Term
| where is the pterion located? describe its structure and what is located directly beneath it |
|
Definition
runs right by sphenoparietal suture,
region is unique because several bones come together, temporal, parietal, sphenoid
bone is rather thin relative to other areas, middle meningeal branch that supplies specific areas of brain runs right beneath this area |
|
|
Term
|
Definition
|
|
Term
| what joins the bones of the cranium? |
|
Definition
The bones are joined by interlocking fibrous suture joints except for the mandible which articulates at the synovial temporomandibular joint
Sphenoid and occipital bone are united by hyaline cartilage (synchondrosis) during childhood |
|
|
Term
| the cranium can be divided into what 2 parts? |
|
Definition
| neurocranium and viscerocranium |
|
|
Term
| the only real moveable joint in the cranium is the? |
|
Definition
|
|
Term
| what composes the neurocranium and what does it contain? |
|
Definition
Bony covering of the brain and its meninges
Contains the proximal parts of the cranial nerves and the vasculature of the brain
Comprised of 8 bones: frontal, 2 parietal, 2 temporal, occipital, sphenoid, and ethmoid
Has a calvaria (skull cap) and a cranial base or floor |
|
|
Term
| describe the bones of the calvaria in the neurocranium |
|
Definition
skull cap
Bones of the calvaria are flat bones derived from neural crest tissue that becomes head mesenchyme
Flat bones of the calvaria are formed by intramembranous ossification |
|
|
Term
| flat bones of the calvaria are derived from? |
|
Definition
|
|
Term
| flat bones of the calvaria are formed by _______ ossification. |
|
Definition
|
|
Term
| bones of the cranial base are formed by __________ ossification. |
|
Definition
| endochondral or both methods |
|
|
Term
| what are the bones of the viscerocranium? |
|
Definition
Viscerocranium has 14 bones
2 lacrimal, 2 nasal, 2 maxillae, 2 zygomatic, 2 palatine, 2 inferior nasal conchae, mandible, and vomer
Contains the orbits (eye sockets) and nasal cavities, upper and lower jaws |
|
|
Term
| the calvaria have 2 layers of compact bone with a spongy bone layer in between termed? |
|
Definition
|
|
Term
| arachnoid granulations leave impressions on what part of the calvaria? |
|
Definition
| protrude cranially and leave impressions on the interior superior aspect of the calvaria |
|
|
Term
|
Definition
| the periosteum of the cranium |
|
|
Term
| the compact bone layers of the calvaria are frequently termed? |
|
Definition
|
|
Term
| what does the diploe of the calvaria transmit? |
|
Definition
transmits the diploic veins that communicate with the cranial dural sinuses via emissary veins
contains red marrow early in life |
|
|
Term
| which bone is the cheek bone? |
|
Definition
|
|
Term
| what does the frontal bone form? |
|
Definition
| the skeleton of the forehead |
|
|
Term
| what makes up the nasal septum? |
|
Definition
| Nasal septum divides nasal cavity in two halves and is predominantly made up of the perpendicular plate of the ethmoid bone and the vomer, but also includes the palatine bone |
|
|
Term
| where are nasal conchae located? |
|
Definition
Nasal conchae (curved bony plates) occupy lateral wall of nasal cavity
Superior and middle conchae are part of the ethmoid bone. The inferior nasal conchae are individual bones. |
|
|
Term
| what does the maxillae bone form? |
|
Definition
Maxillae form the upper jaw and contain the alveolar process which include the tooth sockets (alveoli).
Paired maxillae unite at the intermaxillary suture |
|
|
Term
| what does the mandible hold? |
|
Definition
|
|
Term
| describe what injury of the ethmoid bone may cause |
|
Definition
The ethmoid bone is easily injured by a sharp upward blow to the nose, such as a person might suffer by striking an automobile dashboard in a collision
Force of the blow can drive bone fragments through the cribriform plate into the meninges or brain tissue
This can cause leakage of cerebrospinal fluid into the nasal cavity and maybe followed by the spread of infection from the nasal cavity to the brain
CSF may leak out of nasal cavity |
|
|
Term
| the piriform aperture is an opening in the skull for which cavity? |
|
Definition
|
|
Term
| the foramina of the anterior skull allow for passage of sensory branches from which nerve? |
|
Definition
|
|
Term
| the supraorbital notch transmits what vessels? |
|
Definition
| the supraorbital nerve and vessels |
|
|
Term
| the zygomaticofacial foramen transmits which nerve? |
|
Definition
| the zygomaticofacial nerve |
|
|
Term
| the infraorbital foramen transmits which vessels? |
|
Definition
| the infraorbital nerve and vessels |
|
|
Term
| the mental foramen transmits which vessels? |
|
Definition
| the mental nerve and vessels |
|
|
Term
| the optic canal goes through which bone? |
|
Definition
|
|
Term
|
Definition
a reference point on the anterior skull
Glabella is the prominence of frontal bone above root of nose (depression between the supercilliary arches) |
|
|
Term
| what are superciliary arches and what are their clinical importance? |
|
Definition
| Superciliary arches are relatively sharp ridges and a blow here, such as during a boxing match or fist fight, may lacerate the skin and cause bleeding. Tissue fluid and blood can accumulate around the orbit and into the thin skin of the eyelids leaving a “black eye” (echymosis). |
|
|
Term
|
Definition
| in the lacrimal sac/depression |
|
|
Term
|
Definition
Sutures are fibrous joints between the bones of the skull
At ages 30-40 the sutures of the calvaria begin obliteration on the internal surface and about 10 years later on the external surface
if you see the skull of an elderly individual you may not even see sutures; bone is completely remodeled so there's almost no trace of sutures and no mobility at this point |
|
|
Term
| what is craniosynostosis? |
|
Definition
the premature closure of the cranial sutures
it results in cranial malformations
1 in 2000 births |
|
|
Term
| the coronal suture lies between which bones? |
|
Definition
| the frontal bone and the 2 parietal bones |
|
|
Term
| the sagittal suture lies between which bones? |
|
Definition
|
|
Term
| the squamous suture lies between which bones? |
|
Definition
| the parietal bone and the squamous part of the temporal bone |
|
|
Term
| the lambdoid suture lies between which bones? |
|
Definition
| (resembles Greek letter λ) lies between the two parietal bones and the occipital bone |
|
|
Term
| where can sutural (wormian) bones be found? |
|
Definition
| occur along the lambdoid suture |
|
|
Term
| if an infant has hydrocephalous, you will see more of which bones? |
|
Definition
|
|
Term
| what are found on the parietal bone? |
|
Definition
| superior and inferior temporal lines |
|
|
Term
| what can be found on the temporal bone? |
|
Definition
| has mastoid and styloid processes, zygomatic arch, external acoustic meatus, and a squamous part |
|
|
Term
| where is the lacrimal bone located? |
|
Definition
| in the medial wall of the orbit |
|
|
Term
| what can be found on the occipital bone? |
|
Definition
| Occipital bone has external occipital protuberance (inion) and superior & inferior nuchal lines |
|
|
Term
| where is the lambda landmark located? |
|
Definition
| junction of the lambdoid and sagittal sutures |
|
|
Term
| where is the bregma landmark located? |
|
Definition
| junction of the sagittal and coronal sutures |
|
|
Term
| where is the pterion landmark located? |
|
Definition
junction of frontal, parietal, temporal bones, and greater wing of the sphenoid on the lateral aspect of the skull
Clinical significance: It is a thin part of the calvaria overlying anterior branch of the middle meningeal artery |
|
|
Term
| where is the nasion landmark located? |
|
Definition
| intersection of the frontal and 2 nasal bones |
|
|
Term
|
Definition
| the highest point of the superior aspect of the skull |
|
|
Term
|
Definition
Glabella is the prominence of frontal bone above root of nose (depression between the supercilliary arches)
is a reference point |
|
|
Term
| fracture of the pterion can result in what? |
|
Definition
Fracture of the pterion can result in rupture of the anterior branch of the middle meningeal artery causing an extradural “epidural” hematoma
extremely dangerous
bleeding under high pressure outside of the dura |
|
|
Term
| describe some signs of an epidural hematoma |
|
Definition
A fracture at the pterion, the thinnest part of the calvaria may lacerate the anterior branch of the middle meningeal artery causing a epidural hematoma.
The hematoma may compress the lateral part of the cerebral hemisphere and result in herniation of the medial part of the temporal lobe through the tentorial notch of dura. This in turn compresses the brainstem causing all or some of these signs: limb weakness, dilated pupil from compression of the oculomotor nerve, and deterioration of cardiovascular and respiratory function.
These neurological signs may occur several hours after the initial injury, as blood accumulates to the point at which pressure on the brain reaches a critical value.
patient may experience a lot of pain, may cause momentary loss of consciousness
eventually will compress brain after a few hours, occulomotor nerve, dilated pupil, limb weakness, can herniate brain or put pressure on brain stem (vegetative state) |
|
|
Term
| on the internal surface of the cranial base, which is the shallowest of the cranial fossae? |
|
Definition
| the anterior cranial fossa |
|
|
Term
| which bones make up the anterior cranial fossa? |
|
Definition
| frontal bone, ethmoid, body and lesser wings of the sphenoid |
|
|
Term
| what does the middle cranial fossa contain? |
|
Definition
|
|
Term
| which is the largest of the 3 cranial fossa in the cranial base? |
|
Definition
posterior cranial fossa
comprised mostly of occipital bone
holds cerebellum, pons and medulla |
|
|
Term
| which foramen and features can be found in the anterior cranial fossa? |
|
Definition
Foramen cecum
Olfactory foramina of cribriform plate
Anterior and posterior ethmoidal foramina |
|
|
Term
| which foramen and features can be found in the middle cranial fossa? |
|
Definition
Optic canal
Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
Carotid canal
Hiatuses and canals for the greater and lesser petrosal nerves
Foramen lacerum (only a foramen in a preserved skull, in life it is filled with cartilage) |
|
|
Term
| which foramen and features can be found in the posterior cranial fossa? |
|
Definition
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Foramen magnum
Condylar canal |
|
|
Term
| what runs through the optic canal? |
|
Definition
Optic nerve (CN II)
Ophthalmic artery |
|
|
Term
| what is found in the superior orbital fissure? |
|
Definition
Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Lacrimal, frontal and nasociliary branches of ophthalmic nerve (CN V1)
Abducent nerve (CN VI)
Superior ophthalmic vein |
|
|
Term
| what runs through the foramen rotundum? |
|
Definition
|
|
Term
| what runs through the foramen ovale? |
|
Definition
Mandibular nerve (CN V3)
Accessory meningeal artery
Lesser petrosal nerve |
|
|
Term
| what runs through the foramen spinosum? |
|
Definition
Middle meningeal artery and vein
Meningeal branch of mandibular nerve |
|
|
Term
| what runs through the carotid canal? |
|
Definition
| Internal carotid artery with internal carotid nerve plexus |
|
|
Term
| what can be found in the foramen lacerum? |
|
Definition
| It is filled with cartilage. The greater petrosal nerve passes horizontally across foramen lacerum and traverses the cartilage. |
|
|
Term
| what can be found in the internal acoustic meatus? |
|
Definition
Facial nerve (CN VII)
Vestibulocochlear nerve (CN VIII)
Labyrinthine artery |
|
|
Term
| what can be found in the jugular foramen? |
|
Definition
Inferior petrosal sinus
Glossopharyngeal nerve (CN IX)
Vagus nerve (CN X)
Accessory nerve (CN XI)
Sigmoid sinus
Posterior meningeal artery |
|
|
Term
| the carotid canal and foramen lacerum are located in which cranial fossa? |
|
Definition
|
|
Term
| the internal acoustic meatus and jugular foramen are located in which cranial fossa? |
|
Definition
|
|
Term
| what can be found in the hypoglossal canal? |
|
Definition
| the hypoglossal nerve (XII) |
|
|
Term
| what can be found in the foramen magnum? |
|
Definition
Medulla oblongata
Meninges
Vertebral arteries
Meningeal branches of vertebral arteries
Spinal roots of accessory nerves |
|
|
Term
| the hypoglossal canal and foramen magnum are located in which cranial fossa? |
|
Definition
| the posterior cranial fossa |
|
|
Term
| the hard palate of the external cranial base is formed by which bones? |
|
Definition
| The hard palate is formed by the palatine process of the maxillae anteriorly and the horizontal plates of the palatine bone posteriorly |
|
|
Term
| what can be found superior to the posterior edge of the hard palate (of the external cranial base)? |
|
Definition
| Superior to the posterior edge of the palate are 2 large openings, the choanae (posterior nasal apertures) |
|
|
Term
| what can be found in the incisive foramen? |
|
Definition
| the nasopalantine nerve (it is posterior to the central incisor teeth) |
|
|
Term
| the greater and lesser palantine foramina transmit what vessels? |
|
Definition
| Greater & lesser palatine foramina transmit the greater & lesser palatine nerves and vessels |
|
|
Term
| the stylomastoid foramen transmits which nerve? |
|
Definition
|
|
Term
| what can be found in the carotid canal? |
|
Definition
| Carotid canal transmits the internal carotid artery and sympathetic plexus |
|
|
Term
|
Definition
| air filled spaces lined with mucosa |
|
|
Term
| where is the frontal sinus located? |
|
Definition
| right in the middle of the frontal bone |
|
|
Term
|
Definition
soft spots
Regions of membrane between skull bones that are not yet ossified. The membrane is blended with the pericranium externally, and the dura matter internally. They allow skull deformation during birth and allow for rapid brain growth of the brain during the 1st two years.
The fontanelles are usually closed by the 2nd year.
flat bones develop through intramembranous ossification, stay membranous for first two years of life, then they ossify |
|
|
Term
| palpation of the fontanelles during infancy allows the physician to determine what? |
|
Definition
Progress of growth of frontal and parietal bones
Degree of hydration
a depressed fontanelle indicates dehydration and can occur after a bought of severe fever or diarrhea
Level of intracranial pressure
bulging fontanelle indicates increased pressure on the brain |
|
|
Term
| where is the metopic suture found in the infant skull? |
|
Definition
Metopic suture lies between 2 developing frontal bones
Allows skull deformation during the birthing process
Closes during the 6th year leaving 1 frontal bone in the adult skull (there is short remnant of the metopic suture superior to the nasion) |
|
|
Term
| deformation of the calvaria (cone head) during the birth process is allowed by what structures? |
|
Definition
| fibrous sutures and fontanelles |
|
|
