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Anatomy 1 > Skull > Flashcards

Flashcards in Skull Deck (25):
1

The skull base forms ...

the floor of the cranial cavity, separates the brain from the other facial structures, its a complex anatomical region

2

The 3 parts of the skull base are ...

Endocranial (inner) skull base, Skull Base Foramina, Extracranial (outer) skull base

3

Describe the Endocranial (inner) skull base

the inner surface of the skull, consists of the cranial cavity on which the brain rests

4

The 4 types of bone forming the skull base are ...

Frontal bone, Sphenoid bone, Temporal bone, Occipital bone

5

Anatomically, the inner surface of the skull base is formed by ...

The anterior cranial fossa, middle cranial fossa, posterior cranial fossa

6

Describe the anterior cranial fossa - limits - 2 points

it's limited anteriorly by frontal bone & by the posterior wall of the frontal sinus, limited posteriorly by the margin of the lesser wing of sphenoid bone

7

What is the anterior cranial fossa formed by

ethmoid bone, sphenoid bone, frontal bone

8

Describe what the lateral part of the anterior cranial fossa forms and what the median (central) part of the anterior cranial fossa is formed by

lateral part = form the roof of the orbits
median (central) part = formed by crista galli, the cribriform plate of the ethmoid plane and the sphenoid bone

9

Describe the middle cranial fossa - formed by, limits - 3 points

formed by sphenoid and temporal bones, limited anteriorly by the lesser wings of the sphenoid bones, limited posteriorly by petrous bones

10

Describe the posterior cranial fossa - formed by, limits - 3 points

formed by occipital bones, limited anteriorly by posterior walls of petrous bones, limited posteriorly by grooves of transverse sinuses

11

Describe skull base foramina - 2 points

these are the several foramina which are in the bones of the skull base, nerves/arteries/veins pass through them

12

Skull Base Foramina in the Ethmoid Bone

olfactory foramina

13

Skull Base Foramina in Sphenoid Bone

optic canal, superior orbital fissure, foramen rotundum, foramen ovale, foramen spinosum, foramen lacerum

14

Skull Base Foramina in Temporal Bone

internal acoustic meatus, jugular foramen

15

Skull Base Foramina in Occipital Bone

hypoglossal canal, foramen magnum

16

Describe the what forms the anterior part of the extracranial skull base

Zygomatic bone, Maxillary bone, Palatine bones

17

Describe the remainder of what forms the extracranial skull base

Occipital bones, temporal bones, sphenoid bones

18

Describe skull base fractures etc - 5 points

skull base fractures are of high importance in neurotrauma, often associated with cranial vault, mid face fractures occur in head injuries and are often related to brain injuries, involvement of nerves passing through a foramen in a respective region should always be considered, CT = gold standard for detecting these fractures

19

What are the %'s of fractures which have occurred in various places

70% occur in anterior fossa
20% occur in the middle central skull base
5% occur in the middle or posterior fossa

20

Clinical Signs - Battle's Sign

bruising over the mastoid sinus (just behind auricle), delayed physical finding associated with base of skull fractures

21

Clinical Signs - Hemotympanum =

blood behind ear drum, "racoon eyes" (periorbital bruising), other delayed findings

22

Examples of what you should look for when keeping general close observations to ensure no late sequela

Delayed CSF leak - most relevant clinical sign, neurological symptoms - if deterioration then surgery may be considered

23

monitoring must include ... - 2 points

close clinical observation with regular neurological checks, re-scan

24

Describe CSF leak

where cerebrospinal fluid leaks through the mouth/nose due to a tear in dura mater related to a traumatic brain injury, requires surgical intervention

25

Surgical approaches to remove tumours from skull

range from traditional neurosurgery to minimally invasive endonasal/endoscopic surgery