Cranial Cavity

Question 0

What is the neurocranium? What are the parts of the neurocranium?

Answer 0

. Bony covering of the brain and the cranial meninges
. Calvaria (skull cap)
. Basicranium (floor or cranial base)

Question 1

What are the two parts of the cranium?

Answer 1

. Neurocranium

. Viscerocranium

Question 2

Which 8 bones form the neurocranium?

Answer 2

. Frontal
. Ethmoid
. Sphenoid
. Occiptal
. Temporal (2)
. Parietal (2)

Question 3

What is the viscerocranium and what 15 bones make it up?

Answer 3

. The viscerocranium is made up of facial bones that developed mainly from the mesenchyme of the embryonic pharyngeal arches
. The viscerocranium forms the anterior part of the cranium
. Ethmoid
. Mandible
. Vomer
. Maxilla (2)
. Inferior nasal concha (2)
. Zygomatic (2)
. Palatine (2)
. Nasal (2)
. Lacrimal (2)

Question 4

What is the point where the frontal, sphenoid, temporal, and parietal bones come together?

Answer 4

Pterion

Question 5

What is the name of the palpable bump on the back of the head?

Answer 5

External occiptal protuberance

Question 6

What is lambda and where is it?

Answer 6

. It is the point between the sagittal and lambdoid sutures

. Located above the occipital bone

Question 7

What bones do the coronal, sagittal, and lambdoid sutures connect?

Answer 7

. Coronal suture = frontal + parietal bones
. Sagittal suture = parietal bones
. Lambdoid suture = occipital + parietal bones + temporal bones

Question 8

What is bregma and where is it?

Answer 8

. Connection of coronal and sagittal sutures

Question 9

What is the vertex and where is it?

Answer 9

Most superior part of the skull, mid-sagittal suture

Question 10

What is the hard palate formed by?

Answer 10

Palatine processes of the maxillae and the horizontal plates of the palatine bones

Question 11

What is the vomer?

Answer 11

Thin, flat bone that forms a portion of the nasal septum

Question 12

What are the choanae? Where are they?

Answer 12

. Posterior nasal apertures
. Its inferior boundary is formed by the posterior edge of the hard palate
. The nasal apertures are separated from each other by the vomer

Question 13

What do the occipital condyles articulate with?

Answer 13

C1 vertebra

Question 14

The cranial cavity has three cranial fossa. What does each hold?

Answer 14

. Anterior cranial fossa supports the frontal lobes
. Middle cranial fossa supports the temporal lobes and the pituitary
. Posterior cranial fossa supports the pons, medulla, cerebellum

Question 15

Which three bones form the anterior cranial fossa?

Answer 15

. Frontal
. Ethmoid
. Body and lesser wing of sphenoid

Question 16

What is the crista galli?

Answer 16

. Ridge of bone that projects from the ethmoid bone
. Makes up the cribriform plate of the ethmoid bone
. Olfactory foramina are the holes in the cribriform plate

Question 17

Which two bones form the middle cranial fossa?

Answer 17

. Greater wings of sphenoid

. Squamous and petrous parts of temporal bones

Question 18

What are the three parts of the sella turcica and what borders it?

Answer 18

. It is bordered by the anterior/posterior clinoid processes
. Tuberculum sellae
. Hypophysial fossa
. Dorsum sellae

Question 19

What are the sphenoidal crests?

Answer 19

Posterior border of the lesser wings of the sphenoid, end as the anterior clinoid processes

Question 20

What is the prechiasmatic sulcus?

Answer 20

Extends between the left and right optic canals… anterior to the tuberculum sellae

Question 21

Which bones form the posterior cranial fossa?

Answer 21

Mostly occipital, with contributions from sphenoid and temporal

Question 22

What is the clivus?

Answer 22

The dip from the sella turcica that leads to the foramen magnum

Question 23

What is the internal occiptal crest?

Answer 23

. It divides the posterior part of the posterior cranial fossa into two cerebellar fossa (its a line perpendicular to the foramen magnum)
. It ends superiorly as the internal occipital protuberance

Question 24

What are the two layers of the dura mater?

Answer 24

. External periosteal layer | . Internal meningeal layer

Question 25

Blood supply and innervation of the dura?

Answer 25

. Middle meningeal artery (anterior/posterior branches) | . Meningeal branches of V1, V2, V3, and to a lesser extent C2 and C3 via X and XII

Question 26

When the internal meningeal layer reflects away from the external periosteal layer, what 4 infoldings does it create?

Answer 26

. Falx cerebri . Falx cerebelli . Tentorium cerebelli . Diaphragma sellae

Question 27

Describe what the 4 dural infoldings separate.

Answer 27

. Falx cerebri = two cerebral hemispheres . Falx cerebelli = partially the two cerebellar hemispheres . Tentorium cerebelli = cerebellum from occipital cerebrum (leaves a gap anteromedially called the tentorial notch) . Diaphragma sellae = covers pituitary (suspends between clinoid processes)

Question 28

The internal meningial layer also creates the dural sinuses, which drain into what?

Answer 28

IJV

Question 29

What are the lateral venous lacunae?

Answer 29

Lateral expansions of the superior sagittal sinus

Question 30

What are arachnoid granulations?

Answer 30

. They transfer CSF to the venous system | . Prolongations of arachnoid mater that pierce the meningeal layer of the dura mater

Question 31

Where does the superior sagittal sinus receive blood from and where does it end?

Answer 31

. Superior cerebral veins | . Confluence of sinuses

Question 32

Where does the inferior sagittal sinus drain?

Answer 32

Straight sinus

Question 33

Which two structures form the straight sinus and where does it drain?

Answer 33

. Inferior sagittal sinus + great cerebral vein | . Confluence of sinuses

Question 34

What sinus does the transverse sinus become? And where does this sinus drain?

Answer 34

. Sigmoid sinus | . IJV at jugular foramen

Question 35

What does the occipital sinus communicate with?

Answer 35

. Internal vertebral sinus

Question 36

Where is the cavernous sinus and where does it receive blood from?

Answer 36

. Its on both sides of the sella turcica . Superior/inferior opthalmic veins . Superficial middle cerebral vein . Sphenoparietal sinus

Question 37

Where are the superior and inferior petrosal sinuses?

Answer 37

. The superior petrosal sinus joins the cavernous sinus to the transverse sinus . The inferior petrosal joins the cavernous sinus to the origin of the IJV

Question 38

What is the basilar plexus?

Answer 38

. It connects with the inferior petrosal sinuses and communicates with the internal vertebral venous plexuses

Question 39

What are emissary veins?

Answer 39

. They connect the dural sinuses to veins outside the cranium . They connect the cavernous sinus to the pterygoid venous plexus

Question 40

The lateral walls of the cavernous sinus contain which nerves and what artery?

Answer 40

``` . CN III . CN IV . CN V1 . CN V2 . (distal portion) Internal Carotid Artery ```

Question 41

What covers the ICA and which nerve crosses over it within the cavernous sinus?

Answer 41

. Carotid plexus of sympathetic nerves | . CN VI

Question 42

What are the 4 parts of the ICA?

Answer 42

. Cervical . Petrous . Cavernous . Cerebral

Question 43

What is the leptomeninx?

Answer 43

Arachnoid and pia maters

Question 44

Where is the CSF?

Answer 44

The space between the arachnoid and pia, the subarachnoid space

Question 45

What is the blood supply and innervation to the arachnoid mater?

Answer 45

None!

Question 46

The pia mater is _______ vascularized

Answer 46

highly

Question 47

What does the pia mater do in relation to the cerebral arteries?

Answer 47

When the cerebral arteries penetrate the cerebral cortex, the pia follows them for a short distance, creating a pial coat and periarterial space

Question 48

What is the innervation of the pia mater?

Answer 48

None!

Question 49

What are the three meningeal spaces and which of them is a true space?

Answer 49

. Dura-cranium interface (extradural or epidural space) . Dura-arachnoid junction (subdural space) . Subarachnoid space = true space between arachnoid and pia

Question 50

Generally, trauma involving which artery creates an epidural hematoma?

Answer 50

. Middle meningeal artery | . So epidural hematomas are arterial in nature

Question 51

Is a subdural hematoma venous or arterial in nature?

Answer 51

Venous

Question 52

What is in the subarachnoid space?

Answer 52

. CSF . Trabecular cells . Cerebral arteries . Bridging superior cerebral veins that drain into the superior sagittal sinus

Question 53

Is a subarachnoid hematoma venous or arterial in nature?

Answer 53

Arterial

Question 54

What is a Le Fort I fracture?

Answer 54

Horizontal fracture of the maxilla

Question 55

What is a Le Fort II fracture?

Answer 55

. Fracture passes through the posterolateral parts of the maxillary sinus, superomedially through the infraorbital foramina, lacrimals, or ethmoids to the bridge of the nose . The entire central part of the face is separated

Question 56

What is a Le Fort III fracture?

Answer 56

. Horizontal fracture that passes through the superior orbital fissures, ethmoid and nasal bones, and extends laterally through the greater wings of the sphenoid and the frontozygomatic sutures