260 LABORATORY MANUAL OF HUMAN ANATOMY 



Cut the auricle off close to the skull ; macerate the cartilages 

 and scrape clean. 



Study the following: 



(a) Isthmus of cartilage of ear (isthmus cartilaginis auris). 



(b) Terminal notch of ear (incisura terminates auris). 



(c) Antitragohelicine fissure (fissura antitragohelicina). 



(d) Transverse anthelicine groove (sulcus anthelicis trans versus). 



(e) Groove of sulcus of crus (sulcus cruris helicis). 



TEMPORAL REGION AND RETROMANDIBULAR 



FOSSA. 



Clean away the superficial fascia and expose the deep fascia 

 above the zygomatic process. Preserve the arteries, veins, and 

 nerves on its surface, and watch especially for blood-vessels and 

 nerves perforating the fascia. 



Temporal Fascia. 



The temporal fascia (fascia temporalis) should now be 

 studied. What are its attachments? Demonstrate the two lay- 

 ers below. What structures perforate the fascia? Trace the 

 peripheral distribution of the following : 



(a) Zygomaticotemporal ramus of facial nerve (ramus zygomaticotem- 



poralis N. facialis) (0. T. temporal branch of temporomalar). 



(b) Temporal rami of facial nerve (rami temporales N. facialis). 



(c) Zygomaticofacial ramus of zygomatic nerve (ramus zygomaticofa- 



cialis N. zygomatici). 



Follow the middle temporal artery (A. temporalis media] 

 from its origin from the A. temporalis superficialis to the point 

 where it pierces the fascia. 



Masseter Muscle. 



The masseter muscle (M. masseter) may now be dissected 

 out. Divide the N. facialis below the ear and throw it forward. 

 If the other structures superficial to the M. masseter impede the 

 dissection, they may also be reflected. Study the form, position, 

 origin, and insertion of the muscle. Cut through the fascia tem- 

 poralis just above the processus zygomaticus and reflect it 

 upward, saving the vessels and nerves which pass through it. 

 Cut through the bony arch of the zygoma in front of and behind 

 tlie^ origin of the M. masseter. The anterior saw-cut must be 

 obliquely made. Throw the bony arch with the M. masseter 



