Identifying Bones of the Skull - Anatomy

While many bones are responsible for the formation of the orbit, it is the zygomatic bones that make up the lateral portion of the orbitals. You can remember this by keeping in mind that the zygomatic bones are also called the cheek bones, and are on the lateral sides of your face.

The frontal bone forms the superior region of the orbital, and the lacrimal bone forms the medial border. The maxillary and zygomatic bones each form part of the inferior border, with the zygomatic bone extending into the lateral border. The sphenoid and ethmoid bones both form the posterior wall, with the sphenoid region lateral to the ethmoid region.

There are four paranasal sinuses in the head: the frontal, maxillary, sphenoid, and ethmoid sinuses. They function in lightening the skull, and creating mucous for the nasal cavity. The temporal bone does not contain a sinus.

The parietal bones of the skull reside over the parietal lobes of the brain. The parietal lobe is just on top of the occipital lobe and is responsible for various sensory information processing. The parietal bones of the skull lie on either side of the head, slightly posterior to the ear area, and meet on top of the head.

The coronal suture is the area at the "top" of the skull where the parietal bones and the frontal bones meet, and is not normally closed at birth (thus, the traditional "soft spot" near the exact top of a newborn's head).

Remember that the coronal plane traverses the body from left to right, separating the anterior and posterior dimensions. As such, the coronal suture can be expected to fall within this plane.

The parietal bones (one on each side of the skull) form a shield-shaped dome across the top of the skull, creating most of the bulging sides and top of the cranium. The parietal bones are useful in distinguishing the skulls of modern man from Australopithecine ancestors. The bone has a large opening, the parietal foramen, through which blood supply and nerves enter.

The occipital bone forms the base of the skull, and contains the opening (foramen magnum) through which the thick nerve fibers that will form the spinal cord emerge. It houses the occipital lobe of the cerebrum, which is responsible for visual processing and holds the visual cortex.

The temporal bones (one on each side) form the mandibular fossae, which join the mandible to stabilize the jaw. The bone also forms part of the prominence of the cheek, the meatus for neck and tongue muscles, and contains the gap through which the ear is formed.

The frontal bone forms the "forehead" and anterior part of the superior skull. It contains the roof of the nasal cavity, the roof of the orbital sockets, and in some skeletons shows a bony notch or supraforamen.

The sphenoid bone, located posterior and inferior to the face, supports most of the immovable bones of the face and is thus critical to the development of facial structure. The bone also contains two "wing" projections that curve towards the sides of the skull, which may help to stabilize the cranium during lateral impacts, and the sella turcica, a concave space that houses the pituitary gland.

The lambdoid suture is located at the junction of the parietal and occipital bones. It lies just inferior the parietal bones and superior the occipital bone. It is located on the posterior or "back" of the skull.

The sphenoid bone contains important openings through which specific nerves pass, including foramen rotundum, foramen spinosum, and foramen ovale.

The hard palate is comprised of the maxillary and palatine bones. The anterior two-thirds is the palatine process of the maxillary bone, while the posterior one third is the horizontal plate of the palatine bone

All answer choices are found on the ethmoid bone, except for the mastoid process, which is found on the temporal bone.

The squamosal suture is located where the parietal and temporal bones meet on the lateral side of the skull.

The neurocranium is the part of the skull that forms a protective covering around the brain. The other part of the skull is the facial skeleton, which forms the bones of the face. The vomer bone is not part of the neurocranium, rather it forms the inferior part of the nasal septum.

The stapes is "U"-shaped and is the smallest bone in the body located in the outer ear. The stapes, malleus, and incus (collectively known as the ossicles) convey sound to the inner ear. The hyoid is also "U"-shaped, but it is larger and located in the throat not the skull. The mandible is located in the skull and is "U"-shaped, but is massive in comparison to the stapes because the ossicles could all fit on a penny. The maxilla is not "U"-shaped.

The frontal bone if the skull bone that is the most anterior and superior bone of the skull. It is the bone located in the forehead region of the face. The parietal bones are located on each side of the skull, near the ears. The occipital bone is located in the posterior and inferior aspect of the skull. The zygomatic bone is responsible for forming the cheekbones underneath the orbits.

The mandible is the lower jaw bone that forms the chin and jawline. The zygomatic bone forms cheekbones, the nasal bone forms the nose. The ears are formed from cartilage and have no bones in the visible portions.

The sagittal suture is the longest suture in the skull and runs from the frontal bone, between the parietal bones, to the lambdoid suture. The lambdoid suture is the suture that forms between the parietal and occipital bones. There are no major sutures in the facial bones.