Introduction to Immunology Flashcards
Where are all the cells involved in immune system derived from?
Common pluripotent haematopoietic stem cell in bone marrow
What cells fall under myeloid lineage?
- Polymorphonuclear leukocytes (neutrophils, eoisinophils, basophils)
- Dendritic cells
- Mast cells
What cells fall under lymphoid lineage?
- B lymphocytes
- T lymphocytes
- Natural Killer (NK) lymphocytes
What occurs at primary lymphoid tissue?
Development and maturation of B and T lymphocytes
What occurs at secondary lymphoid tissue?
Mature lymphocytes encounter antigens/pathogens
Where do ‘virgin’ B and T cells from bone marrow and thymus migrate to?
Specific sites in lymph nodes
Why do lymph nodes change shape during infection?
In response to activation and proliferation of lymphocytes
What is primarily found in outer layer (cortex) of lymph node?
B cells found in 1ary and 2ary lymphoid follicles
What is primarily found in middle layer (paracortex)
T cells and dendritic cells
What is primarily found in medullary cord (cords of lymphatic tissue)?
Macrophages and plasma cells
What is the spleen?
Lymphoid organ in abdomen
What is job of spleen?
- Removes old and damaged erythrocytes
2. Key site of activation of lymphocytes from blood borne pathogens
At what part of the spleen is erythrocytes removed?
Red pulp
At what part of the spleen is lymphocytes stimulated?
White pulp
What is the innate immune system?
First line of defence that is non-specific
What are key components of innate immune system?
- Mechanical barriers
- Physiological barriers
- Chemical mediators
- Phagocytic leukocytes
- Natural Killer cells
What is stomach acid an example of?
Physiological barrier
What are normal flora, mucous membranes and cilia examples of?
Mechanical barriers
What is involved in humoral immunity?
Mediated by antibodies produced by B lymphocytes that bind to antigens
What is involved in cellular immunity?
T lymphocytes recognise and destroy invading cells directly (cytotoxic cells and T helper cells)
What are the 5 ways that the immune system can kill bacteria?
- Phagocytosis by macrophages
- Phagocytosis by neutrophils that infiltrate infected tissue from blood (stop, roll exit)
- Complement system producing MAC
- Opsonisation by antibodies or iC3b binding to bacterial cell surface
- Antibodies clump together and unable to replicate
What are the first cells to first to invading bacteria? What are their functions?
- Neutrophils
- Phagocytose pathogens - Macrophages
- Phagocytose pathogens
- Present antigens
- Clean up cell debris after phagocytosis - Dendritic cells
- Phagocytose pathogens
- Present antigens
- Specialised at recognising patterns on surface of foreign organisms that mark them out for generating immune response
