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Thyroid Gland: Structure

ENDOCRINE PHYSIOLOGY

Hyoid bonę

Lymph node Phrenic nerve

Superior vena cava

Superior laryngeal nervc Thyrohyoid membranę Thyroid cartilage

Pyramidal 1

lobe

Leftlobe ^T!'V^,°^id I gland

Right lobe Isthmus J

bcternal carotid Superior thyroid Superior thyroid vein Common carotid artery Internal jugular Cricoid cartilage Middle thyroid vein Interior thyroid Interior thyroid artery Vagus

Brachiocephalic tinnominate) vcins and artery

Figurę 8.8 Thyroid Gland Structure_

The thyroid gland is a ducriess endocrine gland that weighs about 20 grams and consists of a right and lett lobe joined by an isthmus. In 15% ot thc population. there is a smali pyramidal lobe extending cra-nially, as in this figurę. Ihe gland lies anterior to the trachea and just interior to the cricoid cartilage. As with all endocrine glands. the thy roid has a rich yascular supply and venous drainage.

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