| loop of hypoglossal nerve | A loop in the cervical plexus consisting of fibres from the first three cervical nerves. Fibres from a loop between the C-1 and C-2 spinal nerves accompany the hypoglossal nerve for a short distance, leaving it as the superior root of the ansa cervicalis. Fibres from a loop between the C-2 and C-3 spinal nerves form the inferior root of the ansa cervicalis. Most commonly, the roots merge, forming the ansa cervicalis, which gives rise to branches innervating infrahyoid muscles. Synonym: cervical loop, loop of hypoglossal nerve. (05 Mar 2000) |
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