cranial fossa

Question 1

anterior cranial fossa boundaries

Answer 1

ant and lat: frontal bone

floor: orbital part frontal bone
cribriform plate ethmoid
ant border sphenoid’s lesser wings

posterior: posterior border of lesser wing of sphenoid
anterior CLINOID process
Sulcus chiasmaticus

Question 2

middle cranial fossa boundaries

Answer 2

ant: posterior border lesser wing sphenoid, ant clinoid process and sulcus chiasmaticus

floor: greater wing sphenoid
petrous and squamous parts of temporal bone
centre: sella turcica of body of sphenoid

post: superior borders petrous part of temporal
dorsum sella of sphenoid

lat: squamous part of temporal
some part of parietal
greater wings of sphenoid

Question 3

sella turcica

Answer 3

saddle like

part of body of sphenoid

surrounded by ant and post clinoid processes

Question 4

clinoid

Answer 4

4 processes surround the hypophyseal fossa (like 4 posters of a bed)

Question 5

3 parts of sella turtica

Answer 5

tuberculum sellae
hypophyseal fossa
dorsum sellae

Question 6

tuberculum sellae

Answer 6

horn of saddle
prominent MEDIAN elevation-post boundary prechiasmatic sulcus

ant boundary hypophyseal fossa

Question 7

Hypophyseal fossa

Answer 7

seat of saddle
median depression in body of sphenoid
accommodates the pit gland

Question 8

dorsum sellae

Answer 8

back of saddle
square plate of bone projecting superiorly from body of sphenoid
post boundary sella turcica
prominent superolateral angles make up the post clinoid processes

Question 9

NB foramina in middle cranial fossa

Answer 9

Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen lacerum

Question 10

Superior orbital fissure

Answer 10

between greater and lesser wings

opens anteriorly into orbit

Question 11

foramen rotundum

Answer 11

posterior to MEDIAL end sup. orb. fissure

opens into pterygopalatine fossa

Question 12

foramen ovale

Answer 12

large
posterolateral to f. rot.
opens inferiorly into infratemporal fossa

Question 13

foramen spinosum

Answer 13

posterolat to foramen OVALE

opens into infratemporal fossa (in relation to spine of sphenoid)

Question 14

foramen lacerum

Answer 14

posterolat to HYPOPHYSEAL FOSSA
artifact of dried cranium
life: closed by cartilage plate

Question 15

Posterior cranial fossa boundaries

also has jugular foramen and hypoglossal canal, foramen magnum

Answer 15

ant: superior border petrous part of temporal bone
dorsum sellae

floor: basilar, squamous, condylar parts of occipital bone
mastoid part foramen magnum (central part of floor)

post: internal surface squamous part of occipital bone

Question 16

internal acoustic meatus

Answer 16

posterior cranial fossa/ear and neck via stylomastoid foramen
CN 7, 8
labyrinthine artery and vein (to and from inner ear)

Question 17

carotid canal

Answer 17

MIDDLE CRANIAL FOSSA

internal carotid artery