Osteology of the Skull and TMJ

Question 1

2 components of the skull

Answer 1

• Cranium
• Mandible

Question 2

How many bones form the skull?

Answer 2

22

Question 3

What type of joint joins most of the bones of the skull?

Answer 3

Sutures

Question 4

What is the bilateral moveable joint in the skull?

Answer 4

Temporomandibular joint

Question 5

What is the cranium?

Answer 5

Skull with the mandible removed

Question 6

2 gross compartments of the cranium

Answer 6

• Neurocranium
• Viscerocranium

Question 7

What is the neurocranium?

Answer 7

Part of cranium that houses the brain and attendant anatomical structures

Question 8

What is the viscerocranium?

Answer 8

All parts of cranium that aren’t neurocranium (facial skeleton)

Question 9

What are the calvaria and skull base?

Answer 9

• Calvaria = upper, box-like bony structure housing brain
• Skull base = base of calvaria articulating with vertebral column

Question 10

Basic functions of the skull

Answer 10

• Enclose and protect brain and special sense organs
• Create specialised environment for brain to thrive
• Site of attachment for muscles and meninges

Question 11

What type of bones are the bones of the skull?

Answer 11

Flat bones

Question 12

3 layers of flat bones of the skull

Answer 12

• Compact bone (outer plate)
• Spongy bone (diploe)
• Compact bone (inner plate)

Question 13

Which parts of the cranium are very thick?

Answer 13

• Occipital bone
• Frontal bone

Question 14

Which part of the cranium is very thin?

Answer 14

Pterion

Question 15

Gross divisions of the calvaria

Answer 15

• Base
• Cap

Question 16

Main bones of the cranial cap

Answer 16

• Frontal
• Parietal
• Occipital
• Temporal

Question 17

Suture lines of the cranial cap

Answer 17

• Coronal
• Longitudinal
• Lambdoid
• Bregma (point)
• Lambda (point)

Question 18

3 fossae of cranial floor

Answer 18

• Anterior
• Middle
• Posterior

Question 19

Functions of foramina of cranial floor

Answer 19

• Allow passage between intra- and extra-cranial compartments
• Lessen weight of skull

Question 20

What joint joins the left and right mandibles?

Answer 20

Mental symphysis (midline fibrous joint)

Question 21

What does the articular disc/meniscus do in the TMJ capsule?

Answer 21

• Separates bony surfaces from making direct contact
• Creates 2 cavities

Question 22

2 cavities of the TMJ capsule

Answer 22

• Upper cavity
• Lower cavity

Question 23

What type of movements do the 2 TMJ cavities allow?

Answer 23

• Upper = translational movements (gliding joint)
• Lower = rotational movements (modified hinge joint)

Question 24

Where do the muscles of mastication receive motor innervation from?

Answer 24

Mandibular division of CNV

Question 25

4 primary muscles of mastication

Answer 25

- Masseter - Temporalis - Lateral pterygoid - Medial pterygoid

Question 26

Which muscles of mastication are jaw-depressors?

Answer 26

Lateral pterygoid

Question 27

Which muscles of mastication are jaw-elevators?

Answer 27

- Masseter - Temporalis - Medial pterygoid

Question 28

Where do muscles of facial expression receive motor innervation from?

Answer 28

Motor division of CNVII

Question 29

2 categories of muscles of facial expression

Answer 29

- Sphincter muscles - Muscles of facial expression proper

Question 30

What do sphincter muscles of facial expression do?

Answer 30

Attend orifices of cavities (eyes, mouth)

Question 31

What do muscles of facial expression proper do?

Answer 31

Alter facial expression