Brain: Horizontal Sections

1 Genu of corpus callosum

2 Head of caudate nucleus

3 Putamen

4 Claustrum

5 Globus pallidus

6 Third ventricle

7 Thalamus

8 Pineal body

9 Splenium of corpus callosum

10 Choroid plexus of the lateral

ventricle

11 Anterior horn of lateral ventricle

12 Cavity of septum pellucidum

13 Septum pellucidum

14 Anterior limb of internal capsule

15 Column of fornix

16 External capsule

17 Lobus insularis (insula)

18 Genu of internal capsule

19 Posterior limb of internal capsule

20 Posterior horn of lateral ventricle

21 Anterior commissure

22 Optic radiation

23 Falx cerebri

24 Maxillary sinus

25 Position of auditory tube

26 Tympanic cavity

27 External acoustic meatus

28 Medulla oblongata

29 Fourth ventricle

30 Cerebellum (left hemisphere)

31 Temporomandibular joint

32 Tympanic membrane

33 Base of cochlea

34 Mastoid air cells

35 Sigmoid sinus

36 Vermis of cerebellum

37 Intermediate mass

Horizontal section through the brain, showing the subcortical nuclei and internal

capsule. Section 1.

Horizontal section through the head. Section 2. Horizontal section through the head. Section 4.

Brain: Horizontal Sections 121

1 Upper lid (tarsal plate)

2 Lens

3 Ethmoidal sinus

4 Optic nerve (n. II)

5 Internal carotid artery

6 Infundibulum and pituitary gland

7 Temporal lobe

8 Basilar artery

9 Pons (cross section of brain stem)

10 Cerebral aqueduct (beginning of fourth ventricle)

11 Vermis of cerebellum

12 Straight sinus

13 Transverse sinus

14 Nasal septum

15 Eyeball (sclera)

16 Nasal cavity

17 Lateral rectus muscle

18 Sphenoidal sinus

19 Oculomotor nerve (n. III)

20 Tentorium of cerebellum

21 Skin of scalp

22 Calvaria

23 Occipital lobe

24 Striate cortex (visual cortex)

Horizontal section through the head. Section 3.

Horizontal section through the head. (CT scan.) Section 3.

Sagittal section through the head.

Levels of the horizontal sections are indicated.

122 Auditory and Vestibular Apparatus

Longitudinal section through the right temporal bone. The outer and middle ear and auditory ossicles and tube are shown

(anterior aspect).

Right auditory and vestibular apparatus (anterior aspect).

(Schematic drawing.)

Outer ear

1 Auricle

2 Lobule of auricle

3 Helix

4 Tragus

5 External acoustic meatus

Middle ear

6 Tympanic membrane

7 Malleus

8 Incus

9 Stapes

10 Tympanic cavity

11 Mastoid process

12 Auditory tube

13 Tensor tympani muscle

Inner ear

14 Anterior semicircular duct

15 Posterior semicircular duct

16 Lateral semicircular duct

17 Cochlea

18 Vestibulocochlear nerve

19 Petrous part of the temporal bone

Additional structures

20 Superior ligament of malleus

21 Arcuate eminence

22 Internal carotid artery

23 Anterior surface of pyramid with dura

mater

24 Stapes

25 Levator veli palatini muscle

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Auditory and Vestibular Apparatus

Longitudinal section through the right outer, middle, and inner ear. The cochlea and semicircular canals have been further dissected

(anterior aspect).

Internal acoustic meatus, left side. The bone was partly removed to show the bottom of

the meatus.

1 Roof of tympanic cavity

2 Lateral osseous semicircular canal

3 Facial nerve

4 Incus

5 Malleus

6 External acoustic meatus

7 Tympanic cavity and tympanic

membrane

8 Vestibulocochlear nerve

9 Anterior osseous semicircular canal

10 Geniculate ganglion and greater

petrosal nerve

11 Cochlea

12 Stapes

13 Tensor tympani muscle

14 Auditory tube

15 Levator veli palatini muscle

16 Area of facial nerve

17 Superior vestibular area

18 Transverse crest

19 Foramen singulare

20 Foraminous spiral tract (outlet of

cochlear part of vestibulocochlear

nerve)

21 Base of cochlea

124 Auditory and Vestibular Apparatus

Longitudinal section through the outer, middle, and inner ear. Deeper dissection to display facial nerve and lesser and greater

petrosal nerves (anterior aspect).

Right auricle (lateral aspect).

1 Helix

2 Scaphoid fossa

3 Triangular fossa

4 Concha

5 Antihelix

6 Tragus

7 Antitragus

8 Intertragic notch

9 Lobule

1 Anterior osseous semicircular canal (opened)

2 Posterior osseous semicircular canal

3 Lateral osseous semicircular canal (opened)

4 Facial nerve and chorda tympani

5 External acoustic meatus

6 Auricle

7 Facial nerve

8 Trigeminal nerve

9 Bony base of internal acoustic meatus

10 Internal carotid artery within cavernous sinus

11 Cochlea

12 Facial nerve with geniculate ganglion

13 Greater petrosal nerve

14 Lesser petrosal nerve

15 Tympanic cavity

16 Auditory tube

17 Levator veli palatini muscle

18 Internal carotid artery and internal jugular vein

19 Styloid process

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Auditory and Vestibular Apparatus: Temporal Bone

1 Anterior semicircular canal (red)

2 Posterior semicircular canal

(yellow)

3 Lateral or horizontal semicircular

canal (green)

4 Fenestra vestibuli

5 Fenestra cochleae

6 Tympanic cavity

7 Mastoid process

8 Petrotympanic fissure (red probe:

chorda tympani)

9 Lateral pterygoid plate

10 Mastoid air cells

11 Facial canal (blue)

12 Foramen ovale

13 Carotid canal (red)

14 Tympanic ring

15 Petromastoid part of temporal bone

16 Squamous part of temporal bone

17 Squamomastoid suture

18 Zygomatic process of temporal

bone

19 Incisure of tympanic ring

20 Promontory

21 Apex of cochlea (cupula)

22 Spiral canal of cochlea at base

of cochlea

23 Epitympanic recess

24 Auditory ossicles and tympanic

cavity

25 Hypotympanic recess

26 Canaliculus chordae tympani

(green probe)

27 Mastoid process

28 Canaliculus for stapedius nerve (red)

29 Cochlea

30 Canaliculus mastoideus (red probe)

Right temporal bone (lateral aspect). Petrosquamous portion has been partly removed

to display the semicircular canals.

Right temporal bone (lateral aspect). Mastoid air cells and facial canal had been

opened. The three semicircular canals were dissected.

Right temporal bone of the newborn (lateral aspect). Frontal section through petrous part. (CT scan.)

126 Auditory and Vestibular Apparatus: Middle Ear

Tympanic membrane with malleus and incus (internal aspect;

right side).

Tympanic cavity, medial wall. External acoustic meatus and lateral wall of tympanic

cavity together with incus. Malleus and tympanic membrane have been removed;

mastoid air cells are opened (left side).

1 Head of malleus

2 Anterior ligament of malleus

3 Tendon of tensor tympani muscle

4 Handle of malleus

5 Short crus of incus

6 Long crus of incus

7 Chorda tympani

8 Lenticular process

9 Tympanic membrane

1 Tympanic antrum

2 Lateral semicircular canal (opened)

3 Facial canal

4 Stapes with tendon of stapedius

5 Mastoid air cells

6 Chorda tympani (intracranial part)

7 Greater petrosal nerve

8 Tensor tympani muscle (processus

cochleariformis)

9 Lesser petrosal nerve

10 Anterior tympanic artery

11 Middle meningeal artery

12 Auditory tube

13 Promontory with tympanic plexus

14 Fenestra cochleae

1 Tympanic membrane

2 Chorda tympani (intracranial part)

3 Floor of the external acoustic meatus

4 Facial nerve and facial canal

5 Incus

6 Head of malleus

7 Mandibular fossa

8 Spine of sphenoid

9 Chorda tympani (extracranial part)

10 Styloid process

Tympanic membrane (lateral aspect). External acoustic meatus

and facial canal have been opened to expose the chorda tympani

(magn. ~1.5) (left side).

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Auditory and Vestibular Apparatus: Middle Ear

Frontal section through the petrous

part of the left temporal bone at the

level of the cochlea (posterior aspect).

Position of tympanic membrane

indicated by dotted line.

Medial wall of tympanic cavity and

its relation to neighboring structures of

the inner ear, facial nerve, and blood

vessels (schematic drawing). Frontal

section through the right temporal bone

(anterior aspect).

1 Anterior surface of the pyramid

2 Mastoid antrum

3 Lateral semicircular canal

4 Cochleariform process

5 External acoustic meatus

6 Jugular fossa

7 Foramen lacerum

8 Apex of petrous part

9 Position of cochlea (modiolus with

crista spiralis ossea)

10 Carotid canal

11 Pterygoid process

12 Anterior semicircular duct

13 Facial nerve

14 Geniculate ganglion

15 Greater petrosal nerve

16 Lesser petrosal nerve

17 Internal carotid artery

18 Mastoid air cells

19 Lateral semicircular duct

20 Posterior semicircular duct

21 Stapes with stapedius muscle

22 Stylomastoid foramen

23 Inferior recess of tympanic cavity

(hypotympanon)

24 Internal jugular vein

25 Promontory with tympanic plexus

(position of cochlea)

26 Tensor muscle of tympanum

27 Auditory tube

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Auditory and Vestibular Apparatus: Auditory Ossicles

Tympanic cavity with malleus, incus, and stapes, left side

(lateral aspect). Tympanic membrane removed, mastoid antrum

opened.

Position and movements of the auditory ossicles

(schematic drawing).

Auditory ossicles (isolated).

Chain of auditory ossicles in connection with the inner ear, left

side (antero-lateral aspect).

Malleus

1 Head

2 Neck

3 Lateral process

4 Handle

Incus

5 Articular facet for malleus

6 Long crus

7 Short crus

8 Body

9 Lenticular process

Stapes

10 Head

11 Neck

12 Anterior and posterior crura

13 Base

Walls of tympanic cavity

14 Tympanic membrane

15 Promontory

16 Hypotympanic recess of

tympanic cavity

Internal ear (labyrinth)

17 Lateral semicircular duct

18 Anterior semicircular duct

19 Posterior semicircular duct

20 Common crus

21 Ampulla

22 Beginning of endolymphatic

duct

23 Utricular prominence

24 Saccular prominence

25 Incus

26 Malleus

27 Stapes

28 Cochlea

Tympanic cavity

29 Epitympanic recess

30 Mastoid antrum

31 Chorda tympani

32 Tendon of stapedius muscle

33 Round window

(fenestra cochleae)

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Auditory and Vestibular Apparatus: Internal Ear

Cast of the right labyrinth (postero-medial aspect).

Cast of the right labyrinth (lateral aspect).

Dissection of bony labyrinth in situ. Semicircular canals and

cochlear duct opened.

Auditory and vestibular apparatus. Arrows = direction of sound

waves; blue = perilymphatic ducts (schematic drawing; from

Lütjen-Drecoll, Rohen, Innenansichten des menschlichen Körpers,

2010).

Cast of the labyrinth and mastoid cells.

Life size (posterior aspect).

1 Ampulla (anterior

semicircular canal)

2 Elliptical recess

3 Aqueduct of the vestibule

4 Spherical recess

5 Cochlea

6 Base of cochlea

7 Anterior semicircular canal

8 Crus commune or common

limb

9 Lateral semicircular canal

10 Posterior bony ampulla

11 Posterior semicircular canal

(posterior canal)

12 Fenestra cochleae

13 Bony ampulla

14 Fenestra vestibuli

15 Cupula of cochlea

16 External acoustic meatus

17 Mastoid air cells

18 Tympanic cavity and

fenestra cochleae (probe)

19 External acoustic meatus

20 Facial canal

21 Base of cochlea and

musculotubal canal

22 Malleus and incus

23 Stapes

24 Tympanic membrane

25 Tympanic cavity

26 Aqueduct of cochlea

27 Endolymphatic sac

28 Endolymphatic duct

29 Macula of utricle

30 Macula of saccule

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Auditory and Vestibular Apparatus: Internal Ear

Bony labyrinth, petrous part of the temporal bone (from above). At left: semicircular canals opened; at right: closed.

Arrows: internal acoustic meatus.

1 Facial canal and semicanal of auditory tube 9 Posterior semicircular canal 17 Fenestra vestibuli

2 Superior vestibular area 10 Groove for sigmoid sinus 18 Promontory

3 Foramen ovale 11 Sigmoid sinus 19 Zygomatic process

4 Foramen lacerum 12 Tympanic cavity 20 Fenestra cochleae

5 Cochlea 13 Auditory tube 21 Mastoid process

6 Vestibule 14 Mastoid air cells

7 Anterior semicircular canal 15 Facial and vestibulocochlear nerves

8 Lateral semicircular canal 16 Temporal fossa

Bony labyrinth (left lateral aspect). Temporal and tympanic

bone partly removed, semicircular canals opened.

Internal ear. Diagram showing the position of the

membranous labyrinth and the tympanic cavity.

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Auditory and Vestibular Apparatus: Auditory Pathway and Areas

Dissection of the brain stem showing the auditory pathway. Cerebellum and posterior part

of the two hemispheres have been removed (dorsal aspect).

Auditory pathway (schematic drawing, compare with figure above).

Red = descending (efferent) pathway (olivocochlear tract of Rasmussen);

green and blue = ascending (afferent) pathways.

Auditory areas in the left hemisphere (superolateral aspect). Parts of the frontal and parietal lobes

have been removed.

1 Left lateral ventricle

and corpus callosum

2 Thalamus

3 Pineal gland (epiphysis)

4 Superior colliculus

5 Superior medullary velum and

superior cerebellar peduncle

6 Rhomboid fossa

7 Vestibulocochlear nerve (n. VIII)

8 Dorsal acoustic striae and

inferior cerebellar peduncle

9 Insular lobe

10 Caudate nucleus and thalamus

11 Temporal lobe (superior temporal

gyrus) (area of acoustic centers)

12 Transverse temporal gyri of

Heschl (area of primary

acoustic centers)

13 Acoustic radiation of internal

capsule

14 Lateral geniculate body and

optic radiation (cut)

15 Medial geniculate body and

brachium of inferior colliculus

16 Inferior colliculus

17 Cerebral peduncle

18 Lateral lemniscus

19 Middle cerebellar peduncle

20 Dorsal (posterior) cochlear

nucleus

21 Ventral (anterior) cochlear

nucleus

22 Inferior olive with olivo -

cochlear tract of Rasmussen (red)

23 Ganglion spirale

24 Obex

25 Frontal lobe

26 Temporal lobe

27 Middle temporal gyrus (area of

tertiary acoustic centers)

28 Trapezoid body