Skull Osteology

Question 1

Name the 5 pneumatic bones of the skull.

Answer 1

1. Maxilla
2. Sphenoid
3. Ethmoid
4. Frontal
5. Temporal

Question 2

Thinnest part of skull’s lateral wall

Answer 2

Pterion

Question 3

Bones that make up the pterion

Answer 3

*MNEMONIC: Please Get Some Freaking Plan

1. Greater wing of sphenoid
2. Squamous part of temporal bone
3. Frontal bone
4. Parietal bone

Question 4

Structures passing deep to pterion

Answer 4

Middle meningeal vessels anterior divisions

Sylvian fissure of cerebrum

Question 5

Clinical significance of trauma to pterion

Answer 5

Risking tearing or damage to middle meningeal vessels which can lead to extradural hematoma, causing brain compression

Question 6

Name of pterion in the newborn

Answer 6

anterolateral/Sphenoidal fontanelle

Question 7

By when does the sphenoidal fontanelle ossify?

Answer 7

2-3 months after birth

Question 8

Asterion formed by which bones?

Answer 8

*MNEMONIC: A More Plausible One

1. Mastoid part of temporal bone
2. Parietal bone
3. Occipital

Question 9

Name of asterion in newborn

Answer 9

Mastoid/Posterolateral fontanelle

Question 10

Asterion ossifies by

Answer 10

6 months - 1 year after birth

Question 11

Part of temporal bone that can’t be seen in norma lateralis

Answer 11

Petrous part

Question 12

Parts of the temporal bone that can be seen in norma lateralis

Answer 12

Mastoid 
Squamous 
Zygmatic process
Tympanic plate 
Styloid process

Question 13

Structures attaching to zygomatic arch

Answer 13

2 muscles and 1 fascia

Temporal fascia
Temporalis muscle (both attach on its upper border)
Masseter (attaches on its inferior border)

Question 14

Artery whose pulsation can be felt when palpated against zygomatic arch

Answer 14

Superficial temporal artery

Question 15

Termination of superficial temporal artery

Answer 15

Into 3 branches:

1. frontal
2. parietal
3. transverse facial

Question 16

Coronal and sagittal sutures meet at the

Answer 16

bregma

Question 17

Highest point of the skull

Answer 17

vertex

Question 18

Parietal foramen transmits the

Answer 18

emissary vein connecting superior sagittal sinus with scalp veins

Question 19

How many fontanelles are in a newborn? Name them

Answer 19

6

2 mastoid fontanelles
2 sphenoid fontanelles
1 anterior/bregmatic fontanelle
1 posterior/lambdoid fontanelle

Question 20

State order in which fontanelles close

Answer 20

1. Posterior fontanelle (1-3 months)
2. Sphenoidal fontanelle (2-3 months)
3. Mastoid fontanelle (6-12 months)
4. Anterior fontanelle (9-18 months)

Question 21

Nerve that carries preganglionic secretomotor fibers to sublingual and submandibular glands

Answer 21

Chorda tympani

Question 22

Locations of auriculotemporal and chorda tympani nerves

Answer 22

Chorda tympani is medial to temporal bone’s spine while auriculotemporal nerve is lateral to the spine

Question 23

Type of fibers carried by auriculotemporal

Answer 23

postganglionic secretomotor fibers to parotid gland