Medulla oblongata and pons Flashcards
which cranial nerve nuclei are located in the medulla oblongata
CN 5-12 minus 6
general functions of the MO
- passive fiber conduction
- relay nuclei; gracilis, cuneatus, inferior olivary nucleus
MO measurements (length and depth)
- 5-3 cm long
1. 25 cm deep (anterior to posterior)
which structure of the MO relays information into the cerebellum’s central nuclei and cortex?
inferior olivary nucleus
where is the superior olivary nucleus located and what is its function?
located in the pons and is auditory in function
which structure of the MO is composed of a matrix of fibers running in all directions and nuclei?
reticular formation
the reticular formation of the MO is continuous with the reticular formations of which 4 other structures?
cervical cord, pons, midbrain and diencephalon
what does the complete reticular formation control?
general arousal of activity states in the CNS. Plays a role in wakefulness and all states of attention
these bilateral ventromedial structures run along the entire length of the MO and are easy to locate but do not look like their name
pyramids
what fibers are located in the pyramids?
pyramidal- UMN
corticospinal
which fibers cross(decussate) in the pyramids?
90% of the lateral corticospinal
which structure is a bilateral strand of ascending fibers seen through the length of the MO, pons, midbrain and terminate in the thalamus
medial lemniscus of the brain
the medial lemniscus of the brain enlarges halfway up the midbrain as it receives about a million ____1_____ from the opposite ___2___ and ____3____
- arcuate fibers
- gracilis
- cuneatus
which nuclei has parasympathetic control of ciliary and pupillary constrictor smooth muscles of the eye?
accessory oculomotor nuclei
which nuclei has somatic muscle control for 4 of the 6 extraocular eye muscles and upper eyelid?
7 muscles total- oculomotor nuclei
which nuclei has somatic motor muscle control for the superior oblique extraocular eye muscle?
trochlear nucleus
which nuclei has proprioception from muscles of mastication and periodontal ligaments of the teeth?
trigeminal mesencephalic nucleus
which nuclei has somatic motor to muscles of mastication?
trigeminal motor nucleus- also tensor villi palatini, tensor tympani, anterior belly of digastric and mylohyoid
which nuclei has somatic motor control for the lateral rectus extraocular eye muscle?
abducens nucleus
which nuclei has most superficial somatic motor muscles of the scalp and face(facial expression)
facial nucleus
which nuclei has parasympathetic control of lacrimal glands, submandibular glands and sublingual salivary glands?
superior salivary nucleus
which nuclei has parasympathetic control of parotid salivary gland?
inferior salivary nucleus
equilibrium and hearing are in these nuclei and are 6 nuclei together subdivided into parts
vestibular and cochlear nuclei
which nuclei has somatic motor control for 16 of the 18 tongue muscles
hypoglossal nucleus
which nucleus is sensory and motor for organs supplied such as voice, heart, lung and intestines in the X CN?
posterior (dorsal) nucleus of valgus
CN IX, X, and XI all share this nucleus in the delivery of visceral efferent fibers to the pharynx musculature
nucleus ambiguus
which nuclei has sensory reception via the VII IX and X CN primarily dealing with taste from tongue, palate and pharynx?
nucleus solitarius
which nuclei is the main sensory reception nucleus for the face dealing with pain, thermal, discriminative, tactile and proprioception
spinal nucleus of the trigeminal nerve- CN VII IX and X also contribute here; caudal section extends down to C3-C4 levels
which nuclei has somatic motor for movement of the important neck/head muscles called the SCM and trapezius?
spinal nucleus of the accessory nerve- most fibers originate in upper 5 cerv. cords and lower MO
what are axons with cell bodies in the cerebral cortex that descend to MO?
corticobulbar fibers- UNM- pyramidal
what is the medial longitudinal fasciculus responsible for?
another tract that is involved with swallowing, chewing, balance, coordination and eye movements
which type of stroke comes from a dissection of the vertebrobasilar arteries or branches and is the most common in chiropractic adjustments?
lateral medullary stroke syndrome or wallenberg’s stroke
what are the clinical manifestations of a wallenberg’s stroke?
loss of pain/temp on one side of face and opposite side body
what are the functions of the pons?
- fiber conduction
- important relay center for fibers going into cerebellum
- the pontine reticular formation is an important control center for respiratory and cardiovascular control via the medial reticulospinal tracts
what CN nuclei are in the pons?
5-8
what does the dorsal part of the pons form?
rhomboid fossa
what CN has its origin in the lateral wall of the pons?
the largest, CN V trigeminal
what are the 2 subdivisions of the pons?
tegmentum- dorsal
basilar- ventral
where are the corticospinal fibers of the pons found?
the basilar division just off the ventral boundary
where is the medial lemniscus of pons?
basilar division
what do the pontine nuclei do?
relay input from cerebral cortex back to cerebellum via the middle cerebral peduncle
which part of the pons is an auditory pathway?
lateral leminiscus
which nuclei contribute axons to the lateral lemniscus of the pons?
anterior and posterior cochlear nuclei and superior olivary nuclei
which pathway ascends to the diencephalons medial geniculate body?
lateral lemniscus- but many terminate in the inferior colliculus of the midbrain
where is the exact inferior border of the MO?
superior most ventral rootlet of C1
origin of CN IX, X, and XI
posterolateral sulcus
origin of CN VI
inferior pontine sulcus
origin of CN VII and VIII
pontocerebellar angle
origin of CN XII
ventrolateral sulcus
chemoreceptors in what 2 areas of the brainstem detect toxins in the blood and trigger vomiting?
obex and area postrema
