1) General organisation of H&N

Question 1

What are the major muscle groups in the head?

Answer 1

Muscles of facial expression
Buccinators (muscles of cheek)
Occipitofrontalis muscle
Muscles of mastication

Question 2

What are the actions of facial muscles?

Answer 2

Move the skin & change facial expressions
Sphincters & dilators (open & close eyes, mouth)
Buccinators keep cheeks taut & aid chewing

Question 3

What is the innervation of the muscles of mastication?

Answer 3

Mandibular division of the Trigeminal nerve (CNViii)

Question 4

What does the facial nerve (CNVII) innervate?

Answer 4

Platysma (superficial muscle of neck & chin)
Muscles of facial expression
Buccinators
Muscles of the ear
Occipitofrontalis muscle
(CN VII enters the parotid gland where it divides into extra-cranial branches)

Question 5

Name a non-traumatic cause of facial paralysis

Answer 5

Inflammation of CN VII near its exit from cranium at stylomastoid foramen

Question 6

Describe Bell’s palsy

Answer 6

Inflammation causes oedema & compression of facial nerve in intracranial facial canal
Affected area sags, facial expression distorted, face appears passive or sad

Question 7

What injuries can occur to the branches of the facial nerve?

Answer 7

Branches are superficial
Injured in wounds, cuts & childbirth
Parotid gland surgery or disease (pain in auricle of ear, external acoustic meatus, temporal region & TMJ)

Question 8

What is the arterial supply to the face?

Answer 8

Facial artery (main supply)
External carotid artery (branches)

Question 9

Describe the facial artery

Answer 9

Artery winds round inferior border of mandible.
Pulse can be palpated
Lots of anastomoses, if lacerated both facial arteries must be compressed

Question 10

Describe the venous drainage of the face

Answer 10

Facial vein (main) drains into the Internal Jugular vein
Superficial temporal, maxillary & other veins form the EJV
Both IJV & EJV drain into subclavian vein

Question 11

Describe the fascia surrounding structures in the neck

Answer 11

Covered by layer of subcutaneous superficial fascia
Compartmentalised by deep cervical fascial layers
(determine direction infection may spread)

Question 12

Describe the superficial cervical fascia

Answer 12

Fatty connective tissue
Lies between dermis of skin & investing layer of deep cervical fascia
Thin anteriorly
Contains cutaneous nerves, blood & lymph vessels and anterolaterally the Platysma

Question 13

Describe the platysma

Answer 13

Broad thin sheet of muscle, tenses the skin
Develops from 2nd pharyngeal arch
Supplied by branches of facial nerve (CN VII)
Covers anterolateral aspect of neck
Inferiorly, gap anterior to larynx & trachea
Depresses the mandible, draws corners of mouth inferiorly (grimace)

Question 14

Describe the layers of the deep cervical fascia in the neck

Answer 14

3 layers:
Investing
Pretracheal
Prevertebral

Condenses around common carotid arteries, IJVs & Vagus nerve to form CAROTID SHEATH

Question 15

What are the functions of the deep cervical fascia in the neck?

Answer 15

Support (viscera e.g. thyroid gland, muscles, vessels & deep lymph nodes)
Limit the spread of abscesses from infections
Slipperiness allows structures to move and pass over one another (swallowing, turning head)

Question 16

Describe the investing layer of deep cervical fascia

Answer 16

Most superficial
Surrounds entire neck deep to skin
Encloses: SCM, Trapezius, Submandibular & Parotid salivary glands

Question 17

Describe the pretracheal layer of deep cervical fascia

Answer 17

Thin layer, anterior part of neck only
Inferiorly extends into thorax & blends with fibrous pericardium, laterally blends with carotid sheath
Muscular layer: encloses Infrahyoid muscles
Visceral layer: Thyroid gland, trachea, oesophagus

Question 18

Describe the prevertebral layer of deep cervical fascia

Answer 18

Innermost layer of deep fascia
Sheath for vertebral column & assoc. muscles
From base of cranium of 3rd thoracic vertebrae
Extends laterally as axillary sheath (axillary vessels & brachial plexus)

Question 19

What is the carotid sheath?

Answer 19

Tubular, fibrous structure
Base of cranium to root of neck
Contains: Common carotid artery, IJV, CN X (Vagus)

Question 20

What are cleavage planes?

Answer 20

Layers of deep cervical fascia form natural cleavage planes

Separation of tissues during surgery

Question 21

If an infection occurs between the investing layer and muscular part of the pretracheal layer surrounding the infrahyoid muscles, where will it spread?

Answer 21

Won’t spread beyond the manubrium

Question 22

If an infection occurs between the investing layer and visceral pretracheal layers, where will it spread?

Answer 22

Into the thoracic cavity anterior to the pericardium

Question 23

Where will pus from an abscess behind the prevertebral layer extend?

Answer 23

Laterally in the neck
May perforate fascial layer and enter retropharyngeal space
Bulge in pharynx (retropharyngeal abscess) causing dysphagia (difficulty swallowing) & dysphonia (difficulty speaking)

Question 24

What is the retropharyngeal space?

Answer 24

Potential space between prevertebral fascia and superficial fascia surrounding pharynx
Major route of spread of infection from neck to thorax
Space runs to diaphragm

Question 25

Name the borders of the anterior triangle of the neck

Answer 25

``` Anterior - mid-line Posterior - anterior border of SCM Superior - inferior border of mandible Apex - jugular notch in the manubrium Roof - superficial cervical fascia & platysma Floor - pharynx, larynx, thyroid gland ```

Question 26

What are the 4 triangles within the anterior triangle?

Answer 26

Submandibular (digastric) triangle Submental triangle Carotid triangle Muscular (omotracheal) triangle

Question 27

Contents of the submandibular (digastric) triangle

Answer 27

Submandibular gland & lymph nodes Hypoglossal & mylohyoid nerves Parts of facial artery & vein

Question 28

Contents of the submental triangle

Answer 28

Submental lymph nodes | Small veins which unite to form ant. jugular vein

Question 29

Contents of the carotid triangle

Answer 29

``` Carotid sheath (CCA, IJV, Vagus N, Deep cervical lymph nodes) Thyroid gland Larynx & Pharynx ECA & some branches Hypoglossal & spinal accessory nerves Branches of cervical plexus ```

Question 30

Contents of the muscular (omotracheal) triangle

Answer 30

Sternothyroid Sternohyoid Thyroid Parathyroid

Question 31

Name the borders of the posterior triangle of the neck

Answer 31

Anterior - posterior border of SCM Posterior - anterior border of Trapezius Inferiorly - middle third of clavicle, between trapezius & SCM Apex - where SCM & Trapezius meet on sup. nuchal line of occipital bone Roof - Investing layer of deep cervical fascia Floor - Muscles covered by prevertebral deep cervical fascia

Question 32

What are the 2 triangles within the posterior triangle?

Answer 32

Occipital triangle | Omoclavicular (subclavian) triangle

Question 33

Contents of the occipital triangle

Answer 33

``` Spinal accessory nerve (CN XI) Trunks of brachial plexus Part of EJV Posterior branches of cervical plexus Cervicodorsal trunk Cervical lymph node ```

Question 34

Contents of the omoclavicular (subclavian) triangle

Answer 34

3rd part Subclavian artery Part of subclavian vein Suprascapular artery Supraclavicular lymph nodes

Question 35

What is the function of the hyoid bone?

Answer 35

Anterolateral part of neck: Attachments for Suprahyoid muscles superiorly, Infrahyoid muscles inferiorly (muscles steady or move hyoid & larynx)

Question 36

Name the suprahyoid muscles

Answer 36

Mylohyoid Geniohyoid Stylohyoid Digastric muscles (ant. & post. bellies joined by tendon & fibrous sling)

Question 37

What are the functions of the suprahyoid muscles?

Answer 37

Constitute the floor of the mouth Support hyoid - base for tongue to function Elevate hyoid & larynx (swallowing & tone prod.)

Question 38

Name the infrahyoid muscles

Answer 38

Superficial plane: Sternohyoid Omohyoid (sup. & inf. bellies joined by tendon & fibrous sling) Deep plane: Sternothyroid Thyrohyoid

Question 39

What are the functions of the infrahyoid muscles?

Answer 39

"strap muscles" - (ribbon-like) Anchor the hyoid, sternum, clavicle & scapula Depress the hyoid & larynx (swallowing & speaking) Work with suprahyoids to steady hyoid & provide firm base for tongue

Question 40

What are the muscles of mastication?

Answer 40

Masseter Temporalis Medial pterygoid Lateral pterygoid