W19/L4 + L10: Skull anatomy

Question 1

What is the upper part of the cranium called

Answer 1

The vault

Question 2

What are the three layers of all of the bones of the skull?

Answer 2

External & internal layers of compact bone, with a middle layer of spongy bone (the diploe)

Question 3

What are the skull sutures?

Answer 3

Immobile joint between the seperate bones

Question 4

Name the four “main” sutures

Answer 4

Coronal
Saggital
Lamboid
Pterion

Question 5

What bones form the coronal suture?

Answer 5

Frontal bone and the 2 parietal bones

Question 6

What bones form the saggital suture?

Answer 6

The two parietal bones

Question 7

<p>What bones form the lambdoid suture?</p>

Answer 7

<p>The two parietal bones and the occipital bone</p>

Question 8

Which two sutures are in the coronal plane?

Answer 8

Coronal & lamboid

Question 9

What bones form the pterion?

Answer 9

Frontal
Parietal
Temporal
Sphenoid

Question 10

What is the significance of the pterion?

Answer 10

The bones are thin at this point, making it a site of weakness

The middle meningeal artery runs directly deep to the pterion

Question 11

What are the 2 parts of the frontal bone?

Answer 11

The vertical part (forehead)

The horizontal part (forming the anterior cranial fossa and roof of the orbit)

Question 12

What is the line of demarcation between the 2 parts of the frontal bone?

Answer 12

The supraorbital margins

Question 13

Describe the parietal bone

Answer 13

Flat, rectangular bone moulded to brain contour

Question 14

Describe the features of the occipital bone

Answer 14

Flat, moulded to posterior aspect of brain

Prominent external occipital protuberance

Question 15

What are the 4 processes of the temporal bone?

Answer 15

Zygomatic
Mastoid
Styloid
Petrous

Question 16

What is the flat “body” of the temporal bone called?

Answer 16

The squamous part

Question 17

Describe the zygomatic process

Answer 17

A thin, forward projection that articulates with the zygomatic bone

Question 18

Describe the mastoid process

Answer 18

A thick, chunky, downwards projection

Question 19

Describe the styloid process

Answer 19

Deep, sharp, downwards projection

Question 20

What structures attach to the styloid process of the temporal bone?

Answer 20

Ones for the oral cavity & pharynx

Question 21

Describe the petrous process of the temporal bone

Answer 21

A chunky, pyramid shaped, inwards projection

Question 22

<p>What are the main features of the sphenoid bone</p>

Answer 22

<p>A body with two wings The body (including sella turcica) has a depression (the hypophysial fossa) for the pituitary gland The superior orbital fissure divides the wings into the lesser (anterosuperior) and greater (posterior) wings</p>

Question 23

<p>What features of the ethmoid bone are visible from inside the cranium?</p>

Answer 23

<p>The cribiform plate, with lots of tiny holes The christa galli</p>

Question 24

What is the only group of foramina in the anterior cranial fossa? And what posses through them?

Answer 24

The holes of the cribiform plate of the ethmoid bone containing the olfactory nerves

Question 25

What's the hypophysial fossa?

Answer 25

The depression in the body of the sphenoid bone where the pituitary sits

Question 26

What are the 6 paired foramina in the middle cranial fossa?

Answer 26

Optic canal ``` Superior orbital fissure Foramen rotundum Foramen ovale Foramen spinosum (these 4 form that nice arch) ``` Foramen lacerum

Question 27

What does the optic canal transmit?

Answer 27

Optic nerve | Opthalmic artery

Question 28

What does the superior orbital fissure transmit?

Answer 28

Nerves for the extra-ocular muscles V1 of trigeminal Inferior opthalmic vein

Question 29

What does the F. rotundum transmit?

Answer 29

Maxillary nerve

Question 30

What does the F. ovale transmit?

Answer 30

Mandibular nerve

Question 31

What does the F. spinosum transmit?

Answer 31

Middle meningeal artery

Question 32

What does the F. lacerum transmit?

Answer 32

Nothing! It's covered by a cartilage membrane in living people

Question 33

What are the 4 foramina of the posterior cranial fossa?

Answer 33

Internal acoustic meatus Jugular foramen Hypoglossal canal Foramen magnum

Question 34

What does the int. acoustic meatus transmit?

Answer 34

Facial and vestibulocochlear nerves

Question 35

What does the jugular foramen transmit?

Answer 35

Cranial nerves IX, X, XI Internal jugular vein (glossopharyngeal, vagus, accessory)

Question 36

What does the hypoglossal canal transmit?

Answer 36

The hypoglossal nerve

Question 37

Is the jugular foramen a foramen within a bone?

Answer 37

No - it's a deficiency between the petrous process of the temporal bone and it's joint with the occipital bone

Question 38

From what aspect is the hypoglossal canal best seen?

Answer 38

From the inferior aspect, looking up

Question 39

What are the 3 layers of the meninges?

Answer 39

Dura (outer) Arachnoid (middle) Pia (inner)

Question 40

What part of the brain does the anterior cranial fossa house?

Answer 40

Frontal lobe

Question 41

What part of the brain does the middle cranial fossa house?

Answer 41

Temporal lobe

Question 42

What part of the brain does the posterior cranial fossa house?

Answer 42

Occipital lobe | Cerebellum

Question 43

What bones form the anterior cranial fossa?

Answer 43

Horizontal plate of the fronal bone Cribiform plate of ethmoid Lesser wings of sphenoid

Question 44

What bones form the middle cranial fossa?

Answer 44

Body in greater wings of sphenoid | Petrous part of temporal bone

Question 45

What bones form the posterior cranial fossa?

Answer 45

Petrous part of temporal bone | Occipital bone