Martin chapter 11 Flashcards
the cranial nerve motor nuclei are organized into 3 columns
somatic skeletal, branchiomeric and autonomic
what do nuclei in the somatic skeletal motor column contain?
motor neurons that innervate extra ocular and tongue muscles (all striated)
what do nuclei in the branchiomeric column contain?
motor neurons that innervate facial, jaw, palatal, pharyngeal and laryngeal muscles (all striated)
what do nuclei of the autonomic motor column contain?
preganglionic parasympathetic neurons that regulate the function of cranial exocrine glands, smooth muscle and many body organs
4 nuclei comprise the somatic skeletal motor column
three of these nuclei contain motor neurons that innervate extra ocular muscles: oculomotor nucleus, trochlear nucleus, abducens nucleus
the fourth nucleus is the hypoglossal nucleus and innervates intrinsic tongue muscles (genioglossus, hypoglossus and styloglossus)
the motor axons of the oculomotor nucleus course within?
the oculomotor nerve (III)
the motor axons of the trochlear nucleus course in?
the trochlear nerve (IV)
the abducens nucleus motor axons course in?
the abducens nerve (VI)
the axons of the motor neurons in the hypoglossal nucleus course within?
the hypoglossal nerve (XII)
three cranial nerve nuclei constitute the branchiomeric motor column
facial motor nucleus, trigeminal motor nucleus and the nucleus ambiguous
the axons of the neurons in the facial motor nucleus course in?
the facial nerve (VII)
the axons of motor neurons of the trigeminal motor nucleus course within?
the trigeminal nerve (V)
axons of the motor neurons in the nucleus ambiguous course within?
a small number of motor neurons in the rostral portion of the nucleus ambuguus course in the glossopharyngeal nerve (IX)
most motor neurons send their axons through the vagus nerve (X)
the most caudal portion of the nucleus ambiguous contains motor neurons whose axons travel within the accessory nerve (XI)
NB: only the axons in the cranial root of the accessory nerve have their cell bodies in the nucleus ambiguous
The vagus nerve is the efferent component of which reflex?
the GAG reflex
where are cell bodies of axons in the spinal root of the accessory nerve located?
in the spinal accessory nucleus
this nucleus is part of the ventral horn of the upper cervical spinal cord (from the pyramidal decussation to the 4th or 5th cervical segment)
the parasympathetic nervous system is a division of?
the autonomic nervous system
the innervation of smooth muscle and glands is accomplished by two types of neurons
preganglionic and postganglionic neurons
where are parasympathetic preganglionic neurons located? and parasympathetic postganglionic neurons?
pre ganglionic ones are located in the nuclei that comprise the autonomic motor column
postganglionic ones are located in the peripheral autonomic ganglia (they are part of the peripheral nervous system)
the autonomic motor column contains 4 nuclei
- edinger westphal nucleus
- superior salivary nucleus
- inferior salivary nucleus
- dorsal motor nucleus of the vagus nerve
nuclei within the somatic skeletal and branchiomeric motor columns are controlled by what?
by cortical motor areas (primary motor cortex, supplementary and cingulate motor areas and pre motor cortex)
the cranial motor areas project to the brain stem motor nuclei through which tract?
corticobulbar tract
nuclei comprising the autonomic motor column are influenced by projections from?
cerebral cortex and hypothalamus
where does the corticobulbar projection from the primary motor cortex descend? the ones from the other motor areas?
the projection from the primary motor cortex descends in the genu and in the adjoining posterior limb of the internal capsule
the projections from the other motor areas descend in the anterior limb of the internal capsule
the facial colliculus is formed by?
the genu of the facial nerve and the abducens nucleus
