BIOCHAP7C Flashcards
Phagocyte:
leukocytes responsible for endocytosis and destruction of pathogens and foreign material
Neutrophil:
common type of leukocyte in body, engages in phagocytosis
Antigen presenting cell:
subgroup of phagocytosis, displaying antigens from consumed pathogens and interact with adaptive immune system
Cytokine:
signaling molecule aiding in communication between immune cells and protects against pathogen
Histamine:
released by mast cells that plays a key role in inflammation
Mast cells:
type of leukocyte responsible for releasing histamine during allergic and inflammatory responses.
Cellular components of the second line of defense
Consume and destroy foreign materials through engulfment via endocytosis. One consumed, lysosomes destroy it
3 main phagocytosis:
Neutrophil
Macrophage: leukocyte found throughout the body that engages in phagocytosis and antigen presentation
Dendritic cells: leukocyte that engages in phagocytosis and antigen presentation
Process of phagocytosis and antigen presentation
- Phagocytosis of pathogen
- Fusion with lysosome
- Enzymes start to degrade pathogen
- Pathogen broken down to small fragments
- Fragments of antigen presented on cell surface
Natural killer (NK) cells
large granulated cells that target both abnormal and infected cells
NK CELLS
Achieved through 2 receptors
killer inhibitory receptor > examined surface of cells for MCH class 1 markers
Killer activation receptor > binds to molecules which appear on cells undergoing cellular stress
NK CELLS
Presence of MCH class 1 markers may be absent due to number of different disease processes
due to presence of viral infection,
cancerous cells may reduce gene expressed of MHC class 1
Mast cells and Eosinophils
When they detect injury they become activated and degranulate, releasing histamine
Eosinophils are large granulated cells containing toxic chemical mediators to destroy invading pathogens
Interferons
Released when cell is infected with virus, prevents spreading of virus between cells
Non-cellular components of second line of defense
(Key molecules and process)
Complement proteins
in presence of certain pathogen, they react with one another in a complement cascade causing opsonization, chemotaxis and lysis
Non-cellular components of second line of defense
(Key molecules and process)
Initiation of a fever
Temporary increase in core body temperature as a response to a potential infection
Steps in the inflammatory response process
initiation
vasodilation
migration
Steps in the inflammatory response process
Initiation:
pathogens enters body to damaged cells. Macrophages in tissue becomes activation, cytokines released and cells denature, releasing histamine
Steps in the inflammatory response process
Vasodilation:
Mast cells travels to nearby blood vessels and binds to specific receptors causing vasodilation, increasing blood flow to site of injury. Causes swelling, pain, heat, redness.
Steps in the inflammatory response process
Migration:
increased ‘leakiness’ of blood vessels allow for phagocytes guided by cytokines and complement proteins. Complement proteins are attracted to pathogens, making it easier for the phagocytes to destroy them digestion using lysozymes.
