AND PHYSIOLOGY. 



55 



126. Hyoid Bone. — The 

 Hyoid Bone is the bone which 

 forms the base of the tongue, 

 and the upper extremity of 

 the trachea. It has the 

 shape of the Greek letter U 

 (or Upsilon) and articulates 

 with no other bones, but is 

 completely enveloped by the 

 soft parts. It has a consi- 

 derable range of motion in a 



vertical direction, and hence gives attachment to no less 

 than eleven pairs of muscles. 



127. Sternum, — The Breast Bone is flat, about eight 

 inches in length, one and a half in width, and is located on 

 the median line of the body upon the front portion of the tho- 

 rax or chest, articulating with the seven upper ribs on both 

 sides, and also with the clavicle. 



128. Ribs. — There are twenty-four ribs in the human 



An Anterior View of the Os Hyoides, 



1, The Anterior Convex Side oi the Body. 



2, The Cornu Majus of the Left Side. S. 

 The Cornu Minus of the same Side. Th* 

 Cornua were ossified to the Body of th*i 

 Bone, in this specimen. 



Fig. 68. 



Fig. 69. 



A View of the Upper Side of the First 

 Eib of the Right Side, half the size of na- 

 ture. 1, The Head. 2. The Tubercle. 3, 

 Anterior Surface. 4, Groove for the Sub- 

 clavian Artery. 5, Groove for the Sub- 

 clavian Vein. 6, Anterior Extremity for 

 A Front View of the Sternum. 1, First the Cartilage. 7, Tubercle for the Scalenus 

 Piece. 2, Second Piece. 3, Ensiform Car- Anticus Muscle, 

 tilagc, or Third Piece. 4, Articular Face 



for the Clavicle. 5, Articular Face for the First Rib. 6, Articular Face for the Second 

 Eibf 7, 8, 9, 10, Articular Faces for the Last Five True Ribs. 



126. Where is the Hyoid Bone? What Greek letter does it resemble ? 127. Describe 

 the Sternum. With what bones does it articulate ? 12S. Number of Ribs in man ? 



