Head and neck gross anatomy 1: Front of neck Flashcards
What are the boundaries of the posterior triangle?
Anterior -sternocleidomastoid
Posterior - trapezius
Superior - mastoid process
Inferior - Clavicle
What might be the consequences of a stab wound to the posterior triangle?
Pneumothorax
Injury to the internal jugular vein (runs behind sternocleidomastoid
Injury to the brachial plexus - arm hangs by side, elbow cannot flex, arm medially rotated, forearm pronated in ‘waiters tip’ position.
Which neck muscles are supplied by the accessory nerve (CNXI)?
Sternocleidomastoid and trapezius
What are the boundaries of the anterior triangle?
Superior - mandible
Inferior - clavicle
Anterior - ?skin
Posterior - sternocleidomastoid
What are the surface markings of the external jugular vein?
Earlobe -> sternocleidomastoid -> clavicular head -> sternal head -> mid clavicle
What, in general, is the function of the sternohyoid and omohyoid muscles?
Stabilising hyoid and swallowing.
What is the nerve supply to sternohyoid and omohyoid?
C1-3 by a branch of ansa cervicalis.
What are the attachments of the two bellies of the digastric muscle?
Anterior, origin - digastric fossa on lower inside of mandible
Anterior, insertion - attachment of tendon between two bellies
Posterior, origin - mastoid notch on medial side of mastoid process of temporal bone
What is the function of the digastric muscle?
Anterior - Opens mouth by lowering mandible, raises hyoid bone
Posterior - raises hyoid bone
What are the surface landmarks of the internal jugular vein?
Earlobe to sternoclavicular joint.
From which nerve(s) do the roots of ansa cervicalis take origin?
Cervical plexus and C2-3
At which vertebral level does the carotid bifurcation lie?
C4
Which laryngeal landmark lies at the level of the carotid bifurcation?
Thyroid cartilage
Name the other function of the larynx in addition to its role in phonation?
Protection of the lower airway
Define the term intrinsic muscle of the larynx.
Those responsible for controlling sound phonation.
Which nerve supplies the instrinsic muscles of the larynx?
Reccurant laryngeal innervates all but the cricothyroid which is innervated by the superior laryngeal.
Which cranial nerve supplies the orbicularis oris?
Buccal branch of facial nerve (VII).
Which cranial nerve provides the motor supply to the tongue?
Hypoglossal (XII)
Where does the external laryngeal nerve enter the larynx?
Descends on the larynx beneath the sternohyoid muscle to supply the cricothyroid muscle.
Where does the left recurrent laryngeal nerve arise.
Loops under the arch of the aorta.
Through which foramen does the vagus nerve exit the skull and which nerves accompany it?
Jugular foramen - glossopharyngeal (IX) and accessory (XI)
What are the three subdivisions of the pharynx and the structures the separate them?
Nasopharynx - base of skull to soft palate
Oropharynx - soft palate to epiglottis
Laryngopharynx - epiglottis to oesophagus
Which group of muscles is involved in the voluntary phase of swallowing?
Superior longitudinal muscle elevates the apex of the tongue to make contact with the hard palate.
What is the nerve supply to the voluntary swallowing muscles?
Hypoglossal (XII)
Which cranial nerve supplies sensory fibres to the posterior 1/3rd of the tongue and the oropharynx?
Glossopharyngeal (IX)
Why is the soft palate tense and elevated during swallowing?
To occlude the nasopharynx
Aside from the hyoid bone, which other laryngeal structures help to close off the laryngeal inlet during swallowing?
True vocal fold closure
Adduction of the aryepiglottic folds
