296 LABORATORY MANUAL OF HUMAN ANATOMY 



(c) Palatine nerves (Nn. palatini), from the N. trigeminus through the 

 ganglion sphenopalatinum. 



(ca) Middle palatine nerve (N. palatinus medius) (0. T. exter- 



nal palatine). 



(cb) Posterior palatine nerve (TV. palatinus posterior}. 



Palatine Tonsils (Tonsillae palatinae). (Vide Spalteholz, Figs. 545- 



548.) 



Observe the exact situation of the palatine tonsil on each side. 

 How is it related to neighboring structures? What especial 

 danger might be run in lancing a peritonsillar abscess ! 



(a) Tonsillar crypts or fossulae (fossulae tonsillares). Are any of them 



filled with yellowish- white plugs? 



(b) Tonsillar sinus (sinus tonsillaris). Is it completely filled by the 



tonsil or is there a fossa supratonsillarisf Note the plica triangu- 

 laris. 



How is the tonsil supplied with blood? How is the tonsil 

 related to the cervical lymph-glands? 



Auditory or Eustachian Tube (Tuba auditiva [Eustachii]). 



Of its two parts, one is lateral and bony (pars ossea tubae 

 auditivae), the other medial and cartilaginous (pars cartilaginea 

 tubae auditivae). The cartilaginous part is now studied. Its 

 pharyngeal opening (ostium pharyngeum tubae auditivae) has 

 already been examined. Pass a bristle or probe into it and ascer- 

 tain the direction of the tuba auditiva. What is the position of 

 the tuba as regards the M. levator veli palatini and the M. tensor 

 veli palatini ? 



Dissect the mucous membrane cautiously away around the 

 pharyngeal opening of the tube and examine the constitution of 

 the cartilaginous portion. 



The cartilage of the Eustachian tube (cartilago tubae audi- 

 tivae) consists of two laminae, one medial (lamina cartilaginis 

 medialis) and one lateral (lamina cartilaginis lateralis). (Cf. 

 Spalteholz, Fig. 552.) Where cartilage is lacking, a strong mem- 

 branous layer (lamina membranacea) takes its place. Open the 

 tuba auditiva and examine the mucous membrane (tunica mu- 

 cosa). Are there any glands (glandulae mucosae) or solitary 

 lymph-nodules (noduli lympJiatici tubarii) visible! Observe the 

 trumpet-shape of the canal. 



From which of the inner branchial pockets of the embryo do 

 the Eustachian tube and cavity of the middle ear arise? 



