Neurology: Anatomy - Base of skull and cranial nerves Flashcards
Which bones make up the anterior cranial fossa?
Frontal
Ethmoid
Body and lesser wings of sphenoid
Which bones make up the middle cranial fossa?
Body and greater wings of sphenoid (including sella turcica)
Squamous and petrous parts of temporal
Which bones make up the posterior cranial fossa?
Mainly occipital
Contribution from petrous and mastoid parts of temporal
Foramen caecum
Nasal emissary vein (1% of population)
Anterior and posterior ethmoidal foramina
Anterior and posterior ethmoidal nerves and vessels
Cribiform foramina
Axons of olfactory cells
Optic canal
Optic nerve
Ophthalmic artery
Superior orbital fissure
Ophthalmic branch of trigeminal nerve
Oculomotor nerve
Trochlear nerve
Abducens nerve
Sympathetic fibres
Ophthalmic vein
Foramen rotundum
Maxillary branch of trigeminal branch
Foramen ovale
Mandibular branch of trigeminal branch
Accessory meningeal artery
Foramen spinosum
Middle meningeal artery and vein
Meningeal branch of mandibular nerve (V3)
Foramen lacerum
Deep petrosal nerve
Some meningeal arterial branches and small veins
Internal acoustic meatus
Facial nerve
Vestibulocochlear nerve
Labyrinthine artery
Jugular foramen
Glossopharyngeal nerve
Vague nerve
Accessory nerve
Superior bulb of IJV
Inferior petrosal and sigmoid sinuses
Meningeal branches of ascending pharyngeal and occipital arteries
Hypoglossal canal
Hypoglossal nerve
Foramen magnum
Accessory nerve
Medulla
Meninges
Vertebral arteries
Dural veins
Anterior and posterior spinal arteries
Which bones and sutures form the anterior fontanelle?
Bones: frontal and parietal bones
Sutures: frontal, sagittal and coronal
Which bones and sutures form the posterior fontanelle?
Bones: parietal and occipital bones
Sutures: lambdoid and sagittal
When do the anterior and posterior fontanelles close?
Anterior: fused by 18 months
Posterior: begins closing within few months, no longer palpable by 12 months
Nerve cell bodies (and synapse), exit, and function of olfactory nerve
SPECIAL SENSORY:
- Nerve cell bodies (and synapse): olfactory epithelium (olfactory cells)
- Exit: cribiform foramina
- Function: smell
Nerve cell bodies (and synapse), exit, and function of optic nerve
SPECIAL SENSORY:
- Nerve cell bodies (and synapse): retina (ganglion cells)
- Exit: optic canal
- Function: vision
Nerve cell bodies (and synapse), exit, and function of oculomotor nerve
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): midbrain (nucleus of oculomotor nerve)
- Exit: superior orbital fissure
- Function: SR, IR, IO, MR, levator palpebrae superioris
VISCERAL MOTOR:
- Nerve cell bodies (and synapse): presynaptic in midbrain (Edinger-Westphal nucleus), postsynaptic in ciliary ganglion
- Exit: superior orbital fissure
- Function: parasympathetic innervation to sphincter pupillae and ciliary muscle (miosis and accommodation)
Nerve cell bodies (and synapse), exit, and function of trochlear nerve
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): midbrain (nucleus of trochlear nerve)
- Exit: superior orbital fissure
- Function: SO
Nerve cell bodies (and synapse), exit, and function of ophthalmic division of trigeminal nerve
SOMATIC SENSORY:
- Nerve cell bodies (and synapse): trigeminal ganglion (sensory nucleus of trigeminal nerve)
- Exit: superior orbital fissure
- Function: sensation from cornea, forehead, scalp, eyelids, nose, nasal mucosa, paranasal sinuses
Nerve cell bodies (and synapse), exit, and function of abducens nerve
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): pons (nucleus of abducens)
- Exit: superior orbital fissure
- Function: motor to LR
Nerve cell bodies (and synapse), exit, and function of facial nerve
SOMATIC SENSORY:
- Nerve cell bodies (and synapse): geniculate ganglion (sensory nucleus of trigeminal)
- Exit: internal acoustic meatus, facial canal, and stylomastoid foramen
- Function: sensation from skin of auricle
SPECIAL SENSORY:
- Nerve cell bodies (and synapse): geniculate ganglion (nuclei of solitary tract)
- Exit: internal acoustic meatus, facial canal, and stylomastoid foramen
- Function: taste to anterior 2/3 of tongue and palate
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): pons (motor nucleus of facial)
- Exit: internal acoustic meatus, facial canal, and stylomastoid foramen
- Function: muscles of facial expression and scalp, stapedius, stylohyoid, posterior belly of digastric
VISCERAL MOTOR:
- Nerve cell bodies (and synapse): presynaptic in pons (superior salivatory nucleus), postsynaptic in pterygopalatine and submandibular ganglia
- Exit: internal acoustic meatus, facial canal, and stylomastoid foramen
- Function: parasympathetic innervation to submandibular and sublingual salivary glands, lacrimal gland, and glands of nose and palate
Nerve cell bodies (and synapse), exit, and function of vestibulocochlear nerve
SPECIAL SENSORY (balance):
- Nerve cell bodies (and synapse): vestibular ganglion (vestibular nuclei)
- Exit: internal acoustic meatus
- Function: vestibular sensation from semicircular ducts, utricle and saccule
SPECIAL SENSORY (hearing):
- Nerve cell bodies (and synapse): spiral ganglion (cochlear nuclei)
- Exit: internal acoustic meatus
- Function: hearing from spiral organ
Nerve cell bodies (and synapse), exit, and function of glossopharyngeal nerve
SPECIAL SENSORY:
- Nerve cell bodies (and synapse): inferior sensory ganglion (nuclei of solitary tract)
- Exit: jugular foramen
- Function: taste to posterior 1/3 of tongue and pharynx
SOMATIC SENSORY:
- Nerve cell bodies (and synapse), and function: superior sensory ganglion (sensory nucleus of trigeminal) -> posterior auricle, tragus, pharynx, posterior 1/3 of tongue, soft palate; inferior sensory ganglion (sensory nucleus of trigeminal) -> tympanic cavity and membrane, pharyngotympanic tube, mastoid cells
- Exit: jugular foramen
VISCERAL SENSORY:
- Nerve cell bodies (and synapse): inferior sensory ganglion (nuclei of solitary tract)
- Exit: jugular foramen
- Function: carotid body (chemoreceptors) and sinus (baroreceptors)
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): medulla (nucleus ambiguus)
- Exit: jugular foramen
- Function: motor to stylopharyngeus
VISCERAL MOTOR:
- Nerve cell bodies (and synapse): presynaptic in medulla (inferior salivatory nucleus), postsynaptic in otic ganglion
- Exit: jugular foramen
- Function: parasympathetic innervation to parotid
Nerve cell bodies (and synapse), exit, and function of vagus nerve
SPECIAL SENSORY:
- Nerve cell bodies (and synapse): inferior ganglion (nuclei of solitary tract)
- Exit: jugular foramen
- Function: taste from epiglottis and palate
SOMATIC SENSORY:
- Nerve cell bodies (and synapse): superior ganglion (sensory nucleus of trigeminal)
- Exit: jugular foramen
- Function: sensation from auricle, external acoustic meatus, dura mater of posterior cranial fossa
VISCERAL SENSORY:
- Nerve cell bodies (and synapse): inferior ganglion (nuclei of solitary tract)
- Exit: jugular foramen
- Function: visceral sensation from base of tongue, pharynx, larynx, and major organs
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): medulla (nucleus ambiguus)
- Exit: jugular foramen
- Function: motor to constrictor muscles of pharynx, intrinsic muscles of larynx, muscles of palate (except tensor veli palatini), striated muscle in superior 2/3 of oesophagus
VISCERAL MOTOR:
- Nerve cell bodies (and synapse): presynaptic in medulla, postsynaptic in target organ ganglia
- Exit: jugular foramen
- Function: parasympathetic innervation to smooth muscle of trachea, bronchi, GIT, myocardium
Nerve cell bodies (and synapse), exit, and function of accessory nerve
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): cervical spinal cord
- Exit: jugular foramen
- Function: motor to sternocleidomastoid and trapezius
Nerve cell bodies (and synapse), exit, and function of hypoglossal nerve
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): medulla
- Exit: hypoglossal canal
- Function: motor to muscles of the tongue (except palatoglossus)
Nerve cell bodies (and synapse), exit, and function of maxillary division of trigeminal nerve
SOMATIC SENSORY:
- Nerve cell bodies (and synapse): trigeminal ganglion (sensory nucleus of trigeminal)
- Exit: foramen rotundum
- Function: sensation from maxillary face (upper lip, maxillary teeth, mucosa of nose, maxillary sinuses and palate)
Nerve cell bodies (and synapse), exit, and function of mandibular division of trigeminal nerve
SOMATIC SENSORY:
- Nerve cell bodies (and synapse): trigeminal ganglion (sensory nucleus of trigeminal)
- Exit: foramen ovale
- Function: sensation from skin over mandible (lower lip, side of head, mandibular teeth, TMJ, mouth mucosa, anterior 2/3 of tongue)
SOMATIC MOTOR:
- Nerve cell bodies (and synapse): pons (motor nucleus of trigeminal)
- Exit: foramen ovale
- Function: motor to muscles of mastication, mylohyoid, anterior belly of digastric, tensor veli palatini, tensor tympani
Which parasympathetic nerve passes through the ciliary ganglion? What is the function?
Inferior branch of CN III
Innervates ciliary muscle and sphincter pupillae
Which parasympathetic nerve passes through the otic ganglion? What is the function?
Tympanic nerve from CN IX (continues as lesser petrosal nerve)
Innervates parotid gland (via auriculotemporal nerve of CN V3)
Which parasympathetic nerve passes through the pterygopalatine ganglion? What is the function?
Greater petrosal nerve from CN VII
Innervates lacrimal gland (via zygomatic nerve of CN V2)
Which parasympathetic nerve passes through the submandibular ganglion? What is the function?
Joins CN VII and leaves as chorda tympani
Innervates sublingual and submandibular nerves
What is the function of the sympathetic fibres which pass through the ciliary ganglion?
Branches from internal carotid plexus in the cavernous sinus innervate dilator pupillae and blood vessels of the eyes
What is the function of the sympathetic fibres which pass through the otic ganglion?
Superior cervical ganglion via plexus on middle meningeal artery innervates blood vessels of parotid gland
What is the function of the sympathetic fibres which pass through the pterygopalatine ganglion?
Deep petrosal nerve from internal carotid plexus innervates blood vessels of nasal cavity, palate and superior pharynx
What is the function of the sympathetic fibres which pass through the submandibular ganglion?
Sympathetic fibres via plexus on facial artery innervate sublingual and submandibular glands
Four branches of the ophthalmic nerve (CN V1)
- Tentorial
- Lacrimal
- Frontal
- Nasociliary
Ten branches of the maxillary nerve (CN V2)
- Meningeal
- Zygomatric
- Ganglion branches to pterygopalatine ganglion
- Posterior superior alveolar branches
- Infra-orbital
- Greater palatine
- Lesser palatine
- Posterior superior lateral nasal
- Nasopalatine
- Pharyngeal
Eleven branches of the mandibular nerve (CN V3). Which of these are sensory and which are motor?
Sensory:
1. Meningeal (nervus spinosum)
2. Buccal
3. Auriculotemporal
4. Lingual
5. Inferior alveolar
Motor:
6. Masseteric
7. Deep temporal nerves
8. Nerve to medial and lateral pterygoid
9. Nerve to mylohyoid (and anterior belly of digastric)
10. Nerves to tensor veli palatini
11. Nerve to tensor tympani
Describe the course of the facial nerve through the skull
- Enters internal acoustic meatus and runs in facial canal, gives off:
- Nerve to stapedius
- Chorda tympani - Emerges from base of skull through stylomastoid foramen, gives off:
- Posterior auricular nerve (supplies auricularis posterior and occipital belly of occipitofrontalis)
- Muscular branch (divides into two, supplies posterior belly of digastric and stylohyoid) - Approaches posteromedial surface of parotid gland and divides initially into temporofacial and cervicofacial branches (then divides further, re-joins, and divides again), gives off five major branches:
- Temporal
- Zygomatic
- Buccal
- Marginal mandibular
- Cervical
Muscles innervated by the temporal branch of the facial nerve
Part of frontalis
Anterior and superior auricularis
Muscles innervated by the zygomatic branch of the facial nerve
Orbicular oculi
Muscles innervated by the buccal branch of the facial nerve
Buccinator
Muscles innervated by the marginal mandibular branch of the facial nerve
Depressor labii inferioris
Depressor angulioris
Mentalis
Risorius
Muscles innervated by the cervical branch of the facial nerve
Platysma
Which is the largest paranasal sinus?
Maxillary
What forms the roof and floor of the maxillary sinus?
Roof: floor of orbit
Floor: alveolar part of maxilla
Describe the relations of the sphenoidal sinus
Above: pituitary fossa, middle cranial fossa
Below: roof of nasopharynx
Lateral: cavernous sinus, ICA
Behind: pons, posterior cranial fossa
Which paranasal sinus is not present at birth? When does it appear?
Frontal
Appears during 2nd year of life
