Immune System Pictures

English	Photos
B & T Cell Development
Presentation of Exogenous Immunogens on MHC Class 2
Presentation of Endogenous Immunogens on MHC Class 1
CD & Surface Immunoglobin Table
Indterdigitating dendritic cell (APC; left) & Lymphocyte (right) in a lymph node
Lymph Node
Lymph Node -->Identify capsule, germinal center, subscapular sinus, lymphatic follicles/nodules, trabecle, trabecula sinus, cortex (ligher than paracortex), paracortex (denser than cortex), medullary cords (darker structures), & medullary sinus (white area)
Germinal Center of Secondary lymphatic nodule in lymph node -->macroscopically contains large, medium lymphocytes & plasma cells -->HEV seen (bottom picture; paramedial to the right -->Insert contains: 1)MITOSIS of lymphocytes 2)ERC's (ovoid, pale-staining large nucleus surrounded by reticular fibers)
Epithelial Reticular Cells
Reticulin fibers of lymph node (Bottom left of picture on right)
Lymph node
Paracortex area -->HEV seen (area where lymphocytes enter lymph node; part of venous system)
Sinus macrophage -->Surrounded by cytoplasmic projuection of dendritic cells -->Contains reticular fibers (RF)
Mantle Zone & Germinal Center of lymph node
Lymphatic follicle/nodule -->Germinal center (left) -->Mantle Zone (right)
B Cells in Follicles (CD20 marker; left) T Cells in paracortex (CD3 marker; right)
High endothelial vessels (HEV)
Medullary cords & sinuses (on left) vs. plasma cells (on right) -->Plasma cells located in the MEDULLARY CORD
Plasma Cell on EM -->negative golgi image to the right of nucleues -->***Clockface nucleus -->Basophilic cytoplasm
Hilum of lymph node -->Venule & arteriole visible -->Valves surround efferent v
Thymus of infant (left) vs. adult (right) -->Medulla & cortex is seen -->Lobules seen **Involution of thymus results in fatty cells of thymus in adult**
Lobules of Thymus -->Cortex & Medulla -->Arrows point to Hassall's corpuscles
Thymus -->See Capsule with mitotic figures, trabeculae, and macrophage (Ma)
Thymic Medulla -->Contains ERC & Hassall's corpuscles
Thymus -->Cortex (left) -->Medulla (right; with hassall's corpuscle)
Epithelial Reticular Cells (ERC's0 -->Hassell's corpuscles & lymphocytes (small blue dots) are visible
Hassall's corpuscles (ERC Type 6)
Spleen -->See Capsule, trabeculae, white pulp ("splenic nodule"), and red pulp
Thick capsule of the spleen -->RED PULP seen underneath capsule
Spleen
Splenic White Pulp -->Contains mantle and marginal zone -->Contains **PERILYMPHOID/PERIFOLLICULAR ZONES** 1)Zone surrounding the white pulp 2)Region where blood flows SLOWLY to increase interaction with antigen & antibodies 3)Contains NO SINUSES & sparse reticulin
Central artery in splenic white pulp ***HAS A LUMEN, so it CANNOT be a Hassell's Corpsule of the Thymus -->Central artery surounded by the PALS containing T Cels -->Red pulp on the far right
Red & white pulp of the spleen
Splenic white pulp & central arteriole (surrounded by PALS)
Spleen -Trabeculae, with trabecular artery & vein. -Splenic nodule (white pulp): germinal center & marginal area -Central arteriole -Red pulp & venous sinuses
Venous Sinus (**Not a billroth cord**) -->Travels along fusiform length of RBC's; form slits in the endothelium
Red pulp -->Contains venous sinus (VS), macrophages with red pigment inside, & slits for RBC's to re-enter blood circulation -->Endothelial cells on inner surface of VS (right image) -->***Bilroth cords of red pulp (BC) also seen
Venous sinuses = Suinosoids = red pulp sinus
Red Pulp -->Reticulin fibers in basement membrane of venous sinuses (***TYPE 3 COLLEGEN)
Palatine Tonsil -->Stratisfied Squamous non-ker. epithelium -->**DEEP CRYTPS** -->Many lymphoid follicles (F) with germinal centers -->Capsule on bottom of palatine tonsil
Palatine tonsil -->See epithelium & lightly stained ERC cells
Lymph nodule in palatine tonsil -->Contains a germinal center
Linguial tonsil -->Contains strat. squamous non-ker. epithelium -->Medium sized crypts
Pharyngeal Tonsils ("Adenoids") -->Composed of pharyngeal, nasopharyngeal, & tubal tonsils ***Covered by a psuedostratisfied columnar epithelium WITHOUT crypts
Peyer's Patch in the Small Intestine -->Represents a single LARGE follicle with a germinal center -->Right image-->Uses CD20 marker for B Cells on the periphery of the germinal center