HEAD AND NECK I

Question 1

What is the zygomatic arch?

Answer 1

The cheekbone, formed by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone

Question 2

What are the rami of the mandible?

Answer 2

The vertical parts on either side of the jawbone. Flat quadrilateral bones marked by oblique ridges. Their outer surface is an attachment for the masseter muscle

Question 3

What is the coronoid process?

Answer 3

A thin, triangular eminence of the mandible which is flattened from side-to-side and varies in shape and size. Its anterior border is convex and is continuous below with the anterior border of the ramus

Question 4

What is the condyle of the mandible?

Answer 4

The head of the mandible, which presents an articular surface for articulation with the articular disk of the temporomandibular joint. It is convex in the AP aspect, and from side to side

Question 5

What is the external auditory meatus

Answer 5

The passageway that leads from the outside of the head to the tympanic membrane, or eardrum membrane, of each ear. It conducts soundwaves to the tympanic membrane. It is a partly cartilaginous and partly bony canal of diameter 6mm and length 25mm

Question 6

What does the tympanic membrane separate?

Answer 6

The external ear from the middle ear

Question 7

What’s the infratemporal fossa?

Answer 7

A complex area located at the base of the skull, deep to the masseter. It is closely associated with both the temporal and pterygopalatine fossae and acts as a conduit for neurovascular structures entering and leaving the cranial cavity

Question 8

What is the lateral pterygoid plate of the sphenoid bone?

Answer 8

The lateral pterygoid plate is a broad, thin and everted and forms the lateral part of a process from the inferior part of the sphenoid bone. It’s an origin for the lateral pterygoid muscle

Question 9

What is the medial pterygoid plate of the sphenoid bone?

Answer 9

A horse-shoe shaped process that arises from the underside of the sphenoid bone. It’s narrower and longer than the lateral pterygoid plate and has a hook-like process, the pterygoid hamulus, around which the tensor veli palatini glides

Question 10

What is the carotid canal?

Answer 10

A passage within the petrous temporal bone that transmits the internal carotid artery and sympathetic plexus. Its inferior opening is called the carotid foramen and is situated anteriorly to the jugular foramen and medially to the carotid plate

Question 11

What does the carotid canal open into?

Answer 11

The middle cranial fossa, superior to the foramen lacerum

Question 12

What is the styloid process of the temporal bone?

Answer 12

A slender, pointed part that projects anteroinferiorly from the inferior surface of the petrous temporal bone. It serves as an anchor for several muscles of the tongue and larynx

Question 13

What is the stylomastoid foramen?

Answer 13

A rounded opening on the inferior surface of the petrous temporal bone, between the base of the styloid and mastoid processes. It transmits the facial nerve

Question 14

What divides the jugular foramen into 2 parts and what are these parts?

Answer 14

A fibrous or bony septum called the jugular spine separates the jugular foramen into the smaller pars nervosa and the larger pars vascularis

Question 15

What does the pars nervosa of the jugular foramen contain?

Answer 15

The inferior petrosal sinus and the glossopharyngeal nerve

Question 16

What does the pars vascularis of the jugular foramen contain?

Answer 16

The jugular bulb (a venous expansion), the vagus nerve and the accessory nerve

Question 17

What is the occipital condyle?

Answer 17

A round protuberance of the occipital bone

Question 18

What is the pterygopalatine fossa?

Answer 18

A bilateral, conical depression extending deep from the infratemporal fossa to the nasal cavity via the sphenopalatine foramen

Question 19

What is the calvaria?

Answer 19

The top part of the skull, which includes the superior portions of the frontal, occipital and parietal bones

Question 20

What is a fontanelle?

Answer 20

An anatomical feature of the infant human skull comprising any of the soft membranous sutures between cranial bones that make up the calvaria of a foetus or infant

Question 21

What is craniosynostosis?

Answer 21

A birth defect where 1 or more sutures of the skull close too early, which can limit or slow the growth of the baby’s brain. The baby’s head will stop growing in the affected area(s), leading to abnormal shaping of the head

Question 22

What is sagittal synostosis?

Answer 22

The baby’s head grows long and narrow (scaphocephaly)

Question 23

What is coronal synostosis?

Answer 23

The baby may have a flattened forehead on the side of the skull that closed early (anterior plagiocephaly)

Question 24

What is bicoronal synostosis?

Answer 24

The baby’s head will grow broad and short (brachycephaly)

Question 25

What happens in lambdoid synostosis?

Answer 25

The baby's head may be flattened on the back side (posterior plagiocephaly)

Question 26

What is the mental foramen?

Answer 26

One of the 2 foramina on the anterior surface of the mandible. It transmits the terminal branches of the inferior alveolar nerve and vessels (the mental artery)

Question 27

What is the auriculotemporal nerve?

Answer 27

A sensory branch of the posterior division of the mandibular nerve (V3) that runs with the superficial temporal artery an vein, and provides sensory innervation to various regions on the side of the head

Question 28

What is the maxillary artery?

Answer 28

The largest terminal branch of the external carotid artery that arises at the back of the neck of the mandible. It supplies deep structures of the face, such as the mandible, maxilla, teeth, muscles of mastication, palate, nose and part of the cranial dura mater

Question 29

What is the mandibular nerve?

Answer 29

The third branch of the trigeminal nerve. It has a sensory role in the head, and also has motor function. V3 exits the cranium through foramen ovale. It courses through the infratemporal fossa

Question 30

Describe the masseter and its points of origin and insertion

Answer 30

A strong, thick rectangular muscle that originates from the zygomatic arch and extends down to the mandibular angle. It has a superficial part and a deep part

Question 31

What's the function of the masseter?

Answer 31

Elevation and protrusion of the mandible, as well as supporting the articular capsule of the temporomandibular joint

Question 32

What innervates the masseter?

Answer 32

The masseteric nerve of the mandibule nerve

Question 33

What's the blood supply to the masseter?

Answer 33

The masseteric artery

Question 34

What are the 4 muscle of mastication?

Answer 34

Masseter, temporalis muscle, the lateral pterygoid muscle and the medial pterygoid muscle

Question 35

Describe temporalis

Answer 35

Temporalis is a flat, broad, fan-shaped muscle that lays within the temporal fossa, superior to the zygomatic arch, so it covers much of the temporal bone

Question 36

Origin and insertion of temporalis

Answer 36

Origin- the temporal fossa | Insertion- the apex and medial surface of the coronoid process of the mandible

Question 37

Innervation of temporalis

Answer 37

Deep temporal branches of the mandibular nerve

Question 38

Actions of temporalis

Answer 38

Elevates the mandible and retracts the mandible

Question 39

What covers temporalis?

Answer 39

A dense layer of deep temporal fascia

Question 40

Describe the lateral pterygoid muscle and its origin and insertion

Answer 40

Origin- the underside of the greater wing of the sphenoid and the lateral aspect of the lateral pterygoid plate Insertion- the anterior condylar process, the capsule of the temporomandibular joint and the front edge of the articular disc. Its fibres run posterolaterally

Question 41

Innervation of the lateral pterygoid muscle

Answer 41

Lateral pterygoid nerve of the mandibular nerve

Question 42

Describe the actions of the lateral pterygoid on bilateral and unilateral contraction

Answer 42

Bilateral contraction causes protrusion and depression of the mandible and stabilisation of the condylar head during closure. Unilateral contraction allows medial movement of the mandible

Question 43

Describe the medial pterygoid muscle and its origin and insertion

Answer 43

Origin- deep head from the lateral pterygoid plate; superficial head from the tuberosity of the maxilla Insertion- the medial surface of the ramus and angle of the mandible Fibres run posteroinferolaterally

Question 44

Innervation of the medial pterygoid muscle

Answer 44

Innervated by the medial pterygoid nerve of the mandibular nerve

Question 45

Describe actions of the medial pterygoid muscle on bilateral and unilateral contraction

Answer 45

Bilateral contraction causes elevation and protrusion of the mandible Unilateral contraction causes medial rotation of the mandible

Question 46

What does orbicularis oculi surrouns?

Answer 46

The palpebral aperture

Question 47

What are the parts of orbicularis oculi?

Answer 47

A thin palpebral part and a more substantial orbital part

Question 48

Origin and insertion of orbicularis oculi

Answer 48

Origin- medially from the medial palpebral ligament and the bone above and below it Insertion- lateral to the palpebral aperture

Question 49

Action of orbicularis oculi

Answer 49

Contraction of the palpebral part closes the eye gently, while contraction of the whole muscle screws up the eyes by closing the eyelids tightly

Question 50

What do the superficial fibres of orbicularis oris encircle?

Answer 50

The oral commissure

Question 51

Origin and insertion of orbicularis oris

Answer 51

Origin- the medial aspects of the maxilla and mandible | No insertion

Question 52

Action of orbicularis oris

Answer 52

Close the oral commissure and press the lips together

Question 53

What fills the deep hollow between the buccinator and masseter?

Answer 53

The buccal fat pad

Question 54

What 2 muscles are used t smile?

Answer 54

``` Zygomaticus major (pulls on orbicularis oris superoposteriorly) Risorius (pulls on orbicularis oris posteriorly ```

Question 55

Describe platysma

Answer 55

It lies partly in the face, but mainly in the neck. It lies within the subcutaneous fascia of the neck. Most of its fibres insert along the border of the mandible, but its more posterior fibres insert into orbicularis oris

Question 56

What is the action of platysma?

Answer 56

Pulls the corners of the mouth inferoposteriorly