Diffuse Lymphoid Tissue Histology
guard the pharynx (common tube for digestive & respiratory tracts)
Tonsils (in ring of Waldeyer): singular are pharyngeal and lingual, paired are palatine
macrophage (prominent nucleolus and big euchromatic pale nucleus)
blue circle
situated in the transition zone between nasal cavity & pharynx; covered with stratified squamous epithelium and pseudostratified ciliated columnar epithelium with goblet cells (so upper "nasal" portion is lined by respiratory epithelium)
pharyngeal tonsils
blast cells in germinal center (aka lymphoblasts)
red circles
secondary nodules (w/ pale germinal centers since nuclei are farther apart in stimulated lymphocytes)
type of majority of nodules in the tonsils
small numbers of white blood cells in connective tissue underlying epithelial cells - region will have an overall basophilic appearance when compared to other surrounding connective tissue
Diffuse lymphoid tissue
blast cells in germinal centers of palatine tonsils (aka lymphoblasts)
ID black arrows
macrophage in palatine tonsils
ID red arrow
macrophages in germinal centers of palatine tonsils
ID red arrows
blast form (largest nuclei, clearly dividing cells) of lymphocytes in germinal center of secondary nodules in palatine tonsils
ID the black arrows
septa
ID the green arrows
septum
ID the green arrows
mitotic figures (lymphocytes undergoing proliferation in the germinal center)
ID the green circles
corona (thicker side) of secondary nodules of palatine tonsils
ID the yellow area
tonsillar crypt
ID the yellow arrows
tonsillar crypts
ID the yellow arrows
palatine tonsillar tapered cells w/ flattened nuclei: reticular cells (synthesize collagen framework) or dendritic cells (process and present antigen to lymphocytes)
ID yellow arrows
specialized diffuse lymphoid tissue in small intestine, digestive tract
Peyer's patches