. Anatomy, descriptive and surgical. functionis unknown, but from its situation in connec-tion with the trachea and larynx the thyroidbody is usually described with those organs,although it takes no part in the function ofrespiration. It is situated at the upper partof the trachea, and consists of two laterallobes placed one on each side of that tubeand connected together by a narrow trans-verse portion, the isthmus. Its anterior surface is convex, and cov-ered by the Sterno-hyoid, Sterno-thyroid,and Omo-hyoid muscles. Its lateral surfaces, also convex, lie incontact with the sheath of the com
. Anatomy, descriptive and surgical. functionis unknown, but from its situation in connec-tion with the trachea and larynx the thyroidbody is usually described with those organs,although it takes no part in the function ofrespiration. It is situated at the upper partof the trachea, and consists of two laterallobes placed one on each side of that tubeand connected together by a narrow trans-verse portion, the isthmus. Its anterior surface is convex, and cov-ered by the Sterno-hyoid, Sterno-thyroid,and Omo-hyoid muscles. Its lateral surfaces, also convex, lie incontact with the sheath of the commoncarotid artery. Its posterior surface is concave, and em- a braces the trachea and larynx. The pOSte- small glandular vesicles with their cells; b, the .., „. --.^ , r-ii same with incipient colloid metamorphosis, more nor borders 01 the gland extend as lar back strongly marked at c; d, coarse lymph-canals; . .i i , % ,i l e, fine radicles of the same;/, an efferent vessel as the lower part of the pharynx. of considerable 940 ORGANS OF VOICE AND RESPIRATION. The thyroid is of a brownish-red color. Its weight varies from one to two is larger in females than in males, and becomes slightly increased in size duringmenstruation [and after maternity]. It occasionally becomes enormously hypertro-phied, constituting called bronchocele or goitre. Each lobe is somewhatconical in shape, about two inches in length and three-quarters of an inch to an inchand a quarter in breadth, the right lobe being the larger of the two. The isthmus connects the lower third of the two lateral lobes ; it measures abouthalf an inch in breadth and the same in depth, and usually covers the second andthird rings of the trachea. Its situation presents, however, many variations, apoint of importance in the operation of tracheotomy. Sometimes the isthmus isaltogether wanting. A third lobe, of conical shape, called the pyramid, occasionally arises from theupper part of the isthmus
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Keywords: ., boo, bookcentury1800, booksubjectanatomy, booksubjecthumananatomy
