Innate Immunity: Immune Cells In The Blood Flashcards
What is blood composed of?
Plasma and cells
What portion of the blood is plasma?
55%
What portion of the blood is formed elements?
45%
What is included in the plasm?
Proteins (including antibodies and immunoglobulin), other solutes and water
What is included in formed elements?
Platelets, white blood cells (leukocytes) and red blood cells
What are bone marrow stem cells the source of?
Blood cells
What is hematopoiesis?
The process where a stem cell develops into a blood cell
What are hematopoietic cells?
Those which can become blood cells
What are the three blood lineages?
Erythroid, myeloid and lymphoid
What are the 3 blood lineages derived from?
Henatopoietic stem cells in the bone marrow
What does erythroid lineage make?
Red blood cells (erythrocytes)
What does myeloid make?
Granulocytes, monocytes, dendritic cells, platelets (innate immune cells)
What does lymphoid make?
B and t lymphocytes (adaptive immune cells)
What lineages make white blood cells?
Myeloid and lymphoid
What are granulocytes in blood?
Neutrophils
What portion of leukocytes are neutophils?
75%
How phagocytic are neutrophils?
Highly
What happens to neutrophils during infection?
The numbers in the blood increase
What do granulocytes do?
Circulate in the blood and can move into tissue during inflammation
What are granulocytes in tissues?
Mast cells
Where are mast cells found?
Lining mucosal surfaces (not in blood)
What do mast cells do?
Release granules that attract white blood cells to areas of tissue damage
Where are monocytes?
Present in the blood
How much phagocytosis do monocytes do?
Low phagocytosis
What do monocytes do?
Leave blood and develop into macrophages in tissues (spleen, liver)
How much phagocytosis do macrophages do?
High phagocytosis
What can macrophages do?
Become resident (sessile) or move through tissues (migratory)
What are the 3 important functions of monocytes and macrophages?
Phagocytosis, release of chemical messengers, show information about pathogenic microbes to T cells (linking innate and adaptive immunity)
Where are dendritic cells found?
In low numbers in the blood and all tissues in contact with the environment
Are dendritic cells phagocytosis?
Yes
What are dendritic cells important for?
They are the most important cell type to help trigger adaptive immune responses
How do immune system cells move around the body?
They are carried in the blood and lymph
What can immune cells being carried around the body do?
Leave the blood and enter into tissues
What does lymph in tissues do?
Collects into lymphatic vessels. These drain lymph into lymph nodes
What is a virus composed of?
Nuclei acid, nucleocapsid (protein coat) and some have an envelope
What are the common building blocks (PAMP’s) of viruses?
Nucleus acid (ssRNA and dsRNA)
What is bacteria composed of?
Capsule, cell wall, cell membrane, nucleus acid and flagella
What are the common building blocks (PAMP’s) of bacteria?
Cell wall, flagella, nucleus acid
What part of the cell wall is PAMP?
Lipopolysaccharide (LPS)/endotoxins, lipoteichoic acid
What part of the flagella is PAMP?
Flagellin which is a protein
What part of the nuclei acid is PAMP?
Unmethylated CpG DNA
Where are pattern recognition receptors found?
In the cell membrane
What do pattern recognition receptors do?
Bind to PAMPS
What do pattern recognition receptors do once bound to a PAMP?
Sends a signal to upregulate gene transcription for genes which encode proteins which help the immune system to fight the infection
Where must viruses be to be detected and why?
Inside the cell because their coating just be removed
What are virus and bacteria PAMPS sensed by?
Receptors in phagolysosomes (organelles within the cell)
What can phagolysosome receptors do?
Signal to regulate gene transcription
What is an example of receptors in phagolysosomes?
Toll like receptors
What is a fever?
Abnormally high temperature above 37
How does fever occur?
By resetting of the thermostat (hypothalamus)
What are pyrogens?
They are released by cells of the immune states to regulate the action of the hypothalamus
What happens after ingesting bacteria?
Phagocytes produce the chemical messenger and pyrogens interleukin 1 (IL-1). More IL-1 increases the temperature more
Why might a fever be useful?
It inhibits the growth of microorganisms and improves the function of some of the immune cells and molecules
What happens as a result of a fever?
Decreased phagocytosis, decreased IL-1 and therefore decreased temperatures
