Anatomy of Cranium, Meninges and Brain

Question 1

What are the cranial fossa?

Answer 1

any of the three large depressions in the posterior, middle, and anterior aspects of the floor of the cranial cavity

Question 2

What are the main foramina?

Answer 2

A foramen (plural: foramina ) is an opening inside the body that allows key structures to connect one part of the body to another. The skull bones that contain foramina include the frontal, ethmoid, sphenoid, maxilla, palatine, temporal, and occipital. There are 21 foramina in the human skull.

Question 3

What sits in the anterior cranial fossa?

Answer 3

frontal lobe

Question 4

what sits in the middle cranial fossa?

Answer 4

temporal lobe

Question 5

what sits in the posterior cranial fossa?

Answer 5

cerebellum and brain stem

Question 6

What does the cribriform plate do, which bone is it part of, and where does it lie?

Answer 6

Where the olfactory neurons run from the top of the nose to snyapse in the olfactory bulb of the brain. It is part of the ethmoid bone, lies centrally in the anterior cranial fossa

Question 7

Where is the optic canal?

Answer 7

One on either side on the border between the anterior and middle cranial fossae

Question 8

What runs through the optic canal?

Answer 8

Optic nerves pass into the back of the orbit to supply the eye

Question 9

Where does the superior orbital fissure lie?

Answer 9

towards the back of the optic canal

Question 10

What passes through the superior orbital fissure?

Answer 10

the nerves involved in extrinsic muscle contraction of the eye pass through into the orbit

Question 11

What is the orbit?

Answer 11

In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated.

Question 12

Which small aperture lies directly behind the superior orbital fissure, and what passes through here?

Answer 12

Foramen rotundum, maxillary division of the trigeminal nerve passes out of the skull

Question 13

Where does the foramen ovale lie, what passes through it and

Answer 13

posterior part of sphenoid bone, where the mandibular division of the trigeminal nerve passes through

Question 14

Which small aperture lies lateral to the foramen ovale and what passes through it?

Answer 14

foramen spinosum, middle meningeal artery passes through to supply the dura around the brain

Question 15

Which foramen lies near the border of the middle and posterior cranial fossa on the temporal bone? What passes through?

Answer 15

internal acoustic meatus, where cranial nerves 7 - facial nerve and 8 - vestobular cochlear - inner ear, pass through

Question 16

Which nerves exit through the jugular foramen?

Answer 16

9 - glossopharangeal , 10- vagus and 11 - accessory

Question 17

What passes through the hypoglossal canal?

Answer 17

hypoglossal nerve (12), tongue

Question 18

what passes through the foramen magnum?

Answer 18

spinal cord and brainstem come together

Question 19

structural function of meninges

Answer 19

stabilise and protect brain, also form sinuses through which venous blood circulates in the cranial cavity

Question 20

where do the spider-like projections from the arachnoid mater lie?

Answer 20

sub-arachnoid space

Question 21

where do the two layers of the dura, the periosteal and meningeal layers separate?

Answer 21

to form the venous sinuses eg. superior sagittal sinus

Question 22

what does the falx cerebri do?

Answer 22

stabilise brain within cranial cavity

Question 23

what lies in subarachnoid space?

Answer 23

cerebrospinal fluid and arachnoid projections. Cerebrospinal fluid bathes the brain, protects it against movement and supplies nutrients to the brain

Question 24

how thick is the pia mater?

Answer 24

2 cells thick, essentially the surface of the brain

Question 25

how does the relationship between the dura and the bony structures differ between the skull and vertebral column?

Answer 25

within the cranial cavity there is no space between the dura and the bone, however when we exit through the foramen magnum, there is an extradural space

Question 26

how can anaesthetists take advantage of the extradural space?

Answer 26

put extradural or epidural anaesthetic, particularly in mothers who are in labour and need pain relief

Question 27

what does the tentorium cerebelli do?

Answer 27

provides postural support for the brain and prevents it moving around too much when it is shaken or hit

Question 28

what is the cranial vault?

Answer 28

space within neurocranium, occupied by the brain

Question 29

why is it important to know the location of the sutures of the skull?

Answer 29

to differentiate them between fracture lines on x rays

Question 30

mandible

Answer 30

lower jaw bone

Question 31

maxilla

Answer 31

cheek bone, forming upper jaw

Question 32

which bone lies on the lateral part of the orbit?

Answer 32

zygoma

Question 33

which bone makes up most of the forehead?

Answer 33

frontal bone

Question 34

which bone lies directly inferior to the frontal suture?

Answer 34

nasal bone

Question 35

which 2 bones lie directly behind the frontal bone?

Answer 35

parietal bone

Question 36

which bone lies behind the parietal bone?

Answer 36

occipital bone

Question 37

which bone lies laterally on either side of the skull behind the ear?

Answer 37

temporal bone

Question 38

which bone is joined to the temporal bone, parietal bone and frontal bone by the pterion?

Answer 38

greater wing of sphenoid bone

Question 39

what is the pterion?

Answer 39

weak spot where temporal, parietal, frontal and sphenoid bones join together

Question 40

a blow to which area of the skull can cause an intracranial bleed?

Answer 40

pterion

Question 41

which bone lies around the foramen magnum?

Answer 41

occipital bone

Question 42

which suture joins the two parietal bones and the occipital bone?

Answer 42

lamda/ lamboid suture

Question 43

which suture joins the parietal bones and the frontal bone?

Answer 43

coronal suture

Question 44

which suture joins the two parietal bones?

Answer 44

sagittal suture

Question 45

what is the name of the point where the sagittal and coronal sutures meet?

Answer 45

bregma

Question 46

what is the area of unfused bone (soft spot) called on a neonatal skull?

Answer 46

anterior fontanelle

Question 47

what benefit does the anterior fontanelle give to the baby?

Answer 47

gives the skull flexibility in case the birth canal is too tight

Question 48

how long does the soft spot last?

Answer 48

18-24 months after birth

Question 49

3rd layer of scalp tissue

Answer 49

aponeurotic layer (a tough layer of dense fibrous tissue) which covers the upper part of the cranium

Question 50

1st layer of scalp

Answer 50

skin

Question 51

2nd layer of scalp

Answer 51

connective tissue (dense)

Question 52

4th layer of scalp

Answer 52

loose areolar tissue

Question 53

5th layer of scalp

Answer 53

periosteum

Question 54

where is the scalp bone usually thickest?

Answer 54

occipital bone?

Question 55

where is the scalp bone the thinnest?

Answer 55

pterion

Question 56

which artery is close to the pterion?

Answer 56

middle meningeal artery

Question 57

what type of intracranial haemorrhage is associated with damage to the middle meningeal artery

Answer 57

Epidural hemorrhage (extradural hemorrhage) which occur between the dura mater (the outermost meninx) and the skull, is caused by trauma. It may result from laceration of an artery, most commonly the middle meningeal artery.

Question 58

where is the straight sinus located?

Answer 58

sagittal across posterior 2/3 of cerebellum

Question 59

where is the transverse sinus located?

Answer 59

located laterally on either side around posterior 2/3 of cerebellum

Question 60

which sinuses meet at the confluence of sinuses?

Answer 60

superior sagittal sinus, straight sinus, occipital sinus and transverse sinuses

Question 61

where is the occiptal sinus located?

Answer 61

caudal end of cerebellum

Question 62

which sinus is enclosed in the falx cerebri?

Answer 62

superior sagittal sinus

Question 63

name the arteries of the circle of willis from anterior to inferior

Answer 63

anterior cerebral artery, anterior communicating artery, middle cerebral artery, opthalmic artery, internal carotid artery, anterior choroidal artery, posterior communicating artery, posterior cerebral artery, superior cerebellar artery, pontine arterior, basilar artery, anterior inferior cerebellar artery, vertebral artery, anterior spinal artery, posterior inferior cerebellar artery

Question 64

location of olfactory bulb

Answer 64

posterior to ethmoid bone

Question 65

optic nerve location

Answer 65

inferior to sphenoid bone, enters brain through optic canal in the sphenoid bone

Question 66

location of oculomotor nerve (3)

Answer 66

The oculomotor nerve is the third cranial nerve (CN III). It enters the orbit via the superior orbital fissure

Question 67

location of pituitary gland

Answer 67

in the pituitary fossa (sella turcica) within the body of the sphenoid bone on the midline, in the middle of the pituitary gland

Question 68

location of cavernous sinus

Answer 68

on either side lateral to the sella turcica

Question 69

Trigeminal (Meckel’s) cave contains what?

Answer 69

containing the trigeminal ganglion

Question 70

trigeminal cave is where?

Answer 70

cerebrospinal fluid-containing dural pouch in the middle cranial fossa and opening from the posterior cranial fossa that houses the trigeminal ganglion.

Question 71

which lobes of the brain lie in which fossa? frontal lobe temporal lobe brainstem/cerebellum

Answer 71

The frontal lobe sits in the anterior cranial fossa, the temporal lobe in the middle cranial fossa and the brainstem/cerebellum in the posterior cranial fossa