An Electron Microscopic Study of the Tympanojugular Glomus

Seven temporal bones from four human foetuses of crown-rump length 55-62 mm were prepared for electron microscopy and stepwise sectioned. Seven glomera were found along the tympanic and auricular branches and/or in the adventitia of the superior bulb of the jugular vein. The glomus parenchyma was made up of chief cells characterized by a content of membrane-bound, osmiophilic granules 114 nm in mean diameter. The cells were almost completely invested by supporting cells, in which nerve fibres were embedded as well. The numerous vessels contained fenestrae in the endothelium. The fine structure of the tympanojugular glomus is similar to that of the carotid body.ZUSAMMENFASSUNGSieben Schlafenbeine von vier menschlichen Foten (Scheitel-Steiss-Lange 55-62 mm) wurden fur die Elektronenmikroskopie prapariert. Es wurden sieben Glomera gefunden, die in der Nachbarschaft des N. tympanicus und des R. auricularis und/oder in der Adventitia des Bulbus venae jugularis superior lagen. Das Glomusparenchym bestand haupts...