A10 - the neck Flashcards
what vertebral level is they hyoid bone?
C3
what vertebral level is the thyroid cartilage?
C4-C5
what vertebral level is the cricoid cartilage?
C6-C7
what vertebral level is the trachea?
C6-T5
what vertebral level is the isthmus of the thyroid gland?
C7
what vertebral level is the suprasternal notch?
T2/T3
what does the cricoid cartilage indicate the level of?
- junction between the larynx and trachea
- junction between the pharynx and oesophagus
- level where the recurrent laryngeal nerve enters the larynx
(C6-C7)
what does the superior articular facet of the atlas articulate with? what movement does it allow?
occipital condyles allowing nodding and lateral flexion
what passes through the foramen transversarum?
vertebral vessels
what does the dens of the axis articular with? what holds it in position?
anterior arch of atlas — held in position against the posterior aspect of ther anterior arch of ther atlas by the transverse ligament of the atlas
what ligaments are involved in the dens articulation with the atlas?
apical, alar and cruciate
what features distinguish the cervical vertebra from other vertebra?
short, bifid process, foramen transversarum, triangular shaped vertebral foramen, small body
describe C7
- vertebra prominens
- long spinous process, and non-bifid
- small transverse foramina — transmits vertebral vein not artery
what suspends the hyoid bone from the styloid process?
stylohyoid ligament
how is the hyoid bone attached to the thyroid cartilage?
thyrohyoid membrane
describe the lesser horn of the hyoid bone
- projects superoposteriorly (towards styloid process of temporal bone)
- where the stylohyoid ligament attaches
what are the 3 main ligaments that attach to the hyoid bone, and act to support the position of the hyoid in the neck?
- Stylohyoid ligament – extends from the styloid process of the temporal bone to the lesser horn of the hyoid bone.
- Thyrohyoid membrane – originates fromthe superior border of the thyroid cartilage and attaches to the posterior surface of the hyoid bone and the greater horns.
- Hyoepiglottic ligament – connects the hyoid bone to the anterior aspect of the epiglottis.
what are the 4 suprahyoid muscles?
- stylohyoid
- mylohyoid
- digastric (anterior and posterior bellies)
- geniohyoid
O, I and A of stylohyoid
O = styloid process of temporal bone
I = lateral aspect of hyoid bone
A = initiates a swallowing action by pulling the hyoid bone in an superoposterior direction
innervation of stylohyoid. where does this nerve arise?
- stylohyoid branch of CNVII
- arises proximally to the parotid gland
O, I and A of digastric
O : anterior belly from digastric fossa of mandible. posterior belly from mastoid process of temporal bone
I : 2 bellies connected by an intermediate tendon which attaches to the hyoid bone by a fibrous sling
A : depresses the mandible and elevates the hyoid
innervation of digastric
anterior belly = inferior alveolar nerve (branch of V3)
posterior belly = digastric branch of CN VII
O, I and A of geniohyoid
O : inferior mental spine of mandible
I : travels inferiorly and posteriorly to attach to hyoid bone
A : depresses mandible and elevates hypoid bone
innervation of geniohyoid
C1 nerve roots that run in the hypoglossal nerve
what muscle forms the floor of the oral cavity and supports the floor of the mouth?
mylohyoid
O, I and A of mylohyoid
O = mylohyoid line of mandible
I = hyoid bone
A = elevates the hyoid bine and the floor of the mouth
innervation of mylohyoid
inferior alveolar nerve (V3 branch) branch = nerve to mylohyoid
what are the infrahyoid muscles? which are deep plane and which are superficial plane?
- omohyoid = superficial
- sternohyoid = superficial
- sternothyroid = deep
- thyrohyoid = deep
what infrahyoid muscle is comprised of 2 muscular bellies connected by a muscular tendon?
omohyoid
O, I and A of omohyoid
O : inferior belly from scapula - runs superomedially under the sternocleidomastoid, superior belly from hyoid bone
I : intermediate tendon (anchored to clavicle by deep cervical fascia)
A : depresses hyoid bone
O, I and A of sternohyoid
O : sternum amd sternoclavicular joint
I : hyoid bone
A : depresses hyoid bone
O, I and A of sternothyroid
O : manubrium of sternum
I : thryoid cartilage
A : depresses thyroid cartilage
O, I and A of thyrohyoid
thought to be a continuation of the sternothyroid
O : thyroid cartilage of larynx
I : hyoid bone
A : depresses hyoid. if the hyoid is fixed it can elevate the larynx
innervation of the infrahyoid muscles
omohyoid, sternohyoid and sternothyroid = anterior rami of C1-C3, carried by a branch of the ansa cervicalis
thyrohyoid = anterior ramus of C1, carried with the hypoglossal nerve
what divides the neck into anterior and posterior triangles?
sternocleidomastoid (SCM)
O, I, A and innervation of SCM
O : sternal head from anterior surface of manubrium of sternum, calvicualr head from medial 1/3 of clavicle
I : mastoid process of temporal bone and superior nuchal line of occipital bone
A : flexes and laterally flexes neck, rotates head
innervation : accessory nerve CNXI
what are the boundaries of the anterior triangle?
midline, SCM, mandible
what covers the floor and roof of the anterior triangle?
investing fascia covers the roof
visceral fascia covers the floor
what are the subtriangles of the anterior triangle?
carotid, submental, submandibular, muscular
what is the anterior triangle subdivided by?
superior belly of omohyoid, and the anterior and posterior bellies of the digastric
what does the submental triangle contain?
submental lymph nodes
what does the submandibular triangle contain?
submandibular glands, submandibular lymph nodes
what does the carotid triangle contain?
carotid sheath containing common carotid artery (bifurcates in triangle into external and internal), IJV, vagus and hypoglossal nerves, deep cervical lymph nodes, larynx
what does the muscular triangle contain?
infrahyoid muscles = omohyoid, sternohyoid, sternothyroid, thyrohyoid
what does the posterior triangle contain?
muscles = omohyoid (inferior belly)
nerves = CNXI (spinal part), branches of cervical plexus, trunks of the brachial plexus
arteries/veins = transverse cervical artery, suprascapular artery, EJV, subclavian artery and vein, occipital artery
lymph nodes
what are the boundaries of the posterior triangle?
SCM, trapezius, clavicle
what are the sub triangles of the posterior triangle?
occipital and supraclavicular
what is the posterior triangle divided by?
the inferior belly of the omohyoid muscle
what is the floor of the (posterior?? ) triangles formed by?
scalene muscles and prevertebral fascia
what does the superficial cervical fascia lie between?
the dermis and deep cervical fascia
what does the superficial cervical fascia contain?
- neurovascular supply to the skin
- superfical veins (eg. external jugular)
- superfical lymph nodes
- fat
- platysma muscle
what triangles are the IVJ and EJV in?
IVJ = anterior
EJV = posterior
platysma:
it has 2 heads, which originate from the fascia of the ______ and ____. the fibres from the 2 heads cross the _____ and meet in the midline, fusing with the muscles of the face. superiorly, the platysma inserts into the inferior border of the _____
innervation is via the _____ branch of the _____ nerve
it has 2 heads, which originate from the fascia of the pectoralis major and deltoid. the fibres from the 2 heads cross the clavicle and meet in the midline, fusing with the muscles of the face. superiorly, the platysma inserts into the inferior border of the mandible
innervation is via the cervical branch of the facial nerve
what are the deep cervical fascia layers from superfical to deep?
- investing layer
- pretracheal layer
- prevertebral layer
- carotid sheath
describe the investing layer
- most superficial of the deep cervical fascia
- surrounds all structures in the neck
- where it meets the trapezius and SCM it splits into 2, completely surrounding them
what are the superior, inferior, anterior and posterior attachments of the investing layer?
- superior — external occipital protuberance and the superior nuchal line of the skull
- anterior — hyoid bone
- inferior — spine and acromion of scapula, the clavicle and the manubrium of the sternum
- posterior — nuchal ligament of the vertebral column
what layer fuses with the fibrous pericardium?
pretracheal layer
what does the pretracheal layer enclose?
muscular part — encloses infrahyoid muscles
visceral part — encloses thyroid gland, trachea and oesophagus
what does the pretracheal layer span between?
hyoid bone superiorly and the thorax inferiorly
the posterior part of the visceral fascia of the pretracheal layer is formed by contributions from what?
the buccopharyngeal fascia (a fascial covering of the pharynx)
what layer surrounds the vertebral column and its associated muscles (scalenes, prevertebral muscles and deep muscles of the back)?
prevertebral layer
what are the superior, anterior, posterior and inferior attachments of the prevertebral layer?
> superior — base of skull
anterior — transverse processes and vertebral bodies of the vertebral column
posterior — nuchal ligament of vertebral column
inferior — fusion with the endothoracic fascia of rib cage
what does the anterolateral portion of prevertebral fascia form the floor of?
posterior triangle of the neck
what does the prevertebral layer extend laterally as and what does it surround?
axillary sheaths — surrounds axillary vessels and brachial plexus
what are the contents of the carotid sheath?
- common and internal carotid arteries
- IJVs
- vagus nerve
- deep cervical nodes
what bifurcates in the carotid sheath?
the carotid artery into its external and internal parts
clinical importance of carotid sheath?
pathway for spread of infection
the carotid fascia is organised into a column which runs between what?
the base of the skull to the thoracic mediastinum
where are the parathyroid glands located?
posterior aspect of the thyroid gland within the pretracheal fascia
what are the 2 superior parathyroid glands derived from?
fourth pharyngeal pouch
what are the 2 inferior parathyroid glands derived from?
third pharyngeal pouch
arterial supply of parathyroid glands?
- mainly inferior thyroid artery
- also superior thyroid and thyroid ima arteries
venous drainage of parathyroid glands
superior, middle and inferior thyroid veins
nerve supply of parathyroid glands
- sympathetic from thyroid branches of cervical ganglia
what do the parathyroid glands do?
responsible for production of parathyroid hormone — acts to increase the serum Ca++ level
what vertebra does the thyroid gland span?
C5-T1 vertebrae
where is the thyroid gland located?
- anterior neck
- lobes wrapped around cricoid cartilage and superior rings of trachea
- in the visceral co parent of the neck (along with trachea, oesophagus and pharynx) — this compartment is bounded by the pretracheal fascia
arterial supply of thyroid gland
- superior thyroid artery
- inferior thyroid artery
- thyroid ima artery present in 10% of people (arises from the brachiocephalic trunk and supplies the anterior surface and isthmus of the thyroid gland)
what is the first branch of the ECA?
superior thryoid artery
what does the inferior thyroid artery arise from?
thyrocervical trunk (a branch of the subclavian artery)
what do the superior and inferior thyroid arteries lie in close proximity with?
superior — external branch of superior laryngeal nerve
inferior — recurrent laryngeal nerve
at what level does the common carotid bifurcate into the internal and external arteries?
C3/4
what do the left and right common carotids arise from?
left — aortic arch
right — brachiocephalic trunk
the internal carotid artery passes beneath the _____ , being crossed by what?
- parotid gland
crossed by: hypoglossal nerve, digastric muscle and stylohyoid muscle, the occipital artery and posterior auricular
what arteyr has no branches in the neck?
internal carotid
the internal carotid enters the skull via ______ , emerging at the ______ and passes to the petrolingual ligament.
- carotid canal
- foramen lacerum
the internal carotid travels throguh what sinus before entering the subarachnoid space?
cavernous
what does the external carotid enter and bifurcate into its 2 terminal brancehs?
parotid gland
what are the branches of the external carotid artery?
SOME ANATOMISTS LIKE FREAKING OUT POOR MEDICAL STUDENTS
vertebral artery
- arise from ______ arteries
- enter deep to the transverse process on either side of the __ vertebrae
- then proceed superiorly in the transverse foramen of each cervical vertebra
- after passing through the transverse process of C1, they travel across the ______ arch of C1 and through the suboccipital triangle before entering the ____________
- inside the skull the 2 unite to form the ___________
- subclavian
- C6
- posterior
- foramen magnum
- basilar artery
the IJV begins as a continuation of what?
sigmoid sinus
what does the IJV exit the skull throguh?
jugular foramen
what does the IJV descend throguh the neck in?
carotid sheath
the IJV unties with ____ to form the brachiocephalic vein
subclavian vein
where is the EJV formed?
behind the anlge of the mandible
the EJV is formed by the union of what?
posterior retromandibular vein with posterior auricular
what do the superfical temproal and maxillary veins unite to form?
retromandibular vein
what unites to form the common facial nvein?
anterior retromandibular and facial veins
what does the common facial vein join?
IJV
where does the retromandibular vein divide into the anterior and posterior parts?
parotid gland
what bifurcates at the level of the upper border of thyroid cartilage?
common carotid artery
what vessel lies superficial to the SCM before transversing the posterior triangle?
external jugular
what nerve lies on the anterior surface of the anterior scalene muscle?
phrenic
what nerve descends in the carotid sheath posterolateral to internal and common carotid arteries and medial to the IJV?
vagus nerve
identify A-H
A = trachea
B = left brachiocephalic vein
C = right internal jugular vein
D = left common carotid artery
E = brachial plexus
F = anterior scalene muscle
G = phrenic nerve
H = vagus nerve
A = cricoid
B = arytenoid
C = thyroid
D = aryepiglottic/quadrangular
upper = aryepiglottic fold
lower = false vocal fold/cord (vestibular fold)
E = cricovocal/conus elasticus
true vocal cord/fold
A = cricothyroid
- increases the length of the vocal cords and therefore raises the pitch of the voice
- external branch of superior laryngeal nerve
A = posterior cricoarytenoid
- abducts the vocal cords
B = interarytenoid (transverse arytenoid)
- adducts the vocal cords
C = aryepiglottic
- narrows the laryngeal inlet
recurrent laryngeal
label 1-18
- carotid sheath
- IJV
- common carotid artery
- sternohyoid
- sternothyroid
- SCM
- omohyoid
- carotid sheath (red)
- prevertebral fascia (orange)
- investing fascia (green)
- trapezius
- C7
- platysma
- vagus nerve
- pretracheal fascia (purple)
- oesophagus
- trachea
- thyroid gland
cervical sympathetic chain
it ascends anterior to the _______ but posterior to the ________ , and laterally is the ipsilateral ______ artery
- prevertebral fascia
- carotid sheath
- vertebral
what supplies sensation to the mucosa from the epiglottis to just above the level of the vocal cords and pierces the thyrohyoid membrane above the superior laryngeal artery?
internal aryngeal
what is a branch of the vagus nerve that innervates the cricothyroid?
external laryngeal
what is formed at the lateral borders of the anterior scalene muslces, mainly from C4 but with some contribution from C3 and C5?
phrenic nerve
what nerve exits from the jugular foramen and arises within the carotid sheath?
vagus nerve
what enters the submandibular triangle deep to the posterior belly of the digastric muscle and gives off a branch to thyrohyoid?
hypoglossal
what provides parasympathetic innervation to the parotid gland?
glossopharyngeal
carotid sheath contents
IC 10CC’s in the IV
- internal carotid
- vagus nerve
- common carotid
- internal jugular vein
