U3 AOS2 P4 Innate Immune System Flashcards
(27 cards)
What are the 5 types of Immune Cells involved in this part of the Immune System?
Dendritic Cells Macrophages Neutrophils Mast Cells Leukocytes
What are 4 characteristics of the Innate Immune System?
It is non-specific, meaning it attacks anything detected as foreign
Is fast acting
Present in all animals
Has no immunological memory
What are Leukocytes?
Type of WBC that has TLRs on their surface which recognise PAMPs
What does TLR stand for?
Tool-like Receptor
What does PAMP stand for?
Pathogen Associated Molecular Patterns
What are the 4 types of Phagocytic Cells?
Neutrophils, Monocytes (which include Dendritic Cells and Macrophages)
What is a Phagocytic cell?
An immune cell that can undergo the process known as phagocytosis.
What does the process of Phagocytosis involve?
Phagocytes engulf the microbe via Endocytosis, forming a Vacuole called a Phagosome. Lysosomes full of digestive enzymes fuse with the phagosome to break down the microbe. Fragments are then presented on the PM by MHC II proteins.
What does APC stand for?
Antigen Presenting Cell
What are the 2 immune cells that are also APCs?
Dendrites and Macrophages
What do APCs do?
The APCs have the ability to present fragments of the broken down microbe via phagocytosis on their PM, which can trigger an Adaptive Immune Response.
What are Complement Proteins?
Proteins present in body fluids that may be activated to fight pathogens directly or to assist in destroying them.
What cells make Complement Proteins?
Liver Cells (and other body cells)
Macrophages
Monocytes
What are 3 ways that Complement Proteins assist in breaking down a pathogen?
- Stick to invading micro-organisms making them more identifiable by phagocytes
- Attract phagocytes to the site of infection
- Destroy the membranes of invading microbes
How do Cytokines help in the Innate Immune System?
Become released by cells when they are damaged or a pathogen is detected, which coordinate an immune response. They can also cause leukocytes to proliferate, inducing fever and inflammation.
What is an Interferon?
Type of cytokine that is secreted by a cell when it becomes infected by a virus, which also interfere with viral replication and help cells to resist infection.
Why are Interferon’s important?
They are produced early on in a viral infection, and are important in our ability to resist infection
What is an Inflammatory Response?
Response of injured or infected body tissue that consist of the dilation of blood vessels, and increased phagocytosis which causes swelling, redness and heat.
What do Phagocytes do in the Inflammatory process?
Phagocytes release complement proteins and cytokines when they engulf pathogens
Steps of Inflammation
Cytokines attract neutrophils first.
Mast cells then release histamine which dilates the blood vessels
Platelets release clotting factors
Neutrophils and Cytokines activate Macrophages
Neutrophils and Macrophages form pus
Response continues until pathogen is eliminated and wound is healed
Why do Mast Cells release histamine to dilate blood vessels?
They release histamine so that blood vessels become more permeable. Meaning more phagocytes, leukocytes and nutrients found in the blood can reach the site of inflammation
What is pus?
Pus is the broken down remnants of microbes from phagocytosis as well as dead neutrophils.
What is a disadvantage of Mast Cells releasing histamine irregularly?
Causes hypersensitivity known as allergies
What is a Mast Cell?
Large cell that produces and secretes histamine.
