314 



ANATOMY FOR NURSES 



[Chap. XVI 



parts by an isthmus. The lobes are broadest below and taper 

 to a point above. Small masses of thyroid tissue are sometimes 

 found along the trachea as far down as the heart. They are called 

 accessory thjrroids. Comparatively little is known about the action 

 of the thyroid secretion, but much clinical evidence supports the 



RIGHT LOBE OF. 

 THYROID BODY 



. PYRAMID OF 

 THYROID BODY 



Fig. 163. — The Thyroid Body axd thk Related Blood-vessels. (Gerrish.) 



belief that it is necessary for the normal growth and functions of 

 almost all the tissues of the body. 



Cretinism is a condition caused by congenital defects of the 

 thyroid or atrophy occurring in early life. The growth of the 

 skeleton ceases and there is complete arrest of mental development. 

 Children so afflicted may live for many years, but at twenty-five 

 or thirty, they have the intelligence of a child of four or five, and 

 present a childish appearance. 



Myxcedema is a disturbed condition of metabolism that follows 

 the removal or atrophy of the gland. The individual so afflicted 

 presents a peculiar appearance, as the subcutaneous connective 

 tissue becomes thickened, so that the face and hands are swollen 



