Inner Ear & Auditory Pathways Lab 8 Inner Ear & Auditory Pathways

7 1 8 2 9 3 4 10 5 6 Part of spiral ganglion Scala vestibuli Auditory part of VIII nerve Scala media (cochlear duct) 2 modiolus 9 3 Scala tympani Artifact space 4 Vestibular membrane Part of spiral ganglion 10 Stria vascularis 5 6 Basilar membrane

2 1 (space) 4 3 (space) 5 7 6 9 8 11 10 (space) Vestibular membrane Scala vestibuli 1 (space) stria vascularis 4 Cochlear duct 3 (space) 5 Tectorial membrane Outer hair cells 7 Inner hair cell 6 Spiral lamina 9 Auditory nerve fibers 8 Basilar membrane 11 10 (space) Scala tympani

inner hair cell outer hair cells Tectorial Membrane 2 1 3

1 (fluid) 4 5 7 2 (fluid) 6 8 9 3 (fluid)

Cross section through one cochlear turn 5 Vestibular Membrane 1 6 2 3 4 7 Cross section through one cochlear turn

Endolymphatic hydrops result from what disease? This is a cross-section of a cochlea affected by what pathology? Meniere’s Disease Endolymphatic Hydrops

Chorda tympani nerve Styloid process Mastoid process 1 (bony recess) Petrotympanic fissure Mastoid process 2 (bony landmark) 5 (nerve) Chorda tympani nerve Facial nerve exiting the stylomastoid foramen 3 nerve & opening LATERAL ASPECT OF TEMPORAL BONE MODEL Styloid process 4 (bony landmark)

Tympanic membrane 1 LATERAL WALL OF MIDDLE EAR

Epitympanic recess 1 (space) LATERAL WALL OF MIDDLE EAR

1 Mastoid antrum and air cells LATERAL WALL OF MIDDLE EAR

Auditory tube 1 LATERAL WALL OF MIDDLE EAR

Facial nerve entering the internal acoustic meatus Semicircular canals 2 Facial nerve entering the internal acoustic meatus 1 nerve & opening 3 Jugular bulb MEDIAL ASPECT OF THE TEMPORAL BONE MODEL

Incus Malleus: head handle Chorda tympani nerve 2 (nerve) 1 Tensor tympani muscle Incus 4 3 Malleus: head handle LATERAL WALL OF MIDDLE EAR

Stapes (on the oval window) 1 Stapedius muscle Stapes (on the oval window) MEDIAL WALL OF MIDDLE EAR

Facial nerve exiting facial canal through the stylomastoid foramen 1 (internal opening) Facial canal Facial nerve exiting facial canal through the stylomastoid foramen 2 nerve & opening Promontory (basal turn of cochlea) - tympanic plexus containing fibers of CN IX covers the promontory during life 3 MEDIAL WALL OF MIDDLE EAR

SUPERIOR VIEW OF TEMPORAL BONE MODEL 1 Semicircular canal 2 Cochlea

3 Semicircular Canals Semicircular Canal 1 Vestibule 2

2 1 3

1 2 3

1 2 (2 nerves)

What is the ~location of the: Auditory Association Cortex? Wernicke's Area Planum Temporale Auditory Association Cortex 1 What is the ~location of the: Auditory Association Cortex? Wernicke’s Area? Planum Temporale?

Rostral Medulla 1 2 3 4 Inferior cerebellar peduncle Ventral cochlear nucleus Dorsal cochlear nucleus 3 Vestibular nuclei 4 Rostral Medulla

lateral lemniscus Superior cerebellar peduncle 1 2 Rostral Pons

Pons/Midbrain Junction Lateral lemniscus 1 Inferior colliculus 2 Pons/Midbrain Junction

Midbrain/Thalamus Transition Brachium of inferior colliculus 1 Medial geniculate nucleus 2 brachium of superior colliculus 3 4 Superior colliculus Midbrain/Thalamus Transition

Midbrain/Thalamus Transition Medial geniculate nucleus 1 Lateral geniculate nucleus 2 brachium of superior colliculus 3 4 Superior colliculus Midbrain/Thalamus Transition

Lateral aperture IV ventricle General position 3 (nucleus) of cochlear nuclei VIII C.N. 1 (nerve) Lateral aperture 4 (opening) inferior cerebellar peduncle 2 IV ventricle 5

4 1 2 5 (opening) 3 (nerve) basilar artery with origin of bircumferential branches 4 1 cochlea 2 semicircular canals vestibulo- cochlear n. nerve 3 (nerve) 5 (opening) internal auditory meatus (opening in skull)

1 Inferior colliculus We DON’T need to distinguish b/t superior/inferior colliculi in clinical scans.

1 Transverse temporal gyrus or planum temporale

Ventral Cochlear Nucleus Dorsal Cochlear Nucleus - located lateral & dorsal to the inferior cerebellar peduncle (restiform body) - contain cell bodies of second order neurons in auditory path - receive fibers from cochlear nerve - will send axons into the acoustic stria What is the ~location of the: Dorsal Cochlear Nucleus? Ventral Cochlear Nucleus? Rostral Medulla Level

lateral lemniscus and nuclei of lateral lemniscis What is the ~location of the Lateral Lemniscus? Rostral Pons Level

What is the ~location of the: Inferior Colliculus? Lateral Lemniscus Snake eating egg Inferior Colliculus What is the ~location of the: Inferior Colliculus? Lateral Lemniscus Pons/Midbrain Junction

Superior Colliculus Brachium of Superior Colliculus Brachium of Inferior Colliculus Medial Geniculate Nucleus – receives fibers from brachium of inferior colliculus What is the ~location of the: Superior Colliculus? Brachium of the Superior Colliculus? Medial Geniculate Nucleus Brachium of the Inferior Colliculus Rostral Midbrain Level

MGN What is the ~location of the Medial Geniculate Nucleus? Rostral Midbrain Level