Kinesiology 3222A/B Lecture Notes - Lecture 7: Inferior Thyroid Artery, Superior Thyroid Artery, External Carotid Artery
30 Jan 2020
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Document Summary
Largest pure endocrine gland: butterfly-shaped gland in the anterior neck, 2 lateral lobes, connected via isthmus. Isthmus at tracheal rings 2-3: spans c5-t1 vertebrae, blood supply, highly vascular, superior thyroid artery (from external carotid artery) Inferior thyroid artery (from thyrocervical trunk of subclavian artery) Thyroid hormones: thyroid hormone, from fluid filled follicles, triiodothyronine (t3, thyroxine (t4, calcitonin, from parafollicular cells located between follicles. Thyroid hormone: t3 and t4, tyrosin and iodine. Increase body"s heat production: trh and tsh released to stimulate process, tsh enters follicles, th synthesis starts, basal metabolic rate increases as t3/t4 released into bloodstream, rising t3/t4 levels feedback to hypothalamus and pituitary. Calcitonin: released by para follicular cells, decreases blood ca2+ levels. Inhibits ca2+ absorption in intestines and kidney: promotes deposition of ca2+ into bones (inhibits osteoclast activity, produced in response to increases in blood ca2+ levels.
