Within the lesson click the red linked headings to bring up the desired starting point within the cadaver for your work. Use the provided images on the worksheet to annotate and identify specific anatomical structures.
Using the highlight tool identify the following bones of the anterior skull.
You are watching: Why can the sphenoid bone be called the keystone of the cranial floor
frontal bone zygomatic bones (right & left) maxilla mandible (note: 9 parts of the mandible are identified. At this point you are only responsible for the single unified bone.) nasal bones (right & left) (note: these are identified as a single bone in your virtual cadaver) ethmoid
At birth, the frontal bone has two parts separated by a frontal suture (immovable joint). This suture generally disappears by the age of six when the frontal bones unite.
Identify the bones and test your identification knowledge with your virtual cadaver. Additionally, you should mark the diagrams in your worksheet. Labeling and highlighting diagrams is VERY helpful when learning anatomy.
Again, using the highlight tool identify the following bones of the lateral skull.
temporal bone (right) frontal bone parietal bone (right) occipital bone (note: 2 parts of the occipital bone are identified. You, however, are only responsible for the single unified bone at this point.) maxilla mandible zygomatic bone (right) sphenoidal bone nasal bone (right)
Using the interactive image, identify the following and record them on your worksheet.
Again, using the interactive image, identify the following parts of the temporal bone.
Dissect away the maxilla, frontal, and nasal bones.
Locate and highlight the ethmoid. Ethmoid means “like a sieve” which is a bit apparent from your dissection. Structurally, the ethmoid forms part of the cranial floor, the medial wall of the orbits (eye sockets), part of the nasal septum, and part of the sidewalls of the nasal cavity.
Using the interactive image, identify each of the following parts of the ethmoid, which are too small to observe in your dissection.
Dissect away the maxilla, the right and left zygomatic bones, the ethmoid, and the nasal bone.
Sphenoid means “wedge shaped” but from the anterior view it looks more like a butterfly. It is frequently referred to as the “keystone of the cranial floor” because it articulates with all the other cranial bones and holds them together. From a superior vantage point, you can really see how it is central in its location and holds the surrounding cranial bones in place.
Using the interactive image, identify each of the following parts of the sphenoid. As with the ethmoid, these structures are not easily viewed in the dissection.
Using the highlight tool identify the following bones of the posterior skull.
occipital bone temporal bones (right & left) parietal bones (right & left) sphenoidal bone
Locate the following with the interactive image. Then locate them on the cadaver, and record them on your worksheet.
Sutures are the immovable joints between skull bones. Names, such as the frontozygomatic or sphenoparietal sutures, clearly reflect the bones they unite. Others, such as the coronal suture, do not.
These sutures are clearly visible in your dissection, but they are not specifically identified. Identify each of the following. Then locate them on your specimen, and record them on your worksheet.
Sutural bones, also called wormian bones, are small bones located within the sutures. The number of sutural bones varies widely between individuals.