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
where is the pulse of the subclavian artery
behind the clavicle
superficial veins in the posterior triangle
external jugular vein - main drainage vein of the face
clinical significance of the external jugular vein
signal to clinicians of the functioning of the R side of the heart - pulse in here indicates R heart function
nerves in the posterior triangle
anterior rami of C3 4 5 - travel to innervate diaphragm // vagus that is enclosed in the carotid sheath // brachial plexus trunks from C5 to T1 - go into axilla and upper limb, to supply the upper limb and the hand // a lot of sensory nerves supplying the skin of the ear
what do some of the nerves in the posterior triangle emerge between
the anterior scalene and posterior scalene
what is the recurrent laryngeal nerve vul to
surgery and diseases from the lung
describe the lymphatic drainage
vocal cord have no lymphatic drainage knowing flow of lymph suggests whether tumour in the lymph is primary or secondary run under mandible // either side of SCM // some at neck - receive structures from abdo/chest
what innervates the mylohyoid
the mandibular division of the trigeminal nerve
what is the innervation of the digastric muscles
anterior - mandibular division of the trigeminal nerve posterior - facial nerve `
what is the innervation of the omohyoid, sternothyroid, sternohyoid muscles
ansa cervicalis
what is the innervation of the thyrohyoid
supplied by C1 fibres via the hypoglossal nerve
where is the phrenic nerve in the posterior triangle of the neck
lying on the anterior surface of the scalenus anterior
what spinal nerves contribute to the phrenic and what is its function
C3 4 5 innervate the diaphragm
describe the course of the subclavian artery and the course of its vertebral branches in the root of the neck
R and L branches out of the thorax, R begins posteriorly to the sternoclavicular joint, arches superiorly and laterally and posterior to the anterior scalene muscle // L is posterior to the L common carotid and lateral to the trachea, ascends and arches laterally, posterior to the anterior scalene muscle // vertebral artery is the 1st branch of subclavian as it enters the neck - medial to the anterior scalene muscle, ascends and enters the foramen in the transverse process of C6 - continues through the foramen of C5-1. at superior border of C1 - artery turns medially and crosses the posterior arch of C1 - passes through the foramen magnum
describe the thyrocervical trunk
second branch of the subclavian artery, arises medial to the anterior scalene muscle and divides into inferior thyroid, transverse cervical and suprascapular arteries // inferior thyroid - anterior to the anterior scalene muscle, eventually turns medially crossing posterior to the carotid sheath and anterior to the vertebral artery // transverse cervical - passes laterally across the anterior scalene and the phrenic nerve and enters the abse of the posterior triangle of the neck, continues to the deep surface of the trapezius where it divides // suprascapular artery - passes laterally, anterior to anterior scalene, phrenic nerve, subclavian artery and trunks of the brachial plexus. At the superior border of the scapular crosses over the superior transverse scapular ligament and enters the supraspinatus fossa
where is the origin and insertion of the trapezius
superior nuchal line, occipital prominence, nuchal ligament and spinus process C7-T12 to the lateral 1/3 clavicle, acromion and spine of scapular
describe the brachial plexus
forms the anterior rami of the cervical nerves C5-C8 and thoracic nerve T1 // the contributions of these nerves which are between the anterior and middle scalene muscles are the roots of the brachial plexus // as the roots emerge from between the muscles they form the trunks of the brachial plexus - anterior rami of C5 6 = upper trunk, C 7 = middle trunk, C8 and T1 = lower trunk // trunks cross the base of the posterior triangle - branches that may be visible: dorsal scapular nerve, long thoracic nerve, suprascapular nerve
what are the main sites of central venous access
internal jugular / subclavian vein
describe the path of the accessory nerve
exit the jugular foramen / descends medially to the internal jugular vein / emerges between the internal carotid artery and internal jugular vein, crosses lateral surface of the internal jugular vein - disappears into or beneath the anterior border of the SCM / continues to descend entering the posterior triangle, then descends in the investing layer of the cervical fascia between the SCM and trapezius - nerve continues on the deep side of the trapezius
path of the R common carotid
medial to anterior border of R SCM, lateral to trachea, from sternoclavicular joint ot lobe of ear
path of L common carotid
from the aortic arch towards the L sternoclavicular joint, L of trachea, medial to anterior of L SCM up to L ear lobe
path of internal jugular vein
begins as a dilated continuation fo the sigmoid sinus
initial dilated part iss the superior bulb of the jugular vein it recieces the inferior petrousal sinus
exits the skull throug the jugular foramen and enters te carotid sheath
initially posterior to the common carotid arteries but becomes more lateral further down to sternoclavicular joint
join with the subclavicular veins forming the R and L subclavian veins
list the laryngeal cartilages *
cricoid
thyroid
epiglottis
arytenoid
corniculate
cuneiform
Summarise the cricoid cartilage *
most inferior of cartilages, completely encircles the airway, nroad lamina of cricoid cartilage posterioly and narrower arch of the cricoid anteriorly
posterior has 2 oval depressions separated by vertical ridge - oesophagus attached to ridge, depressions for the crico-arytenoid muscles
2 articular facets on each side for articulation with other laryngeal cartilages - arytenoid (superiolateral of cricoid), thyroid cartilage (lateral of cricoid)
summarise the thyroid cartilage *
largest
formed by R and L lamina - separated posteriorly and converge anteriorly - most superior site of fusion between 2 laminae projects forwards as the laryngeal prominence
angle bewteen laminae is more acute in men = more obvious laryngeal prominance
superior to the laryngeal prominance is the superior thyroid notch
inferior thyroid notch - midline, base of thyroid cartilage
posterior margin of each lamina forms a superior and inferior horn
inferior horn articulates with cricoid cartilage
superior horn attached to hyoid bone by lateral thyrohyoid ligament
lateral surface of lamina has oblique line where extrinsic muscles of larynx attach
describe the epiglottis *
leaf shaped
stem is attached to thyroid cartilage by the thyro-epiglottic ligament
upper margin of the epiglottis is behind the pharyngeal part of the tongue
inferior half of the posterior epiglottis is raised = epiglottic tubercle
describe the arytenoid cartilages *
pyramid shaped
2
have apex, base, medial surface, anterolateral surface, and posterior surface
base is concave - articulates with superiolateral cricoid facet
apex articulates with the corniculate cartilage
medial surfaces face each other
anterolateral surfaces have 2 depressions for muscle and ligamnet attachment
anterior angle of base is elongated into vocal process
lateral angle is elongated into muscular angle
describe the corniculate cartilages *
2 small conical cartilages
bases articulate with the arytenoid cartilages
apexes project posteriomedially towards each other
describe the cuneiform cartilages *
2
club shaped
anterior to the corniculate
suspended in fibroelastic membrane of the larynx that attaches the arytenoid cartilages to the lateral margin of the epiglottis
describe teh lateral masses of the atlas *
when viewed from superior view - atlas is made of 2 lateral masses joined by antor and posterior arch
the lateral masses articulate with the condyle of skull and superior articular process of axis
what nerve are the muscles of the face innervated by *
facial nerve
describe the orbital group of muscles of the face *
orbicularis oculi - large muscle that surrounds each orbital orifice and extends into each eyelid. closes eyes
corrugator supercilii - smaller, deep to eyebrows and orbicularis muscle, actiive when frowning - draws eyebrows towards the midline
describe the nasal group of muscles of the face *
nasalis - largest, active when the nares are flared. transverse part compresses the nares. alar part draws alar cartilages down and laterally
procerus - small, superficial to the nasal bone, active when frowning - draws the medial border of eyebrows downward - to produce transverse wrinkles over the bridge of the nose
depressor septi nasi - widens the nares, pulls the nose inferiorly assisting nasalis
describe teh oral group of muscles of the face *
move the lips and cheeks
orbicularis oris -fibres encircle the mouth - contraction narrows the mouth and closes the lips
buccinator - forms the muscular component of the cheek - contraction presses the cheek against the teeth - keeps cheek taut and aids in mastication
lower group of oral muscles: depressor anguli oris - active in frowning, depresses corner od mouth. depressor labii inferioris - depresses lower lip and moves it laterally. mentalis - helps position mouth when drinking, raises and protrudes the lower lip
upper group: risorius - produce smile, contraction pulls mouth laterally and up. zygomaticus major and minor - smile, raise corner of mouth and move it laterally. lavator labii superioris - deepens furrow between nose and corner of the mouth during sadness. levator labii superioris alaeque nasi - flaring of nares, levator anguli oris - elevates corner of mouth and helps deepen the furrow between nose and corner of the mouth in saddness
describe the articular muscles *
anterior - pulls ear upward and forward
superior - elevates the ear
posterior - retracts and elevates the ear
describe the occipitofrontalis *
associated with the scalp
consists of a frontal and occipital belly with an aporneurotic tendon between them
moves the scalp and wrinkles the forehead
consequences of nerve injury to the facial nerve *
Bell’s palsy
primary brainstem lesion affects the motor nucleus of CN 7 = ipsilateral weakness of the whole face. however because the upper part of nucleus recieves input from R and L cerebral hemispheres - a lesion here = contralateral lower facial weakness
lesions around geniculate ganglion = loss of ipsilateral motor function of the face, taste to the anterior 2/3 tongue, lacrimation and salvation
lesion at the stylomastoid foramen - ipsilateral loss of function of face = difficulty chewing
what are the branches of the maxillary artery and what is their path *
maxillary artery is the larger of the 2 branches of the external carotid
infra-orbital artery - enters face through infra orbital foramen, supplies lower eyelid, upper lip and areas in between
buccal artery - enter face of the superficial surface of the buccinator muscle and supplies structures in this area
mental artery - enters face through mental formane and supplies muscles of the chin
significance of the middle meningeal artery and extradural haemorrhage *
it travels in the periosteal layer of dura
can be damaged by blows to the head
the vessels are torn and leak, separating the dura mater from its attachment to bone = extradural haemotoma
describe the anatomy of the trigeminal nerve *
major general sensory nerve of the head
innervates muscles of the lower jaw
general somatic afferent fibres - sensory input from face, anterior 1/2 scalp, mucous mem of oral and nasal cavities and the paranasal sinuses, nasopharynx, external axoustic meatus, part of the tympanic membrane, the orbital contents and conjugtiva and the dura mater in the anterior and middle cranial fossae
brachial efferent fibres - innervate muscles of mastication, tensor tympani, tensor veli palatini and mylohyoid muscles and anterior belly of the digastric muscle
the nerve exits from the anterolateral surface of the pons as a large sensory and small motor root - enter the middle cranial fossa over the medial tip of the petrous part of the temporal bone
in the middle cranial fossa the sensory root expands into theh trigeminal ganglion
motor root is below and completely separate from the sensory
branches of the sensory aspect - opthalamic, maxillary, mandibular
describe the origen course and branches of the common carotid arteries *
R common originates from brachiocephalic trunk posterior to R sternoclavicular joint - it is entirely in the neck
L common - begins in thorax as branch of aortic arch - pass superiorly to enter the neck near L sternoclavicular joint
both pass up neck lateral to the trachea in the carotid sheath
they give off no branches through the neck
near edge of thyroid cartilage they divide into internal and external - this division happens in the carotid triangle (a sub-division of the anterior triangle of the neck)
here the common carotid and internal carotid are dilated, this is the carotid sinus
describe the origin, course and branches of the internal carotid artery *
ascends to base of skull
gives no branches in neck
enters cranial cavity through carotid canal in petrous part of temporal bone
it supplies the cerebral hemispheres, eyes and contents of the orbits and the forehead
describe the origin course and branches of the external carotid artery *
begin giving branches immediately after bifurcation of the common carotid:
superior thyroid artery - arises fro, anterior surface, passes down and forward to reach superior pole of thyroid gland
ascending pharyngeal - smallest, arises from posterior aspect, ascends between internal carotid and pharynx
lingual artery - arises from anterior at level of hyoid bone, passes deep to hypoglossal nerve - passes between middle constrictor and hypoglossus muscles
facial - anterior, passes deep to stylohyoid and posterior belly of digastric muscles, continues deep to submandibular gland and mandible, emerges over edge of mandible
occipital artery - posterior, passes up and deep to posterior belly of digastric - emerges at posterior aspect of scalp
posterior auricular artery - from posterior, passs upward and posteriorly
superficial temporal - appears as upward continuation of external carotid artery, begins posterior to neck of mandible, passes anterior to ear, across the zygomatic process to temporal bone - above this divides into anterior and posterior branches
maxillary artery - arise anterior to the neck of the mandible, passes through the parotid gland, continues medial to neck of mandible and into infratemporal fossa and continues through this area into pterygopalatine fossa
locate the carotid pulse *
common carotid - posterolateral to the pharynx
external carotid - immediately lateral to the pharynx, midway between the superior margin of the thyroid cartilage and teh greater horn of the hyoid bone
describe the path of the vagus nerve *
exits the cranial cavity through the jugular foramen, between the glossopharyngeal and accessory nerves
enters the carotid sheath
branches as it passes through the anterior triangle: motor branch to the pharynx, a branch to the carotid body, superior laryngeal nerve and possibly a cardiac branch
describe the course of the phrenic nerve *
branch of the cervical plexus
arises from anterior rami of C3 4 5
hooks around the upper lateral border of the anterior scalene muscle - the nerve continues inferiorly across anterior surface of scalene within prevertebral fascia
describe the anatomy of major groups of lymph nodes in the head and neck *
5 groups of superficial nodes form a ring around the head
occipital nodes - near attachment of trapezius muscle - lymphatic drainage from the posterior scalp and neck
mastoid nodes - posterior to ear near attachment of SCM - drain posterolateral half of scalp
pre-auricular and parotid nodes - anterior to ear - drain anterior surface of auricle, the anterolateral scalp, upper half of face, eyelids and cheeks
submandibular nodes - inferior to body of mandible - drain structures along the path of the facial artery - forehead, gingivae, teeth and tongue
submental nodes - inferior and posterior to the chin - drain centre part of the lower lip, chin, floor of mouth, the tip of tongue and lower incisor teeth
superficial cervical lymph nodes - along externl jugular vein on superficial surface of SCM
deep cervical lymph nodes - chain along internal jugular vein, divided into upper and lower groups
describe the flow of lymph *
occipital and mastoid nodes drain into superficial cervical nodes
pre-auricular, parotid, submandibular, submental nodes pass to deep cervical nodes
describe the lymph in the neck as a potential route for spread of infection and disease *
soft tender lymph nodes suggests an acute inflammatory process - infective
firm and multi-nodularly suggests diagnosis of lymphoma
level system to evaluate nodal spread:
path of external jugular vein *
forms near the angle of the mandible
descends down neck in teh superficial fascia
after crossing the SCM the external jugualr vein enters the posterior triangle and continues the vertical descent
in lower part of posterior triangle it pierces the cervical fascia and joins the subclavian vein
position of the trachea in the anterior triangle *
begins at C6 - continuous from the larynx
position of the larynx in the anterior triangle *
upper end of lower airway
position of the thyroid and parathyroid glands in the anterior triangle *
begin as pharyngeal outgrowths, migrate caudally to final positions as development continues
parathyroid glands are on the posterior of the thyroid
describe the course anatomy and relations of the subclavian arteries *
arch up out of thorax
R subclavian artery begins posterior to the sternoclavicular joint - arches superiorly and laterally to cross the extension of the pleural cavity anteriorly and posterior to the anterior scalene muscle. continuing laterally across rib 1 becomes the axillary artery as it crosses the lateral border
L - branch of arch of aorta, posterior to L common carotid, lateral to trchea. ascends and passes laterally to cross anterior of the extension of pleura and posterior to anterior scalene. continues laterally over rib 1 and becomes the axillary artery
describe the structures passing out of the root of the neck *
vertebral arteries - ascends from subclavian artery and enters vertebral foramen in C vertebrae then through the foramen magnum
thyrocervical trunk - aries from subclavian artery, branches into 3 arteries
internal thoracic artery - branch of the subclavian, passes posterior to clavicle, enters thoracic cavity posterior to ribs
costocervical trunk - final branch of the subclavian artery - ascends passing posteriorly over dome of pleural cavity, beehind anterior scalene divides into 2 branches
subclavian veins join with internal jugular veins forming the brachiocephalic veins
phrenic nerves - in the prevertebral layer of cervical fascia, pass between subclavian artery and vein to enter the thorax
vagus - pass between common carotid and internal jugular vein - in root pass anterior to subclavian artery and vein
recurrent laryngeal nerves - R is a branch of the R vagus nerve - passes around the subclavian artery and upward and medially into a groove between the trachea and oesophagus. L - crosses arch of aorta, passes behind and below teh arch and ascends beside the trachea
SNS - cervical part of sympathetic trunk, ganglia associated with this and cardic nerves branching from here. sympathetic trunk is posterior to common carotid and internal carotid
thoracic duct - ends in venous channels in the neck, passes through the root of the neck to the L of the oesophagus, terminatees in the junction between the L internal jugular and L subclavian veins
why would you do a central venous cannulation
long term admin of drugs
TPN - when cant swallow anything
inability to gain peripheral acces
Extracorporeal membrane oxygenation
contraindications of central line
consent
cause local infection
pt has inability to lie flat - needed for procedure
clotting abnormality - need to be able to clot in case go into the carotid
thrombus in vein
how can you differentiate between the common carotid and internal jugular vein on an x-ray
vein is not pulsitile and will collapse under pressure
complications of a central line
pneumothorax
haemothorax
nerve damage
catheter can move - so have to do xhest x ray before use the line
identify c7 spine *`
it is seen in the midline at the base of the neck as a visible prominence
describe course, anatomy and relations of subclavian vein *
in the posterior triangle it is anterior to and lower than the subclavian artery and anterior to the anterior scalene muscle
it is a continuation of the axillary vein and begins at the lateral border of rib 1
as it crosses the base of the posterior triangle the external jugular and possibly suprascapular and transverse cervical bones enter it
it ends by joining with internal jugular vein to form brachiocephalic vein near the sternoclavicular joint
