Innate immunity Flashcards
Why do we need an immune response?
Prevent infections and cancers
Remove dead/non-functioning components
Physical barriers
Skin Cilia Hairs Mucus Flushing action of tears/urine
Characteristics of viruses
Obligate intracellular pathogen
20-800 nm
Characteristics of bacteria
Prokaryote
0.2-20 micrometers
Characteristics of fungi
Eukaryote
2 micrometers to a centimetre
Characteristics of a protozoal parasite
Two or more hosts
10-200 micrometers
Characteristics of multicellular parasites
Multiple lifestyles
1 cm to 3 m
What is desquamination?
Constant turnover of skin cells
What do goblet cells do?
Produce mucus
Which cells are part of gastric immunity?
Goblet and dendritic cells
Chemical defences of the body
Lysozymes
Normal flora
Stomach acid
Why is normal flora beneficial?
Gets rid of pathogens and stops them binding
What is the order of defence in the body?
1st line - physical barriers
2nd line - innate immune system
3rd line - adaptive immune system
What do all cells in the innate immune system start as?
Pluripotent stem cell
Which cell do most defence cells come from?
Myeloid progenitor
What do granulocytes do?
Degranulate contents to fight pathogens
What do neutrophils do?
Phagocytosis
What do basophils do?
Granulocyte, similar to neutrophil
What do monocytes do?
In tissue, they differentiate into macrophages
What do megakaryocytes do?
Produce platelets/phagocytose/present antigensW
What do mast cells do?
Initiate inflammatory immune response
What do dendritic cells do?
Present antigens
Where do cells in the adaptive immune system come from?
Lymphoid progenitor
Characteristics of mast cells
Granulocyte
Large nucleus
Signals from DAMP/PAMP
Releases granules
What do the granules released from mast cells do?
Recruit immune cells
Regulates phagocytosis
Repairs tissues
Vascular permeability
What impact do mast cells have on vasculature during inflammation?
Cause vasodilation in smooth muscle cells
Makes blood vessels leaky and swell
Endothelial cells have adhesion molecules activated by mast cells and they get sticky. This is where WBCs bind to enter tissue
Plasma proteins leak into tissue to fight infection
Symptoms of inflammation
Rubor/calor
Dolor
Swelling