Skull Anatomy Flashcards
The frontal bone forms the forehead and the superior portion of the orbits (eye sockets). It is located at the anterior portion of the cranium and contains the supraorbital foramen which allows passage for the supraorbital nerve and vessels.
What is the frontal bone and where is it located?
The frontal bone forms the forehead and the superior portion of the orbits (eye sockets). It is located at the anterior portion of the cranium and contains the supraorbital foramen which allows passage for the supraorbital nerve and vessels.
What are the two parietal bones and what sutures connect them?
The parietal bones form the superior and lateral aspects of the cranium (the roof and sides of the skull). They are connected to each other at the sagittal suture, to the frontal bone at the coronal suture, and to the occipital bone at the lambdoid suture.
Describe the occipital bone and its important structures.
The occipital bone forms the posterior base of the cranium. It contains the foramen magnum, which allows passage for the spinal cord. It also has occipital condyles which articulate with the atlas (C1 vertebra), and the external occipital protuberance, a bony prominence at the back of the skull.
What is the sphenoid bone and why is it considered the “keystone” of the cranium?
The sphenoid bone is located at the base of the skull and is considered the “keystone” because it articulates with all other cranial bones, holding them together. It has a butterfly shape with greater and lesser wings, and contains important structures like the sella turcica (housing the pituitary gland), optic canal, and multiple foramina.
Describe the temporal bone and list three important structures it contains.
The temporal bone forms the lateral sides of the skull and houses the structures of the ear. Three important structures it contains are:
External auditory meatus (ear canal)
Mastoid process (attachment site for neck muscles)
Mandibular fossa (articulation point for the mandible)
It also contains the petrous portion which houses the inner ear structures.
What is the ethmoid bone and what are its key features?
The ethmoid bone is located between the eyes and forms part of the nasal cavity and orbits. Key features include:
Cribriform plate (with numerous foramina for olfactory nerve fibers)
Crista galli (attachment point for the falx cerebri of the dura mater)
Perpendicular plate (forms part of the nasal septum)
Middle and superior nasal conchae (turbinates)
Describe the maxilla and its functions.
The maxilla forms the upper jaw and supports the upper teeth. It contributes to the formation of the hard palate, nasal cavity, and orbit. Important features include:
Alveolar process (houses the upper teeth)
Palatine process (forms anterior portion of hard palate)
Infraorbital foramen (passage for infraorbital nerve and vessels)
Maxillary sinus (largest paranasal sinus)
What is the mandible and what are its key anatomical features?
The mandible is the lower jaw bone and is the only movable bone of the skull. Key features include:
Body (horizontal portion containing teeth)
Ramus (vertical portion)
Condylar process (articulates with temporal bone)
Coronoid process (attachment for temporalis muscle)
Mental foramen (passage for mental nerve and vessels)
Mandibular foramen (entry point for inferior alveolar nerve)
Angle (junction between body and ramus)
What is the function of sutures in the skull and name the three major cranial sutures.
Sutures are fibrous joints between the bones of the skull. They allow slight movement in the infant skull to facilitate birth and brain growth, but become increasingly rigid in adulthood. The three major cranial sutures are:
Coronal suture (between frontal and parietal bones)
Sagittal suture (between the two parietal bones)
Lambdoid suture (between parietal and occipital bones)
What are the zygomatic bones and what is their function?
The zygomatic bones form the prominence of the cheeks and part of the lateral orbital wall. They articulate with the frontal, maxillary, temporal, and sphenoid bones. The zygomatic arch (formed by the temporal process of the zygomatic bone and the zygomatic process of the temporal bone) provides attachment for the masseter muscle, important for chewing.
