H4 THE POCKET ANATOMY 



The deep inguinal glands : surround the femoral vessels 

 (a constant one in the crural canal) . The afferent vessels come 

 from the superficial inguinal glands and the deep lymphatics 

 of the limb ; the efferent vessels join the external iliac glands. 



THE SPINAL CORD. 



The spinal cord is the part of the cerebro-spinal axis whick 

 occupies the spinal canal. In the adult it occupies about 

 of the length, but in the foetus, before the third month, it 

 extends the whole length of the canal. 



Extent. The spinal cord extends from the lower border of 

 the foramen magnum, where it is continuous with the medulla 

 oblongata above, to the lower border of the ist lumbar ver- 

 tebra, there terminating in a slender filament, the filum 

 terminal*. 



Contents of the Neural Canal. 



Venus plexus between bone and dura mater. 



( dura mater. 

 Membranes < arachnoid. 



( pia mater, with ligamenta denticulata. 

 Cerebro-spinal fluid. 



So'nal essels i anterior s P inal artery and vein. 



\ two posterior spinal arteries and veins. 

 Spinal cord, with anterior and posterior roots of nerves. 



Shape. In transverse section, nearly round, except at the 

 enlargements, where it is more elliptical. 



Enlargements. Presents two enlargements. The upper or 

 cervical extends from the upper limit of the cord downwards 

 to the ist or 2nd dorsal vertebra. 



The lower or lumbar commences opposite the loth dorsal 

 vertebra; is largest at the 1 2th dorsal, and thence tapers, 

 forming the conns medullaris, from the tip of which the filum 

 terminate descends. 



The filum terminale (central ligament of the cord) : passes 

 from the end of the conus medullaris downwards in the middle 

 of the cauda equina ; becomes closely invested with dura 

 mater opposite the ist or 2nd sacral vertebra, and blends 

 with the periosteum at the lower end of the sacral canal. 



It is a process of pia mater, containing in its upper half the 

 continuation of the central canal of the cord, together with a 

 little grey matter for a short distance. The lower half con- 

 sists of connective-tissue, bloodvessels and medullated nerve- 



