POSTERIOR PART OF LOWER EXTREMITY. 



3 6 7 



Why this relation of artery and vein ? 



The rule is : Veins are behind their arteries below the diaphragm, and in 

 front of them above the diaphragm where they are not on the same plane. 

 Exception to rule : the renal vessels. 



What can yon say about the internal popliteal nerve ? (Fig. 266.) 



It begins at the bifurcation of the great sciatic, and ends at the lower border 

 of the popliteal space, where its continuation through the leg is called posterior 

 tibial. In its course it throws off these branches : 



i. The communicans tibialis or communicans poplitei. 



LAST 

 THORACIC 

 ILIO-HYPO- 

 GASTRIC 



EXTERNAL 



CUTANEOUS 



EXTERNAL 

 CUTANEOUS 



COMMUNI- 

 CANS 

 FIBULARIS 



SHORT 

 SA PHENOL'S 



POSTERIOR 

 BRANCHES 

 OF LUMBAR 

 NERVES 



POSTERIOR 

 BRANCHES 

 OF SACRAL 

 NER VES 



PERFORATING 

 CUTANSOU8OF 



SECOND AND 

 THIRD SACRAL 



LONS 

 PUDENDAL 



BRANCHES OF 

 SMALL 

 SCIATIC 



OBTURATOR 



POSTERIOR 

 BRANCH OF 

 INTERNAL 

 CUTANEOUS 



CO.VMUNI- 

 CANS 

 TIBIALIS 



TWIGS FROM 

 LONG 

 S A PHENOL'S 



INTERNAL 

 CALCANEAN 



FIG. 255. DISTRIBUTION OF CUTANEOUS NERVES ON THE POSTERIOR ASPECT OF THE 



INFERIOR EXTREMITY. 



2. Three articular branches to the knee-joint. 



3. Muscular branches to the gastrocnemius, soleus, plantaris, popliteus. 

 The articular branches reach the knee-joint how ? 



One goes with the azygos artery, and two accompany the internal articular 

 arteries, superior and inferior. 



Describe the external popliteal nerve. 



It begins at the bifurcation of the great sciatic, is found in the outer side of the 

 popliteal space in the sheath of the biceps muscle. It leaves the space between 

 the biceps and the outer head of the gastrocnemius muscle. It crosses the neck 

 of the fibula, having passed behind the head of this bone, and terminates in the 

 anterior tibial and musculo-cutaneous nerves. In its course it gives off these 



