Anterior Triangle Of The Neck Flashcards
What is the role of fascial compartments ?
They control the spread of infection and allow gliding of components over each other
What are the different compartments found in the neck ?
- musculoskeletal compartment
- visceral compartment
- neurovascular compartment
- superficial compartment
What is platysma ?
The platysma are the muscles of facial expression
When they contract they relieve the pressure on the jugular veins
What is the origin of the sternocleidomastoid muscles ?
The manubrium and the medial clavicle
What is the contents of the submental triangle ?
Mylohyoid and lymph nodes
What is the contents of the submandibular triangle ?
Submandibular gland and facial artery
What does the carotid triangle contain ?
- internal jugular vein
- bifurcation of the common carotid artery
- vagus nerve
- accessory nerve
- hypoglossal nerve
What does the muscular triangle contain ?
It contains -
• larynx
• trachea
• thyroid gland
• oesophagus
• the infrahyoid strap muscles -
- sternohyoid muscles
- sternothyroid muscles
- thyrohyoid muscles
Describe the thyroid gland
- H shaped
- sits around the 3rd to 4th tracheal ring
- has 2 lobes connected by an isthmus
Where does the thyroid gland develop ?
It develops in the foremen caecum
Which 3 arteries supply the thyroid gland ?
- superior thyroid artery
- middle thyroid artery
- inferior thyroid artery
What are the 4 pairs of infrahyoid or strap muscles ?
- sternohyoid
- omohyoid
- sternothyroid
- thyrohyoid
What is the nerve supply of the infrahyoid muscles ?
- sternohyoid, omohyoid and sternothyroid = ansa cervicalis (C1 - C3)
- thyrohyoid = C1 via hypoglossal nerve
What are the 4 pairs of suprahyoid muscles ?
- digastric
- mylohyoid
- geniohyoid
- stylohyoid
What is the action of the digastric muscle ?
- elevates hyoid bone if mandible is fixed
- depresses mandible if hyoid bone is fixed
What is the origin and insertion of the posterior belly of the digastric muscle ?
Origin = mastoid process of temporal bone (digastric notch)
Insertion = intermediate tendon tethered to hyoid bone by fascial sling
What is the nerve supply of the posterior belly of the digastric muscle ?
Facial nerve (CNVII)
What is the origin and insertion of the anterior belly of the digastric muscle ?
Origin = intermediate tendon
Insertion = digastric fossa on inferior border of mandible
What is the nerve supply of the anterior belly of the digastric muscle ?
Nerve to mylohyoid (mandibular division of the trigeminal nerve)
What is the origin and insertion of the stylohyoid muscle ?
Origin = styloid process of temporal bone
Insertion = greater horn of hyoid bone
What is the nerve supply of the stylohyoid muscle ?
Facial nerve (CNVII)
Where are the mylohyoid and geniohyoid muscles found ?
They are the muscles in the floor of the mouth
What is the connective tissue dividing line between the mylohyoid muscle known as ?
Raphé
What is the innervation of the mylohyoid muscle ?
Nerve to mylohyoid
What is the innervation of the geniohyoid ?
C1
What type of gland is the submandibular salivary gland ?
Mixed serous and mucous gland
What 2 parts is the submandibular salivary gland divided into ?
Superficial part - between mylohyoid and submandibular fossa of mandible
Deep part - wraps around free posterior border of mylohyoid muscle in the floor of the mouth
What are the branches of the external carotid artery ?
- superior thyroid
- ascending pharyngeal
- lingual
- facial
- occipital
- posterior auricular
- maxillary
- superficial temporal
What are the 3 main veins of the neck ?
- external jugular vein
- anterior jugular vein
- internal jugular vein
Which nerve innervates the platysma muscle ?
Cervical branch of the facial nerve
What is the function of the hypoglossal nerve and how would you test for damage to this nerve ?
- movement of the tongue
- damage to this nerve will cause paralysis of the tongue and so if the person sticks out their tongue it will point towards the side that is damaged
What is the function of the sternocleidomastoid muscle ?
Lateral rotation of the head
What are the boundaries of the carotid triangle ?
- anterior border of the sternocleidomastoid
- posterior belly of digastric muscle
- superior belly of the omohyoid
What is the name of the nervous structure located posterior to the carotid sheath ?
Sympathetic chain
At what vertebral level does the common carotid artery bifurcate ?
C3-C4
