Brainstem Flashcards
Spinal Trigeminal Tract
Descending pathway of peripheral processes of axons from the trigeminal nucleus; synapse in the spinal nucleus of V
Spinal Tract and Nucleus of V
Found in the rostral medulla; contain info about pain/temp in the face
*Part of a column continuous w/ dorsal gray matter w/ the spinal cord
=>essentially a continuation of this tract
Trigeminothalamic Tract
Ascending axon that synapse in the VMP in the thalamus, superior colliculus, PAG, and reticular formation
- Fibers decussate @ various levels in the PONS
- Pain processing, visual reflexes, vertical gaze center, and RAS
Restiform body
“Inferior Cerebellar Peduncle”
Clarke’s Nucleus
Found in the rostral medulla; receives proprioceptive info from the dorsal column and projects axons thru the restiform body
Accessory cuneate nucleus
Sends neurons thru the cuneocerebellar tract to relay unconscious proprioceptive info
Dorsal nucleus of X
Lies in the dorsal medulla; relays parasympathetic axons to the thoracic region
-Is just lateral to hypoglossal nucleus
Nucleus tractus solitarius
Primarily relays gustatory information (rostral medulla)
Nucleus ambiguus
LMNs for IX and X; innervation of soft palate, pharynx, larynx, and upper esophagus
-If it could be seen, it would be just dorsal to the ION
False localizing sign
Compression of nerve VI from increased ICP; results in medial strabismus
Paramedian pontine reticular formation
Horizontal gaze center that coordinates CN III, IV, and VI fnxn
Facial colliculus
Bulge on the floor of the 4th ventricle in the pons due to the wrapping of axons of VII
SON
Sharpens auditory info and fnxns in acoustic reflex
-Axons decussate to hear thru the trapezoid body
Chief sensory nucleus of V
Relays info about fine touch, vibration, and conscious proprioception from the face
-Also called the principal, main, superior, or PONTINE TRIGEMINAL NUCLEUS
Motor Nucleus of V
Lies medial to chief sensory nucleus of V; branchiomotor to muscles of mastication
Mesencephalic tract and nucleus
Relays unconscious proprioception from muscles of mastication
- Fibers run to motor nucleus of V and motor nucleus of VII (corneal reflex)
- Only pseudounipolar neurons found in CNS
Nucleus locus coreulus
Reticular formation important in arousal, attention, sleep cycles
-Found dorsolaterally in the rostral pontine tegmentum
Pontine nuclei
In the basal pons; contains corticospinal and corticobulbar axons
Superior Colliculus
Found in tectum of rostral midbrain
-Outputs to the cervical spinal cord, gaze centers, and to the pulvinar
PAG
Contains:
1. Mesencephalic nucleus of V
- Descending neurons for transmission of pain; stimulated by opiods which can produce analgesia*
- Vertical gaze center
Red nucleus
Lies at the level of the superior colliculus; output is part of the indirect corticospinal system
*Lesions will produce tremors
Decorticate posturing contralaterally
Lesion above the red nucleus; flexed arm/extended leg
Decerebrate posturing contralaterally
Unilateral lesion below the red nucleus; extend arm/extend leg
Substantia nigra
Contains:
- Pars compacta- dopamine NTs; first area to go in Parkinson’s*
- Pars reticularis- GABA NTs; efferent area of nucleus
Crus cerebri
Contains projection axons and is continuous w/ the internal capsule
-Middle 1/3 contains corticobulbar and corticospinal axons
Herpes Zoster
Can involve the ophthalmic division of V resulting in corneal ulcerations and possible blindness
Vestibular nuclei
Found in rostral-most medulla
(Found about where dorsal nucleus of X would be)
*PICA=main blood supply
Cochlear nuclei
Lies in lateral part of the most-rostral medulla
*AICA= main blood supply
Brachium conjunctivum
Superior Cerebellar Peduncle
*Major output center of cerebellum
