Tissues and Organs of the Immune System Flashcards
What is big question to ask about pathogen?
How big is it? Intra or extra cellular
First thing that happens
Inflammation
Goal of immunity
maintain homeostasis
2 steps of immunity
Recognition
Effector functions
Hematopoietic stem cell becomes
COmmon myeloid progenitor and common lymphoid progenitor
Common lymphoid vs common myeloid
Lymph - adaptive
Myeloid - innate
What allows ID of lymphocytes?
CD markers
Small lymphocyte amounts
20-40%
Types of small lymphocytes and their percentages of the lymphocytes
T lympho - helper (50%), cytotoxic (25%)
B lympho - 25%
Plasma cells…where are they from, what do they do, where are they found
From B cells
Secretes antibodies (eliminate micro organisms)
Not often found in blood
NK cell amount and what does it do?
Kills virus-infected/tumor cells
5% of lymphocytes in blood
Resident in tissue sites
Monocyte location, shape, function, differentiation
Kidney nucleus with lots of cytoplasm
Weekly phagocytic and microbicidal
Differentiates to macrophage or dendritic cell upon leaving blood
Mostly found in blood
Macrophage function and location
Tissue sites
Phagocytic, microbicidal, tissue repair, activate T cells
Dendritic cell location and function
Activate T helper cells, phagocytic,
Mostly in tissue sites
Neutrophil morphology, function
Phagocytic and microbicidal
Segmented nucleus
Eosinophil morphology, function
Immune response to parasites and allergic immune responses
Red staind granules in cytoplasm
Basophil morphology and function
Parasites and allergic responses
Contains histamine (vasodilation) and heparin (anti-coagulant)
Darkly stained nucleus
Mast cells and function
Immune and allergic response
Close to blood vessels, skin, etc…similar to basophils
Megakaryocyte
Platelet production
Leukocyte amounts
Neutrophils - 40-75 Eosinophil - 1-6 Basophil - <1 Monocyte - 2-10 Lymphocyte - 20-50
If lymphocyte count high
Then probably viral infection
Lymphatic circulatin
Vessels pick up fluid at venule end of capillary network and return to the heart…lymph nodes filter
How to lymphocytes get to lymph node from heart?
Arteries
How do lymphocytes get from lymph node to heart
Efferent venule to venous system (essentially thoracic duct)
Diffuse tissues
Associated with mucosal epithelial surfaces
Encapsulated types and what theydo
Primary lymphoid - site of immune cell production
Secondary lymphoid - site of immune cell function
Myelopoiesis occurs in
bone marrow
Lymphoposiesis occurs in
B - bone marrow
T - thymus
Both B and T cells originate during development in the
Liver
Clonal proliferation
Happens to B and T cells after exposure to an antigen…those that are specific to a given type proliferate
Activation occurs in
Lymph nodes and spleen
MALT
Mucosa associated lymphoid tissue - found under any wet epithelium…must be passed through to get into the body
Skin lined by
Stratified squamous epithelium
Skin cell adhesion
Tight junctions - must be broken to enter
Commensal bacteria
Found on surface of skin
Mechanical epithelial barriers
Tight junctions
Logitudinal flow of air or fluid
Movement of mucous by cilia
Chemical epithelial barriers
Fatty acids
Enzymes
Low pH
Antibacterial peptides (defensins, cryptidins)
Microbiological epithelial barriersa
Commensal bacteria compete for nutrients and attachment and can produce antibacterial substances
Organized MALT
Tonsils, Peyer’s patches, appendix
Diffuse MALT
Lamina propria
GALT will have
Epithelium with M cells and dendritic cells inside…follicle for B cells and germinal center
M cell
Captures things on mucosal surfaces and presents into germinal centers
Central tolerance induction
Occurs in the thymus…lymphocytes that posses self-reactivity are eliminated…moves from cortex to medulla
Bone marrow is unique in that
It is a primary AND secondayr lymphoid organ
How do cells exit marrow
Central sinus
What is compartmentalized in the bone marrow
Hematopoeisis
Bone marrow is important reservoir for
Neutrophils
Neutrophil lifespan
Short (6-8 hours)
How to neutrophils get to tissue
Leave bone marrow and pass through endothelium…eat material and degraded by macrophages
Spleen is site of
Adaptive immune response to blood borne pathogens
Red pulp
Rich in macrophages that filter blood of foreign materials and old RBCs
White pulp
Multiple immune cell types present to initiate adaptive immune response
PALS
Area surrounding central arterioles rich in T cells
Lymphoid follicle
Outpocketing of lymphocytes from PALS rich in B cells
Primary lymphoid follicles contain
Naive B cells
Secondary lymphoid follicles contain
Outer mantle of naive B cells with germinal center of activated B cells
Visceral lymph node types
Pre-vertebral/mesenteric
Lymph node is site of
Adaptive immune response to tissue-borne antigens
Filtration units for affarent lymphatic vessels
Normal lymph carries
Interstitial fluids/proteins to blood
In infection, lymph carriers
Microorganisms and antigens from tissue site
What always migrates from lymph nodes to tissue
Dendritic cells
High endothelial venule (HEV)
How Naive lymphocytes enter the lymph node (B and T cells)
How to lymphocytes exit lymph node?
Single efferent lymphatic
Paracortical region
Contains follicles and T-cell rich regions
Medulla
Rich in macrophages and plasma cells
What enters via affarent lymphatic vessels?
DCs and antigens
What enters via artery and vein
Naive lymphocytes (B and T cells)
Lymph filtered by
Lymph nodes