Immunology Flashcards
(52 cards)
What is the immunological role of mucus membranes?
Prevents attachment of pathogens
Continuously shedded to remove any pathogens which do attach
Describe the innate immune system?
Non specific- Will produce the same response time and again to invading pathogens
Describe the adaptive immune system?
Highly specific; Exhibits immunological memory; Involves antibody production
Describe the process of phagocytosis.
Phagocyte surrounds and engulfs pathogen
Encloses pathogen in phagosome
Phagosome fuses with lysosome
Lysosome releases cocktail of hydrolytic enzymes onto pathogen
Pathogen is digested
Remains often ‘burped’ out and acts as signal to other immune cells.
What leukocytes are phagocytic?
Macrophages (and so monocytes), Granulocytes (neutrophils, basophils and eosinophils).
What causes redness upon injury?
Macrophages release chemical signals to other cells when they encounter a pathogen. (This signal alerts cells of the invasion) These chemicals often restrict blood flow away from the site of injury, causing redness.
What are the 3 active complement pathways called?
Classical, Alternative and Lectin
Why can the complement system be considered innate?
It does not change over time
What is the argument for the complement system possibly not being part of the innate immune system.
It can be brought into action by the adaptive immune system
What shared outcome do all three complement pathways have?
Lysis of the target cell and/ or making pathogens more susceptible to phagocytosis.
Brief overview of complement process..?
About 20 individual proteins working together in an enzyme cascade to form a membrane attack complex which basically punches a hole in the pathogen, preventing it maintaining homeostasis- It dies
What is the most common complement protein?
C3
Which complement pathway(s) is/are effector mechanisms of the innate immune system?
Alternative and Lectin
Which complement pathway(s) is/are effector mechanisms of the adaptive immune system
Classical
What is MAC?
Complement legions in the membrane of erythrocytes, formed by poly C9
How do Natural Killer cells destroy cells?
- Secrete perforin onto a cell to bore holes in it, creating a MAC. Enzymes then secreted which enter cell via hole, causing cell to commit suicide.
- Use of FasL protein to connect with Fas protein on target cell, giving target cell the signal to commit suicide.
What are cytokines?
Chemicals used by cells to communicate with other cells.
What are the functions of complement? (4)
- Lysis of Pathogens
- Stimulates phagocytosis of microbes
- Stimulates inflammation by activating mast cells and neutrophils
- Stimulates activation of B cells and antibody production
Describe autocrine action of cytokines?
Cell using cytokines for self stimulation
Describe paracrine action of cytokines?
Cell using cytokines to stimulate another (local) cell.
Describe endocrine action of cytokines?
Cell releasing cytokines into the circulatory system to stimulate another (distant) cell
What are the functions of the lymphatic system?
- Drainage of tissue
- Absorption/ transport of fats/ fatty acids to circulatory system
- Immunity
How is lymph formed?
ISF entering channels of lymphatic system
How is lymph moved around the system?
Contractions of the skeletal muscles
