LOWER EXTREMITY. 



BONES. 



The os innominatum is described with the abdomen and 

 pelvis (see page 184). [214] 



Femur. The upper extremity comprises the head, neck, and 

 trochanters. The head is hemispherical, and directed up- 

 ward, inward, and slightly forward; its circumference is an ir- 

 regular lip, most prominent above and behind; just below its 

 summit is an oval pit for the ligamentum teres. The neck is 

 compressed, thickest vertically, and directed upward, inward, 

 and slightly forward; it expands internally to support the 

 head, and externally, in its vertical diameter, to join the upper 

 end of the shaft at an angle of 125. Anteriorly a ridge (an- 

 terior intertrochanteric line), running downward and inward 

 from a prominence (tubercle of the femur) , separates it from the 

 shaft. Posteriorly another ridge (posterior intertrochanteric 

 line) connecting the trochanters, separates it from the shaft; 

 above the middle of this ridge is a fulness (quadrate tubercle) . 

 On its upper part, under the trochanter major, is a fossa 

 (digital) from which a groove runs across the back of the 

 neck. [224] 



The trochanter major is quadrilateral and caps the upper and 

 outer part of the shaft; an oblique line connecting the postero- 

 superior and anterior inferior angles bisects its outer surface; a 

 horizontal ridge bounds it below. Its anterior surface is ob- 

 long and bounded in front by an oblique line ascending to the 

 tubercle. Its superior border is curved and joins the thick 

 posterior border (upper part of posterior intertrochanteric 

 line) in a prominent angle. The trochanter minor is a pyram- 



[250] 



