Anatomy of the neck Flashcards
What are the borders of the posterior triangle?
Posterior border of sternocleidomastoid
Anterior border of trapezius
Middle 1/3 of the clavicle
How can the posterior triangle be further divided?
Occipital and supraclavicular
4 neuronal structures contained in posterior triangle?
Brachial plexus, cervical plexus, phrenic nerve and spinal accessory nerve
Which vein is found in posterior triangle?
External jugular vein
What causes external jugular vein to be visible through its entire course?
Raised venous pressure (could be caused by heart failture, SVC obstruction, raised intra-thoracic pressure)
What does the spinal accessory nerve supply?
Somatic supply to trapezius and SCM
Which cranial nerves do the rootlets of spinal accessory travel up the neck with?
IX and X
How do rootlets of XI enter and leave cranial cavity
enter through foramen magnum, exit through jugular foramen
What are the signs of a XI nerve injury?
weakened shoulder shrugging
atrophy of trapezius
drooping of shoulder
What roots make up cervical plexus?
C1-C4
Where do the branches of the cervical plexus emerge?
Middle of the posterior border of the sternocleidomastoid
How does the phrenic nerve descend the body?
Obliquely with the internal jugular vein across scalene and into thorax
What muscles is cervical plexus motor into?
Infrahyoid
What roots make up ansa cervicalis?
C1-C3
What are the borders of the anterior triangle?
midline of neck (chin- jugular notch)
anterior border of sternocleidomastoid
lower border of mandible (mastoid process)
3 divisions of the anterior triangle?
Carotid, submandibular, submental
Which division of the anterior triangle takes up the most room?
Submandibular
What are the borders of the carotid triangle?
Posterior diagastric
Superior omohyoid
Anterior sternocleidomastoid
2 main vascular structures found in carotid triangle?
Internal juguar vein
Common carotid and bifurcation
Where does the carotid artery bifurcate within the carotid triangle?
Superior border of thyroid cartilage
What type of receptors does carotid sinus contain?
Baroceptors which measure stretch
Does the internal carotid branch within the carotid triangle?
No- only branches when it enters skull
Name the 8 branches of the external carotid (some anatomists like frollicking others prefer scaring medics)
Superior thyroid artery Ascending pharyngeal Lingual Facial Occipital Posterior auricular Superior temporal Maxillary
7 main structures found in the carotid sheath
Common carotid Internal carotid Internal jugular vagus Ansa cervicalis Lymph node Cervical part of sympathetic trunk
What syndrome arises due to lesion of sympathetic trunk in neck?
Horner’s syndrome
Symptoms of Horner’s syndrome?
pupil contraction (miosis) drooping of superior eyelid sinking of eye vasodilation and absence of sweating all ipsilateral
Which vein does IVJ puncture use (right or left)
right
Where does the thoracic duct drain
at venous angle on left
Name 3 things that a raised IVJ pulse can indicate
mitral valve disease
increased pulmonary pressure
right sided heart failure
What is unique about the hyoid bone?
doesn’t articulate with other bones- support for tongue
what are the suprahyoid muscles?
mylohyoid, diagastric, stylohyoid
function of suprahyoid muscles?
swallowing and tone production
what are the infrahyoid muscles?
sternohyoid, thyrohyoid, sternthroid, omohyoid
function of infrahyoid muscles?
depress hyoid and larynx during speaking and swallowing
Name the 6 muscles of the pharynx
Superior constrictor Middle constrictor Inferior constrictor Palatopharyngeus Salipigophayngeus Stylopharyngeus
What is the innervation of pharynx muscles?
All vagys except from stylopharyngeus which is IX
What are the extrinsic muscles of the larynx?
Suprahyodi and infrahyoid muscles
What is the rima glottidis?
aperture between vocal folds
Function of intrinsic muscles of the larynx?
Alter the length and tension of vocal cords, and the size/ shape of the rima glottidis
How does larynx appear during normal respiration?
laryngeal muscles relaxed
rima glottidsis is narrow slit but wide enough to let air into lungs
How does larynx appear during deep respiration
Vocal ligaments abducted by contraction of posterior cricoartenoid muscles
Rima glottidis opens widely
How does larynx appear during phonation?
Arytenoid muscle adduct arytenoid cartilage
Cricoarytenoids adduct vocal ligaments
Air forced between vocal ligaments giving sounds
How does larynx appear during whispering?
Vocal ligaments strongly adducted, but arytenoids relaxed so can’t get same levels of vibration/ amplitude
What does the superior laryngeal innervate?
Sensory to larynx above vocal cords
Motor to cricothyroid
What does the recurrent laryngeal innervate?
Motor to all intrinsic apart from cricothyroid
Sensory to area below vocal cords
Result of superior layngeal paralysis?
Loss of cough reflex
Monotonous voice as paralysed cricothryoid can’t vary in length or tension
Result of injury to recurrent laryngeal?
Dysphonia/ hoarse voice
Can’t get same tension on vocal cords
