Lecture 1: Skull

Question 1

Name all of the bones in the skull

Answer 1

1. Frontal bone
2. Temporal bone
3. Parietal bone
4. Zygomatic bone
5. Occipital bone
6. Sphenoid bone
7. Nasal bone
8. Ethmoid bone
9. Maxilla
10. Mandible
11. Vomer

Question 2

What is this?

Answer 2

Anterior Fontanelle

Found in new-borns

There is a membrane sitting there

The largest fontanelle found at the junction of the sagittal suture, coronal suture, and frontal suture;

(There is also lateral and posterior fontanelle- lateral closes first)

Question 3

Name the parts of this skull (8)

Answer 3

1) Frontal bone
2) Parietal bone (x2)
3) Occipital bone
4) Coronal suture
5) Lambdoid suture
6) Saggital suture
7) Bregma
8) Lmabda

Question 4

What is the name of the case where there is a delay in closing of the anterior fontanelle

Answer 4

Cleidocranial dysplasia

Question 5

Name the parts of the posterior skull

Answer 5

1) Sutural bone
2) Parietal bone
3) Squamous part of the occipital bone
4) Lamboid suture
5) Occipitomastoid suture
6) Saggital suture
7) Inion
8) Sueprior Nuchal line
9) Inferior nuchal line
10) External occiciptal crest
11) Mastoid process
12) Styloid process

Question 6

Whe the anterior fontanelle closes, it forms the _____

Answer 6

Bregma

Question 7

What is the name of the case (not disorder) where the posterior fontanelle closes early

Answer 7

Craniosynostosis

Question 8

What bones make up the Anterior of the Skull?

Answer 8

1) Frontal bone
2) Zygomatic
3) Maxilla
4) Nasal bone
5) Mandible

Question 9

Label

Answer 9

1) Frontal bone
2) Maxilla
3) Zygomatic
4) Nasal bone
5) Mandible

Question 10

Label

Answer 10

1) Frontal bone
2) Parietal bone
3) Temporal bone
4) Occipital bone
5) Zygomatic bone
6) Sphenoid
7) Maxilla
8) Nasal bone
9) Mandible

Question 11

Label

Answer 11

Mastoid process

Question 12

Where is the mastoid process?

Answer 12

In the temporal bone

Question 13

Where is the weakest point of the skull?

What is its clinical significance?

Answer 13

Pterion

Where lots of different bones come together

(anterior part of the) Middle menangial artery runs just behind here

Question 14

Describe the Surface anatomy of the pterion

Answer 14

____See next lecture_____

Question 15

What are fontanelles?

Answer 15

A fontanelle is an anatomical feature of infant human skull comprising any of the soft membranous gaps/sutures between cranial bones. It should close at the right time (not earlier or later).

• Anterior fontanel: Not fully ossified, membrane exists. Close ~18 months becomes bregma
• Posterior fontanel: Close at ~9months becomes lambda
• Lateral fontanel

Question 16

Coronal suture: groove for __________ artery.

Sagittal suture: groove for ________ artery.

Answer 16

Coronal suture: groove for anterior branch of middle meningeal artery.

Sagittal suture: groove for middle meningeal artery.

Question 17

What happens if the pterion is damaged?

Answer 17

Damage the anterior branch of the Middle Meningial artery

Extradural haemorrhage

Question 18

The intracranial fossa is divided into…….

Answer 18

1) Anterior fossa
2) Middle fossa
3) Posterior fossa

Question 19

Name the important foramen in the intracranium (Superior)

Answer 19

Question 20

What is Cleidocranial Dysplasia?

Answer 20

• Cleidocranial Dysplasia s a birth defect that mostly affects the bones and teeth.[1]
• The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together.[1]
• The front of the skull often does not close until later, and those affected are often shorter than average.[1]
• Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose.[1]
• Symptoms vary among people; however, intelligence is typically normal.[1]

delayed closure of anterior fontanelle

Question 21

What is Craniosynotosis

Answer 21

Clinical: Craniosynostosis

Craniosynostosis is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. Because the skull cannot expand perpendicular to the fused suture, it compensates by growing more in the direction parallel to the closed sutures

Question 22

What is a suture?

Answer 22

A suture is a type of fibrous joint, which only occurs in the skull (e.g. coronal suture is formed by the articulation of the frontal (1) and parietal bones (2)).

Question 23

identify the lambdoid, squamous, sphenoparietal and occipitomastoid sutures on a dry skull.

Answer 23

Question 24

What are the different areas of the Mandible?

Answer 24

• Ramus of the mandible
• Body of the mandible
• Condyle of the mandible
• Coronoid of the mandible
• Angle of the mandible

Question 25

Label

Answer 25

A) Body B) Ramus C) Condylar Process D) Coronoid process E) Mental foramen F) Madnibular foramen

Question 26

Label

Answer 26

1) Lingula 2) Mandibular foramen 3) Submandibular fossa 4) Mylohyoid line 5) Sublingual fossa

Question 27

What is Paget's Disease?

Answer 27

_Paget’s disease_ Skull bones getting thicker.

Question 28

Name the Bones forming the base of the skull. (Inferior view)

Answer 28

Bones forming the base of the skull. 1. Hard palate (maxilla) 2. Hard palate (palatine bone) 3. Zygomatic bone 4. Sphenoid bone 5. Vomer 6. Temporal bone 7. Occipital bone

Question 29

Name 3 bonny processes

Answer 29

Paired bony prominences. 1. Mastoid process (posterior belly of digastric muscle attaches to the medial aspect of mastoid process) 2. Occipital condyle (the atlas (vertebra CI) articulates with occipital condyle) 3. Styloid process

Question 30

Describe the boudaries AND name the bones forming each fossa. Anterior Intracranial fossae

Answer 30

Parts of _frontal, ethmoid, and sphenoid bones_ form the anterior cranial fossa. * **Anteriorly border:** inner surface of the frontal bone. * **Posteriorly border:** anterior border of prechiasmatic _sulcus of sphenoid_ (medial), _lesser wings of sphenoid bone_ (lateral) * **Floor**: frontal bone, ethmoid bone and the anterior aspects of the body and lesser wings of the sphenoid bone

Question 31

Describe the boudaries AND name the bones forming each fossa. Middle Fossa

Answer 31

The middle cranial fossa consists of _parts of the sphenoid and temporal bones_ * **Anterior border:** anterior edge of chiasmatic sulcus of body of sphenoid (midline) and greater wing of sphenoid (laterally). * **Posterior border:** posterior edge of dorsum sellae of body of sphenoid (midline) and petrous part of temporal bone (laterally). * Fl**oor**: the body and greater wing of the sphenoid, and the squamous and petrous parts of the temporal bone.

Question 32

Describe the boudaries AND name the bones forming each fossa. Posterior fossa

Answer 32

The posterior cranial fossa consists mostly of _parts of temporal and occipital bones_, with small contributions from _sphenoid and parietal bones_. *It is the largest and deepest of the three cranial fossae and contains the brainstem (midbrain, pons, and medulla) and the cerebellum.* * **Anterior border:** dorsum sellae of body of sphenoid bone (medial), superior border of petrous part of temporal bone (lateral). * **Posterior border:** internal surface of the squamous part of the occipital bone*, (petromastoid part of temporal bone and small parts of occipital and parietal bones).* * **Floor**: mastoid part of the temporal bone and the squamous, condylar and basilar parts of the occipital bone.

Question 33

Label

Answer 33

1) Foramen rotundum 2) Foramen Ovale 3) Carotid canal 4) Foramen spinosum 5) Jugular foramen 6) Foramen magnum 7) Hypoglossal canal 8) Internal acoustic meatus 9) Foramen lacerum 10) Superior orbital fissure 11) Optic canal 12) Cribiform plate

Question 34

What structures pass through the base of the extracranial foramina?

Answer 34

1. Incisive foramen: nasopalatine nerves and sphenopalatine vessels (artery and vein). 2. Greater palatine foramen: greater palatine nerve, greater palatine vessels 3. Foramen ovale: V2 (mandibular division of trigeminal) 4. Foramen spinosum: middle meningeal artery 5. Carotid canal: internal carotid artery 6. Jugular foramen: CN IX (glossopharyngeal), X (vagus), XI (accessory), internal jugular vein 7. Foramen magnum: spinal cord, vertebral arteries, (root of CN XI), meninges 8. Foramen lacerum: closed in life by a cartilaginous plug, and no structures pass through it completely (near internal carotid artery). 9. Forman rotundum: V2 (maxillary division of trigeminal) 10. Hypoglossal canal: CN XII (hypoglossal) 11. Internal acoustic meatus CN V2 (facial), C3 (vestibulocochlear), (labyrinthine a. and v.) 12. Optic canal: CN II (optic), ophthalmic a. 13. Cribriform plate: CN I (olfactory) 14. Superior orbital fissure: V1 (Ophthalmic division of trigeminal), III (Oculomotor), IV (Trochlear), VI (Abducent), superior opthalmic vein

Question 35

Label

Answer 35

1) Incisive fossa 2) Greater platine foramen 3) Formane Ovale 4) Foramen spinosum 5) Carotid canal 6) Jugular foramen 7) Foramen Magnum

Question 36

Name the Extracranial foramina and structures passing through it

Answer 36

**1) Incisive fossa** * Nasopalatine nerve * Sphenopalatine vessles **2) Greater platine foramen** * Greater palatine nerve and vessles **3) Formane Ovale** * Mandibular nerve * Lesser petrosal nerve **4) Foramen spinosum** * Middle meningeal artery **5) Carotid canal** * Internal carotid artery and nerve plexus **6) Jugular foramen** * Internal jugular vein * Inferior petrosal sinus * glossopharyngeal nerve (IX) * vagus nerve (X) * accessory nerve (XI) **7) Foramen Magnum** * Continuation of brain and spinal cord * Vertebral arteries and nerve plexus * Anteiror spinal artery * Posterior spinal arteries * Roots of accessory nerve (XII) * Meninges

Question 37

What foramina are we able to identify on a dry skull but not a wet one?

Answer 37

Foreamen lacerum

Question 38

Name the sinuses in the skull

Answer 38

Being aware of air-filled spaces within the skull is essential. They are identifiable on radiographs. Name the air-filled spaces and correspond them to the x-ray images. 1/4. Frontal sinuses 2. Ethmoidal cells. 3. Maxillary sinuses (only this sinus in neonates) 5. Sphenoidal sinuses

Question 39

Label

Answer 39

1. Frontal sinuses 2. Ethmoidal cells. 3. Maxillary sinuses (only this sinus in neonates) 4) Frontal sinus 5. Sphenoidal sinuses

Question 40

Name the intracranial foramina, and the structures passing through them

Answer 40

1) Foramen rotundum * (middle cranial fossa) * V2 maxillary division of the V trigeminal nerve 2) Foramen Ovale * V2 Mandibular division of the V trigeminal nerve 3) Carotid canal * Internal carotid artery 4) Foramen spinosum * Middle meningeal artery 5) Jugular foramen * Glossopharyngeal nerve, * Vagus nerve * Accessory nerve * Internal jugular vein 6) Foramen magnum * Spinal cord * Vertebral arteries 7) Hypoglossal canal * Hypoglossal nerve 8) Internal acoustic meatus * Facial nerve * Vestibulocochlear nerve 9) Foramen lacerum * \_\_\_\_ 10) Superior orbital fissure * V1 Opthmalmic division of trigeminal nerve * Occulomotor nerve * Trochlear nerve * Abducent nerve * Superior opthalmic vein 11) Optic canal * Optic nerve * Ophthamic artery 12) Cribiform plate * Olfactory nerves

Question 41

What travels through Foramen rotundum?

Answer 41

1) Foramen rotundum (middle cranial fossa) V2 maxillary division of the V trigeminal nerve 2) Foramen Ovale V2 Mandibular division of the V trigeminal nerve

Question 42

What travels through Carotid canal?

Answer 42

3) Carotid canal Internal carotid artery

Question 43

What travels through the Foramen Spinosum?

Answer 43

4) Foramen spinosum Middle meningeal artery

Question 44

What travels through the jugular foramen?

Answer 44

5) Jugular foramen Glossopharyngeal nerve, Vagus nerve Accessory nerve Internal jugular vein

Question 45

What travels through the foramen magnum?

Answer 45

6) Foramen magnum Spinal cord Vertebral arteries

Question 46

What travels through the hypoglossal canal?

Answer 46

7) Hypoglossal canal Hypoglossal nerve

Question 47

What travels through the Internal Acoustic Meatus?

Answer 47

8) Internal acoustic meatus Facial nerve Vestibulocochlear nerve

Question 48

What travels through the Superior Orbital Fissure?

Answer 48

10) Superior orbital fissure V1 Opthmalmic division of trigeminal nerve Occulomotor nerve Trochlear nerve Abducent nerve Superior opthalmic vein

Question 49

What travels through the optic canal?

Answer 49

11) Optic canal Optic nerve Ophthamic artery

Question 50

What travels through the Cribiform plates?

Answer 50

12) Cribiform plate Olfactory nerves

Question 51

What is Sinusitus?

Answer 51

_Clinical: sinusitis_ [Sinusitis](http://www.webmd.com/allergies/guide/allergies-sinusitis) is an inflammation, or swelling, of the tissue lining the [sinuses](http://www.webmd.com/allergies/picture-of-the-sinuses). Normally, [sinuses](http://www.webmd.com/allergies/video/sinus-function-breathing) are filled with air. But when they become blocked and filled with fluid, germs (bacteria, viruses, and fungi) can grow and cause an infection.