are monocytes

Answer 16

Monocytes are a type of white blood cell that circulate in the bloodstream (not for a very long time) and differentiate into macrophages when they enter tissue
- are not very phagocytic

Question 17

what are macrophages

Answer 17

A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells
- a large, very phagocytic cell

Question 18

what are 2 stages of macrophages

Answer 18

1. can become sessile - remains attached to the tissue or organs and doesn’t move about freely
2. migratory - moves around the tissue, in response to an infection, etc

Question 19

what are the 3 important functions of macrophages

Answer 19

1. phagocytosis
2. release of chemical messengers
3. show information about pathogenic microbes to T cells - linking innate and adaptive immunity

Question 20

what is the most important function of dendritic cells and what aspect of their structure is related

Answer 20

Links the innate and adaptive immune responses, therefore they are the most important cell type to help trigger adaptive immune system.
- their long ‘arm’ structures increases the surface area, therefore they can make more contact and trigger more T cells

Question 21

why are dendritic cells found in low numbers

Answer 21

the cells are very large, therefore not many are needed to come into contact with all tissues that are in contact with the environment

Question 22

how do cells of the immune system travel around the body

Answer 22

cells are carried in the blood and in the lymph

Question 23

how do cells enter tissue

Answer 23

• cells can leave blood to enter tissues
• the lymph in tissues collects into lymphatic vessels, these then drain the lymph into the lymph nodes

Question 24

what are pathogen associated molecular patters (PAMP)

Answer 24

Pathogen-associated molecular patterns (PAMPs) are conserved structural motifs found in microorganisms that are recognized by the immune system as foreign

Question 25

what are the 3 common structures of viruses

Answer 25

1. envelope (not in all of them) 2. nucleocapsid - made of proteins 3. nucleic acids

Question 26

what are the PAMPs for viruses

Answer 26

the nucleic acids - ssRNA and dsRNA

Question 27

what are the 5 common structures of bacterium

Answer 27

1. capsule 2. cell wall 3. cell membrane 4. nucleic acid 5. flagella

Question 28

what are the PAMPs for bacterium

Answer 28

1. cell wall: made of lipopolysaccharide (LPS), endotoxins or lipoteichoic acid 2. flagella: made of flagellin 3. nucleic acids: contains unmethylated CpG DNA

Question 29

what receptors identify the pathogens via PAMPs

Answer 29

Toll-like receptors

Question 30

what are Toll-like receptors

Answer 30

These receptors recognize specific molecules on pathogens, known as pathogen-associated molecular patterns (PAMPs), which trigger the innate immune response.

Question 31

where can Toll-like receptors be found

Answer 31

in the cell membrane of the cell or in the cell membrane of the phagolysosomes

Question 32

what is a fever/pyrexia

Answer 32

an elevation of body temperature above the normal range, often as a sign of an infection or illness, like a resetting of thermostat (hypothalamus)

Question 33

what are pyrogens

Answer 33

Pyrogens are fever-producing substances, typically biological in origin, that can cause a rise in body temperature when introduced into the body

Question 34

how does your body respond after ingesting bacteria in regards to a fever

Answer 34

phagocytes produces the chemical messenger and pyrogens, such as pyrogen interleukin 1 (IL-1) is released by cells in the immune system in order to raise the temperature

Question 35

why is a fever useful

Answer 35

- creates a hostile environment for the pathogen to grow - enhances the immune system