Blood and immune 4 Flashcards
(29 cards)
e.g. of APC
B Cells
Macrophage
MHC Class II
Proteins on the surface of APC that hold the processed antigens
B cell receptor
look like antibodies
Innate Immunity
Recognition of traits shared by broad ranges pathogens, using a small set of receptors
Rapid response
Innate immunity egs
All animals
Barrier defences
skin
mucous membranes
secretion
Internal defences Phagocytic cells Natural killer cells Antimicrobial proteins Inflammatory response
Adaptive Immunity
Vertebrates only
Recognition of traits specific to a particular pathogens, using a vast array of receptors
slower response
Adaptive immunuty eg.s
Humoral response
Antibodies defend against infection in body fluids
Cell mediated response
Cytotoxic cells defend against infection in body cells
Immune response steps
- Immediate inflammatory response
– Neighbourhood watch - Mast cells, neutrophils macrophages/ dendritic cells
- Specific helper T-cell activation
– Alarm #1 antigen presentation by APC to appropriate T-cells in lymph nodes (APC = Antigen Presenting Cells)
3 B-cell activation
– Alarm #2 specific T-cells and B-cells interact in lymph nodes. B Cell APC get activated when they meet the previously activated T Cells
4 B-cell clonal expansion
– Response B-cells then divide and produce antibodies
5 Memory update
Mast cells
When broken histamines release which attract neutrophils and macrophages
cut skin
cut mast cells
After cut
Dilation and increases permeability of membrane
Neutros and macros hop out out capillary attracted by histamine and bacteria
macrophages go snitch to nodes
WBC in vessels
The signal is sensed in blood vessels by leukocytes rolling along vessel wall which adhere to wall (due to active selectins which bind carbohydrates)
and squeeze between epithelial cells to connective tissues
(only veins, not arteries)
APC
Recognise common features of bacteria
endocytosis
phagosome
lysosome
Antigen residue fuse with MHC class 2
Exocytosis of these molecules and then embedded into membrane
Peptide antigen
is 10 amino acid segments of antigen proteins
Alarm 1
An APC cell carrying processed antigen on a MHC II molecule travels to a lymph node,
finds the appropriate specific T-cell with the right TCR molecule, and stimulates it
to divide.
Alarm 2
A specific B cell with the correct membrane bound Ig molecule binds to the bacteria, ingests it
just like a macrophage and
presents pieces of bacterial proteins on the surface.
This B cell now has to find an appropriate T-cell, and then, finally, after two antigen checks, B cell clonal expansion occurs.
node swells
antibodies
tag things for destruction
Antibody graph doeeeee
Primary and secondary immmune response
Describe relationship between endocytosis and phagocytosis?
Phagocytosis is a subcategory of endocytosis (the engulfing of a molecule). The difference depends on the size engulfed
How is the immune system associated with the lymphatic system
The circulation of lymph allows immune system cells and molecules to circulate through most of the body, not just the arteries, capillaries and veins
Where are most T cells located?
In the spleen and lymph nodes
What is a clone of cells?
A bunch of cells next to each other with the same type antigen receptor on surface
Does the level of lymphocytes in the blood vary?
Yes, they come and go in blood as needed
Cytokines
stimulates epithelial cells in immediate inflammatory response
