136 LABORATORY MANUAL OF HUMAN ANATOMY 



ness at different levels. The deep fascia may next be removed. 

 Follow the rule already given for removal of fascia. Avoid the 

 nervus cutaneus femoris posterior in the median line. 



Muscles of Back of Thigh. 



Note carefully the form, position, origin, insertion, action, 

 and nerve supply of each of the following : 



(a) Biceps muscle of thigh (M. biceps femoris). 



(aa) Long head (caput longum). 



(ab) Short head (caput breve). 



(b) Semitendinosus muscle (M. semitendinosus) . 



(c) Semimembranosus muscle (M. semimembranosus). 



What do you understand by the hamstring muscles ? 



Nerves of Back of Thigh. 



(a) Posterior cutaneous nerve of thigh (N. cutaneus femoris posterior) 



(0. T. small sciatic). This nerve will be found directly underneath 

 the deep fascia in the median line of the thigh. 



(b) Great sciatic nerve (N. ischiadicus] . Note the level at which this 



nerve divides into the N. tibialis and the N. peronaeus communis. 

 What are the muscular branches (rami musculares) of the nerve 

 and to what muscles are they distributed'? What is the relation of 

 the N. peronaeus communis to the biceps muscle? Is there a 

 triangle formed by the hamstring muscles in which you can readily 

 find the N. ischiadicus? 



Blood-vessels and Lymphatics of Back of Thigh. 



The following arteries and accompanying veins will be seen 

 piercing the large muscle inserted into the linea aspera. What 

 muscle is this ? 



Arteries. 



(a) First perforating artery (A. perforans prima). 



(b) Second perforating artery (A. perforans secunda). 



(c) Third perforating artery (A. perforans tertia). 



Determine from which of these arteries the superior nutrient 

 artery of the femur (A. nutricia femoris superior) and the infe- 

 rior nutrient artery of the femur (A. nutricia femoris inferior) 

 are derived. Clean each artery and trace it back to the muscle 

 which it pierces. Dissect out the fibrous passage-way through 

 which each artery passes. Note that these openings are in the 

 same line with and exactly analogous to the one through which 

 the terminal portion of the deep femoral artery (A. prof undo, 

 femoris) passes to the back of the thigh. The terminal part of 

 this artery is sometimes called the " fourth perforating artery." 

 What is the purpose of these fibrous arches ? 



