Cranial Fossae Flashcards Preview

Head & Neck > Cranial Fossae > Flashcards

Flashcards in Cranial Fossae Deck (31):
1

What does the anterior cranial fossa lie over?

Nasal and orbital cavities

2

Which part of the brain is in the anterior cranial fossa?

Anterior inferior portions of the frontal lobes

3

Which bones make up the anterior cranial fossa?

Frontal
Ethmoid
Sphenoid

4

What are the boundaries of the anterior cranial fossa?

Anteriorly and laterally - inner surface of the frontal bone

Posteriorly and medially - limbus of the sphenoid bone

Posteriorly and laterally - lesser wings of the sphenoid

Floor - frontal, ethic and anterior aspects of the body and lesser wings of the sphenoid bones

5

What is the crista galli?

An upwards projection in the midline of the ethmoid bone
Attachment for falx cerebri (sheet of dura mater that divides the two hemispheres)

6

What are the two main large foramen in the cribriform plate and what do they transmit?

Anterior ethmoidal foramen - transmission the anterior ethmoidal artery, nerve and vein

Posterior ethmoidal foramen - transmits the posterior ethmoidal artery, nerve and vein

7

How can fracture of the cribriform plate lead to to rhinorrhoea?

Fragments of the bone can tear the meningeal coverings of the brain, causing the leakage of CSF into the nasal cavity

8

What are the cranial fossae?

Three depressions which divide the floor of the cranial cavity

9

What is the shape of the middle cranial fossa and what is contained within it?

Butterfly shaped
Middle has pituitary gland
The two lateral parts have the temporal lobes of the brain

10

What bones does the middle cranial fossa consist of?

Sphenoid bone and two temporal bones

11

What are the boundaries of the middle cranial fossa?

Anteriorly and laterally - lesser wings of the sphenoid bone

Anteriorly and medially - limbus of the sphenoid bone

Posteriorly and laterally - superior border of the petrous part of the temporal bone

Posteriorly and medially - dorsum stellate of the sphenoid bone

Floor - body and greater wing of the sphenoid, squamous and petrous parts of the temporal bone

12

What supports the pituitary gland?

Sella turicica- saddle-shaped bony prominence of the sphenoid bone. Sits in the pituitary fossa in this

13

Where are the optic canals situated in the middle cranial fossa and what passes through them?

Anteriorly, on the sphenoid bone
Transmit optic nerves and ophthalmic arteries into the orbital cavities

14

What connects the optic canals?

The chiasmatic sulcus - a depressed groove

15

Name the four foramina immediately lateral to the central part of the middle cranial fossa

Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum

16

What passes through the superior orbital fissure

Oculomotor nerve
Trochlear nerve
Ophthalmic branch of the trigeminal
Abducens nerve
Ophthalmic veins
Sympathetic fibres

17

What is transmitted through the foramen rotundum?

Opens into the pterygopalatine fossa
-maxillary branch of the trigeminal nerve

18

What passes through the foramen ovale? Where does it open into?

The infratemporal fossa
Mandibular branch of the trigeminal nerve
Accessory meningeal artery

19

What passes through the foramen spinosum? Where does it open into?

Infratemporal fossa
Middle meningeal artery
Middle meningeal vein
Meningeal branch of CN V3

20

What are the three major foramina of the temporal bone?

Hiatus of the greater petrosal nerve - greater p. nerve (branch of facial) and petrosal branch of middle meningeal artery

Hiatus of the lesser petrosal nerve - l.p. nerve (branch of glossopharyngeal)

Carotid canal - internal carotid artery coming in to supply the brain. Deep petrosal nerve

21

Complications of pituitary surgery?

CSF rhinorrhoea
Meningitis
Diabetes
Diabetes insipidus
Haemorrhage
Visual disturbances

22

What are the bones of the posterior cranial fossa?

Occipital
Temporal x2

23

Boundaries of the posterior cranial fossa?

Anteriorly and medially - dorsum sellae of the sphenoid

Anteriorly and laterally - superior border of petrous part of the temporal bone

Posteriorly - internal surface of the squamous part of the occipital bone

Floor - mastoid part of the temporal bone and squamous, condylar and basilar parts of the occipital bone

24

What is the foramen in the temporal bone and what passes though?

The internal acoustic meatus in the petrous part
-facial nerve
-vestibulcochlear nerve
-labyrinthine artery

25

What are the foramina in the occipital bone?

Foramen magnum
Jugular foramina on either side
Hypoglossal canal
Cerebellar fossae

26

What passes through the foramen magnum?

Medulla of the brain
Meninges
Vertebral arteries
Spinal accessory nerve (ascending)
Dural veins
Anterior and posterior spinal arteries

27

What passes through the jugular foramina?

Glossopharyngeal nerve
Vagus nerve
Spinal accessory nerve
Internal jugular vein
Inferior petrosal sinus
Sigmoid sinus
Meningeal branches of the ascending pharyngeal and occipital arteries

28

What passes through the hypoglossal canal?

Hypoglossal nerve

29

What is cerebellar tonsillar herniation?

Downward displacement of the cerebellar tonsils through the foramen magnum - aka coning

30

What can cause cerebellar tonsillar herniation?

Raised intracranial pressure - varied aetiology
-hydrocephalus
-space occupying lesions
-malformed posterior cranial fossa

31

What does the cerebellar tonsillar herniation result in?

Compression of the pons and medulla which contain the cardiac and respiratory centres
Could lead to death from cardio respiratory arrest