Osteology
|
| Bone |
Structure |
Description |
| temporal |
petrous part (N9, TG7-07) |
contains tympanic cavity & bony labyrinth (Greek, petra = rock) |
|
internal acoustic meatus (N8,N10, TG7-04, TG7-07) |
on posterior surface of petrous part; transmits facial nerve, vestibulocochlear nerve, & labyrinthine artery (Latin, meatus = a passage) |
|
facial canal (N94, TG7-68) |
through petrous part; transmits facial nerve to stylomastoid foramen |
|
carotid canal (N8, TG7-06) |
through petrous part; transmits internal carotid artery & internal
carotid plexus of sympathetic nerves |
|
mastoid process (N94, TG7-06, TG7-68) |
projects inferiorly from junction of petrous & squamous parts; contains
mastoid air cells
that open into tympanic cavity through mastoid
antrum |
|
tegmen tympani (N92, TG7-66) |
on anterior surface of petrous part superiorly; thin bony roof of tympanic cavity (Latin, tegman = a cover or roof; Greek, tympanum = a kettle drum) |
|
jugular fossa (N8, TG7-06) |
on posterior surface of petrous part; forms anterior margin of jugular
foramen |
|
tympanic part (N8, TG7-67A, TG7-67B) |
consists primarily of external acoustic meatus & tympanic ring (Greek, tympanum = a kettle drum) |
|
external acoustic meatus (N8,N10, TG7-04, TG7-07) |
opening which allows sound to reach tympanic membrane (Latin, meatus = a passage) |
|
tympanic ring (TG7-04) |
attachment of tympanic membrane |
| |
semicanal for tensor tympani m. (TG7-68A) |
consists of the superior surface of the cartilaginous part of the pharyngotympanic
tube, the greater wing of the sphenoid, and the petrous part of the temporal
bone |
| incus (N92,N93,N94, TG7-65, TG7-68, TG7-69A, TG7-69C) |
|
articulates with head of malleus and head of stapes (Latin, incus = anvil) |
| stapes (N92,N93,N94, TG7-65, TG7-68, TG7-69A, TG7-69D) |
|
articulates with long process of incus and base fills vestibular window (Latin, stapes = step or stirrup) |
| malleus (N92,N93,N94, TG7-65, TG7-68, TG7-69A, TG7-69B) |
|
manubrium is attached to inner aspect of tympanic membrane; head articulates with incus (Latin, malleus = hammer) |
| middle cranial fossa |
hiatus for greater petrosal nerve (N10, TG7-07) |
also houses petrosal branch of middle meningeal artery |
| sphenoid |
body (N6, TG7-07, TG7-08) |
central part, containing sinuses (Greek, sphenoid = wedge-shaped) |
|
medial pterygoid plate (N6,N8, TG7-06, TG7-08) |
projects posteriorly from pterygoid process; attachment of superior pharyngeal constrictor & pharyngobasilar fascia (Greek, pterygoid = wing-shaped) |
|
pterygoid hamulus (N6,N8, TG7-06, TG7-08) |
hook-like projection from the inferior end of the medial pterygoid plate; it acts as a pulley for the tendon of the tensor veli palatini m. (Greek, pterygoid = wing-shaped; Latin, hamus = hook) |
Muscles of Ear
|
| Muscle |
Origin |
Insertion |
Action |
Innervation |
Notes |
Image |
| stapedius (N93,N94, TG7-66, TG7-68) |
walls of pyramidal eminence |
neck of stapes |
dampens vibration of stapes |
facial nerve (VII) |
entirely enclosed in bone, except for its tendon |
 |
| tensor tympani (N93,N94, TG7-66, TG7-68) |
cartilagenous auditory tube & greater wing of sphenoid adjacent to it |
manubrium of malleus |
dampens vibrations of the tympanic membrane |
medial pterygoid branch of mandibular division of the trigeminal nerve (V) |
V3 innervates both tensor muscles (tympani and veli palatini) |
 |
| levator veli palatini (N64,N65,N68, TG7-20, TG7-24) |
apex of the petrous part of the temporal bone and the medial surface of the auditory tube cartilage |
muscles and fascia of the soft palate; palatine aponeurosis |
elevates the soft palate |
vagus nerve (X) via the pharyngeal plexus |
a derivative of the fourth pharyngeal arch (Latin, levator = to lift) |
 |
| tensor veli palatini (N64,N65,N68, TG7-20, TG7-24) |
scaphoid fossa, lateral wall of the auditory tube cartilage |
palatine aponeurosis |
opens the auditory tube; tenses the soft palate |
mandibular division of the trigeminal nerve (V) |
remember: V3 innervates both tensor muscles (tympani and veli palatini); ALL other palatal muscles are innervated by vagus |
 |
Nerves
|
| Nerve |
Source |
Branches |
Motor |
Sensory |
Notes |
| facial (N92, N94, N97,N104,N123, TG7-47, TG7-65, TG7-68, TG7-87) |
pons & medulla: nucleus solitarius of medulla via nervus intermedius (SVA sensory root) from geniculate ganglion; superior salivatory nucleus (GVE preganglionic parasympathetic) of pons via nervus intermedius, facial motor nucleus of pons via motor root |
greater petrosal (preganglionic parasympathetic to pterygopalatine ganglion, postganglionic parasympathetic travels with brs. of maxillary div. of V), chorda tympani (SVA taste from anterior 2/3rds of tongue; preganglionic parasympathetic to submandibular ganglion, postganglionic parasympathetic to submandibular & sublingual glands), n. to stapedius, posterior auricular, intraparotid plexus with temporal, zygomatic, buccal, marginal mandibular & cervical brs. |
stapedius, stylohyoid, posterior belly of digastric, muscles of facial expression; secretomotor to lacrimal, submandibular, sublingual, and mucous glands of nasal & oral cavities |
taste (SVA) from anterior 2/3rds of tongue; part of skin of external auditory meatus |
also known as: CN VII, 7th cranial nerve; passes into internal acoustic meatus, goes through facial canal, exits at stylomastoid foramen |
| ganglion, geniculate (N92, N94, N97, N123, TG7-67B, TG7-68B) |
chorda tympani, from facial n. (VII) |
nucleus solitarius of medulla via nervus intermedius (SVA sensory root of facial n.) |
|
taste (SVA) from ant. 2/3rds of tongue |
a sensory ganglion equivalent in structure and function to a dorsal root ganglion; some taste from palate travels through greater petrosal n. to geniculate ganglion; located in facial canal of petrous temporal bone (Latin, geniculate = to bend) |
| petrosal, greater (N104,N123, TG7-67B, TG7-68B) |
facial (VII) |
joins deep petrosal n. to form n. of pterygoid canal |
secretomotor (preganglionic parasympathetic) to lacrimal gland & mucous glands of lower nasal cavity, maxillary sinus, palate |
|
contains: preganglionic parasympathetic axons bound for the pterygopalatine ganglion where they will synapse; passes through hiatus of canal of greater petrosal n. in petrous part of temporal bone |
| chorda tympani (N94, N123, TG7-67B, TG7-68A) |
facial (VII) |
|
secretomotor to submandibular & sublingual glands (preganglionic parasympathetic to submandibular ganglion) |
taste to anterior 2/3rds of tongue |
joins lingual nerve in infratemporal fossa and continues with it to the tongue (Latin, chorda = a cord; Greek, tympanum = a kettle drum) |
| vestibulocochlear (N92, N97, N104,N124, TG7-65, TG7-67B, TG7-89C) |
pons & medulla: vestibular nuclei from vestibular ganglion of semicircular ducts; cochlear nuclei in inferior cerebellar peduncle from spiral ganglion of cochlea |
divides within the temporal bone into vestibular and cochlear parts |
|
vestibular: balance/proprioception (SSA); cochlear: hearing (SSA) |
also known as: CN VIII, 8th cranial nerve; auditory nerve; passes into internal auditory meatus |
| cochlear (N92, N97, TG7-89C) |
vestibulocochlear n., cochlear nuclei in inferior cerebellar peduncle from spiral ganglion of cochlea |
|
|
hearing (SSA) |
passes into internal acoustic meatus |
| vestibular (N92, TG7-89C) |
pons & medulla: vestibular nuclei from vestibular ganglion of semicircular ducts |
|
|
balance/proprioception (SSA) |
part of vestibulocochlear n., CN VIII; passes into internal auditory meatus |
| glossopharyngeal (N104, TG7-90C) |
medulla: spinal trigeminal nucleus from superior ganglion (GVA); nucleus solitarius from inferior ganglion (SVA); nucleus ambiguus (GVA); inferior salivatory nucleus (GVE preganglionic parasympathetic) |
tympanic nerve to tympanic plexus & lesser petrosal n., carotid sinus n., stylopharyngeus brs., pharyngeal brs. |
GSE: stylopharyngeus; GVE: secretomotor to parotid gland (preganglionic parasympathetic via tympanic n. to lesser petrosal n. to otic ganglion, postganglionic parasympathetic via auriculotemporal n.) |
GVA: carotid body & sinus, pharynx, middle ear; GSA: skin of external ear; SVA: taste from posterior 1/3rd of tongue |
also known as: CN IX, 9th cranial nerve; passes through jugular foramen; may penetrate the stylopharyngeus m. |
| tympanic (TG7-90C) |
glossopharyngeal |
tympanic plexus, which gives rise to lesser petrosal n. |
secretomotor (pregang. parasymp., synapsing in otic gang.) to parotid gland |
mucous lining of middle ear cavity |
passes from inferior ganglion of CN IX through tympanic canaliculus to middle ear (Greek, tympanum = a kettle drum) |
| ganglion, spiral |
fibers of cochlear hair cells |
cochlear n. of vestibulocochlear n. to cochlear nuclei in inferior cerebellar peduncle |
|
hearing (SSA) |
sensory ganglion of cochlear part of CN VIII |
| olfactory nn. (N42,N43, TG7-41 TG7-77AB TG7-77C) |
the filaments of the bipolar olfactory epithelial cells constitute the olfactory
nerves |
second order olfactory nerve cell bodies located in the olfactory bulb |
none |
smell (SVA) |
also known as CN I, 1st cranial n.; multiple olfactory filaments pass through
the cribriform plate to enter the anterior cranial fossa and synapse in the
olfactory bulb; the olfactory tract carries the signal from the bulb to olfactory
cortex of the forebrain |
Viscera/Fascia
|
| Organ |
Location/Description |
Notes |
| torus tubarius (TG7-23) |
mucosal fold covering the anteromedial end of the auditory
tube cartilage |
torus tubarius projects toward the midline from the lateral wall of the nasopharynx (Latin, torus = knot) |
| arcuate eminence (anterior semicircular canal) (TG7-67) |
communicate with the vestibule of the bony labyrinth |
the canals lie posterosuperior to the vestibule into which they open and at right angles to each other (Latin, arucuate = bowed) |
| auditory (pharyngotympanic) tube (TG7-65, TG7-67) |
joins the middle ear to the nasopharynx |
|
| epitympanic recess (TG7-68) |
space superior to the tympanic membrane in the middle ear |
|
| oval window (TG7-70) |
an oval opening on the medial wall of the tympanic cavity leading
to the vestibule of the internal ear (bony labyrinth) |
|
| promontory of the cochlea (TG7-70) |
bulging of the medial wall of the tympanic cavity produced
by the large basal turn of the cochlea |
|
| round window (TG7-70) |
an opening in the medial wall of the middle ear leading into
the cochlea |
|
| outer ear (N92, TG7-65) |
comprises the auricle, which collects sound, and the external
acoustic meatus |
|
| middle ear (N92, TG7-65) |
located in the temporal bone, it consists of the tympanic
cavity and the epitympanic recess |
|
| inner ear (N92, TG7-65) |
contains the vestibulocochlear organ and the sacs and ducts
of the membranous labyrinth |
|
| choanae (N37, N66, TG7-22, TG7-43) |
posterior opening of the nasal cavities into the nasopharynx |
(Latin/Greek, choanae = a funnel-shaped hollow in the brain) |
| soft palate (TG7-24, TG7-43) |
the movable posterior third of the palate, which is suspended from the posterior border of the hard palate |
|
| uvula (TG7-41) |
conical process that is the posteroinferior extension of the soft palate |
(Latin, uva/uvula = a grape) |
Lymphatics
|
| Structure |
Location |
Afferents from |
Efferents to |
Regions drained |
Notes |
| tonsil, pharyngeal (TG7-43) |
roof and posterior wall of the nasopharynx |
lymphatic vessels of the wall of the pharynx |
superior deep cervical nodes |
"guards" the entrance to the nasopharynx |
part of the tonsillar ring (of Waldeyer); known as adenoids when inflamed |
| tonsil, palatine (TG7-38, TG7-39) |
lateral wall of the oropharynx between the palatoglossal and palatopharyngeal arches |
lymphatic vessels of the posterior tongue and palatoglossal/palatopharyngeal arch region |
superior deep cervical nodes, especially the jugulodigastric node |
"guards" the entrance of the oropharynx |
part of the tonsillar ring (of Waldeyer); often referred to as "the" tonsils |
| tonsil, lingual (TG7-39) |
superior surface of root of tongue |
lymphatic vessels of the root of tongue and valleculae epiglottica |
superior deep cervical nodes |
"guards" entrance of oropharynx |
part of tonsillar ring (of Waldeyer) |
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