Lecture 8 - Cranial Nerves V and VII Flashcards
The trigeminal nerve (CN V) consists of what 2 types of nuclei?
- somatic sensory
- branchial motor
The somatic sensory trigeminal nerve (CN V) nuclei whose peripheral fibers supply the skin and deep tissues of the head and dura are the ______ and _____ _____ nuclei. The somatic sensory CN V nucleus that supplies peripheral muscle spindles and other mechanoreceptors is the _______ nucleus.
- spinal
- main sensory
- mesencephalic
The branchial motor trigeminal nerve (CN V) nucleus whose peripheral fibers supply the MOM, tensor tympani, and several other muscles is the ______ ______ nucleus. It forms the _____ limb of the jaw-jerk reflex.
- trigeminal motor
- efferent
- innervated muscles = “MOM & the tensor twins.” These are the muscles of mastication, tensor tympani, tensor veli palatini, as well as the mylohyoid and anterior belly of the digastric muscles
What 4 types of sensory information does the trigeminal nerve (CN V) transmit to the cortex, cerebellum, and reticular formation?
- tactile
- proprioceptive
- pain
- temperature
The trigeminal nerve (CN V) has 3 branches. The sensory division that supplies the upper face is the ______ division (V1). The sensory division that supplies the middle face is the ________ division (V2). The mixed sensory and motor division that supplies the lower face is the ______ division (V3).
- ophthalmic
- maxillary
- mandibular
Three of the trigeminal nuclei (mesencephalic, main sensory, trigeminal motor) can be viewed from an XS of the middle _____.
pons
The trigeminal SPINAL nucleus sends ascending [contralateral/bilateral] projections to the _____ _____ nucleus of the thalamus. The trigeminal MAIN SENSORY nucleus sends [contralateral/bilateral] projections to the same place. Both then travel through the internal capsule to the ________ ______ of the parietal lobe.
- contralateral
- ventral posteromedial (VPM)
- bilateral
- postcentral gyrus
Sensory fibers of the trigeminal nerve serve the face, oral cavity, teeth, and meninges. These areas transmit sensory info to the trigeminal ______. These then send feedback to the ____ _____ _____ nucleus. Senses included are _____ touch and ______.
- ganglion
- trigeminal main sensory
- discriminative
- vibration
The main trigeminal sensory nucleus is at mid-____ level, and sends a thick ______ of cells through much of the brainstem.
- pons
- column
The trigeminal main sensory nucleus is homologous to the _______ _______ nuclei that receives proprioceptive info from the appendicular skeleton.
- posterior column (PCML)
The trigeminal main sensory nucleus has 2 pathways. The [crossed/uncrossed] pathway joins the medial lemniscus on its way to the ______ _______ nucleus of the thalamus. The [crossed/uncrossed] dorsal trigeminal tract representing the oral cavity goes to the _____ _____ nucleus of the thalamus.
- crossed
- ventral posterolateral (VPL)
- uncrossed
- ventral posteromedial (VPM)
The trigeminal spinal nucleus senses ______, ____ ____, and ________. It is directly ______ of the trigeminal ______ _______ nucleus, and uses similar pathways.
- pain
- crude touch
- temperature
- inferior
- main sensory
- homologous to Lissauer’s tract of the anterolateral spinal pathway (ALP) that transmits the same senses
The trigeminal spinal nucleus is divided into 3 parts based on histology. (Rostral to Caudal)
- _____ nucleus: main sensory nucleus to pontomedullary junction
- _____ nucleus: pontomedullary junction to obex
- _____ nucleus: obex to spinal cord
- oral
- interpolar
- caudal
As part of the spinal trigeminal nucleus the _____ ______, receives input from intraoral and perioral structures. The part of the nucleus directly inferior to this that activates trigemino-autonomic reflexes is the ____ ______ proper. The most inferior of all 3 portions is responsible for pain, crude touch, and temperature sensation - the _____ ______.
- pars oralis
- pars interpolaris
- pars caudalis
Where the spinal trigeminal nucleus transitions from the pars interpolaris to the pars caudalis, there is a lack of ______ organization, and the region responds to and possibly supresses _____ from many areas served by the trigeminal nerve (CN V).
- somatotopic
- pain
The pars caudalis serves both superficial structures like the ______ _____ and teeth, and deep muscles such as the _______, and the ____. The convergence of these structures may be a basis for referred ______.
- oral cavity
- MOM (muscles of mastication)
- TMJ
- pain
Spinal trigeminal fibers join the ______ tract and terminate in the VPM.
spinothalamic
Pars caudalis has a ____ structure with ______ organization. This makes it look like an “_____ _____” representation from rostral to caudal of the peripheral face. Mostly _____ fibers are present here.
- laminar (lamina II)
- somatotopic
- onion peel
- pain
The pars caudalis is in _______ ___ of the substantia gelatinosa, and contains both excitatory and inhibitory interneurons. It receives afferents from CN ____, ___, and ____ for the near ear.
- lamina II
- VII
- IX
- X
The “onion-like” somatotopic arrangement of the pars caudalis is arranged as follows:
- mandibular division (V3): ______
- ophthalmic (V1): _______
- maxillary (V2): _______
- dorsal
- ventral
- in between
Due to the onion-like distribution of sensory loss, the more ______ a spinal trigeminal tract injury, the more sensory function is preserved around the mouth.
caudal
In the tooth pulp (V3), 70-80% of fibers are ____ and ___ for fast and slow pain. 20-30% are _____ for touch and pressure (faster) from the inferior alveolar nerves into the predentin and dentinal tubules of teeth.
- Aδ
- C
- Aβ
In tooth pulp, the sensory fibers project to the trigeminal _____ _____ nucleus and trigeminal _____ nucleus. In the latter, their projections decrease from the pars oralis to the inferior pars caudalis. They also project to the upper cervical _____ ____.
- main sensory
- spinal
- spinal cord
Brief episodes of excruciating pain caused by one or more divisions of the trigeminal nerve is called _____ _____. It is most common in the ____ division.
- trigeminal neuralgia
- mandibular (V3)
