Flashcards in Head and neck 1.1 general anatomy Deck (26)
What 4 anatomical landmark features lie within the neck, and what is their relation to each other?
(in this order)
What attaches to the hyoid bone?
8 strap like muscles, 4 above (suprahyoid) and 4 below (infrahyoid).
They aid elevation and depression of the hyoid during swallowing.
What are the 3 large muscles of the neck?
What nerves innervate the large muscles of the neck?
trapezius- spinal accessory muscle
Sternocleidomastoid- spinal accessory
Platysma- facial nerve
Give features of the platysma including it's action.
Broad and sheetlike, covering many features underneath it-including sternocleidomastoid.
Action- draws corners of mouth down, skin of neck moves superiorly if teeth are clenched (grimace)
Give features of the sternocleidomastoid muscle including its action.
Where does it originate and insert?
thick, strap like muscle coming from the mastoid process of the temporal bone to the clavicle and sternum.
It's action unilaterally- to tilt the neck in that dire ction, bilaterally- flexion at the neck
give features of the trapezius, including origin, insertion and action.
Large fan like muscle.
Comes from the base of skull, nuchal ligament, spinous process' of vertabrae, and insters into the lateral 1/3 of the clavicle, acromion and spine of scapula.
action is to elevate the shoulders.
How do you test the integrity of the trapezius muscle and the sternocleidomastoid muscle?
trapezius- shurg shoulders against resistance.
sternocleidomastois- rotate head against resistance (look for it protruding, should be visible)
What are the borders of the anterior triangle?
-invisible line down the midline
-inferior margin of the mandible
-anterior border of the sternocleidomastoid
What are the borders of the posterior triangle?
-posterior border of the sternocleidomastoid
-superior border of middle clavicle
-anterior margin of trapezius
what structures are found within the posterior triangle?
Muscles- including omohyoid, and levator scapulae, scalenes
Vasculature- external jugular vein, subclavian vein, transverse cervical and suprascapular veins and accompanying arteries,
Nerves- accessory nerve, cervical plexus, phrenic nerve, brachial plexus trunks.
Whats the significance fo the omohyoid in the posterior triangle?
It divides it into 2 smaller triangles:
The occipital and the subclavian.
whats the function of the facial layers?
Fascial layers envelope structures and allow ease of movement over each other, eg when turning the head, or swallowing.
They also contain spread of infection, so it cannot spread too deep, or between the layers.
What different fascial layers are there in the head and neck?
Deep cervical fascial layers (investing, pre-tracheal, pre-vertebral, carotid sheath)
Describe the superficial cervical fascia.
Loose connective tissue layer which contains fat, the platysma, cutaneous nerves and vessels, and superficial lymph nodes.
What is the retropharyngeal space?
The space between the prevertabral, pretracheal and carotid sheaths.
What's the significance of the retropharyngeal space?
It communicates with the mediasteinum.
Therefore any infection has potential to spread down into the mediasteinum and cause mediasteinitis (high mortality)
What surgical procedures may introduce infection into the pre-tracheal space?
Tracheostomy, or other means of inserting surgical airways.
What innervates the muscles of facial expression?
Facial nerve (CN VII)
What innervates muscles of mastication?
Trigeminal nerve (CN V)
What are the 3 divisions of the trigeminal nerve? what do they innervate?
Opthalmic- sensory to forehead, nose
Maxillary- sensory to nose, cheeks
Mandibular- sensory to chin, jaw. Motor to muscles of mastication.
What are the 5 key branches of the facial nerve?
- (marginal) mandibular
What other functions other than motor, does the facial nerve have?
Special sensory to the anterior 2/3 of tongue (chorda tympani)
parasympathetic innervation to submandibular and sublingual glands
What important relationship does the facial nerve have?
The parotid gland, it runs through but doesn't innervate.
pathology of the parotid gland can cause facial nerve palsys.
What are the main vessels of the head and neck?
Common carotid arteries,
Internal and external jugular vein.