Lecture 31 Flashcards
What is blood composed of?
Plasma and cells
How much of the blood does plasma make up?
55%
How much blood does the formed elements make up?
45%
What is found in the plasma?
Proteins (including antibodies/ immunoglobulin), other solutes and water.
What is found in the formed elements?
Platelets, white blood cells (leukocytes) and red blood cells
Where is the source of blood?
Bone marrow stem cells
What are the three blood cell lineages?
Erythroid, Myeloid and lymphoid
What is erythroid cell lineages?
Red blood cells (erythrocytes)
What is myeloid cell lineages?
Granulocytes, monocytes, dendritic cells and platelets (innate immune cells)
What is lymphoid cell lineages?
B and T lymphocytes (Adaptive immune cells)
Neutrophils are 75% of all leukocytes, true or false?
True
Are neutrophils highly phagocytic?
Yes
When do the numbers of neutrophils increase?
When there is an infection.
What is neutrophils job?
To “eat and kill” bad bacteria
What can neutrophils do to trap microbes?
They can eat them or spit out DNA net traps
Where do mast cells line?
Mucosal surfaces, they are not found in blood
What do mast cells release to attract white blood cells?
Granules? fix
Are monocytes present in blood?
Yes
What happens when a monocyte leaves the blood?
It forms a macrophage, as it gains cytoplasm and nucleus increase, it also becomes high in phagocytosis
What are the 3 important functions of the macrophage?
- phagocytosis (professional eaters)
- Release of chemical messengers
- Show information about pathogenic microbes to T cells
What are dendritic cells most important for?
To help trigger adaptive immune responses
Where are dendritic cells found?
Found in all tissues in contact with the environment and in small amounts in the blood.
How do cells of the immune system move around the body?
Cells are carried in the blood and in the lymph
What are pathogens?
Disease-causing microbes
What are some of the common building blocks of viruses?
Nucleic acids: ssRNA, dsRNA
What is some common building blocks of bacteria?
Cell wall: lipopolysaccharides (LPS)/ endotoxins, lipoteichoic acid
Flagella: Flagellin
Nucleic acid: Unmethylated CpG DNA
How do you recognise patterns in bacteria and viruses?
Toll-like receptors
How do toll-like receptors allow the cell to identify bacteria and viruses?
Cell signalling to regulate gene transcription
Why do you find phagolysosomes inside the cell?
Intact molecules are swallowed in the cell whole, so the phagolysosomes engulf the virus/bacteria to digest it/ break it down.
What occurs when you get a fever?
- 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.
What do granulocytes do?
Circulate in the blood and can move into the tissue during inflammation
Why does a dendritic cell have such a large surface area?
Increases the chance that it will come in contact with a bacteria or invading organism
Why are dendritic cells in very low numbers?
Because they are very potent and they are found in all tissues that are in contact with the environment.
Can cells leave blood to enter tissues?
Yes
What do lymphs in tissues do?
They collect into lymphatic vessels. These drain lymph into lymph nodes
How do you recognise pamps?
Through PRR or pattern recognition receptors.
Where are the PRR on innate cells and platelets and what do they do?
On the surface, which allows them to recognise common bacterial cell wall components or yeast cell wall components.
Where are the toll like receptors?
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.
Why are there toll-like receptors in the cell and what does it do?
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.
Can the phagolysosome also send out messages to the nucleus to alter gene transcription?
Yes
