Notes Flashcards
(27 cards)
Function of Immune System
- monitors tissue homeostasis
- protect against foreign substance/organisms
- eliminate damaged self
What is Immune System
intricate set of molecules/proteins, cells and tissues in our body that are interconnected
Immune molecules or proteins
Chemokines, cytokokines and complement
- Attract cells to site of damage and initiate/activate cells for function
(snitches)
Immune cells
Granulocytes (phagocytes), lymphocytes in blood and tissue
- can directly ingest pathogens (e.g. phagocytes) (policemen)
Immune tissues or organs
Bone marrow, thymus, spleen and lymph nodes
bone marrow = blood cell production
thymus = production of immune cells
spleen = blood filter in kidney
lymph nodes = filter substance and contains lymphocytes
Inflammation
outcome of immunte system responding to infection or energy
Innate Immunity
- non specific (rapid response)
- broad recognition
Adaptive Immunity
- reliant on innate and more specific (takes time)
- specific pathogens e.g. vaccines
Myeloid Lineage
- rbcs, platelets and granular leukocytes (fight bacterial infections)
- circulate in blood
innate immunity
Lymphoid Lineage
- t-cells, b-cells and natural killer cells
- creation of antibodies
adaptive immunity
T-cells, B-cells and Natural Killer cells
T-cells = cell mediated immunity (attack foreign cells)
B-cells = produce antibodies
NK-cells = detect and destroy cells
RBC and WBC differentiation
all cells aside from platelets and erythrocytes, are leukocytes
Non-Self and Altered Self
pathogen or tumour
Innate and Adaptive Differences
Innate
- cells walls activate neutrophils to engulf and digest bacteria
- complement can form complex to destroy bacteria
- NO MEMORY OF PATHOGEN
Adaptive
- B and T cells will remember exposure e.g. vaccination
Process of Phagocytosis
- The phagocyte attaches to the pathogen or debris.
- The phagocyte extends pseudopods (projections of its cell membrane) to surround and engulf the particles, forming a phagosome (a vesicle containing the engulfed material).
- A lysosome (a cell organelle containing enzymes) fuses with the phagosome, creating a phagolysosome.
- The enzymes and toxic compounds inside the phagolysosome break down and destroy the pathogens or debris.
- Sometimes, the phagocyte expels the remaining indigestible material through exocytosis, a process where the phagolysosome fuses with the cell membrane and releases its contents outside the cell.
Toll-Like Receptors
receptors detect and recognise bacteria or foreign substances
Maturation of Antibodies
Development of antibodies to respond to bacteria
- development of memory cells that can stay for years in case of secondary exposure
Inflammation response to sickness or injury
- recognition = recognise damage to stimulate process
- activation = cytokines and chemokines communicate immune response. phagocytes and tissue macrophages to enhance vascularity for recruitment of neutrophils from blood stream
- chemotaxis = recruit more cells to change or modify blood flow and permeability vascularity to allow cells to enter tissue
- cell to cell communication = direct and indirect means
causes pain, heat, swelling and redness
3 Barriers to Immune System
- physical barriers (skin, mucous membranes, flushing via urination, diarrhea, etc.)
- innate immunity (phagocytosis, inflammatory resonse)
- adaptive immunity (cellular response w/ T and Cytotoxic T cells and B cells w/ memory B cells and plasma cells/antibodies
Thymus Function
training centre for T-cells
Lymph Node Functions
sites for immune interaction
Leucoytosis
increase of white blood cells (mostly neutrophils) after exercise
J-Shape Curve
shows risk of upper respiratory tract infection
- 40-50% decrease in risk during moderate exercise but 2-6fold increase during heavy exertion
Benefits of Moderate Exercise
- reduced systemic inflammation
- augmented immuno-surveillance against pathogens and cancer cells
- neutrophils stimulate other cells
