[Plate 71, Nerves of Oral and Pharyngeal Regions]Sensory
Above vocal folds: internal laryngeal nerve (branch of superior laryngeal)
Below vocal folds: inferior laryngeal nerve (branch of recurrent laryngeal nerve)
Motor:
Recurrent laryngeal nerve to all intrinsic muscles except cricothyroid
External laryngeal nerve to cricothyroidThyroid Gland
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H-shaped endocrine gland
Produces two hormones
Thyroid hormone-controls metabolic rate
Calcitonin-controls calcium metabolism
Overlies anterior and lateral surface trachea
Enclosed in thin fibrous capsule with septa into gland
Surrounded by pretracheal fascia (therefore moves on swallowing)
Two lateral lobes linked by isthmus
Lobes extend from second to fifth tracheal ring
Isthmus lies at third tracheal ring
Occasionally a pyramidal lobe extends superiorly from isthmus on left side
Anatomic relationships
Anteriorly: sternohyoid and sternothyroid muscles jugular vein
Anterolaterally: infra-hyoid muscles sternocleidomastoid
Posterolaterally: carotid sheath
Posteromedially: trachea
larynx
esophagus
Innervation
Parasympathetic: external branch superior laryngeal nerve (branch vagus n.)
Sympathetic