13 Cranial Base and Topography of the Endocrine System

Question 1

What are the 2 divisions of the neurocranium?

Answer 1

Chondrocranium

Membranous neurocranium

Question 2

How does the chondrocranium ossify?

Answer 2

endochondral route

Question 3

How does the membranous neurocranium ossify?

Answer 3

intramembranously

Question 4

Which landmark in the skull marks the division between anterior and posterior cranial bases?

Answer 4

sella turica

Question 5

What is the embryological origin of the anterior cranial base?

Answer 5

neural crest cells

Question 6

What is the embryological origin of the posterior cranial base?

Answer 6

paraxial mesoderm

Question 7

What is the embryological origin of the adenohypophysis?

Answer 7

Rathke’s pouch

Question 8

What is the embryological origin of the neurohypophysis?

Answer 8

diencephalon

Question 9

How might you divide the cranial base into 3 parts?

Answer 9

anterior fossa
middle fossa
posterior fossa

Question 10

Which fossa of the cranial base is the highest?

Answer 10

anterior fossa

Question 11

what are the 5 bones of the cranial base?

Answer 11

ethmoid
frontal
sphenoid
temporal
occipital

Question 12

Where does the faux cerebri attach anteirorly?

Answer 12

crista galli

Question 13

Which bones comprise the anterior boundary of the cranial base?

Answer 13

upper surface of ethmoid (horizontal and perpendicular plate)
orbital plate of frontal bone

Question 14

Which bones comprise the middle portion of the cranial base?

Answer 14

sphenoid bone

temporal bone

Question 15

Whihc bones comprise the posteior bouundary of the cranial base?

Answer 15

occipital bone

Question 16

What is the ethmoid bulla?

Answer 16

the largest and most consistent anterior ethmoid air cell

Question 17

What are the potential consequences of an ethmoid fracture?

Answer 17

tearing of meninges at crista galli
anosmia
CSF rhinorrhea

Question 18

What test would you use quickly to test for rinorrhea?

Answer 18

ring sign

Question 19

What lies between the greater and lesser wings of the sphenoid?

Answer 19

superior orbital fissure

Question 20

What pit is within the sella turcica?

Answer 20

hypopyhseal fossa

Question 21

What structure allows the pituitary stalk to descend?

Answer 21

foramen sellae

Question 22

Name 6 parts of the temporal bone

Answer 22

squamous
mastoid
tympanic
styloid
zygomatic
petrous

Question 23

What is the most dense bone in the body?

Answer 23

petrous temporal bone (survives cremation)

Question 24

Where in the cranial base is the petro-occipital fissure?

Answer 24

lateral to foramen magnum

Question 25

What are the contents of the optic canal?

Answer 25

CN II | Opthalmic artery

Question 26

What are the contents of the superior orbital fissure?

Answer 26

``` CN III CN IV CN V1 CNVI opthalmic veins ```

Question 27

What are the contents of the foramen rotundum?

Answer 27

CN V2

Question 28

What are the contents of the foramen ovale?

Answer 28

CN V3

Question 29

What are the contents of the foramen spinosum?

Answer 29

``` Middle meningeal Artery Meningeal nerve (V3) ```

Question 30

What covers the foramen lacerum?

Answer 30

plate of cartilage

Question 31

What are the contents of the foramen lacerum?

Answer 31

external carotid canal greater petrosal nerve deep petrosal nerve

Question 32

what links the foramen lacerum and the pterygopalatine fossa?

Answer 32

pterygoid canal

Question 33

What lies in the pterygopalatine fossa?

Answer 33

sphenopalatine ganglion

Question 34

Which 2 bones mark the boundaries of the foramen lacerum?

Answer 34

petrous temporal bone | sphenoid bone

Question 35

What lies in the pterygoid canal?

Answer 35

vidian nerve

Question 36

What links the pterygopalatine fossa and the foramen lacerum?

Answer 36

pterygoid canal

Question 37

What links the foramen lacerum and jugular foramen?

Answer 37

petro-occipital fissure

Question 38

What is the posterior extension of the jugular foramen called?

Answer 38

hypoglossal canal

Question 39

What 2 foramena are connected to teh pterygopalatine fossa?

Answer 39

``` foramen lacerum foramen rotundum (higher level) ```

Question 40

What foramina are between sphenoid spine and foramen rotundum?

Answer 40

foramen ovale | foramen spinosum

Question 41

What indicator arouund the ear would suggest serious cranial base injury?

Answer 41

battle sign (ecchymosis)

Question 42

What sign on the face might indicate cranial base injury?

Answer 42

Racoon's eyes

Question 43

Name the 3 major pathways for CSF rhinorrhoea

Answer 43

anterior cranial fossa middle cranial fossa posterior cranial fossa

Question 44

Which sinus lies underneath cavernuos sinus?

Answer 44

sphenoid sinus

Question 45

What structure marks the pasage of the internal carotid artery through the carotid sinus?

Answer 45

Carotid siphon

Question 46

What is Rathke's pouch?

Answer 46

a finger of ectoderm which grows upwards from the roof of the mouth, ultimately forming the adenohypophysis

Question 47

Name 4 types of supratentorial herniation

Answer 47

uncal central (transtentorial) Cingulate (subfalcine) transcalvarial

Question 48

NAme 2 types of infratentorial herniation

Answer 48

Upward (upward cerebellar or transtentorial) | tonsillar (downward cerebellar)

Question 49

Tonsillar infratentorial herniation, what does the cerebellar tonsil compress against?

Answer 49

medulla

Question 50

How might tonsillar herniation present on a radiograph?

Answer 50

coning