Anatomy - Interior Of The Skull Flashcards Preview

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Flashcards in Anatomy - Interior Of The Skull Deck (33):
1

The roof of the cranial cavity is formed by the

Calvaria

Anterior: Frontal
Middle: Parietal
Posterior: Occipital

2

Attachment of falx cerebri?
What is falx cerebri?

Frontal crest

Falx cerebri is part of the dura mater

3

Frontal crest terminates at the beginning of the __

Groove for the superior sagittal sinus

which is the intradural venous structure

4

Parietal bones have grooves from which artery?

Middle meningeal a.

5

What are granular foveolae?

Small pits and depressions in the calvaria that host arachnoid granulations

6

The floor of the cranial cavity has 3 large depressions:

Anterior
Middle
Posterior cranial fossa

7

Anterior cranial fossa

Shallowest and most superior of the 3 depressions on the cranial cavity

Bones: frontal, ethmoid, sphenoid

Features:
Foramen cecum
Cribriform foramina
Anterior and posterior ethmoidal foramina

8

Foramen cecum

In the frontal bone on the border with the ethmoid

For the passage of nasal emissary veins

9

Cribriform foramina

In the cribriform plate

For the passage of axons of olfactory nerves

10

Anterior and posterior ethmoidal foramina

For passage of ethmoid a. and v.

11

The ethmoid forms a ___, and a ___ for ___.

The ethmoid forms a cribriform plate and a median crest, crista galli, for the attachment of the falx cerebri

12

Middle cranial fossa

Posterior and inferior to anterior cranial fossa.

Bones: sphenoid, temporal

13

Foramina of the Middle Cranial Fossa

Carotid canal
Optic canal
Foramen rotundum
Foramen lacerum
Foramen ovale
Foramen spinosum
Superior orbital fissure

ROLS SOC

14

What is the Sella Turcica?

"Turkish saddle"

centrally located upper part of body of the sphenoid

15

The limbus of the sphenoid forms the __

Anterior boundary of the chiasmatic sulcus, which is formed as the continuation of the optic canals where the optic nerves cross

16

What is the sella turcica formed by?

1. Tuberculum sellae - elevation at the posterior aspect of chiasmatic sulcus

2. Hypophysial fossa - depression housing pituitary gland

3. Dorsum sellae - bony ridge projecting superior with posterior clinoid processes as lateral edges

17

Optic canal

Goes through lesser wing of sphenoid, found in the base

Opens into orbit

For passage of CN II and ophthalmic a.

18

Superior orbital fissure

Located between greater and lesser wings of sphenoid

Opens into the orbit

For passage of:
CN III
CN IV
CN V1 (ophthalmic n.)
CN VI
ophthalmic veins

19

Foramen rotundum

Located posterior to the medial end of he superior orbital fissure

Opens externally into the pterygopalatine fossa

For passage of CN V2 (maxillary n.)

20

Foramen ovale

Opens inferiorly into the infratemporal fossa

For passage of:
CN V3 (mandibular n.)
Lesser petrosal n.
Accessory meningeal a.

21

Foramen spinosum

Located posterolateral to f. ovale

Opens into infratemporal fossa

For passage of middle meningeal a.

22

Blood supply to dura mater?

Middle meningeal a.

23

Carotid canal

Opens into the cranium posteromedial to f. ovale

For passage of internal carotid a. and nerve plexus

24

Foramen lacerum

Posterolateral to hypophyseal fossa

Partially filled with cartilage during life

25

Posterior cranial fossa

Largest, deepest, and most inferior of the 3 cranial fossa

26

The posterior cranial fossa is limited by___

Anteriorly
Laterally
Inferiorly/posteriorly

A: on the midline by dorsum sellae

L: superior border of the petrous part of temporal bone

I/P: occipital bone

27

Bony features of posterior cranial fossa

Clivus - -a shallow depression formed by sphenoid body and basilar part of occipital bone. Slopes posteriorly

Internal occipital crest - runs along midline from f. magnum to internal occ. protuberance. Divides posterior cranial fossa into 2 bilateral depressions, the deep cerebellar fossae

28

Foramen of the posterior cranial fossa

1. Foramen magnum
2. Jugular foramen
3. Internal acoustic meatus
4. Hypoglossal canal
5. Sinuses
A. Inferior petrosal
B. Sigmoid
C. Transverse

29

Foramen magnum

Largest foramen in the skull

Within occipital bone

For passage of:
Brainstem/spinal cord with meninges
Vertebral arteries
CN XI (spinal accessory n.)

30

Jugular foramen

At the base of the petrous ridge of the temporal bone

For passage of:
CN IX
CN X
CN XI
sigmoid sinus as it becomes the superior bulb of the internal jugular vein

31

Internal acoustic meatus

Anterosuperior to jugular foramen within petrous portion

For passage of:
CN VII
CN VIII
Labyrinthine a.

32

Hypoglossal canal

Anterolaterally within the foramen magnum

For passage of:
CN XII

33

Location of sinuses found in posterior cranial fossa

1. Inferior petrosal sinus
- lateral to clivus

2. Sigmoid sinus
- between temporal and occipital bones running towards jugular foramen

3. Transverse sinuses
- extend laterally from internal occipital protuberance to join sigmoid sinuses