1耳解剖生理.pptVIP

Traveling Waves Question High frequencies stimulate this part of inner ear: Apical portion of inner ear Basilar portion of inner ear Utricle Saccule Semicircular canals Inner Ear Etiologies Genetic Connexin 26 Excessive Noise Head Trauma Metabolic Diabetes, kidney disfunction, thyroid dysfunction Ototoxic Gentamiacin, cisplatin, etc. Disease VIII Cranial Nerve Vestibulocochlear nerve Vestibular nuclei, Cochlear nuclei Acoustic Neuroma The wave V latency used in the standard ABR IT5 and I-V delay measures is dominated by neural activity from the high-frequency regions of the cochlea. Thus, unless the tumor affects these high-frequency fibers sufficiently, standard ABR latencies will be normal. TUMOR Large Tumor Abnormal Standard ABR Small Tumor Abnormal Standard ABR Small Tumor Normal Standard ABR Standard ABR HIGH- FREQUENCY FIBERS Facial Nerve Sup. Vest Nerve Inf. Vest Nerve Acoustic Nerve Cross-section of Internal Auditory Canal Spiral Ganglion In the modiolus Sending a representation of sound from the cochlea to the brain  Central Auditory Path Etiologies Central auditory processing disorders Brainstem Cerebrum Corpus callosum Learning disorders Vascular Stoke Head trauma Tumors Thanks！ Helix Scapha Antihelical fold Antihelix Antitragus Fossa Concha Externa auditory meatus Tragus Lobule * * B * * * * These muscles are one reason the mastoid process tends to be larger in men, because men have bigger muscles as a general rule and thus require larger points of attachment * * * * * * * * * * * Ossicles Transmit sounds from the air to the fluid-filled labyrinth (cochlea) The absence cause a moderate-to-severe hearing loss Otosclerosis --- the joints between the ossicles become rigid Mastoid Behind the external acoustic meatus Lateral to the styloid process Its size and form vary somewhat it is larger in the male than in the female Is roughly pyramidal or conical in shape Mastoid Cell Any of numerous air-filled spaces of various sizes in the mastoid proc