184 



THE SKELETON. 



OBTURATOR INTCRNUS 



and QEMELLI. 



PYRIFORMIS. 



Depression for 



. LIGAMENTUN TEHES. 



Sua-CRUREUS. 



FIG. 12G. Right femur. Anterior surface. 



The Upper Extremity presents 

 for examination a head, a neck, 

 and a great and lesser trochan- 

 ters. 



The head, which is globular, 

 and forms rather more than a 

 hemisphere, is directed upward, 

 inward, and a little forward, the greater part 

 of its convexity being above and in front. Its 

 surface is smooth, coated with cartilage in the 

 recent state, except at a little behind and below 

 its centre, where is an ovoid depression, for the 

 attachment for the ligamentum teres. The neck 

 is a flattened pyramidal process of bone which 

 connects the head with the shaft. It varies in 

 length and obliquity at various periods of life 

 and under different circumstances. The angle 

 is widest in infancy, and becomes lessened 

 during growth, so that at puberty it forms a 

 gentle curve from the axis of the shaft. In 

 the adult it forms an angle of about 130 with 

 the shaft, but varies in inverse proportion to 

 the development of the pelvis and the stature. 

 In consequence of the prominence of the hips 

 and widening of the pelvis in the female, the 

 neck of the thigh-bone forms more nearly a 

 right angle with the shaft than it does in man. 

 It has been stated that the angle diminishes in 

 old age and the direction of the neck becomes 

 horizontal, but this statement is founded on 

 insufficient evidence. Sir George Humphry 

 states that the angle decreases during the 

 period of growth, but after i'ull growth has been 

 attained it does not usually undergo any change, 

 even in old age. He further states that the 

 angle varies considerably in different persons 

 of the same age. It is smaller in short than in 

 long bones, and when the pelvis is wide. 1 The 

 neck is flattened from before backward, con- 

 tracted in the middle, and broader at its outer 

 extremity, where it is connected with the shaft, 

 than at its summit, where it is attached to the 

 head. The vertical diameter of the outer half 

 is increased by the thickening of the lower edge, 

 which slopes downward to join the shaft at the 

 lesser trochanter, so that the outer half of the 

 neck is flattened from before backward, and its 

 vertical diameter measures one-third more than 

 the antero-posterior. The inner half is smaller 

 and of a more circular shape. The anterior 

 surface of the neck is perforated by numerous 

 vascular foramina. The posterior surface is 

 smooth, and is broader and more concave than 

 the anterior; it gives attachment to the pos- 

 terior part of the capsular ligament of the 

 hip-joint, about half an inch above the posterior 

 1 Journal of Anatomy and Physiology. 



