Medulla Flashcards
What is the MLF responsible for and what does it have connections to?
Responsible for conjugated lateral gaze. It has connections to the superior colliculus, vestibular nuclei, and CN 3,4,and 6
What function do the raphe nuclei serve (specifically the Raphe Magnus)? What does it receive input from and where does it send output to?
Receives projections from the ALS and send descending serotonergic projections to the spinal chord that inhibit pain.
Describe the somatotopy of the medial lemnisci?
Neck to foot info goes from Dorsal to ventral
What is the inferior olivary complex involved with?
It is a main cerebellar relay station. It receives axons from the red nucleus, spinal chord, and cerebral cortex and sends axons across the midline to the the cerebellum forming much of the inferior cerebellar peduncle.
Describe how CN XII exits the brain stem
It exits between the pyramids and the olives.
Describe what happens when damage to the inferior cerebellar peduncle occurs.
ataxia (incoordination) and intention tremor of the extremities on the ipsilateral side of the body. Patients lean to the side of the lesion and have clumsiness and a tremor while using the ipsilateral hand.
Describe the main function of the nucleus ambiguous and results of lesions to it
Axons from the NA mainly project via the vagus (10) and glossopharyngeal (9) nerves to innervate the larynx and pharynx. Unilateral damage with result in hoarseness, impaired swallowing, and asymmetry of the soft palate.
Describe the function of the dorsal motor nucleus of the vagus.
Preganglionic PNS fibers of the vagus. They terminate on ganglia related to cardiac muscle, to smooth muscle of blood vessels, trachea, bronchi, esophagus, stomach and intestines.
Describe the function of the Solitary Nucleus and its associated tract.
receives afferent info from pharynx and larynx and from the cardiovascular and GI systems via CN 7,9, and 10. The rostral pole receives taste info from the same CNs. It sends axons to man regions of the surrounding brainstem such as the NA, DMV, and CN XII nucleus to mediate relex responses (vomiting, coughing, sneezing) as well as sending projections to higher brain centers such as the hypothalamus and the thalamus
Where do preganglionic PNS originate for salivation and lacrimation?
In the rostral medulla in the salivatory nuclei.
What does damage to the vestibular nuclei cause?
nystagmus, vertigo, and problems with balance.
What are the cranial nerve signs for CN8?
deafness in the ipsilateral ear, nystagmus, vertigo and problems with balance.
What are the cranial nerve signs for CN9?
loss of gag reflex and the side of the oropharynx of the nerve injury (afferent loss to nucleus solitarius)
What are the cranial nerve signs for CN10?
Hoarseness due to loss of control of the larynx, difficulty swallowing, and asymmetry of the soft palate due to loss of the pharyngeal musculature (Nucleus ambiguous)
What are the cranial nerve signs for CN11?
inability to elevate ipsilateral shoulder, difficulty to turn head to opposite side of lesion, fasciculations and atrophy of the affected SCM and trapezius muscles.
