52 ELEMENTS OF MAMMALIAN ANATOMY 



muscle; (2) the angle which is the caiuloventral termination 

 of the bone; (3) the inferior notch immecHately dorsal of the 

 angle; (4) the condyle for the articulation with the glenoid 

 cavity of the temporal; (5) the superior notch dorsal of the 

 condyle; (6) the coronoid process, which is the dorsal termina- 

 tion of the ascending ramus and gives insertion to the tem- 

 poral muscle. 



THE HYOID BONES OR HYOID APPARATUS 



The hyoid bones consist of two jointed rods, one on either 

 side (Figs. 21 and 22), hanging from the temporal bone, and 

 supporting the larynx. Each rod is composed of six parts: 

 the epihyal; the ceratohyal; the tympanohyal; the basihyal; and 

 the thyrohyal. The dorsal end of the thyrohyal is prolonged 

 by a piece of cartilage, the chondrohyal. 



The hyoid apparatus varies greatly among mammals. In 

 man it consists of a single bone composed of the body or 

 basihyal, two small cornua representing the ceratohyals, and 

 two large cornua representing the thyrohyals. The bone is 

 suspended from the skull by ligaments corresponding to the 

 bony chain in the cat. 



LABORATORY STUDIES AND SUGGESTIONS 



1. How many more bones are present in the cat than in man? 



2. In what two parts of the skeleton does the number of bones in the cat 

 exceed those in man? 



3. What is a sesamoid bone? 



4. Find on a specimen a sesamoid bone and describe it. 



5. Draw a lateral aspect of the skull and label all parts. 



6. What are the paired bones of the cranium? 



7. Name the single bones of the face. 



8. Draw the caudal aspect of the skull and label all parts. 



9. Which bones of the skull derive their names from their location? 



10. Which bones of the skull are pierced by more than two foramina? 



11. Write a description of the orbital cavity. 



12. Which foramina of the skull derive their names from their shape or size? 



13. Which foramina derive their names from their location? 



14. Which foramina transmit important blood-vessels? 



15. Draw figures representing relative shapes and sizes of all foramina of the 

 skull. 



