TBANSECTION OF THE THORAX. 



397 



Gng. thyr., Ganglion thyroideum — The thyroid or middle cervical ganglion of the 

 sympathic (Fig. 107, 108, § 1043). 



Gng. vrt., Ganglion vertebrale — The vertebral or inferior cervical ganglion of the 

 sympathic (Fig. 107, 108, § 1043). 



Myelon — The myelon or spinal cord, is the part of the central nervous system situated 

 within the neural canal (Pig. 104, § 479). 



MM. Ig. colli — The longus colli muscles. 



N. thr. (ist) — The first thoracic or dorsal nerve. Th? abbreviation is written on the 

 ventral primary division. Centrad of the abbreviation, the dorsal primary division is seen 



vrt. 



WVV.V. braph.. 



Pig. 109.— Transection op the Thorax, showing the Oeigin ov a Paie op Spinal 

 Nerves and the Relations op the Sympathic and Cekebbo-spinal Systems ; 

 Cephalic View ; x 1.5. 



to join the ventral, and the trunk is formed by the union of the dorsal and ventral nerve 

 roots from the myelon (§ 1007). 



N. thr. (2d), N. thoracicus (2d)— The second thoracic nerve, showing the ramvs com- 

 munieans connecting it with the vertebral ganglion. 



N. sym. (cd.) i, N. sympathicus (caudalis)— The sympathic nerve extending caudad 

 of the vertebral ganglion in the thorax (Pig. 107, § 1042). 



Ramus communicans 2— The communicating branch between the vertebral ganglion 

 of the sympathic and the 2d thoracic myelonal nerve. 



