Exam 1 Flashcards
What are the receptors of the olfactory nerve?
Olfactory hairs
Olfactory neuron axon are ________ however covered by _________ cells
Unmyenlinated, Schwann
Where does the olfactory neurons synapse
Dendrites of mitral cells, this forms a synaptic glomeruli at the synapses
What are the second sensory neurons of the olfactory nerve
Mitral cells, cell bodies are located in the olfactory bulb
Where do the mitral cells split into medial and lateral striae
Anterior perforated substance
Where do medial Stria fibers of the olfactory nerve cross the midline?
Anterior commissure, and then travel to the opposite olfactory bulb
Where do the lateral stria fibers carry information to?
The primary olfactory cortex; the periamygdaloid and prepiriform area, including the uncut Bdmn. Area 34
What nerve is poorly developed in humans but highly developed in other animals
Vomeronasal nerve- important for tracking prey
What is the loss of smell?
Anosmia
Whats an indicator of CSF leakage
halo sign
HOw many layers is the eye composed of
3
What is the outermost layer of the eye made of
AKA the Fibrous tunic
Sclera- white part
Cornea- clear, is the primary refractory structure
What makes up the middle layer of the eye
AKA the vascular tunic
Ciliary body
Iris-colored part of the eye
Choroid
Which layer in the eye is not myelinated
Nerve fiber layer
How many types of cones are there
Red, green, blue
What do cones need
Adequate light to function the best
More concentrated toward center of retina
Where is the best spot for vision
Fovea Centralis
Rods are not located where
Fovea, however the periphery is almost all rods
Where are bipolar cells bodies located?
The inner nuclear layer*****
Where do photoreceptors relay info to bipolar cells in what layer
Plexiform layer
Bipolar cells relay info to ganglion cells in what layer
Inner plexiform layer
Where does the optic nerve enter the skull?
Through the optic canal and unite to form the optic chiasma
Are optic never axons myelinated
Yes
What cells for the myelin
Interfasicular Oligodendrocytes
Which fibers the lateral or medial fibers in the eye cross?
The medial fibers cross, which forms the optic tracts
The optic tract travels around the cerebral peduncles and fibers synapse in 3 nuclei
Lateral Genicuate body- majority synapse there
Superior Colliculus- info relayed to tectospinal tract
Pretectal nucleus of midbrain- deal with light reflexes
How many cells does it take to get to the brain for vision to work
4, 5 if including the cell body in broadmann area 17
What happens with a lesion to the optic nerve
Loss of depth perception
What happens with a lesion to the decussating fibers in the optic chiasma
Tunnel vision
Lesion in the optic tract results in
Loss of 1/2 of the visual field
What is the accommodation reflex
Ability to change focus from objects far to close. Lens changes shape
Whats corneal reflex
Blinking, use cotton ball
Whats convergence
Ability to contract both medial rectus muscles
The oculomotor nerve carries both
Somatic and parasympathetic fibers
Where is the origin of the oculomotor nuclei
Located in the periaquedcutal gray matter, anterior to cerebral aqueduct, at the level of superior colliculi
What part of the cerebral cortex sends axons to the oculomotor nuclei
Broadman area 8,
Also recieves fibers from superior colliculus and medial longitudinal fasiculus
At what point is the oculomotor nerve covered in EPINEURIUM**
Once it travels through the RED nucleus and exits the CNS via the interpeduncular fossa
Where does the oculomotor nerve exit the skull
The superior orbital fissure. Once in eye splits into superior and inferior rami
Superior ramus of oculomotor nerve supplies
Superior rectus
Levator palpebrae superioris
Inferior rectus of oculomotor nerve supplies
Medial rectus
Inferior rectus
Inferior oblique
What type of neurons are found in the accessory oculomotor nucleus
Preganglionic parasympathetic neuron
Where does the accessory oculomotor nucleus synapse in?
Ciliary ganglion
Where is the ciliary ganglion located
Posterior to the eyeball, about 1cm anterior to the superior orbital fissure
Postganglionic parasympathetic axons of the accessory oculomotor nucleus follow what?
The ciliary arteries and pierce the sclera
What does the trochlear nerve supply?
Somatic motor nerve supplying superior oblique
Where is the trochlear nucleus located?
Periaqueductal gray, just caudal to oculomotor nuclei
The LMN from the trochlear nucleus crosses and exits where?
Inferior to the inferior colliculi
The trochlear nucleus receives fibers from
- Cerebral cortex
- Superior colliculus
- Medial longitudinal fascicles
What opening does the trochlear nerve enter the orbit
The superior orbital fissure,
Curves around the brainstem and continues in the lateral wall of the cavernous sinus
Communication with the cavernous plexus
These neurons supply smooth muscles in blood vessels that supply blood to the superior oblique
What is the trochlear nerve named after
The pulley-like mechanism on the medial aspect of the orbit that the superior oblique passes through.
Causes eye to look down and out
What is the abducens nerve
Somatic motor nerve supplying the lateral rectus
Where is the abducens nucleus located
Caudal part of the pons, at the floor of the rhomboid fossa*****
Where does the abducens nerve exit the CNS?
Inferior border of the pons
Where does the abducens nerve exit the skull?
Through the superior orbital fissure and innervated LR
What is strabismus
Eyes are “pointing in different directions”
2 types- Internal eyes converge, external eyes diverge
Whats diplopia
Double vision, subjective, difficult to demonstrate
Whats ptosis
Eyelid droops due to weakness of levator palpebrae superioris. Oculomotor lesions may be the cause
External ophthalmoplegia effects oculomotor nerve and
Diplopia, ptosis, external strabismus
Whats internal ophthalmoplegia
Inability to constrict pupil as well as loss of light and accommodation reflexes
Trochlear paralysis is
Rare, internal strabismus. Results in inability to look down, which results in difficulty descending stairs aka Diplopia
Whats abducens paralysis
Most common, internal strabismus, unable to abduct the eye
Whats internuclear ophthalmoplegia
Involves damage to the MLF- results in nystagmus when abducting during lateral gaze
Which cranial nerve is the largest?
Trigeminal
What is the great sensory nerve of the face
Trigeminal
The trigeminal nerve has more ______ fibers than motor fibers
Sensory
What are the three nuclei of termination with the trigeminal nerve
- Main sensory nucleus
- Spinal nucleus
- Trigeminal mesencephalic nucleus
What is the one peripheral ganglion associated with trigeminal nerve
Trigeminal (semilunar) ganglion
What are the three branches of the trigeminal nerve
Ophthalmic, maxillary, mandibular
The main sensory and spinal nuclei go directly to what nucleus
Trigeminal, main-touch, vibration, joint proprioception. Spinal nuclei- pain and temperature
Dendrites from the periphery pass through ___________ ganglion and enter the CNS and ascend to the mesencephalic nucleus
Trigeminal
Axons from the motor nucleus leaves the CNS and travels through the trigeminal ganglion to be carried to __________
Mandibular branch
What branch of the trigeminal is the only one to carry motor fibers
Mandibular branch
What does the motor nucleus receive info from
Cerebral cortex, reticular formation, red nucleus, tectum, medial longitudinal fasciculus, mesencephalic nucleus (monosynaptic reflex)
What is the apparent origin of the trigeminal nerve
Lateral aspect of the pons
The trigeminal nerve travels anteriorward over the patrons part of the temporal bone to enter the Trigeminal (Meckel’s) cave is where _________ is found
Trigeminal ganglion
Where does the ophthalmic division enter the orbit
Superior orbital fissure
What is the function of the ophthalmic division of trigeminal
Sensory function only
The ophthalmic division carries sensation from what areas
Nose, forehead, and scalp
Also sensation from frontal and sphenoid sinuses and membrane covering nasal septum
What are the four branches of the ophthalmic division of trigeminal
1.meningeal nerve or tentorial branch, 2. lacrimal nerve, 3.frontal nerve, 4.nasociliary nerve
Which branch of the ophthalmic division is given off before it leaves the superior orbital fissure
Meningeal nerve- supplies the dura mater lining the middle cranial fossa
What is the smallest branch of the ophthalmic division of trigeminal
Lacrimal nerve
The lacrimal nerve passes through ___________ and supplies what two structures
Lacrimal gland
Lacrimal gland and skin of the upper eyelid
The lacrimal nerve carries parasympathetic (secretory) fibers to the lacrimal gland which originated in
Pterygopalatine ganglion CN VII
What two nerves parasympathetic fibers meet up with the lacrimal nerve
Zygomatic nerve and zygomaticotemporal nerves CN V
What is the largest branch of the trigeminal
Facial nerve
What are the two branches of the facial nerve
Supratrochlear and Supraorbital
The supratrochlear nerve conveys sensation from the
Medial corner of the eye
The supraorbital nerve carries sensation from the
Conjunctiva, upper eyelid, forehead, and mucous membranes lining frontal sinus
What are the two terminal branches of the nasociliary nerve
Anterior ethmoid and infratrochlear nerves
What are the 5 branches of the nasociliary nerve
Communicating branch, long ciliary nerve, posterior ethmoid, anterior ethmoid, infratrochlear nerve
What supplies the ciliary ganglion in the trigeminal nerve
Communicating branch- conveys sympathetic and somatic sensory fibers, travels with oculomotor nerve
The long ciliary nerve supplies
The eyeball
Posterior ethmoid nerve carries sensory info from the
Sphenoidal and ethmoidal sinuses
The anterior ethmoidal nervesupplies
Skin over the nose, mucous membrane covering the anterior part of the nasal septum by way of internal nasal nerve
Infratrochlear nerve supplies
The medial corner of the eye, including the lacrimal sac
The maxillary division of trigeminal nerve enters the ptergopalatine fossa via
Foramen rotundum
True or False
Maxillary division is sensory function only
TRUE
Maxillary division carries sensation from
The skin between the eyes and mouth, over the cheeks and temples. Also from the mucosa lining the maxillary sinuses, nasal conchae, palate and gingiva
What are the four branches of the maxillary division of trigeminal
Middle meningeal, zygomatic, ganglionic branches, infraorbital nerves
Middle meningeal nerve is given off _________ it exits the round foramen
Before
What does the middle meningeal nerve supply
Meninges of the middle cranial fossa
Zygomatic nerve enters the orbit through
Inferior orbital fissure
Zygomatic nerve gives off a communicating branch carrying postganglionic parasympathetic fibers from the
Pterygopalatine ganglion to the lacrimal gland
Zygomaticotemporal nerve supplies
The skin over the temple
Zygomaticofacial nerve supplies
The skin over the cheek
The ganglionic branches of the maxillary division of trigeminal carries sensory info
From the upper pharynx, nasal cavity, and palate through the pterygopalatine ganglion
The infraorbital nerve supplies
The lower eyelid, skin over the upper jaw and maxillary sinus
What branches does the infraorbital nerve give off before entering the infraorbital canal
Posterior, middle, and anterior superior alveolar nerves and carries sensory info from the teeth
Branches of the maxillary division of the trigeminal nerve are used to distribute ________________ fibers from the ptergopalatine ganglion
Postganglionic parasympathetic
Preganglionic parasympathetic fibers reach the ptergopalatine ganglion from the facial nerve via
Greater pterosaurs nerve
________________ fibers from the superior cervical ganglion pass through the ptergopalatine ganglion
Postganglionic sympathetic
Where does the mandibular division of the trigeminal nerve exit the cranial vault
Foramen ovale
The mandibular division of trigeminal contain what two types of fibers
Large sensory and small motor root
The mandibular division carries sensation to
Skin over the mandible, posterior cheek, and posterior temple.
Also mucosa from lower oral cavity and cheeks
Mandibular division gives motor innervation to how many muscles
8, the muscles of mastication
What two branches of the mandibular division of trigeminal are given off in the infratemporal fossa?
Recurrent meningeal branch
Medial pterygoid nerve
Where does the recurrent meningeal branch enter the cranium
Foramen spinosum
What sensory info does recurrent meningeal nerve carry
Middle cranial fossa, anterior cranial fossa, and calvarium
What does the medial pterygoid branch motor nerve supply
The medial pterygoid muscle, also passes through the OTIC ganglion and supplies the tensor veil palatine and tensor tympani
What division of the mandibular division gives off sensory info anterior or posterior?
Posterior
The anterior division is mainly motor
What four nerves are given off by the anterior division of mandibular nerve
Masseter
Deep Temporal
Lateral pterygoid
Buccal
Masseter nerve gives motor info to
Masseter and sensory info from the TMJ joint
Deep temporal branch supplies
Temporalis muscle, splits into anterior and posterior branches but they both supply it
Lateral pterygoid nerve supplies
Lateral pterygoid muscle
What is the major sensory branch of the anterior division of the mandibular division of trigeminal
Buccal nerve- sensation from the cheek and buccal gingivae of the molars
The posterior division of the mandibular division of trigeminal gives rise to
Auriculotemporal nerve and lingual nerve
What nerve passes through the parotid gland?
The auriculotemporal
The auriculotemporal nerve carries sensory info from the
Skin of the temple and the ear
Also carries, post ganglionic parasympathetic fibers from the OTIC ganglion
The lingual nerve conveys sensory info from
The mucosa of the oral cavity and combines with a branch of the facial nerve, the chorda tympani in the infratemporal fossa
What are the two branches of the inferior alveolar nerve
Incisive branch and the mental nerve
The incisive branch supplies
Incisors canines and 1st premolars and adjacent gingivae
Mental nerve supples the
Labial gingivae adjacent to the incisors and the skin of the lower lip and chin
What two autonomic ganglia communicate with he mandibular division
Submandibular and otic ganglia
The submandibular ganglion recieves some preganglionic fibers from
CNVII via the lingual nerve after it combines with the chorda tympani
The OTIC ganglion sends postganglionic fibers to what
Parotid gland via the auriculotemporal nerve
What is trigeminal neuralgia
Tic doloreaux
What is the nerve of facial expression
The facial nerve
What is the primary nucleus of origin of the facial nerve
The motor nucleus, located at the caudal part of the pons
What nucleus contributes preganglionic parasympathetic fibers to the facial nerve
Superior salivary nucleus
Sensory fibers carried in the facial nerve terminates in
The upper part of the solitary nucleus
The cell bodies of the sensory neurons of the facial nerve is found in
The geniculate ganglion
General sensation from the external ear and lateral tympanic membrane is carried to
The geniculate ganglion, axons carry info to the solitary nucleus
Specific fibers that convey taste from the anterior part of the tongue is carried in the
Chorda tympani
LMN in the motor nucleus of the facial nerve travel through
The geniculate ganglion and innervated muscles of facial expression
The motor nucleus supplying muscles of the inferior part of the face recieves info ONLY from
The contralateral cortex
The motor nucleus also receives info from the
Reticular formation
What two ganglion does the preganglionic parasympathetic fibers from the superior salivary nucleus synapse in
Ptergopalatine and submandibular
What is the apparent origin of the facial nerve
Lateral aspect of the medullopontine sulcus
OR CALLED cerebellopontine recess
What are the two roots present at the origin of the facial nerve
- motor root (facial nerve proper)
2. Intermediate nerve; carries sensory and parasympathetic fibers
Exiting the CNS the facial nerve enters the
Internal acoustic meatus located in the petrous part of temporal bone
Roots of the facial nerve combine and form a single trunk and bends posteriorly and forms the
External genu of the facial nerve
Where does the greater petrosal nerve enter the temporal bone
The foramen lacerum and joins with the ptergopalatine ganglion
What nerve carries preganglionic parasympathetic fibers and stimulates secretions to the lacrimal, nasal, and palatal glands via
The greater petrosal nerve
What is another name for the greater petrosal nerve
Superficial petrosal nerve
What nerve gives off motor fibers in the facial canal
The nerve to the stapedius
The chorda tympani carries what kind of fibers
Preganglionic parasympathetic fibers and taste fibers
The chorda tympani leaves the temporal bone via the
Pterygopalatine fissure, where it combines with the lingual nerve a branch of mandibular division of trigeminal
What are the three branches of the facial nerve between the stylomastoid foramen and parotid gland
- Digastric branch,
- Stylohyoid branch
- Posterior auricular nerve
The posterior auricular nerve divides into what two branches
Occipital and auricular branch
The facial nerve enters the parotid gland and forms the parotid plexus giving off two trunks
Temporofacial and cervicofacial
Temporofacial and cervicofacial give off 5 more branches of the facial nerve
- Temporal branches
- Zygomatic branches
- Buccal branches
- Marginal mandibular branch
- Cervical branch
Temporal branch of the facial nerve supplies the
Intrinsic auricular muscles and superior and anterior auricular muscles. In combo with zygomaticofacial and auriculotemporal nerves to supple orbicularis oculi, corrugator supercilii, frontal belly of occipitofrontalis
Zygomatic branches help supply
Orbicularis oculi
Buccal branches supply
Buccinator, orbicularis oris, and levator anguli oris
Marginal mandibular branch supplies
Risorius, muscles of chin and lower lip
Cervical branch supplies
The platysma muscle
