| auditory threshold | The audibility limit of discriminating sound intensity and pitch. (12 Dec 1998) |
|---|---|
| auditory tract | A bundle of ascending fibres that originate from the cochlear and auditory relay nuclei of the rhombencephalon, enter the trapezoid body, a transverse fibre stratum in which about half their number decussate, and from here turn rostrally along the lateral side of the spinothalamic tract; in the midbrain, it arches dorsally and enters the inferior colliculus in which all of its fibres terminate; the auditory pathway is transsynaptically extended from here by the brachium of the inferior colliculus to the medial geniculate body of the thalamus, from which in turn the auditory radiation leads to the auditory cortex; intercalated in the trapezoid body and along the ascending trajectory of the lemniscus are several cell groups in which part of the fibres synapse. Synonym: lemniscus lateralis, acoustic lemniscus, auditory lemniscus, auditory tract, lateral fillet. (05 Mar 2000) |
| auditory tube | A tube leading from the tympanic cavity to the nasopharynx; it consists of an osseous (posterolateral) portion at the tympanic end, and a fibrocartilaginous (anteromedial) portion at the pharyngeal end; where the two portions join, in the region of the sphenopetrosal fissure, is the narrowest portion of the tube (isthmus); the auditory tube enables equalization of pressure within the tympanic cavity with ambient air pressure, referred to commonly as "popping of the ears". Synonym: tuba auditiva, tuba auditoria, eustachian tube, guttural duct, otopharyngeal tube, otosalpinx, pharyngotympanic tube, salpinx, tuba acustica, tuba eustachiana, tuba eustachii. (05 Mar 2000) |
| auditory vertigo | <neurology> A name applied to recurrent vertigo accompanied by ringing in the ears (tinnitus) and deafness. A dysfunction of the semi-circular canals (endolymphatic sac) in the inner ear. Symptoms include dizziness, hearing loss (one-sided), vertigo, nausea, vomiting and abnormal eye movements. Treatment includes anticholinergics, antihistamines and other medications which relieve vertigo. Diuretic medications have been used to lower pressure in the endolymphatic sac. (27 Sep 1997) |
| auditory vesicle | One of the paired sacs of invaginated ectoderm that develop into the membranous labyrinth of the internal ear. Synonym: acoustic vesicle, otic vesicle. (05 Mar 2000) |
| bony part of auditory tube | The portion of the auditory tube that passes from the tympanic cavity anteromedially through the saemicanal for auditory tube. Synonym: pars ossea tubae auditivae. (05 Mar 2000) |
| brainstem auditory evoked potentials | <investigation, physiology> A special neurologic test which measures the brainstem and brains nervous response to auditory stimulation. It is used to evaluate neurologic integrity and hearing in newborns. Can be used in the evaluation of stroke, acoustic neuroma, Meniere's disease and multiple sclerosis Acronym: BAEP (15 Nov 1997) |
| cartilage of auditory tube | Cartilage of auditory tube or of pharyngotympanic tube; tubal cartilage; the trough-shaped cartilage that forms the medial wall, roof, and part of the lateral wall of the auditory tube. Synonym: cartilago tubae auditivae, cartilage of pharyngotympanic tube, tubal cartilage. (05 Mar 2000) |
| cartilaginous part of auditory tube | That portion of the auditory tube that is supported by cartilage; it continues anteromedially from the osseous part to open into the nasopharynx. Synonym: pars cartilaginea tubae auditivae. (05 Mar 2000) |
| glands of auditory tube | Glands located principally near the pharyngeal end of the auditory tube. Synonym: glandulae tubariae, glands of auditory tube, glands of eustachian tube. (05 Mar 2000) |
| medial lamina of cartilaginous auditory tube | The broad medial portion of the cartilaginous part of the auditory tube. Synonym: lamina medialis cartilaginis tubae auditivae, lamina cartilaginis medialis tubae auditivae, medial cartilaginous layer, medial layer of cartilaginous auditory tube. (05 Mar 2000) |
| medial layer of cartilaginous auditory tube | The broad medial portion of the cartilaginous part of the auditory tube. Synonym: lamina medialis cartilaginis tubae auditivae, lamina cartilaginis medialis tubae auditivae, medial cartilaginous layer, medial layer of cartilaginous auditory tube. (05 Mar 2000) |
| membranous lamina of cartilaginous auditory tube | The connective tissue membrane that, with the lateral lamina, completes the lateral and inferior walls of the cartilaginous part of the auditory tube. Synonym: lamina membranacea cartilaginis tubae auditivae, membranous layer. (05 Mar 2000) |
| groove for auditory tube | A furrow on the inner surface of the posterior border of the greater wing of the sphenoid bone, for the cartilaginous auditory tube. Synonym: sulcus tubae auditivae, pharyngotympanic groove. (05 Mar 2000) |
| pharyngeal opening of auditory tube | An opening in the upper part of the nasopharynx about 1.2 cm behind the posterior extremity of the inferior concha on each side. Synonym: ostium pharyngeum tubae auditivae, pharyngeal opening of eustachian tube. (05 Mar 2000) |