where does the visceral compartment of the neck lie?
anteriorly, and extends from the base of the skull to the thoracic outlet
what bones, muscles, and structures are in the visceral compartment of the neck?
hyoid bone, suprahyoid and infrahyoid muscles, pharynx, esophagus, larynx, and trachea
what layer of the deep cervical fascia encloses the structure in the visceral compartment of the neck?
pretracheal layer buccopharyngeal fascia is a continuation of the pretracheal fascia that surrounds the posterior aspect of the pharynx and esophagus
where does the vertebral compartment of the neck lie?
posteriorly, and extends from the foramen magnum to the thoracic outlet
what bones, muscles, and structures are in the vertebral compartment of the neck?
cervical vertebrae, skeletal muscles that attach to the vertebrae, the ventral rami of the cervical plexus and brachial plexus, and the vertebral arteries and veins
what layer of the deep cervical fascia encloses the structures of the vertebral compartment of the neck?
prevertebral layer (that makes sense...)
what separates the prevertebral layer from the buccopharyngeal fascia?
what is clinically relevant about the retropharyngeal space?
it is a potential space that allows the structures of the visceral compartment to glide against the prevertebral fascia during swallowing an infection in this space may spread inferiorly into the superior mediastinum
both neck compartments are partially covered by what two superficial muscles? what layer of the deep cervical fascia then encloses both the compartments, as well as splits to enclose the two muscles?
investing layer of the deep cervical fascia encloses both compartments and splits to enclose the trapezius and sternocleidomastoid (SCM) which partially cover both neck compartments
what forms the carotid sheath and where does it lie in the neck?
carotid sheath formed by contributions from the pretracheal, prevertebral, and investing layers of the deep cervical fascia it is situated between the vertebral and visceral compartments of the neck
what structures are contained within the carotid sheath?
common carotid artery (which branches into the internal and external carotid arteries) carotid body carotid sinus internal jugular vein vagus nerve glossopharyngeal nerve accessory nerve hypoglossal nerve
where does the common carotid artery branch?
at the upper corder of the thyroid cartilage
what is the course of the internal carotid artery and what does it supply?
no branches in the neck!! enters the skull through the carotid canal gives rise to the ophthalmic artery (supplies orbit, retina, part of nasal cavity and face) ends by branching into anterior and middle cerebral artery
what are the branches of the external carotid artery in the neck? where does the external carotid artery end?
6 branches in neck: Superior thyroid artery Ascending pharyngeal artery Lingual artery Facial artery Occipital artery Posterior auricular artery then ends posterior to mandible by dividing into a Maxillary artery and Superficial temporal artery **Some Aggressive Lovers Find Odd Positions More Stimulating
what does the superior thyroid artery supply and what does it give rise to?
thyroid gland (duh) gives rise to the superior laryngeal artery that passes through the thyrohyoid membrane to supply the laryngopharynx and larynx
where does the ascending pharyngeal artery course and what does it supply?
arises from posterior external carotid pharynx (obviously)
where does the lingual artery course and what does it supply?
passes deep to the mylohyoid tongue (lingual... tongue... k)
where does the facial artery course and what does it supply?
passes deep to the submandibular glands, crosses body of the mandible facial muscles and skin up to medial corner of eye (clearly these aren't that hard)
where does the occipital artery course and what does it supply?
crossed by the hypoglossal nerve posterior neck and posterior scalp (where your occipital bone and occipital sinus are)
what does the posterior auricular artery supply?
what of the terminal branches of the external carotid are larger?
where is the carotid body and what is its function?
bifurcation of common carotid artery chemoreceptor that monitors arterial levels of oxygen and carbon dioxide
where is the carotid sinus and what is its function?
proximal part of the internal carotid artery baroreceptor that monitors arterial blood pressure **"sinus pressure"
what innervates the carotid body and carotid sinus?
glossopharyngeal and vagus nerves (convey signals back into CNS)
what is the baroreceptor reflex? disruption of the reflex results in what?
maintains blood pressure in response to changes in posture disruption of the reflex results in orthostatic hypotension- a decrease in BP when patient assumes an upright position
what is the chemoreceptor reflex?
maintains blood gases by adjusting respiration, cardiac output, and peripheral BP a decrease in oxygen tension (PO2) and an increase in carbon dioxide tension (PCO2) will result in an increase in respiration, HR, and peripheral BP
where does the internal jugular vein course and what does it receive blood from?
courses through the carotid sheath lateral to the common carotid artery formed inferior to the jugular foramen at the junction of the interior petrosal sinus and sigmoid sinus receives the facial, lingual, pharyngeal, and middle thyroid veins
where does the vagus nerve course?
through the length of the neck in the carotid sheath posterior to the internal jugular vein and common carotid artery
where do the glosspharyngeal, accessory, and hypoglossal nerves course?
pass through superior part of sheath to the pharynx, posterior triangle, and tongue, respectively
where does the cervical part of the sympathetic trunk lie is respect to the carotid sheath? what does it contain?
posterior and medial contains superior, middle, and inferior cervical sympathetic ganglia
the superior cervical ganglion receives preganglionic sympathetic axons from which spinal cord segment? its postganglionic sympathetic axons give rise to what to supply what?
T1 supply sweat glands, vascular smooth muscle in face and scalp, dilator pupillae and superior tarsal muscles in the orbit (elevates eyelids) form periarterial plexuses that course with internal and external carotid arteries and branches gives rise to gray rami that course with branches of C1-C4 spinal nerve supplying the neck
the inferior cervical ganglion fuses with the first thoracic ganglion to form what ganglion? it then gives rise to gray rami that course with what ventral rami to supply what?
stellate ganglion course with C7 and C8 ventral rami branches supplies upper limb
lesion of the stellate ganglion, cervical part of the sympathetic trunk or the superior cervical ganglion can cause what? what symptoms are associated?
Horner's syndrome- anhydrosis (lack of sweat), ptosis (eyelid dropping), miosis (constricted pupils)
what can be performed for patients who exhibit excessive vasoconstriction or sweating in the upper limb?
stellate ganglion block
what are the boundaries of the posterior triangle, including the floor and the roof?
bounded by the trapezius, posterior sternocleidomastoid, and clavicle floor contains anterior scalene, middle scalene, posterior scalene, levator scalene, and splenius capitis muscles all covered by the prevertebral fascia roof formed by the investing layer of the deep cervical fascia
what structures course through the posterior triangle?
external jugular vein, subclavian vein, suprascapular, transverse cervical, and occipital arteries, accessory nerve, phrenic nerve, ventral rami and trunks of the brachial plexus, subclavian artery, and cutaneous branches of the cervical plexus
what forms the external jugular vein? where does it course? what does it drain into?
formed by nion of posterior auricular and retromandibular vein crosses the SCM obliquely, pierces the investing fascia drains into the subclavian vein
where does the subclavian vein course? what does it join with and then become? what other structures drain here?
subclavian passes anterior to the phrenic nerve and anterior scalene it joins with the internal jugular vein to form a brachiocephalic vein posterior to the medial end of the clavicle the right lymphatic duct and thoracic duct drain into the right and left brachiocephalic veins, respectively
where do the suprascapular and transverse cervical arteries arise from? where do they course? what do they supply?
thyrocervical trunk of the subclavian pass anterior to the anterior scalene and phrenic nerve, and cross the posterior triangle trapezius, rhomboids, levator scapulae, muscles that attach to posterior scapula
where does the occipital artery arise from and what is its course in the posterior triangle?
external carotid artery (this is in a previous flashcard.....) passes through the apex of the posterior triangle
the accessory nerve (CN XI)'s motor axons arise from which ventral roots? what is its course? what does it innervate?
first 4-5 cervical nerves enters the subarachnoid space, passes through the foramen magnum into the cranial cavity exits skull through the jugular foramen (with glossopharyngeal and vagus nerves) innervates the SCM, then crosses the posterior triangle to innervate the trapezius
what occurs with a lesion to the accessory nerve within the posterior triangle?
weakness of the trapezius muscle-->patient has difficulty elevating the scapula (shrugging shoulder) and in laterally rotating the scapula during abduction of the arm if the lesion is inferior to the jugular foramen, may also have weakness in the SCM-->decreased ability to turn the chin to the side opposite the lesioned nerve
where does the phrenic nerve course in the posterior triangle?
anterior surface of the anterior scalene muscle, deep to the prevertebral fascia
what lies between the anterior and middle scalene muscles in the posterior triangle?
ventral rami and the trunks of the brachial plexus and the subclavian artery
where do the cutaneous branches of the cervical plexus arise from? where do they course?
ventral rami of the C1-C4 spinal segments pierce the investing and superficial fascia emerge posterior to the SCM halfway between its sternal and mastoid atachments
what branches are included in the cutaneous branches of the cervical plexus?
great auricular nerve (C2, C3) lesser occipital nerve (C2) transverse cervical nerve (C2, C3) supraclavicular nerves (C2, C3, C4)
what do the cutaneous branches of the cervical plexus supply?
skin of the anterior and lateral neck (including skin over the angle of the mandible) skin of the scalp posterior to the vertex of the skull, the coronal plane through the most superior aspect of the cranium
what does the superficial cervical fascia contain?
platysma (muscle of facial expression)
what are the boundaries of the anterior triangle of the neck?
anterior border of the SCM, anterior midline, mandible
what is contained in the anterior triangle?
structures in the visceral compartment of the neck hyoid bone infrahyoid muscles suprahyoid muscles
where is the hyoid bone situated?
anterior triangle at the level of the C3 vertebra
what are the 4 infrahyoid muscles?
sternohyoid sternothyroid superior and inferior bellies of the omohyoid thyrohyoid
what innervates the infrahyoid muscles?
muscular branches of the cervical plexus, specifically-- sternohyoid, sternothyroid, superior and inferior bellies of omohyoid: ansa cervicalis thyrohyoid: C1 fibers
what makes up the ansa cervicalis?
superior root from C1 ventral ramus that hitchhikes with the hypoglossal nerve inferior root from C2 and C43 central rami that joins with superior root anterior to carotid sheath
what are the 4 suprahyoid muscles?
geniohyoid, mylohyoid, stylohyoid, and anterior and posterior bellies of the digastric
what innervates the suprahyoid muscles?
mylohyoid and anterior belly of digastric: trigeminal nerve stylohyoid and posterior belly of digastric: fascial nerve geniohyoid: C1 fibers from cervical plexus
what are the parts of the pharynx and where is the pharynx located?
nasopharynx, oropharynx, laryngopharynx fibromuscular tube that extends from the nasal cavity to the cricoid cartilage at the 6th vertebra
where is the nasopharynx located?
superior to soft palate and posterior to naval cavity
the lateral wall of the nasopharynx contains openings for what structures?
auditory tube, levator veli palatini, tensor veli palatini, salpingopharyngeus
what innervates the mucosa of the nasopharynx?
pharyngeal nerve, branch of maxillary division of V2, branches of the glossopharyngeal nerve (CN IX) in the pharyngeal plexus
where is the oropharynx located?
between the soft palate and the tip of the epiglottis (posterior to the oral cavity)
the lateral wall of the oropharynx contains what structures?
palatoglossal arches: containing palatoglossal muscles palatopharyngeal arches: containing palatopharyngeal muscles the two arches are separated by the tonsillar fossa: contains the palatine tonsil
the floor of the oropharynx contains what structure? and what is that structure innervated by?
posterior 1/3 of the tongue both taste and general sensation of the tongue are carried by the lingual branches of the glossopharyngeal nerve (CN IX)
where is the laryngopharynx and what is it continuous with?
extends from the epiglottis behind the larynx to the level of the cricoid cartilage then it is continuous with the esophagus
what does the lateral wall of the laryngopharynx contain?
piriform recess the internal branch of the superior laryngeal nerve of the vagus nerve and the superior laryngeal artery course in the wall of the piriform recess
what innervates the mucosa of the laryngopharynx?
internal branch of the superior laryngeal nerve of the vagus?
the pharynx consists of skeletal muscles that form two layer, which is circular and which is longitudinal?
outer is circular inner is longitudinal
the circular layer is formed by what 3 muscles?
superior, middle, and inferior constrictor muscles which overlap and interdigitate in the posterior midline at the pharyngeal raphe
contraction of the 3 constrictor muscles results in what action?
propels a bolus through the oropharynx and laryngopharynx during swallowing
the inner longitudinal muscle layer is formed by what 3 muscles?
salpingopharyngeus, palatopharyngeus, stylopharyngeus which expand and insert into the pharyngeal wall
what is the action of the inner longitudinal muscles?
elevate the pharynx during swallowingq
all the muscles of the pharynx are innervated by what?
branches of the vagus nerve (through the pharyngeal plexus) EXCEPT the stylopharyngeus is innervated by the glossopharyngeal nerve ADDITIONALLY, the inferior constrictor is also innervated by the external laryngeal nerve and the recurrent laryngeal branches of the vagus
at what level of the vertebra dos the esophagus begin and what pharynx muscle is continuous with it?
C6, inferior constrictor
what structures enter between the superior constrictor of the pharynx and the base of the skull?
auditory tube, levator veli palatini muscle, and ascending palatine artery enter the nasopharynx at this location
what structures enter between the superior and middle constrictors of the pharynx?
stylopharyngeus, stylohyoid ligament, glossopharyngeal nerve (CN IX) enter the oropharynx at this location
what structures enter between the middle and inferior constrictors of the pharynx?
internal branch of the superior laryngeal nerve of the vagus (CN X) and the superior laryngeal artery and vein enter the laryngopharynx at this lcoation
what structures enter the pharynx between the inferior constrictor and the esophagus?
inferior laryngeal nerve of CN X and the inferior laryngeal artery
what types of axons and fibers does the glossopharyngeal nerve (CN IX) contain?
skeletal motor axons, preganglionic parasympathetic axons, taste fibers, general sensory fibers
what part of the skull does the glossopharyngeal nerve transverse?
what muscles does the glossopharyngeal nerve innervate?
only the stylopharyngeus
where do the preganglionic parasympathetic axons of the glossopharyngeal nerve course and what do they innervate?
course in the tympanic nerve and in the lesser petrosal nerve the lesser petrosal nerve passes through the foramen ovale and synapses in the otic ganglion, located in the infratemporal fossa (just below the foramen ovale) post ganglionic parasympathetic axons from the otic ganglion join with the auriculotemporal nerve to innervate the parotid gland
what are the sensory and taste branches of the glossopharyngeal nerve and what do they innervate?
through the pharyngeal plexus (also containing vagus nerve fibers and postganglionic sympathetics), it innervates the mucous membranes of the posterior wall of the oropharynx and the nasopharynx inferior to the entrance of the auditory tube the lingual branch conveys sensation and taste from the posterior 1/3 of the tongue the tonsillar branch supplies the mucosa of the palatoglossal and palatopharyngeal arches and the intervening tonsillar fossa the carotid sinus branch innervates the carotid body and the carotid sinus
what is the gag reflex and how does it work?
uses sensory fibers of the glossopharyngeal nerve in the oropharyngeal mucosa and motor fibers in the vagus nerve when CN IX is stimulated, the pharyngeal musculature bilaterally contracts and elevates the soft palate
what is jugular foramen syndrome and what are the symptoms associated?
lesions of the glossopharyngeal nerve can occur in conjunction with the vagus nerve and accessory nerve in jugular foramen syndrome it is diagnosed by loss of the gag reflex
what can be lesioned during tonsilectomy and what symptoms does this result in?
lingual branch of CN IX loss of all sensation from the posterior 1/3 of the tongue
middle ear infections can infect what nerve and will result in what associated symptoms?
preganglionic parasympathetic axons of CN IX that synapse in the otic ganglion reduced parotid gland secretions this is difficult to evaluate because the submandibular and sublingual salivatory glands which are innervated by the facial nerve continue to contribute to the volume of saliva
what types of axons and fibers does the vagus nerve (CN X) contain?
same as glossopharyngeal.... skeletal motor axons, preganglionic parasympathetic axons, taste fibers, general sensory fibers
what part of the skull does the vagus nerve transverse?
same as glossopharyngeal.... jugular foramen
what muscles does the vagus nerve innervate?
all muscles of the palate EXCEPT the tensor veli palatini all muscles of the pharynx EXCEPT for the stylopharyngeus all the muscles of the larynx
what mucosa does the vagus nerve innervate?
root of the tongue and in the laryngopharynx and larynx
the vagus nerve also carries visceral sensations other than pain from and its preganglionic parasympathetic axons go to terminal ganglia in what areas of the body?
thoracic and abdominal viscera
what occurs with lesions to the vagus nerve?
complete lesions result in weakness of palate, pharyngeal, and laryngeal muscles weakness of the levator veli palatini-->drooping of palate on side of the injured nerve and a deviation of the uvula to the opposite site; nasal speech and nasal regurgitation of liquids during swallowing weakness of pharyngeal constrictors-->dysphagia (difficulty swallowing) if the lesion includes the laryngeal nerves-->weakness of all laryngeal muscles on the affected side so that the vocal cord assume a fixed position midway between abduction and adduction-->hoarse speech and week lesions of the pharyngeal branch and laryngeal nerves-->loss in motor limb of the gag reflex and cough reflex, respectively
what is the general purpose of the larynx?
consists of cartilage and skeletal muscles that open and close the airway to allow phonation
where is the vestibule of the larynx located?
at the inlet of the larynx behind the epiglottis and extends to the vestibular folds
what is the ventricle of the larynx and where is it lcoated?
narrow eclipse-shaped space, situated between vestibular folds and the vocal folds
what is contained in the infraglottic space and where is this space located?
inferior to the vocal folds rima glottis and glottis
what is the rima glottis?
opening between the vocal folds
what is the glottis?
rima glottidis+vocal folds
what cartilages make up the larynx?
single cartilages: cricoid cartilage and thyroid cartilage pair of arytenoid cartilages
where do the cartilages lie in relationship to one another in the larynx?
all articulate with one another at synovial joints thyroid cartilage (V-shaped) articulates inferiorly with the cricoid cartilage (ring-shaped) inferior to that, the cricoid is continuous with the trachea arytenoid cartilages lie on the posterosuperior aspect of the cricoid cartilage and have muscular and vocal processes - the vocal ligaments extend anteriorly from the vocal processes to attach to the posterior thyroid cartilage
what 3 structures make up the vocal fold/cord?
vocal ligament covered by a thyroarytenoid muscle which is then covered by mucosa
what are the two sets of 2 skeletal muscles of the larynx which each have antagonistic actions?
lateral cricoarytenoid muscles (adduct vocal ligaments) and posterior cricoarytenoid muscles (abduct vocal ligaments) - both rotate the arytenoid cartilages on the cricoid cartilage thryoarytenoid muscles (relax vocal ligaments) and cricothyroid muscles (tense vocal ligaments)
how do the thyroarytenoid muscles and cricothyroid muscles relax and tense the vocal ligaments? what regulates both the tension?
thyroarytenoid muscles pull the arytenoid cartilages closer to the thyroid cartilage cricothyroid muscles rock the superior aspect of the thyroid superiorly at its articulation with the cricoid, increasing the distance between the cartilages the vocalis mucles (medial part of the thyroarytenoid) adjusts the tension in small segments of the vocal ligament
what innervates the muscles of the larynx?
inferior laryngeal nerve, a branch of the recurrent laryngeal nerve of the vagus (except the cricohyoid muscle, which is innervated by the external branch of the superior laryngeal nerve)
what innervates the mucosa above and below of the vocal cords?
above: internal branch of the superior laryngeal nerve below: recurrent laryngeal nerve
what symptoms are associated with lesions to the superior laryngeal nerve?
largely asymptomatic because its fibers are mainly sensory if the motor fibers to the cricothyroid are affected by a lesion of the external branch-->mild hoarseness and slight decrease in vocal strength with tendency to produce monotonous speech
during surgeries involving the thyroid gland, which nerves are susceptible to injury? what symptoms will this result in?
both recurrent laryngeal nerves fixed vocal cord and transient hoarseness
which recurrent laryngeal nerve is more at risk for injury? why?
left recurrent laryngeal nerve injured more frequently because in the superior mediastinum it hooks around the arch of the aorta and might be compressed during an aortic aneurysm the right is found only in the neck where it hooks around the subclavian artery
at what level of the vertebra does the trachea begin?
C6 begins inferior to the cricoid cartilage
at what level of the vertebra does the trachea bifurcate?
between T4 and T5
how are the cartilage and muscle of the trachea structured?
cartilage rings that are incomplete posteriorly and a posterior wall of smooth muscle
how is the thyroid gland and its parts positioned in relation to the trachea?
lobes are lateral to the trachea isthmus passes anterior to the second or third tracheal rings and interconnects the lobes
what hormones does the thyroid gland produce?
triiodothyronine (T3), thyroxine (T4) and calcitonin
how many parathyroid glands are there? where are they positioned in relation to the thyroid gland? what do the parathyroid glands produce?
4 (pair of superior glands and pair of inferior glands) posterior to the lobes of the thyroid, nearly embedded parathyroid hormone (has opposite action to calcitonin)
what arteries supply the thyroid and parathyroid glands?
superior and inferior thyroid arteries
which nerve courses with the superior thyroid artery and where? which nerve courses in proximity to the inferior thyroid artery and where?
external branch of the superior laryngeal nerve of the vagus courses with the superior thyroid artery recurrrent laryngeal nerve courses in the groove between the trachea and esophagus in proximity to the inferior thryoid artery