General Organisation of the Head and Neck Flashcards
Which nerve innervates the muscles of facial expression?
Facial nerve - cranial nerve 7
Which nerve innervates the muscles of mastication?
Trigeminal nerve- cranial nerve 5
What are the 5 extra cranial branches of the facial nerve?
- Temporal
- Zygomatic
- Buccal
- Marginal Mandibular
- Cervical
What is the most common cause of non-traumatic facial paralysis and how is it caused?
Bell’s Palsy
- Caused by inflammation of the facial nerve
Inflammation causes oedema which compresses the nerve as it runs through the base of the skull
What important structure does the facial nerve run through?
The Parotid Gland
How may a parotid gland cancer present?
Weakness of the facial muscles on one side in association with ipsilateral (on the same side) parotid enlargement
What are the 3 main muscles of mastication?
- Temporalis
- Masseter
- Pterygoids
What is the collective action of all of the muscles of mastication?
To elevate the jaw (close it)
What muscles are responsible for collectively depressing the mandible?
The Suprahyoids
Which muscle helps to assist opening of the jaw?
The Lateral Pterygoid
What are the 3 key branches of the trigeminal nerve?
- Va Ophthalmic
- Vb Maxillary
- Vc Mandibular
What is the main arterial blood supply to the neck?
The Common Carotid artery ( 2 terminal branches; internal and external)
Which artery supplies blood to the face?
The facial artery branch of the external carotid artery
Which area does the Internal Jugular Vein drain blood from?
Head and neck structures
Where does the External Jugular Vein receive drainage from?
The scalp and face
Which nerve innervates the Platysma muscle?
The facial nerve
Which nerve innervates the Sternocleidomastoid muscle?
The spinal accessory nerve
Which nerve innervates the Trapezius muscle?
The spinal accessory nerve
What structures make up the borders of the anterior triangle of the neck?
Superior- the inferior border of the mandible
Lateral- Anterior border of sternocleidomastoid
Medial- Sagittal line down midline of the neck
What structures make up the borders of the posterior triangle of the neck?
Anterior- Posterior border of sternocleidomastoid
Posterior- Anterior border of trapezius
Inferior- middle 1/3 of the clavicle
Which structures are associated with the anterior triangles?
The structures coursing between head and thorax
Which structures are associated with the posterior triangles?
Structures coursing between thorax/neck and the upper limb
What is the collective action of Suprahyoid muscles? Name the main muscle
Elevates hyoid and Depresses Mandible
Main muscle = Digastric
what is the collective action of Infrahyoid muscles? Name the main muscle
Depress and stabilise the hyoid
Main muscle= omohyoid
Where are the scalene muscles found?
In the floor of the posterior triangle
What are the borders of the carotid triangle?
Superior- posterior belly of digastric
Lateral- medial belly of sternocleidomastoid
Inferior- superior belly of omohyoid
What is the function of fascial compartment layers in the neck?
Allows ease of movement between structures e.g. when swallowing Stops the spread of infection
Name the layers of fascia in the neck from superficial to deep
- Superficial cervical layer
- Investing layer
- Pre-tracheal layer
- Pre-vertebral layer
What structures does the Carotid Sheath encompass?
- Internal Jugular Vein
- Common Carotid Artery
- Vagus Nerve
What does the pre-tracheal fascia become known as, as it passes behind the trachea and oesophagus?
Buccopharangeal fascia
What is the significance of the retropharangeal space?
An infection of the retropharangeal space could travel down to the mediastinum causing mediastinitis
