Lecture 1 - General Organisation of the Head and Neck

Question 1

Which nerve innervates the muscles of facial expression?

Answer 1

Facial Nerve

Question 2

Which branch of the nerve innervating the muscles of facial expression innervates:

1) orbicularis oculi
2) orbicularis oris
3) buccinator

Answer 2

1) Temporal and zygomatic branches of facial nerve
2) Buccal branch
3) Buccal branch

Question 3

What is the action of orbicularis oculi?

Answer 3

Closes eye

Question 4

What is the action of orbicularis oris?

Answer 4

Closes mouth

Question 5

What is the action of buccinator?

Answer 5

Holds cheek close to teeth when chewing to prevent food pooling between cheek and gums

Question 6

Which nerve innervates the muscles of mastication?

Answer 6

Mandibular branch of trigeminal nerve

Question 7

What is the action of the masseter muscle?

Answer 7

Elevates mandible and closes jaw

Question 8

What is the action of temporalis?

Answer 8

Elevates mandible

Question 9

What are the actions of the pterygoids?

Answer 9

Protrudes mandible, opens jaw, elevation and contralateral excursion

Question 10

Which nerve innervates levator palpebrae superioris (LPS)?

Answer 10

Oculomotor nerve

Question 11

What does LPS do?

Answer 11

Elevates upper eyelid

Question 12

Which nerve innervates occipitofrontalis?

Answer 12

Facial nerve

Question 13

What is the action of occipitofrontalis?

Answer 13

Elevates eyebrows

Question 14

Which fascial layer is the platysma muscle found in?

Answer 14

Superficial cervical fascia

Question 15

Which nerve innervates platysma?

Answer 15

Facial nerve

Question 16

What is the action of platysma?

Answer 16

Depresses corner of mouth and assists depression of mandible

Question 17

Where are the attachment sites of platysma?

Answer 17

Originates from lower mandible, runs down neck, over clavicle and inserts into chest wall

Question 18

Which nerve innervates sternocleidomastoid (SCM)?

Answer 18

Accessory nerve

Question 19

What are the attachment sites of SCM?

Answer 19

Arises from sternum and clavicle and inserts into mastoid process

Question 20

What is the action of SCM?

Answer 20

Lateral flexion of neck and tilts chin up to contralateral side. When both muscles contract, neck flexes

Question 21

What is torticollis?

Answer 21

Distonic muscle (abnormally contracts)

Question 22

Which nerve innervates trapezius?

Answer 22

Accessory nerve

Question 23

What are the attachment sites of trapezius?

Answer 23

Originates from external occipital protuberance and superior nuchal line and inserts into spine of scapula, acromion and lateral third of clavicle

Question 24

What is the action of trapezius?

Answer 24

Elevates shoulder

Question 25

True or false: digastric is an infra-hyoid muscle

Answer 25

FALSE - digastric is suprahyoid

Question 26

True or false: omohyoid is a suprahyoid muscle

Answer 26

FALSE - omohyoid is infrahyoid

Question 27

Where does digastric attach?

Answer 27

Mandible, hyoid bone and mastoid process

Question 28

Where does omohyoid attach?

Answer 28

Scapula, passes under SCM

Question 29

What are the borders of the carotid triangle?

Answer 29

SCM, digastric and omohyoid muscles

Question 30

What are the fascial planes of the neck?

Answer 30

``` Superficial cervical fascia Deep cervical fascia: Investing layer Pre-tracheal (+buccopharyngeal fascia) Pre-vertebral layer Carotid sheath ```

Question 31

Which structures pass through the carotid sheath?

Answer 31

Common carotid artery, internal jugular vein and vagus nerve

Question 32

Which structures pass through the pre-tracheal fascia layer?

Answer 32

Thyroid gland, trachea and oesophagus

Question 33

What are the borders of the anterior triangle of the neck?

Answer 33

Inferior margin of mandible Imaginary midline of neck Anterior margin of SCM

Question 34

What are the borders of the posterior triangle of the neck?

Answer 34

Clavicle Posterior margin of SCM Anterior margin of trapezius

Question 35

Describe the implications for the spread of infection within the neck as a result of compartmentalisation by cervical fascial planes

Answer 35

Retropharyngeal space and pre-tracheal spaces extend inferiorly into mediastinum. Infections within these spaces can spread to cause mediastinitis

Question 36

What are the layers of the scalp?

Answer 36

``` Skin Connective tissue (dense) Aponeurosis (epicranial) Loose areolar connective tissue Periosteum ```

Question 37

What is found in the skin layer of the scalp?

Answer 37

Hair follicles and sebaceous glands

Question 38

Which two muscles does the aponeurosis of the scalp connect?

Answer 38

Occipitalis and frontalis

Question 39

Where are scalp infections usually present, why and where can these infections spread to?

Answer 39

Loose CT Pus and blood spread easily within and can pass into cranial cavity along emissary veins therefore infections can spread from scalp to meninges -> meningitis

Question 40

Why do scalp lacerations lead to profuse bleeding?

Answer 40

1) pull of occipitofrontalis muscle prevents closure of bleeding vessels and skin 2) blood vessels stuck to dense CT and therefore cannot constrict fully 3) anastomotic blood supply