Anatomy and Cell Biology 3319 Lecture Notes - Lecture 2: Cranial Nerve Nucleus, Dorsal Root Ganglion, Olfactory Bulb
15 Dec 2017
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12 pairs, attached to brain, pass through various foramina in the skull. Numbered i to xii in rostral to caudal direction. First 2 pairs attach to forebrain, the rest to the brain stem. Except for vagus nerve (x), cranial nerves innervate only head/neck structures. Cell bodies of the sensory neurons lie either in receptor organs, or within cranial sensory ganglia, which lie along some cranial nerves: cranial sensory ganglia comparable to the dorsal root ganglia on the spinal nerves. Cell bodies of most cranial motor neurons occur in cranial nerve nuclei in the ventral gray matter of the brain stem. Cranial nerves iii, vii, ix, x contain visceral motor fibers that regulate visceral muscle/glands in the body: belong to parasympathetic division of the ans, ans innervates body structures through chains of two motor neurons. Cell bodies of the second neurons occupy autonomic motor ganglia in the pns. Olfactory receptor cells (bipolar neurons) in the olfactory epithelium of the nasal cavity.
