, THIGH AND LEG. 329 



Anatomical transition is never abrupt, but gradual. Compact bone-tissue 

 gradually merges into cancellous ; muscle gradually becomes tendinous ; at 

 muco-cutaneous areas skin and mucous membrane gradually partake of the 

 nature of each other. The transition from extension of the leg to adduction of 

 the thigh would be abrupt. This is moderated by the sartorius muscle, which, 

 in consequence of its dual function, has a double nerve-supply and an indepen- 

 dent fascial sheath. The adductor magnus moderates between flexion and 

 adduction ; hence its dual nerve-supply. 



The Femur (Figs. 227 and 228). Name the points of the femur of impor- 

 tance in practical anatomy. 



The head articulates with the acetabulum. 



The neck joins the head of the bone to the shaft. 



The greater trochanter facilitates axial rotation. 



The lesser trochanter facilitates axial rotation. 



The tereal depression is for the ligamentum teres. 



The digital or trochanteric fossa is for the obturator externus. 



The intertrochanteric lines are anterior and posterior. 



The oblique line of the greater trochanter is for the gluteus medius. 



The anterior intertrochanteric line is for the capsule. 



The tip of the greater trochanter is for the gemelli, pyriformis, obturator ex- 

 ternus. 



The condyles articulate with the tibia and patella. 



The condylar ridges limit laterally the popliteal surface. 



The intercondylar notch lodges the crucial ligaments. 



The patellar facet articulates with the patella. 



The adductor tubercle is for the adductor magnus tendon. 



How and ivJicrc are (lie glntcal muscles inserted / 



They are inserted principally by tendon as follows : The gluteus maximus 

 into the gluteal ridge ; the gluteus medius into the oblique line of the greater 

 trochanter ; the gluteus minimus in the anterior border of the greater tro- 

 chanter. 



What is the third trochanter / 



A name given to the gluteal ridge when this is unusually prominent. Growth 

 is the correlative of function ; where extraordinary function is imposed on any 

 group of muscles, or on any single muscle of a group, the bony insertion point 

 of the muscle will be correspondingly increased in size. Trochanter means a 

 bony eminence for muscular attachment, situated favorably for axial rotation of 

 the limb ; hence the name, third trochanter. 



Describe the line a asp era. 



This may be compared to a tree with (i) a trunk, (2) definite roots, (3) definite 

 branches above. Now, when we speak in general terms of a tree, we have in 

 mind the trunk ; when we speak specifically of this object as a shade-tree, we have 

 in mind the branches ; when we speak specifically of its attachments to the earth, 

 we have in mind the roots of the tree. The linea aspera has a trunk which is in 

 the middle one-third of the femur ; branches which ramify definitely in the upper 

 one-third of the femur; roots which are definitely disposed in the lower one- 

 third of the femur. 



Describe the trunk of the linea aspera. 



It is composed of three lips or ridges, produced by muscular traction ; these 

 lips are called outer, middle, inner. This part of the linea aspera occupies the 

 middle one-third of the shaft of the femur, and forms the posterior border of the 

 same. 



How is the root of the linea aspera disposed f 



The outer lip is continued downward and outward to the condyle of the 



