Session 1 - Anatomy of the neck Flashcards
What are the two triangles formed when the neck is viewed anteriorly?
Anterior triangle Posterior triangle
Which of the two triangles which form the head and neck has more structures?
The anterior triangle
What are the borders of the anterior triangle of the neck? Anterior Posterior SUperior Roof Floor
o Anterior – Mid line o Posterior – The anterior border of SCM o Superior – Inferior border of the mandible o Apex – Jugular notch in the manubrium o Roof – Superficial cervical fascia, containing the platysma o Floor – Pharynx, larynx, thyroid gland
What are the four subdivisions of the anterior triangle?
Submandibular Submental Carotid Muscular
What four things are contained within the submandibular triangle?
§ Submandibular gland § Submandibular lymph nodes § Hypoglossal and Mylohoid nerves § Parts of facial artery and vein
What two things are contained within the submental triangle?
§ Submental lymph nodes § Small veins which unite to form anterior jugular vein
What 7 structures are contained within the carotid triangle?
§ Carotid sheath § Thyroid gland § Larynx § Pharynx § External carotid artery and some of its branches § Hypoglossal and Spinal accessory nerves Branches of cervical plexus
What four muscles are contained with the muscular (omotracheal) triangle?
§ Sternothyroid § Sternohyoid § Thryoid Parathyroid
What is 4?
Submandibular triangle
What is 5?
Submental triangle
What is 6?
Carotid triangle
What is 7?
Muscular triangle
Give the borders of the posterior triangle of the neck Anterior Posterior Inferior Apex Roof Floor
o Anterior – Posterior border of SCM o Posterior – Anterior border of Trapezius o Inferiorly – Middle third of the clavicle, between Trapezius and SCM o Apex – Where SCM and Trapezius meet on the superior nuchal line of the occipital bone o Roof – Investing layer of deep cervical fascia o Floor – Muscles covered by the Prevertebral layer of deep cervical fascia
What is 2?
Occipital triangle
What is 3?
Omoclavicular triangle
What is found in the occipital triangle?
§ Spinal Accessory Nerve (CN XI) § Trunks of Brachial Plexus § Part of external jugular vein § Posterior branches of cervical plexus § Cervicodorsal trunk § Cervical lymph node
What is found in the omoclavicular triangle?
§ 3rd part Subclavian Artery § Part of Subclavian Vei § Suprascapular artery § Supraclavicular lymph nodes
What are the three main parts of the neck in cross section?
o Superficial fascia o Platysma o Deep cervical fascia § Investing § Pretracheal § Prevertebral Carotid Sheath
What is the platysma innervated by?
Facial nerve (CN VIII)
What four structures make up the deep cervical fascia (4)
o Investing o Pretracheal Prevertebral Carotid sheath
What are the three main functions of the deep cervical fascia
Support Limit the spread of abscesses that result from infection Fluidity
What does the investing layer enclose?
o Sternocleidomastoid o Trapezius o Submandibular and Parotid Salivary Glands
What does the pretracheal layer enclose?
o Muscular layer § Encloses infrahyoid muscles o Visceral layer § Thyroid gland § Trachea § Oesophagus
What is the prevertebral layer?
The innermost layer of the deep fascia which forms a sheath for the vertebral column. Extends laterally as the axillary sheath that surrounds the brachial plexus.
What four structures are found within the carotid sheath?
• Common carotid artery (ant-med) • IJV (ant-lat) • Vagus nerve (post) • Deep cervical LNs
What are cleavage planes?
The layers of deep cervical fascia form natural cleavage planes allowing separation of tissues during surgery.
What is the clinical significance of cleavage planes?
Deep fascial layer determine the direction in which abscesses in the neck may spread.
What three main places can infection occur between deep fascial layers?
Between the investing layer and the muscular part of the pretracheal Between the investing and visceral pretracheal layers Behind the prevertebral layer
Where will infection spread to if it derives from between the investing layer and the muscular part of the pretacheal?
Will not spread beyond manubrium
Where will infection spread if between the investing and visceral pretracheal layers?
Spread it thoracic cavity anterior to the pericardium
Where will infection spread if begind prevertebral layer?
May extend laterally into the neck § May perforate the fascial layer and enter the retropharyngeal space. § This will produce a bulge (retropharyngeal abscess) in the pharynx, resulting in dysphasia (difficulty swallowing) and dysphonia (difficulty speaking)
What is the retropharyngeal space?
A potential space between the Prevertebral layer of fascia and the fascia surrounding the pharynx superficially. This is the largest, most important interfascial space in the neck because it is the major route of spread of infection from the neck to the thorax. The space runs to the diaphragm.
WHat are the four main muscle groups of the head?
o Muscles of facial expression o Muscle of the cheek (buccinators) o Occipitofrontalis muscle Muscles of mastication
What are the muscles of mastication innervated by?
Mandibular division of the trigeminal nerve (branch of CN V)
What does the facial nerve supply? (CN VII)
Platysma, muscles of facial expression, buccinators, muscles of the ear and the occiptofrontalis muscle. Innervates parotid
What is the most common cause of non-traumatic facial paralysis?
Inflammation of the facial nerve near its exit from the cranium at the stylomastoid foramen
What does inflammation of facial nerve near its exit from the cranium at the stylomastoid foramen cause?
Oedema and compression of the nerve, causing the affected area to sag and distort the facial expression.
Give three places where facial nerve vulnerable to injury?
Child birth Surgery on parotid Parotid inflammation
Where does inflammation of the parotid gland cuase pain?
Auricle of the ear External acoustic meatus Temporal region TMJ
What does the hoid bone provide attachments for?
Suprahyoid muscles superiorly Infrahyoid muscles inferiorly
Name the four suprahyoid muscles
o Mylohyoid o Geniohyoid o Stylohyoid o Digastric Muscles
What are the three main functions of the suprahyoid muscles
Constitute the floor of the mouth Elevate the hyoid and larynx in relation to swallowing and tone production
Name four infrahyoid muscles (and divide into planes)
Superficial - Sternohyoid - Omohyoid Deep - Sternohyoid - Thyrohyoid
What is the significance of the infrahyoid muscles?
Anchor the hyoid, sternum, clavicle and scapula. Depress hyoid and larynx during swallowing and speaking. Provide a firm base for the tounge.
