HEAD AND NECK OF THE HORSE 



73 



the ventral ramus of the first cervical nerve, the internal carotid and 

 occipital arteries, and the ventral cerebral and occipital veins occupy a 

 fold on the posterior dorsal part of the diverticulum. 



The auditory tube runs along the dorsal wall of the diverticulum, 

 and there is no difficulty in recognising the slit through which the 

 diverticulum protrudes. 



M. splenius. 

 M. semispinalis capitis. 



M. obliquus capitis 



cranialis.^ — 



A. spinalis ventralis. 

 V. cerebri inferior. 



N. accessorius. 



Cranial cervical 



ganglion. 



N. vagus. 



M. longus cajntis.. 



Diverticulum of 

 Eustachian tube. 



Pharyr 



M. sternocephalicus. — 



M. jugulomandibularis. 



Arytenoid cartilage. 



Thyroid cartilage. — 



Ligamentum nuchas. 



M. rectus capitis dorsalis major. 

 M. rectus capitis dorsalis minor. 



N. accessorius (spinal root). 

 Dura mater. 



Occipital condyle. 



-- Spinal cord. 



Ligg. alaria. 



M. obliquus capitis 



caudalis. 

 M. rectus capitis 



lateralis. 

 A. occipitalis. 

 M. rectus capitis 



ventralis. 

 M. longus colli. 

 A. cartjtis interna. 



_Pariitid gland. 



_V. maxillaris interna. 



A. carotis externa. 



Lymph glands. 



Submaxillary gland. 



- Mm. vocalis et ventricularis. 



V. maxillaris externa. 

 Mm. sternohvoideus et omohyoideus. 



Fig. 23. — Transverse section of the occipital region at the level indicated 

 by B in Fig, 1 (looking forward). 



Tuba auditiva.— The auditory tube of Eustachius, some 10 or 

 11 cm. in length, runs along the base of the skull from the middle ear 

 to the dorsal part of the pharynx ; and is adherent to the fibrous sheet 

 that closes the irregular opening between the occipital and temporal 

 bones, the temporal wing of the sphenoid bone and the pterygoid bone. 

 For a short distance at the tympanic end, the tube is provided with a 

 complete bony wall (pars ossea), and this extremity of the tube opens 



