10.13.16 Skull Flashcards
The skull is formed from separate bones. There are ___ single bones and ___ paired bones.
6; 8
Many of the bones of the skull articulate with one another at serrated edges called ___.
Sutures
The skull is subdivided into what two main parts?
Cranium, mandible
The skull is studied in different views, also known as ___.
Norma
At birth, there are soft spots on the skull known as ___.
Fontanelles
Fontanelles close ___ months after birth.
18-24
What is the name of the superior view of the skull?
Norma verticalis (skull cap)
What bones can be seen in norma verticalis?
Frontal bone, parietal bones, occipital bone
What is the name of the suture between the parietal bones and the frontal bone?
Coronal suture
What is the name of the suture between the two parietal bones?
Sagittal suture
What is the area of the skull where the sagittal and coronal sutures join?
Bregma
What is the name of the suture between the occipital bone and the parietal bones?
Lambdoid suture
What is the area of the skull where the sagittal and lambdoid sutures join?
Lambda
What is the name of the superior/posterior view of the skull?
Norma occipitalis
What is the main bony feature of the norma occipitalis?
External occipital protuberance with superior and inferior nuchal lines
What is the name of the superior/anterior view of the skull?
Norma frontalis
What are the main bony features of norma frontalis?
- Frontal bone
- Nasal bone
- Bony orbit
- Zygomatic bone
- Maxillary bone
What are three foramina seen in norma frontalis?
- Supraorbital foramen
- Infraorbital foramen
- Mental foramen
Where is the supraorbital foramen found?
Above the orbit
What does the supraorbital foramen transmit?
Supraorbital nerve (derived from frontal nerve, which belongs to the ophthalmic division of V) and supraorbital artery (derived from ophthalmic artery)
Where is the infraorbital foramen found?
Below the orbit
What does the infraorbital foramen transmit?
Infraorbital nerve (branch of maxillary division of V) and infraorbital artery (branch of maxillary artery)
Where is the mental foramen found?
On the mandible
What does the mental foramen transmit?
Mental nerve (branch of mandibular division of V) and mental artery (branch of maxillary artery)
What bone forms the roof of the nose?
Ethmoid bone
Which concha (shelf) are part of the ethmoid bone?
Superior concha and middle concha
What part of the ethmoid bone contains many holes?
Cribriform plate
What does the cribriform plate transmit?
CN I
What are the foramen and fissures in the orbit?
Foramen: Optic canal
Fissure: Superior and inferior orbital fissures
What is the name of the lateral view of the skull?
Norma lateralis
The zygoma and temporal bones articulate to form the ___.
Zygomatic arch
The ___ is located above the zygomatic arch.
Temporal fossa
What is the pterion?
Meeting of temporal, parietal, frontal, and greater wing of sphenoid bones
The pterion is a landmark for the ___.
Middle meningeal artery
Breaking the zygomatic arch allows one to see the ___.
Infratemporal fossa
The ___ has two wings - greater and lesser.
Sphenoid bone
What are the three cranial fossa in the cranial cavity?
- Anterior cranial fossa
- Middle cranial fossa
- Posterior cranial fossa
What forms the anterior cranial fossa?
Orbital plate of frontal bone, lesser wing of sphenoid, cribriform plate of ethmoid bone, crista galli, frontal crest, foramen cecum
What forms the middle cranial fossa?
Greater wing of sphenoid, temporal bone
What is the pyramid-shaped portion of the temporal bone at the base of the skull between the sphenoid and occipital bones?
Petrous
What does petrous protect?
VII and VIII
What forms the posterior cranial fossa?
Temporal and occipital bones
What are the processes of the lesser wing of the sphenoid bone?
Anterior clinoid processes
What is found between the optic nerve canals?
Groove for optic chiasm
What is found medial to the anterior clinoid processes?
Optic canals
What is found between the crista galli and frontal crest?
Foramen cecum
What does the optic canal transmit?
Optic nerve and ophthalmic artery
What is found in the middle of the body of the sphenoid bone?
Pituitary gland
The pituitary gland is located in the ___ fossa.
Hypophyseal
What forms the bony seat for the pituitary gland?
Sella turcica
CN III, IV, V1, and V2 cross the ___ to reach their foramens.
Cavernous sinus
What artery passes through the cavernous sinus?
Internal carotid artery
What are the 4 foramen of the middle cranial fossa?
- Foramen rotundum
- Foramen ovale
- Foramen spinosum
- Foramen lacerum
What does the foramen rotundum transmit?
Maxillary nerve (V2)
What does the foramen ovale transmit?
Mandibular nerve (V3) and lesser petrosal nerve
What does the foramen spinosum transmit?
Middle meningeal artery
What bone contains foramen rotundum, spinosum, and ovale?
Sphenoid bone
What are the two limbs of the sphenoid bone?
Pterygoid process (medial and lateral)
What is found above the foramen rotundum, ovale, and spinosum?
Superior orbital fissure
Where is the internal auditory meatus found?
Petrous part of temporal bone
What does the internal auditory meatus transmit?
CN VII and VIII
The petrous part of the temporal bone protects the ___.
Ear
What nerves exit the trigeminal ganglia?
CN V1, V2, V3
What does the jugular foramen transmit?
CN IX, X, XI
What does the hypoglossal canal transmit?
CN XII
What does foramen magnum transmit?
CN XI