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19 Cards in this Set
- Front
- Back
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what are the 3 parts of the ear |
external: auricle and external acoustic meatus until tympanic membrane middle ear: room and attic, bones and pharygotympanic tube (drain) internal ear: bony structure (very dense), auditory and vestibular nerve, and facial nerve |
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describe the hair cell in the ear |
sensory cell |
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describe the temporal bone |
side of head squamous part, mastoid part, tympanic part petrous styloid process looks like a honeycomb inside |
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describe the auricle of the external ear |
auricle: single elastic cartilage, thin hairy skin, sweat glands, sebaceous glands, auricular muscles helix and antihelix, tragus and antitragus, lobule, external auditory meatus, triangular fossa, concha |
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describe the innervation of the external ear |
auricle: auriculotemporal branch of mandibular nerve V3-- front of ear (auricle, ext acoustic meatus, outer tympanic membrane and temporal skin) lesser occipital nerve C2-- posterior aspect of auricle great auricular nerve C2,C3-- rest of auricle Vagus nerve X-- concha facial nerve VII-- concha EAC: auricular branch of greater auricular, facial nerve from tympanic plexus, auricular branch of vagus |
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describe the blood supply to the external ear |
auricle: superficial temporal artery posterior auricular artery EAC: posterior auricular, deep auricular (maxillary), superficial temporal artery |
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describe the venous drainage of the external ear
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external jugular, maxillary veins |
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describe the lymphatic drainage of the external ear |
mastoid nodes superficial cervical nodes deep cervical nodes superficial parotid lymph nodes (lateral surface of superior half of auricle) |
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describe the external auditory canal of the external ear |
lateral 1/3 is cartilage-- meatus, skin, hair, sebaceous and ceruminous glands (ear wax) medial 2/3 is bony-- thin skin continuous with tympanic membrane sends sound into inner ear |
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describe the middle ear |
needs to be filled with air sound vibrates tympanic membrane 3 bones transmit and amplify sound to inner ear malleous ancus stapes-- super structure and foot plate smallest bones, synovial joints pharyngotympanic tube drains to pharynx 2 openings-- top (oval) foot of stapes bottom (round) covered with membrane (bulges out when stapes pushes in) |
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describe the mechanism of impedance matching |
size difference of surface area of the tympanic membrane and the stapes foot plate |
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describe the tympanic membrane |
3 layers outer-- keratinizing epithelial cells middle-- fibrous inner-- non keratinizing squamous mucosal cells, continuous with inner ear mucosa should be clear and relaxed 2 parts: pars tensa-- vibrates with sound pars flaccida-- notch of rivinus, less tense |
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describe the blood supply of the tympanic membrane |
external: deep auricular artery (maxillary) internal: stylomastoid branch of posterior auricular artery, tympanic branch of maxillary artery |
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describe the venous drainage of the tympanic membrane |
external: external jugular internal: transverse sinus and veins of dura, venous plexus of auditory tube |
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describe the innervation of the tympanic membrane |
external: auriculotemporal branch of trigeminal nerve CN V3 some vagus, glossopharyngeal and facial internal: tympanic plexus formed by VII and IX |
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summarize the contents of the middle ear |
one important nerve: facial (chorda tympani branch of facial, travels through middle ear) two muscles: tensory tympani (V), Stapedius (VII) (dampen loud sound) three ossicles: malleus, incus, stapes tympanic plexus openings: auditory tube (nasopharynx), round window (middle ear), aditis ad-antrum (mastoid) |
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describe the facial nerve |
motor root (brain stem) and sensory root (geniculate ganglion) internal auditory canal sharp bend (first knee/genu)-- greater petrosal nerve nerve to stapedius chorda tympani exits stylomastoid foramen-- branches to posterior auricular, nerve to digastric, nerve to stylohyoid terminal motor branches facial nerve proper-- motor and large trunk nervus intermedius-- sensory root |
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what are the terminal branches of the facial nerve |
temporal zygomatic buccal mandibular cervical |
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what are the sensory branches of the facial nerve |
greater superficial petrosal nerve-- geniculate ganglion, taste and parasymp fibers nerve to stapedius-- vertical segment, motor to stapes to limit mobility in response to loud sounds chorda tympani-- parasymp and taste |
