335 4.3 Neuroanatomy Part 4

• cranial nerve nucleus or cell body originates in the nucleus ambiguus
• in the medulla oblongata of the brainstem
• nerve goes through jugular foramen at the base of the skull by way of the inferior ganglion (a group of cells)

• muscles of the soft palate
• cricothyroid muscles
• remaining intrinsic laryngeal muscles (RILM)

pharyngeal branch of Vagus X

superior laryngeal branch

• recurrent laryngeal branch
• axon branches
• myoneural junction
• muscles themselves

• all muscles are innervated (supplied) by a nerve
• innervation can be senory (afferent) or excitatory (efferent)
• every muscle fiber will be innervated

consist of one efferent nerve fiber and the muscle fibers to which it attaches

sensory components that provide the information to the CNS concerning the state ofo the muscle (afferent)

• corticobulbar neurons
• corticospinal neurons

• organized vertically
• originate in cortex - motor strip/precentral gyrus (frontal lobe)
• now to corona radiata
• to internal capsule
• down to brainstem where synapse occurs
• ALL OF ABOVE IS AN UPPER MOTOR NEURON

fan-shaped mass of fibers in the white matter of the brain

• organized vertically
• originate in cortex - motor strip/precentral gyrus
• now to corona radiata
• to internal capsule
• down to brainstem where btw 70-90% decussate/cross over in the medulla
• down spinal column to lateral corticospinal tract
• to anterior/ventral horn where synapses with muscle fibers occur
• THIS IS AN UPPER MOTOR MEURON

from bulbar nuclei (in brainstem) out to muscles of the face, tongue, velum, lips, etc.

from anterior / ventral horn to muscles of arms, legs, feet, hands, etc.