PHYSIOLOGY FOR BEGINNERS 



The pelvic girdle, thus arching round, makes the lower end 

 of the abdomen basin-shaped, and the cavity so formed is called 

 the pelvic cavity, and the bony walls of the cavity the 

 pelvis. 



The Pectoral Girdle. -The pectoral girdle is an imperfect 

 arch to which the arm bone is articulated. It consists of two 

 bones, the collar bone, or clavicle, and the shoulder bone, 



SLY 



R 



-Coco 



FIG. 15. The pelvis. 



Sac, sacrum ; Cocc, coccyx ; /'/, is, pit, ilium, ischium, pubes, three parts of the 

 innominate or hip bone; act't, acetabulum cup for head of femur; ; L. y, 

 5th lumbar vertebra. 



or scapula. The clavicle is a long narrow bone, about six 

 inches long, passing from the sternum outwards to a promi- 

 nence of the scapula projecting over the shoulder joint. The 

 scapula is placed behind, and is a large, flat triangular 

 bone, with a prominent ridge extending across it at the back 

 outwards to the shoulder. It gives attachment to the large 

 muscles passing to the back of the arm. It articulates with 

 the clavicle at the shoulder and supports the arm, but is other- 

 wise free, not connected to the vertebral column, so that it is 

 very movable. 



