BIOL 171 Lecture Notes - Lecture 30: Inferior Thyroid Artery, Common Carotid Artery, Thyroid
Document Summary
Isthmuses of the thyroid is the central area of the thyroid: one of the largest endocrine glands, secretes hormones into the bloodstream/circulation directly, not ducts, the thyroid is a metabolic organ! Secreted by hypothalamus: when blood is reduced in t3 and t4 tsh is increased! Anatomical positioning: anterior and lateral to trachea, medial of both lobes is the trachea. Lateral borders of the lobes are: common carotid artery & internal jugular vessels. If gland is enlarged: the inferior poles will not be visible because the inferior poles will be underneath the clavicles. Thyroid anatomy: thyroid is more echogenic compared to the muscles! 3 muscles anteriorly: sternocleidomastoid (anterior and lateral & largest!, sternohyoid (at the level of the hyoid bone - most anterior and lateral muscles of both lobes, sternothyroid. 2 muscles posteriorly: longus coli muscle (hypoechoic with striations - echogenic lines) Esophagus: can"t see the lumen, can only see the black structure that moves with peristaltic activity (eating).
