These videos have been excerpted from Netter’s Video Dissection Modules on Student Consult. 
[ Ссылка ]

Step 1
Many features of the ear can be studied on the temporal bones of adults and newborns. In the adult temporal bone, note the three basic parts: the squamous portion, the petrous portion, mainly seen intracranially, and the tympanic portion, which is a C-shaped ring of bone that supports the tympanic membrane and forms the bony part of the external acoustic meatus. In the adult, the petrotympanic fissure, seen in the mandibular fossa, marks the junction between the tympanic and petrous portions. The mastoid process is also a prominent feature of the temporal bone.
Key Terms
• Temporal bone: the bone that occupies the temporal region of the skull. It is formed from three components: 1) a scale-like (squamous) part that forms a portion of the lateral wall of the cranial vault N6; 2) a tympanic part that forms a ring-like support for the tympanic membrane and forms the bony part of the external acoustic meatus; and 3) a petrous portion that forms a ridge between the middle and posterior cranial fossae. The petrous portion develops around the osseous labyrinth of the inner ear and around the internal carotid artery to form the carotid canal. It also forms the facial canal around the facial nerve and around parts of the middle ear to contribute to the walls of the tympanic cavity. Other important parts of the temporal bone are the styloid process and mastoid process.
• Squamous portion of the temporal bone: a scale-like (squamous) part that forms a portion of the lateral wall of the cranial vault N6.
• Tympanic portion of temporal bone: a C-shaped element that lies over the outer surface of the middle ear in the skull of an infant N14. It has a grooved internal surface where the rim of the pars tensa (annulus fibrosis) of the tympanic membrane attaches. In the skull of an adult, the tympanic bone is fused to the other components of the temporal bone, and a lateral extension of the bone forms the bony part of the external acoustic meatus N6.
• Petrous portion of temporal bone: the hard, rock-like (petrous) bone that surrounds most of the otic capsule (bony labyrinth); it is also called the periotic bone N85. In the skull of an infant, the petrous bone is not fused with the tympanic and squamous components N14; in adults, these three components are indistinguishably fused to form the temporal bone N6. Parts of the petrous bone not only surround the inner ear N92, but also part of the middle ear, the auditory tube and the internal carotid artery. Parts of the petrous bone include the mastoid process, the petrous ridge, and the tegmen tympani. During development the mastoid process becomes pneumatized N6, and the air cells may extend throughout much of the petrous bone.
• Petrotympanic fissure: a fissure in the mandibular fossa that lies between the petrous and tympanic portions of the temporal bone N13. It opens into the anterior part of the middle ear cavity and transmits the chorda tympani nerve, the anterior malleolar ligament, and the anterior tympanic artery.


ABOUT:
The project was made possible by several very dedicated faculty and staff at University of North Carolina, Chapel Hill--especially O.W. Henson and Noelle A. Granger--and partner schools, and by a grant from the Fund for the Improvement of Post-Secondary Education of the US Department of Education. This channel includes over 400 short videos highlighting the steps in a full-body human dissection in the gross anatomy lab. Each step is narrated and key structures labeled.

свернуть