Skull and foramina Flashcards
What are the bones of the calvarium?
Frontal, occipital and two parietal bones
What are the bones of the cranial base?
Composed of six bones - Frontal, sphenoid, ethmoid, occipital, parietal and temporal bones
What are the articulations of the bones of the cranial base?
They provide an articulation point for the 1st cervical vertebra(atlas), as well as the facial bones and the mandible(jaw bone)
How many bones are part of the facial skeleton?
- It consists of 14 individual bones
What do the facial bones fuse to house?
- It houses the orbits of the eyes, nasal and oral cavities, as well as the sinuses
Name the bones of the facial skeleton
Zygomatic, lacrimal, nasal, inferior nasal conchae, palatine, maxilla, vomer and mandible
What does the coronal suture fuse?
Fuses the frontal bone with the two parietal bones
What does the sagittal suture fuse?
Sagittal suture fuses both pareital bones together
What does the lamboid and lambda sutures fuse?
Fuses the occipital bone to the two parietal bones
What does the bregma suture fuse?
Frontal bone and parietal bones
What are the cartilaginous spaces that exist in developing skulls called?
Anterior, posterior, mastoid and sphenoid fontanelles
Where does the mandible articulate
Articulates with the base of the cranium at the temporomandibular joint
Describe location of the vomer
Forms the posterior aspect of the nasal septum
Describe location of the maxilla bones
Comprises part of the upper jaw and hard palate
Describe the location of the palatine bones
Situated at the rear of oral cavity, and forms part of the hard palate
Describe the location of the inferior nasal conchae
Located within the nasal cavity, these bones increase the surface area of the nasal cavity, thus increasing the amount of inspired air that can come into contact with the cavity walls
Describe the location of the nasal bones
Two slender bones, located at the bridge of the nose
Describe the location of the lacrimal bones
The smallest bones of the face, they form part of the medial wall of the orbit
Describe the location of zygomatic
Forms the cheek bones of the face, and articulates with frontal, sphenoid, temporal and maxilla bones
Describe the location of the ethmoid bone
Is a small unpaired bone, located in the midline of the anterior cranium - the superior aspect of the skull that encloses and protects the brain
What cavities does the ethmoid bone separate
It separates the nasal cavity(inferiorly) from the cranial cavity(superiorly). It also forms a significant portion of the nasal septum and lateral nasal wall
What nerve has a close relationship with the ethmoid bone
- The olfactory nerve(CN 1) has a close anatomical relationship with the ethmoid bone
- Its numerous nerve fibres pass through the cribriform plate of the ethmoid bone to innervate the nasal cavity with the sense of smell
What projects superiorly from the cribriform plate
Crista galli
What does the crista galli provide an attachment for
It provides an attachment point for the falx cerebri(sheet of dura mater that separates the two cerebral hemispheres)
What are the two large masses located at either side of the perpendicular plate?
They contain the ethmoidal air cells(sinuses)
What can a fracture of the cribriform plate cause?
- Branches of the olfactory bulb may be sheared which may cause anosmia(loss of sense of smell)
- May allow communication between the nasal cavity and the central nervous system. This allows CSF to enter the nasal cavity and drain out from the nose
- this manifests clinically as a clear watery discharge from one side of the nose
- Known as CSF rhinorrhoea
What is the saddle shaped depression on the sphenoid bone?
Sella turcica
What is the groove on the sphenoid caused by optic chiasm
Chiasmatic groove
What bone is the cribriform plate on
Ethmoid bone
What bone is the optic canal a part of
Sphenoid bone
What bone is the superior orbital fissure a part of
In between the greater and lesser wings of the sphenoid bone
What bone is the foramen rotundum a part of
- Circular hole in the sphenoid bone
What bone is the foramen ovale a part of
- Posterior part of the sphenoid bone
What bone is the foramen lacerum a part of
- The foramen lacerum (Latin: lacerated piercing) is a triangular hole in the base of skull located between the sphenoid, apex of petrous temporal and basilar part of occipital
What bone is the internal acoustic meatus a part of
- Within the petrous part of the temporal bone of the skull between the posterior cranial fossa and the inner ear
What bone is the jugular foramen a part of
- It is located behind the carotid canal and is formed in front by the petrous portion of the temporal bone, and behind by the occipital bone; it is generally larger on the right than on the left side
What bone is the hypoglossal canal a part of
- The hypoglossal canal is a foramen in the occipital bone of the skull
