neck Flashcards
what is the root of the neck
a transition between the neck and the thorax// it is a conduit for structures going out of the neck to the thorax and the other way round // recurrent laryngeal nerve (winds around aortic arch/subclavian artery)
functions of the neck
structural - support and move the head visceral - connects mouth and airways to GI tract and lungs
describe the structural function of the neck
structural components - bones and muscles that keep the head up - in the prevertebral fascia (surrounds vertebrae and postural muscles of the neck) conduit for blood vessels and nerves
describe the significance of the fascia in the neck
neck is divided into compartments which are bounded by deep, thick, fascia which is mainly collagen - separates it into planes. // Clinical sig -maintain integrity of body parts, also disease can be confined to these compartments - help understand the spread of disease and maintenance of disease processes in compartments // the fascia depends on the structures that are in it
what fascia are the visceral structures associated with
pretracheal fascia
what fascia surrounds the structure relating to the function as a conduit
inside or associated with carotid sheaths
4 major compartments of the neck
muscular compartment (muscles and a few nerves - hold head up and allow it to move) visceral component - thyroid gland, parathyroid gland, trachea and oesophagus 2 vascular compartments - contain internal jugular vein, carotid artery and vagus nerve (artery is medial to vein, and nerve is behind and between them) //4 compartments and 3 types
describe the muscles on the front of the neck
infrahyoid muscles collection of muscles going up from the hyoid bone to the chin and from the hyoid, larynx and thyroid cartilage that go down. // they resemble straps so can be called the strap muscles
functions of infrahyoid muscles
involved in elevation and depression of the larynx during swallowing open mandible
why is the neck a vulnerable area
doesn’t have a ribcage to protect it so vessels can easily be damaged by trauma up to head and down through axilla and soft tissue that can harbour disease
describe the levels of the neck - vertebral levels
with an open mouth see C1 at back of the mouth C2 level with superior cervical ganglion C3 body of the hyoid bone C4 upper body of the thyroid cartilage and level of the bifurcation of the common carotid artery C6 level with middle cervical ganglion and cricoid cartilage (it is inferior to the thyroid cartilage) C7 level with inferior cervical ganglion
function of superior, middle and inferior sympathetic ganglion
they are part of the SNS and provide SNS innervation to the head because no outflow from the cervical spinal cord sympathetically
describe the hyoid bone
sits superiorly to the thyroid cartilage/adam’s apple/laryngeal prominence // U shaped bone slung in with soft tissue // muscles attached above and below - suprahyoid and infrahyoid muscles
where does the internal carotid artery go
into the brain mostly
where does the external carotid artery supply
the face and thyroid gland
importance of thyroid and cricoid cartilage
for voice production and clinically - access points for emergency airway procedures in membrane between the cricoid and thyroid cartilage
what are the main triangles of the neck
anterior and posterior
describe SCM
SCM - muscle turns the head to look over shoulder in opposite dirn. it is the border of both triangles go from sternum and clavical to mastoid process at the back of the skull
what muscles hold the hyoid bone
the digastric muscles (2 bellies - anterior and posterior) omohyoid - hypoid is the bone, omo Greek for shoulder (go between hyoid and scapular)
summarise the role of the trapezius in the neck
trapezius forms the back of the neck and can lift the scapular (elevate the shoulder)
borders of the posterior triangle of the neck
SCM trapezius middle 1/3 clavicle
borders of the anterior triangle of the neck
line underside the mandible SCM from middle of mandible to sternum
what is the posterior triangle of the neck associated with
nerves travelling to neck and limbs external jugular vein subclavian artery subclavian vein trunks of the brachial plexus phrenic nerve vagus nerve spinal accessory nerve
what is the anterior triangle associated with
muscles associated with moving the mandible, hyoid and larynx or stabilising the hyoid and larynx during swallowing // muscles: platysma, mylohyoid, digastric, infrahyoid (strap)// at top contains the carotid artery that is going through the carotid canal and the internal jugular vein emerging from the jugular foramen// CN9 10 and 11 to supply SCM and trapezius
describe the platysma muscle
big sheet muscle slung under chin to the clavicles supplied by the facial nerve
tenses teh skin of the neck and can move the lower lips and corners of the mouth down
what is the muscle going from the styloid muscle to the hyoid
stylohyoid muscle
action of te stylohyoid and posterior belly of the digastric muscle when contract
pull hyoid up/posteriorly
describe the location of the digastric muscle
goes from the back of the mandible to a tendinous structure and then to the styloid process
path of the thyrohyoid muscle
from the thyroid to the hyoid muscle
path of the sternothyroid muscle
from sternum to thyroid cartilage
path of the omohyoid
shoulder (scapular) to the hyoid
path of the sternohyoid muscle
sternum to hyoid bone
describe the opening of the mandible
normally done under gravity, but muscles can be used to open the mouth
what is the internal jugular vein hidden by in the anterior triangle
the SCM
why would you want to locate the internal jugular vein
to insert a central venous line under US guidance
what muscles in the neck does the accessory nerve supply
the SCM and trapezius
effect of damage to the accessory nerve
can’t lift shoulder up cant turn your head
path of external jugular vein
over the SCM
where are the subclavian artery and vein
at the bottom of the posterior triangle artery - posterior to the scalenus anterior (anterior scalene muscle) vein - anterior to the scalenus anterior
significance of the subclavian vein
central venous access point