D2 - Intro to immunology Flashcards
“land mines”
complement
“marines”
phagocytes
“air force”
B cells
“assassins/secret agents”
CD8
physical barriers to entry
skin
cilia
tears
mucous
chemical barriers to entry
acid
enzymes (pepsin, lysozyme)
biological barriers to entry
normal flora
stromal cells that recognize pathogens
epithelial cells
endothelial cells
fibroblasts
resident immune cells that recognize pathogens
mast cells
dendritic cells
resident macrophages
innate lymphocytes
PRRs
pattern recognition receptors
sense molecules that aren’t “self,” b/c invaders express PAMPs (pathogen-associated molecular patterns)
PAMPs
pathogen-associated molecular patterns
patterns detected by PRRs
5 hallmarks of inflammation
1) calor (heat)
2) dolor (pain)
3) rubor (redness)
4) tumor (swelling)
5) loss of function
innate cells recruited from circulation
neutrophils
monocytes (which become macrophages)
natural killer cells
eosinophils
basophils
How are dendritic cells the “bridge”?
bridge between innate and adaptive
specialized type of phagocyte that takes sample of pathogens, use this to initiate adaptive immune response
when activated, let go of surrounding tissues, migrate to lymphatics/secondary lymphoid organ, so can present “pathogen sample” to naive T & B cells
secondary lymphoid organs
where immune cells develop more, get activated, interact:
- spleen
- lymphatic vessels
- lymph nodes
- tonsils/adenoids
- mucous-associated lymphatic tissues
primary lymphoid organs
where lymphocytes made, develop:
- bone marrow
- thymus
bone marrow
primary site of hematopoiesis & lymphopoiesis in adults
has hematopoietic stem cells that generate and replenish all blood cell types
where all myeloid and lymphoid cells begin to mature
red marrow
where all different types of blood cells are produced
when baby/child, all our bone marrow is red
yellow marrow
as we age, marrow is infiltrated by fat (we get more and more yellow marrow)
yellow can be converted back into red in case of bone marrow stress, blood loss, etc
thymus
primary site of T cell maturation and selection after bone marrow
plays major role in preventing autoimmunity, by helping a lot in immune tolerance
active in kids, slowly atrophies over time (gets infiltrated by fat)
3 main constituents of lymph
1) interstitial fluid: like plasma, but less protein
2) white blood cells
3) chyle: made up of chylomicrons
spleen
where B cells complete maturation after leaving bone marrow
red pulp: filters and clears blood of damaged cells
white pulp: where lymphoid cells reside and interact
lymphatic vessels
“slurp up” interstitial fluid & immune cells that bathes tissues
lymph can circulate through lymphatic system (lymphatic capillaries –> lymphatic collecting vessels –> lymphatic ducts), and be filtered through lymph nodes en route
lymph nodes
integrated into lymphatic vasculature
has many lymphoid follicles, where lymphocytes aggregate
major site where APCs (antigen presenting cells) present antigen
tonsils & adenoids
adenoids at back of nasopharynx
together, form Waldeyer’s ring, so can sample all antigen that comes in through eating/breathing
part of MALT
MALT
Mucosa-Associated Lymphatic Tissue
aggregates of lymphoid tissue along the mucosa
provides immune defense at sites of recurrent exposure to pathogens, foreign proteins (food), etc
3 major modes of cytokine action
autocrine (on self)
paracrine (on neighbors)
endocrine (secrete into circulation –> act on distant cells)
cytokines
direct growth, development, maturation, activation, and life-span of immune cells
chemokines
direct movement of white blood cells in body
3 functional categories of chemokines
1) homeostatic
control migration of cells during normal development
2) inflammatory
direct migration of leukocytes to infection/damage
3) angiogenic
pro-angiogenic or anti-angiogenic: promote or prevent development of blood vessels
