The Anterior Neck and Thyroid gland Flashcards
Why is the neck prone to injury?
it is slender to allow optimal positioning of head
spine is fexible
Where and what is the hyoid bone
- anteriorly in upper neck
inferior to mandible - helps keep pharynx open
provides attachment point for several neck muscles and tongue muscle
How many vertebrae in the neck? What kind?
7 cervical vertebrae
How are cervical vertebrae adapted for the neck?
Small
Articulate at facet joints, orientated obliquely
allows for good range of flexion and extension compared to thoracic spine
What is the larynx?What is its function?
Voice box
Small cartilages connected by membranes and small joints
Protects the airway
muscles attach to laryngeal cartilages and move them (to move vocal chords for phonation)
What are the triangles in the neck?
Anterior and posterior triangles, separated by the sternocleidomastoid muscle
Sternocleidomastoid muscle…
Where is it?
What can it do?
What innervates it?
- Attached to sternum, clavicle and mastoid
process - acts unilaterally or bilaterally
- accessory nerve (CN XI)
What are the boundaries of the anterior triangle?
Anteriorly- midline of neck
Posteriorly - anterior border of sternocleidomastoid
Superiorly - lower border of the mandible
What does the anterior triangle contain?
(11)
- trachea
- larynx
- thyroid gland, parathyroid glands
- submandibular salivary glands
- suprahyoid muscles
- infrahyoid muscles
- common carotid artery
- branches of external carotid atrery
- internal jugular vein
- branches of CN VII, IX, X, XI, XII
- ansa cervicalis
What do suprahyoid muscles do?
Connect hyoid to skull
form floor of mouth, move hyoid and larynx in speech and swallowing
What do infrahyoid muscles do?
Also ‘strap muscles’
connect hyoid to sternum and scapula
move hyoid and larynx in speech and swallowing
Which is CN VII
facial nerve
which is CN IX
glossopharyngeal nerve
which is CN X
vagus nerve
which is CN XI
accessory nerve
which is CN XII
hypoglossal nerve
What are the ansa cervicalis?
fibres from C1-C3 that innervate infrahyoid muscles
What are the boundaries of the posterior triangle?
Anteriorly- posterior border of sternocleidomastoid
Posteriorly - anterior border of trapezius
Inferiorly - the clavicle
What does the posterior triangle contain?(6)
- Muscles that move the head
- part of subclavian artery and vein
- external jugular vein
- accessory nerve CN XI
- roots of brachial plexus
- phrenic nerve