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396 Cards in this Set

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primordia of head and neck development
1. placodes-gives rise to nasal cavity, eye and ear, nasal and otic placodes compose sensory material while the optic placode gives rise to only the lens, optic cup comes from neural ectoderm as an outpouching of the diencephalon and gives rise to the retina
2. somites-give rise to the pre and post-otic somites
3. pharyngeal/branchial arches-gives rise to muscles of facial expression, mastication, larynx, pharynx and palate, mucosal lining, endoderm lining (mucous lining)
placodes
are ectodermal thickenings that form structures for our special senses, three types (olfactory, lens and otic), induced by the underlying neuroectoderm
olfactory placode
gives rise to the nasal mucosa used in smell, have neurons that grow into the olfactory bulb
optic placode
forms the lens, invaginates, breaks off and forms the lens
otic placode
forms the inner ear cavity and ganglion cells
optic cup
gives rise to most of the rest of the eye, sclera, retina, choroid
cornea
deriveds from surface ectoderm
ear development
1. inner ear-comes from the otic placode
2. middle ear and middle ear ossicles-derived from the 1st pharyngeal pouch
3. external ear cavity-derived from the 1st cleft
somites
masses of mesoderm that form skeletal muscles, preotic somites form muscles of the eye, postotic somites form muscles of the tongue
preotic somites
extraocular muscles, CN III, IV, and VI
postotic somites
form muscles of the tongue, CN XII, any muscle that has the word glossys in it is innervated by CN XII except for the pallatoglossus
pharyngeal arches
masses of tissue that flank the developing gut, has a nerve, artery and cartilage, there are 6 arches, only first 4 are significant, 5th disappears and 6th merges with the 4th, each one is lined by endoderm on the inside and ectoderm on the outside, the 1st pharyngeal arch ectoderm is overgrown and lines the inside of the oral cavity
pharyngeal arch derivatives
muscle, bone or cartilage, skin from the overlying ectoderm, lining of the gut from the lining endoderm
bones from the 1st pharyngeal arch
has a maxillary and mandibular process, giving rise to those bones, also gives rise to the malleus and incus
bones from the 2nd pharyngeal arch
gives rise to stapes and styloid process and part of the hyoid bone
bones from the 3rd pharyngeal arch
gives rise to most of the hyoid bone
bones from the 4th and 6th pharyngeal arch
gives rise to the cartilage of the thyroid and cricoid cartilage
muscles from the 1st pharyngeal arch
muscles of mastication, innervated by the trigeminal nerve (CN V), nerve of first pharyngeal arch, has three divisions (V1 (ophthalmic), V2 (maxillary), and V3 (mandibular)), V3 only one that does mastication muscles, sensory and motor, V2 is only sensory
muscles from the 2nd pharyngeal arch
muscles of facial expression, innervated by CN VII (facial)
muscles from the 3rd pharyngeal arch
stylopharyngeous muscle, is motor and sensory, innervated by CN IX (glossopharyngeal)
muscles from the 4th and 6th pharyngeal arch
muscles of the larynx, pharynx and palate, innervated by CN X
Bells palsy
paralysis of muscles of all facial muscles of expression on one side of the face
endodermal lining of 1st arch
innervated by CN V, consists of the anterior 2/3 of the tongue, taste is from CN VII, CN V innervates the nasal cavity and palate as well
endodermal lining of the 2nd arch
is overgrown and lost, no sensory innervation, does innervate the posterior portion of the palate
endodermal lining of the 3rd pharyngeal arch
posterior 1/3 of the tongue, innervated by CN IX, innervates the pharyngeal cavity
endodermal lining of the 4th and 6th pharyngeal arch
mucosal lining down to the laryngeal apparatus, innervated by CN X, innervates trachea
innervation of the nasal placode
CN I
innervation f the optic vesicle and eye cup
CN II
innervation of the otic vesicle (from otic placode)
CN VIII
somatomotor fibers
are the motor fibers to the somites
branchiomotor fibers
are the motor fibers to the pharyngeal arches
V1 and the optic cup
V1 portion of CN V actually invades the optic cup (with CN II) and becomes sensory there, it is not associated with the ectoderm of arch 1
which CN are only sensory
CN I, II, and VIII, the CN’s of the placodes
which CN are only motor
CN, III, IV, and VI, the CN’s of the pre-otic somites
which CN are mixed
CN V, VII, IX, X
CN I and II
come from the rostral brain vesicles, not true cranial nerves
spinal nerve components
all spinal nerves are the same, they contain general sensory (skin), viscerosensory (comes back on sympathetic fibers), somatomotor (innervates some type of skeletal muscle, cell bodies are in the ventral horn), visceromotor (takes care of blood vessels, sweat glands and hair follicles)
cranial nerve components
every cranial nerve is unique, potential contains, special somatosensory (placodes), general somatosensory (skin), general viscerosensory (gut), special viscerosensory (taste buds and nasal placode), somatomotor (muscles from somites), visceromotor (autonomic) and branchiomotor (muscles from branchial arches)
three columns responsible for sensory component of the CN
comes from the alar plate, from the top to mid (spinal canal) the order of the columns is special somatosensory, general somatosensory, then viscerosensory (both general and special)
three columns responsible for the motor component of the CN
comes from the basal plate, from mid to bottom they are the visceromotor (parasympathetic, CN III, VII, IX, and X), branchiomotor (CN V, VII, IX, and X), and somatomotor (CN III, IV, VI, and XII)
sensory innervation of the head and neck
comes from V1 (superior 1/3 of face, through supraorbital foramen), V2 (mid 1/3 of face, through infraorbital foramen), V3 (inferior 1/3 of face, through the mental foramen which is in the mandible and also innervates teeth), branches from cervical plexus (neck, are ventral rami, ex: lesser occipital nerve (C2-3), great auricular nerve (C2-3), transverse cervical nerve (C2-3), supraclavicular nerves (C3-4)), and greater occipital nerve (posterior head and neck, from dorsal rami of cervical spinal nerves (C2))
V1
ophthalmic nerve, cell bodies associated with only the general somatosensory column
V2
maxillary nerve, cell bodies associated with only the general somatosensory column
V3
mandibular nerve, has both sensory and motor columns, has branchiomotor and general somatosensory columns
muscles of facial expression
derived from branchial arch 2, arise from bone and insert into the skin, produce facial expressions and have a protective function, examples include frontalis, orbicularis oculi, buccinator, orbicularis oris, platysma
terminal branches of CN VII
temporal, zygomatic buccal, mandibular, and cervical, goes through the stylomastoid foramen, imbeds into the parotid gland, terminal branches are only motor (branchiomotor), facial nerve passes through the parotid gland and branches, CN VII has general somatosensory, viscerosensory, visceromotor and branchiomotor
arterial supply to the face
superficial arterial branches include the external and internal carotid (via the ophthalmic artery which gives rise to the angular, suprtrochlear and supraorbital arteries that supply the face) arteries, there are lots of anastomoses in the face, along the ear is the superficial temporal artery, the facial artery (which is very curly) runs at the inferior side of the mandible then runs on its surface going superiorly, becomes the angular artery as it passes superiorly where it anastomoses with the internal carotid artery
branches of the external carotid branches
superficial temporal, facial/angular
branches of the internal carotid branches
supraorbital, supratrochlear
scalp
skin, connective tissue (dense), aponeuroses (flat tendon), loose connective tissue, and pericranium, the first three layers are usually considered the scalp proper, numerous arteries anastomose in the CT layer, note significance for bleeding, the loose CT is considered the danger space, note significance for spread of infection
loose connective tissue of the scalp
there are emissary veins that allow for connection from the loose CT to the sinuses, encephalitis and meningitis
innervation of the scalp
comes from all three branches of the trigeminal (V1-supratrochlear and supraorbital, V2-zygomaticotemporal, V3-auriculo-temporal) as well as the cervical plexus (lesser occipital) and the greater occipital nerve
blood supply to the scalp
come from branches that form the internal and external carotid arteries (includes the supratrochlear, supraorbital, superficial temporal, posterior auricular, and occipital)
craniosynostosis
premature suture closure, occurs in 1/2500 births, found in >100 genetic syndromes, can lead to scaphocephaly (57%, premature closure of the sagittal suture) or brachycephaly (premature closure of the coronal and lamboid sutures)
calvaria
the skull cap, during passage of the baby through the birth canal, the pliable and soft bones change their shape and may override each other, within a few days of birth, the shape of the calvaria returns to normal
impressions found on the interior of the calvaria
have grooves for middle meningeal vessels, grooves for superior sagittal sinus, foveolae granulares (for the arachnoid granulations)
location of the facial muscles
are located in the subQ tissue of the anterior and posterior scalp, face and neck, most muscles attach to bone or fascia and produce their effects by pulling the skin, all muscles of facial expression develop from mesoderm in the second pharyngeal arch
frontalis (frontal belly of occipitofrontallis)
1. origin-epicranial aponeurosis
2. insertion-skin and subQ tissue of eyebrows and forehead
3. main actions-elevates eyebrows and wrinkles skin of forehead, protracts scalp (indicating surprise or curiosity), no bony attachment
4. innervation-temporal branch of CN VII
occipital belly of occipitofrontallis
1. origin-lateral two thirds of superior nuchal line
2. insertion-epicranial aponeurosis
3. main action-retracts scalp, INCing effectiveness of frontal belly, has bony attachments
4. innervation-CN VII via posterior auricular nerve
epicranius
composed of both the frontal and occipital belly of the occipitofrontallis
orbicularis oculi (orbital sphincter)
1. origin-medial orbital margin, medial palpebral ligament, lacrimal bone
2. insertion-skin around margin of orbit, superior and inferior tarsal plates
3. main action-closes eyelids: palpebral part does so gently, orbital part tightly (winking)
4. innervation-temporal and zygomatic branch of CN VII
orbicularis oris (oral sphincter)
first of the series of sphincters associated with the alimentary canal
1. origin-medial maxilla and mandible, deep surface of perioral skin, angle of mouth
2. insertion-mucous membrane of lips
3. main action-tonus closes rima oris, phasic contraction compresses and protrudes lips (kissing) or resists distension (when blowing), speech
4. innervation-buccal branch of CN VII
buccinators (cheek muscle)
thin, flat, rectangular muscle, anteriorly, the fibers of the buccinators mingle medially with those of the orbicularis oris
1. origin-mandible, alveolar processes of maxilla and mandible, pterygomandibular raphe (a tendinous thickening of the buccopharyngeal fascia separating and giving origin to the superior pharyngeal constrictor posteriorly)
2. insertion-angle of mouth (modiolus), orbicularis oris
3. main action-presses cheek against molar teeth, works with tongue to keep food between occlusal surfaces and out of oral vestibule, resists distension (when blowing), smiling
4. innervation-buccal branch of CN VII
platysma
a broad, thin sheet of muscle in the subQ tissue of the neck, two muscles decussate over the chin and blend with the facial muscles
1. origin-subQ tissue of infraclavicular suprclavicular regions
2. insertion-base of mandible, skin of cheek and lower lip, angle of mouth (modiolus), orbicularis oris
3. main action-depresses mandible (against resistance), tenses skin of inferior face and neck (conveying tension and stress), releases pressure on the superficial veins
4. innervation-cervical branch of CN VII
facial lacerations
tend to gape (part widely) due to the fact that the face has no distinct deep fascia and the subQ tissue between the cutaneous attachments of the facial muscles is loose, so must be carefully sutured to prevent scarring
elasticity of the skin with INC in age
skin loses its resiliency as a person ages, as a result ridges and wrinkles occur in the skin perpendicular to the direction of the facial muscle fibers, skin incisions along these lines (langer lines) heal with minimal scarring
epicranial aponeurosis
a common tendon shared by the two muscles of the occipitofrontalis (the occipital and frontal bellies), these two bellies work as synergists to each other
muscles that control the shape of the mouth and lips
a complex three-dimensional group of muscular slips that include
1. elevators, retractors and evertors of the upper lip
2. depressors, retractors and evertors of the lower lip
3. the orbicularis oris, the sphincter around the mouth
4. the buccinators in the cheek
labial commisures
the junctions of the upper and lower lips, where fibers of as many as nine facial muscles interlace or merge in a highly variable and multiplanar formation called the modiolus
eyelids
function to protect the eyeballs from injury and excessive light and keep the cornea moist by spreading the tears
palpebral fissure
aperture between the eyelids
parts of the oribularis oculi
1. palpebral part-arising from the medial palpebral ligament and mostly located within the eyelids, gently closes the eyelids (blinking or sleep) to keep the cornea from drying
2. lacrimal part-passing posterior to the lacrimal sac, draws the eyelids medially, aiding drainage of the tears
3. orbital part-overlying the orbital rim and attached to the frontal bone and maxilla medially, tightly closes the eyelids to protect the eyeballs against glare and dust
Bells Palsy
paralysis of facial muscles that occurs due to injury to the facial nerve or its branches, produces paralysis on the affected side, affected area sags, lower eyelid everts leading to vulnerability to ulceration, can affect buccinators and orbicularis oris leading to troubles with chewing
trigeminal nerve and innervation of the face
cutaneous (sensory) innervation of the face is provided primarily by the trigeminal nerve
facial nerve and innervation of the face
motor innervation to the facial muscles is provided by the facial nerve
cutaneous nerves of the face
cutaneous nerves of the neck overlap those of the face, cutaneous brances of cervical nerves from the cervical plexus extend over the posterior aspect of the neck and scalp\
great auricular nerve
innervates the inferior aspect of the auricle and much of the parotid region of the face
trigeminal nerve
originates fromn the lateral surface of the pons of the midbrain by two roots (motor and sensory), sensory nerve for the face and the motor nerve for the muscles of mastication
trigeminal ganglion
the sensory ganglion that contains the pseudounipolar neurons that make up the sensory root
supraorbital nerve from V1
1. origin-largest branch from bifurcation of frontal nerve, approximately in middle of orbital roof
2. course-continues anteriorly along roof of orbit, emerging via supraorbital notch or foramen, ascends forehead, breaking into branches
3. distribution-mucosa of frontal sinus, skin and conjunctiva of middle of superior eyelid, skin and pericranium of anterolateral forehead and scalp to vertex (interauricular line)
supratrochlear nerve from V1
1. origin-smaller branch from bifurcation of frontal nerve, approximately in middle of orbital roof
2. course-continues anteromedially along roof of orbit, passing lateral to trochlea and ascending forehead
3. distribution-skin and conjunctive of medial aspect of superior eyelid, skin and pericranium of anteromedial forehead
lacrimal nerve from V1
1. origin-smallest branch from trifurcation of CN V1, proximal to superior orbital fissure
2. course-runs superolaterally through orbit, receiving secretomotor fibers via a communicating branch from the zygomaticotemporal nerve
3. distribution-lacrimal gland (secretomotor fibers), small area of skin and conjunctiva of lateral part of superior eyelid
infratrochlear nerve from V1
1. origin-terminal branch (with anterior ethmoidal nerve) of nasociliary nerve
2. course-follows medial wall of orbit, passing inferior to trochlea
3. distribution-skin lateral to root of nose, skin and conjunctiva of eyelids adjacent to medial canthus, lacrimal sac and lacrimal caruncle
external nasal nerve from V1
1. origin-terminal branch of anterior ethmoidal nerve
2. course-emerges from nasal cavity by passing between nasal bone and lateral nasal cartilage
3. distribution-skin of nasal ala, vestibule and dorsum of nose, including apex
infraorbital nerve from V2
1. origin-continuation of CN V2 distal to its entrance into the orbit via the inferior orbital fissure
2. course-traverses infraorbital groove and canal in orbital floor, giving rise to superior alveolar branches, then emerges via infraorbital foramen, immediately dividing into inferior palpebral, internal and external nasal and superior labial branches
3. distribution-mucosa of maxillary sinus, premolar, canine and incisor maxillary teeth, skin of cheek, lateral nose and anteroinferior nasal septum, skin and conjunctiva of inferior eyelid, skin and oral mucosa of superior lip
zygomaticofacial nerve from V2
1. origin-smaller terminal branch (with zygomaticotemporal nerve) of zygomatic nerve
2. course-traverses zygomaticofacial canal in zygomatic bone at inferolateral angle of orbit
3. distribution-skin on prominence of cheek
zygomaticotemporal nerve from V2
1. origin-larger terminal branch (with zygomaticofacial nerve) of zygomatic nerve
2. course-sends communicating branch to lacrimal nerve in orbit, then passes to temporal fossa via zygomaticotemporal canal in zygomatic bone
3. distribution-hairless skin anterior part of temporal fossa
auriculotemporal nerve from V3
1. origin-in infratemporal fossa via two roots form posterior trunk of CN V3 that encircle middle meningeal artery
2. course-passes posteriorly deep to ramus of mandible and superior deep part of parotid gland, emerging posterior to temporomandibular joint
3. distribution-skin anterior to auricle and posterior two thirds of temporal region, skin of tragus and adjacent helix of auricle, skin of roof of external acoustic meatus, and skin of superior tympanic membrane
buccal nerve of CN V3
1. origin-in infratemporal fossa as sensory branch of anterior turnk of CN V3
2. course-passes between two parts of lateral pterygoid muscle, emerging anteriorly from cover of ramus of mandible and masseter, uniting with buccal branches of facial nerve
3. distribution-skin and oral mucosa of cheek (overlying and deep to anterior part of buccinators), buccal gingivae adjacent to second and third molars
mental nerve from CN V3
1. origin-terminal branch of inferior alveolar nerve (CN V3)
2. course-emerges from mandibular canal via mental foramen in anterolateral aspect of body of mandible
3. distribution-skin of chin and skin, oral mucosa of inferior lip
greater auricular nerve (derived from anterior rami of cervical spinal nerves)
1. origin-spinal nerves C2 and C3 via cervical plexus
2. course-ascends vertically across sternocleidomastoid, posterior to external jugular vein
3. distribution-skin overlying angle of mandible and inferior lobe of auricle, parotid sheath
lesser occipital (derived from anterior rami of cervical spinal nerves)
1. origin-spinal nerves C2 and C3 via cervical plexus
2. course-follows posterior border of sternocleidomastoid, then ascends posterior to auricle
3. distribution-scalp posterior to auricle
greater occipital nerve (derived from posterior rami of cervical spinal nerves)
1. origin-as medial branch of posterior ramus of spinal nerve C2
2. course-emerges between axis and obliquus capitis inferior, then pierces trapezius
3. distribution-scalp of occipital region
third occipital nerve (derived from posterior rami of cervical spinal nerves)
1. origin-as lateral branch of posterior ramus of spinal nerve C3
2. course-pierces trapezius
3. distribution-scalp of lower occipital and suboccipital regions
ophthalmic nerve
superior division of the trigeminal nerve, smallest of the three divisions, supplies the area of skin derived from the embryonic frontonasal prominence, enters the orbit through the superior orbital fissure then trifurcates into the frontal, nasociliary and lacrimal nerves, reaches skin via the orbital opening
frontal nerve
largest branch produced by the trifurcation of the ophthalmic nerve, runs along the roof of the orbit toward the orbital opening, bifurcating approximately midway into the cutaneous supraorbital and supratrochlear nerves
nasociliary nerve
intermediate branch of V1, supplies branches to the eyeball and divides within the orbit into the posterior ethmoidal, anterior ethmoidal and infratrochlear nerves (terminal branch and is the main cutaneous branch of the nasociliary nerve)
ethmoidal nerves
anterior and posterior, leave the orbit, has a terminal branche called the external nasal nerve (supplies the external nose)
lacrimal nerve
smallest branch of V1, primarily cutaneous, also conveys some secretomotor fibers from a ganglion associated with the maxillary nerve for innervation of the lacrimal gland
maxillary nerve
V2, arises as a wholly sensory nerve, passes anteriorly from the trigeminal ganglion and leaves the cranium through the foramen rotundum in the base of the greater wing of the sphenoid, enters the pterygopalatine fossa where it gives off branches to the pterygopalatine ganglion then enters the orbit through the inferior orbital fissure, gives off the zygomatic nerve and passes anteriorly into the infraorbital groove as the infraorbital nerve
zygomatic nerve
runs to the lateral wall of the orbit giving rise to the zygomaticofacial and zygomaticotemporal nerves (sends secretomotor to the lacrimal nerve)
mandibular nerve
V3, inferior and largest division of the trigeminal nerve, formed by the union of sensory fibers from the sensory ganglion and the motor root of CN V in the foramen ovale in the greater wing of the sphenoid through which V3 emerges from the cranium, has three sensory branches to the skin and motor fibers to the muscles of mastication, has auriculotemporal, buccal and mental divisions
innervation of the scalp
anterior to the auricles through branches of all three divisions of CN V, posterior to the auricles, the nerve supply is from spinal cutaneous nerves (C2 and C3)
infraorbital nerve block
used for treating wounds of the upper lip and cheek or for repairing the maxillary incisor teeth, injection made in the infraorbital foramen
motor nerves of the face
are the facial nerve to the muscles of facial expression and the motor root of V3 to the muscles of mastication (masseter, temporal, medial, and lateral pterygoids)
facial nerve
has both a motor root and sensory/parasympathetic root, motor root supplies the muscles of facial expression (and whatever other muscles are derived from the second pharyngeal arch
course of facial nerve
follows a circuitous route through the temporal bone, emerges from the cranium through the stylomastoid foramen located between the mastoid and the styloid processes, gives off the posterior auricular nerve and a main trunk which runs anteriorly and is engulfed by the parotid gland forming the parotid plexus
posterior auricular nerve
passes posterosuperior to the auricle of the ear to supply the auricularis posterior and occipital belly of the occipitofrontalis muscle
terminal branches of the parotid plexus
temporal, zygomatic, buccal, marginal mandibular and cervical (to zanzibar by motor car)
temporal branch of the facial nerve via the parotid plexus
emerges from the superior border of the parotid gland and crosses the zygomatic arch to supply the auricularis superior and auricularis anterior, the frontal belly of the occipitofrontalis and the superior part of the orbicularis oculi
zygomatic branch of the facial nerve
passes via two or three branches superior and mainly inferior to the eye to supply the inferior part of the orbicularis oculi and other facial muscles inferior to the orbit
buccal branch of the facial nerve
passes external to the buccinators to supply this muscle and muscles of the upper lip (upper parts of the orbicularis oris and inferior fibers of levator labii superioris)
marginal mandibular branch of facial nerve
supplies the risorius and muscles of the lower lip and chin, emerges from the inferior border of the parotid gland and crosses the inferior border of the mandible deep to the platysma to reach the face, may pass inferior to the angle of the mandible (~20% of people)
cervical branch of the facial nerve
passes inferiorly from the inferior border of the parotid gland and runs posterior to the mandible to supply the platysma
superficial vasculature of the face and scalp
richly wupplied by superifical arteries and external veins, free anastomoses including across the midline with contralateral partners, most are branches of the external carotid artery
facial artery
provides the major arterial supply to the face, winds its way to the inferior border of the mandible, anterior to the masseter, crosses the mandible, buccinators and maxilla as it courses over the face to the medial angle of the eye, gives off the superior and inferior labial arteries and the lateral nasal artery, anastomoses with the dorsal nasal branch
1. origin-external carotid artery
2. course-ascends deep to submandibular gland, winds around inferior border of mandible and enters face
3. distribution-muscles of facial expression and face
angular artery
1. origin-terminal branch of facial artery
2. course-passes to medial angel (canthus) of eye
3. distribution-superior part of cheek and inferior eyelid
superficial temporal artery
emerges on the face between the TMJ and the auricle, enters the temporal fossa and ends in the scalp by dividing into the frontal and parietal branches (closely associated with the auriculotemporal nerve)
1. origin-smaller terminal branch of external carotid artery
2. course-ascends anterior to ear to temporal region and ends in scalp
3. distribution-facial muscles and skin of frontal and temporal regions
supraorbital artery
accompany nerves of the same name
1. origin-terminal branch of ophthalmic artery, a branch of internal carotid artery
2. course-passes superiorly from supraorbital foramen
3. distribution-muscles and skin of forehead and scalp and superior conjunctiva
supratrochlear artery
accompany nerves of the same name
1. origin-branch of internal carotid artery
2. course-passes superiorly from supratrochlear notch
3. distribution-muscles and skin of forehead and scalp and superior conjunctiva
transverse facial artery
anastomoses with branches of the facial artery
1. origin-superficial temporal artery within parotid gland
2. course-crosses face superficial to masseter and inferior to zygomatic arch
3. distribution-parotid gland and duct, muscles and skin of face
mental artery
only superficial branch derived from the maxillary artery, accompanies the nerve of the same name
1. origin-terminal branch of inferior alveolar artery
2. course-emerges from mental foramen and passes to chin
3. distribution-facial muscles and skin of chin
arteries of the scalp
has a rich blood supply, course within the second layer of the scalp (connective tissue), anastomose freely with one another, tightly attached to the dense CT so cannot constrict when cut, comes from the external carotid artery through the occipital, posterior auricular and superficial temporal arteries and from the internal carotid arteries through the supratrochlear and supraorbital arteries
supratrochlear vein
1. origin-begins from venous plexus on forehead and scalp, through which it communicates with frontal branch of superficial temporal vein, its contralateral partner and supraorbital vein
2. course-descends near midline of forehead to root of nose, wehre it joins supraorbital vein
3. termination-angular vein at root of nose
4. area drained-anterior part of scalp and forehead
supraorbital vein
1. origin-begins in the forehead by anastomosing with frontal tributary of superficial temporal vein
2. course-passes medially superior to the orbit, joins supratrochlear vein, a branch passes through supraorbital notch and joins with superior ophthalmic vein
3. termination-angular vein at root of nose
4. area drained-anterior part of scalp and forehead
angular vein
1. origin-begins at root of nose by union of supratrochlear and supraorbital veins
2. course-descends obliquely along root and side of nose to inferior orbital margin
3. termination-becomes facial vein at inferior margin of orbit
4. area drained-anterior part of the scalp and forehead, superior and inferior eyelids and conjunctiva, may receive drainage from cavernous sinus
facial vein
courses with or parallel to the facial artery, valveless, primary superficial drainage of the face
1. origin-continuation of angular vein past inferior margin of orbit
2. course-descends along lateral border of nose
3. termination-internal jugular vein opposite or inferior to level of hyoid bone
4. area drained-anterior scalp and forehead, eyelids, external nose, anterior cheek, lips, chin and submandibular gland
deep facial vein
tributary of the facial vein
1. origin-pterygoid venous plexus
2. course-runs anteriorly on maxilla superior to buccinators and deep to masseter, emergin medial to anterior border of masseter onto face
3. termination-enters posterior aspect of facial vein
4. area drained-infratemporal fossa (most areas supplied by maxillary artery), pterygoid venous plexus
superficial temporal vein
1. origin-begins from widespread plexus of veins on side of scalp and along zygomatic arch
2. course-frontal and parietal tributaries unite anterior to the auricle, enters substance of the parotid gland
3. termination-joins maxillary vein posterior to neck of mandible to form retromandibular vein
4. area drained-side of scalp, superficial aspect of temporal muscle, and external ear
retromandibular vein
1. origin-formed anterior to ear by union of superficial temporal and maxillary veins
2. course-runs posterior and deep to ramus of mandible through substance of parotid gland
3. termination-unites with posterior auricular vein to form external jugular vein
4. area drained-parotid gland and masseter muscles
posterior auricular vein
drains the scalp posterior to the auricles, often receives a mastoid emissary vein from the sigmoid sinus
lymphatic drainage of the face and scalp
no lymph nodes in the scalp and, except for the parotid/buccal region, no lymph node in the face, lymph from the face, scalp and neck drains into the superficial ring (pericervical collar) of lymph nodes (submental, submandibular, parotid, mastoid and occipital), superficial lymphatic vessels accompany veins, deep lymphatic accompany arteries
deep cervical lymph nodes and head and neck lymphatic drainage
a chain of nodes mainly located along the IJV in the neck that drains all the lymphatic vessels from the head and neck, pass lymph to the jugular lymphatic trunk which joins the thoracic duct or the brachiocephalic vein
course of the lymphatic drainage of the face
1. lymph from the lateral part of the face and scalp, including the eyelids, drains to the superficial parotid lymph nodes
2. lymph from the deep parotid nodes drains to the deep cervical lymph nodes
3. lymph from the upper lip and lateral parts of the lower lip drains to the submandibular lymph nodes
4. lymph from the chin and central part of the lower lip drains to the submental lymph nodes
parotid gland
largest of three paired salivary glands, enclosed within a tough fascial capsule (parotid sheath) derived from the investing layer of deep cervical fascia, has fatty tissue between the lobes of the gland that confers the flexibility the gland must have to accommodate the motion of the mandible, apex is posterior to the angle of the mandible, base is related to zygomatic arch
parotid duct
passes horizontally from the anterior edge of the gland, turns medially at the anterior border of the massetere, pierces the buccinators and enters the oral cavity through a small orifice opposite the 2nd maxillary molar tooth
things embedded within the substance of the parotid gland
from superficial to deep they are the parotid plexus of the facial nerve, the retromandibular vein and the external carotid artery
auriculotemporal nerve and the parotid gland
closely related to the parotid gland and passes superior to it, conveys postsynaptic parasympathetic fibers from the ganglion to the gland
great auricular nerve and the parotid gland
branch of the cervical plexus innervates the parotid sheath as well as the overlying skin
glossopharyngeal nerve and the parotid gland
parasympathetic, supplies presynaptic secretory fibers to the otic ganglion
external carotid nerve plexus and the parotid gland
derive the sympathetic fibers, the vasomotor activity of these fibers may reduce secretion from the gland
infratemporal fossa
area underneath the parotid gland, deep to the mandible and inferior to the zygomatic arch, houses the muscles of mastication, houses branches of nerves and arteries (external carotid) for teeth, tongue, muscles of mastication and oral mucosa
temporal region
contains the temporal and infratemporal areas, the temporal area is of minimal interest because it houses only the temporalis muscle
temporal fossa boundaries
bounded posteriorly and superiorly by the temporal bone, anteriorly by the frontal and zygomatic bones, laterally by the zygomatic arch, inferiorly by the infratemporal crest
floor of the temporal fossa
formed by parts of the four bones that form the pterion (frontal, parietal, temporal and greater wing of the sphenoid)
roof of the termporal fossa
formed from the temporal fascia which gives rise to the temporal muscle
temporal fascia
fascia attaches to the superior temporal line, splits inferiorly into two layers which attach to the lateral and medial surfaces of the zygomatic arch, also tethers the zygomatic arch superiorly, provides resistance to the contraction of the masseter muscle
borders of the infratemporal fossa
1. anterior border-maxillary bone
2. medial border-lateral pterygoid plate
3. lateral boundary-ramus of the mandible
4. posterior boundary-temporal bone (mastoid process and styloid process), also a stylomastoid foramen present where CN VII leaves
contents of the infratemporal fossa
inferior part of the temporal muscle, lateral and medial pterygoid muscles, maxillary artery, pterygoid venous plexus, mandibular, inferior alveolar, lingual, buccal and chorda tympani nerves and the otic ganglion
pterygoid venous plexus
located partyl between the temporal and the pterygoid muscles, venous equivalent to most of the maxillary artery, anastamoses anteriorly with the facial vein via the deep facial vein and superiorly with the cavernous sinus via emissary veins
mandibular fossa
where the condyle fits into the zygomatic arch
coronoid process
articulation of the mandible for the temporalis muscle
pterygomaxillary fissure
crack between sphenoid bone and maxillary bone, when through this fissure then out of the infratemporal fossa
foramen ovale
where CN V3 leaves the skull
foramen spinosum
posterior to the foramen ovale, where the middle meningeal artery leaves, runs on the lateral side of the skull along the temporal bone, this side of the bone is easily fractured and may cause some high pressure bleeding
mandibular fossa
houses the condyle of the mandible
pterygoid plates
two muscles from the lateral pterygoid plate (lateral and medial pterygoid muscles)
mandibular foramen
branch of V3 to supply the teeth and come out the mental foramen as the mental nerve
movements of the mandible at the TMJ
performs three different actions
1. elevation and depression with hinge movements-condyle travels anteriorlyl with opening of the mouth, hinge motion occurs in the lower joint cavity
2. protraction and retraction with gliding movements-gliding with condyle moving forward and backward, good protractor is the lateral pterygoid muscle, gliding movement occurs in the upper joint cavity
3. grinding motion-protraction and retraction on opposite sides, done by pulling on one lateral pterygoid then the other
temporalmandibular joint
hinge type of synovial joint, mandibular fossa with articular tubercle, has a mobile articular disc, has ligaments (stylomandibular ligament and sphenomandibular ligament), when the capsule gets really tight when pull TMJ forward, ligaments tighten and pull backwards on the inferior part of the mandible pulling it backward
synovial joint of the TMJ
1. hyaline cartilage covers articular surfaces
2. a joint capsule (fibrous CT) connects the bones
3. synovial membranes line non-weight bearing surfaces, two of them, the superior synovial membrane (lines the fibrous layer of the capsule superior to the articular disc) and the inferior synovial membrane (lines the fibrous layer of the capsule inferior to the articular disc)
4. higher range of motion compared to other types
articular disc
divides the TMJ into two separate compartments, superior and inferior joint cavity
temporomandibular ligament (lateral ligament)
formed from the thick part of the joint capsule, strengthens the TMJ laterally, acts to prevent posterior dislocation of the joint
stylomandibular ligament
a thickening of the fibrous capsule of the parotid gland, runs from the styloid process to the angle of the mandible, does not contribute to the strength of the joint
sphenomandibular ligament
runs from the spine of the sphenoid to the lingual of the mandible, is the primary passive support of the mandible, although the tonus of the muscles of mastication usually bears the mandible’s weight, serves as a swinging hinge
TMJ dislocations
TMJ can be dislocated when there is extreme opening of the jaw and a horizontal blow is made, the head of the mandible becomes displaced anterior to the articular tubercle
wide opening of the mandible
to open the mouth wide, the head of the mandible and articular disc must move anteriorly on the articular surface until the head lies inferior to the articular tubercle, translational movement
suprahyoid and infrahyoid muscles
are strap-like muscles on each side of the neck that are primarily used to raise and depress the hyoid bone and larynx respectively during swallowing, can also help depress the mandible, especially when opening the mouth suddenly or against resistance, platysma can be used in a similar manner
what structures near of in the fossa need innervation?
1. muscles of mastication-need branchiomotor, CN V is a sensory nerve except V3 which is also branchiomotor
2. somatosensory fibers for teeth, mucous linings of oral cavity and the tongue
3. special sense-taste to the tongue
4. parasympathetics to the salivary glands-all the glands in the head are innervated by VII except the parotid which is by IX
muscles of mastication
all muscles of mastication stem from the first branchial arch and therefore innervated by CN V, include the masseter, temporalis, medial pterygoid and lateral pterygoi
masseter
is not in the fossa, is outside the mandible, when it contracts it is a powerful elevator, pulls up on the angle and ramus and closes the mandible, attaches to inferior border, medial surface of maxiallary process of zygomatic bone, and angle and lateral surface of ramus of mandible, innervated by CN V3 via masseteric nerve
temporalis
anterior fibers of temporalis are vertically oriented and contribute to elevation (closing) of the mandible, posterior fibers are horizontally oriented and contribute to retraction of the mandible, fills most of the temporal region, enters the infratemporal region, attaches to the coronoid process, wrapping around it, buccal branch is also present here, anterior fibers are powerful closers, posterior fibers are retractors, helping in closing as well, these two fibers help in grinding motion in a side to side motion, broad attachment to floor of temporal fossa, narrow attachment to tip and medial surface of coronoid process and anterior border of ramus of mandible, innervated by CN V3 (deep temporal branch)
medial pterygoid muscle
makes a V with the masseter muscle at the angle of the mandible, medial pterygoid fibers run in the same plane as the masseter, is a powerful closer, also deviates the jaw to the opposite side, quadrangular muscle from medial surface of lateral pterygoid plate and pyramidal process of palatine bone and tuberosity of maxilla, attach to medial surface of ramus of mandible, innervated by CN V3 via via medial pterygoid nerve, elevates mandible, protrusion, smaller grinding movements
lateral pterygoid muscle
directed perpendicular to all other muscles of mastication, pulls the condyle and fibrous disk anteriorly when contracts, is a triangular muscle from the infratemporal surface and crest of greater wing of sphenoid and lateral surface of lateral pterygoid plate, upper head attaches to joint capsule of TMJ, inferior head attaches to pterygoid fovea, innervated by CN V3 via lateral pterygoid nerve, protracts mandible and depresses chin, swings jaw toward contralateral side
muscles of mastication involved in elevation
masseter, temporalis, medial pterygoid
muscles of mastication involved in depression
lateral pterygoid
muscles of mastication involved in protraction
masseter, lateral pterygoid, medial pterygoid
muscles of mastication involved in retraction
temporalis
muscles of mastication involved in rotation (grinding)
temporalis, lateral pterygoid, medial pterygoid, alternating sides
suprahyoid muscles
include the digastric, stylohyoid, mylohyoid and geniohyoid bones, all attach to the hyoid bone, innervated by the facial and manibular nerve, the facial nerve, the mandibular nerve and the nerve to the geniohyoid (C1-2) respectively, depresses mandible against resistance when infrahyoid muscles fix or depress hyoid bone
infrahyoid muscles
include the omobyoid, sternohyoid, sternothryroid and thryohyoid, attached to the hyoid bone, innervated by the ansa cervicalis from cervical plexus (C1-3), fixes or depresses hyoid bone
platysma and facial expression
innervated by the cervical branch of CN VII, depresses mandible against resistance
maxillary artery
comes off external carotid, has multiple branches, leaves through pterygomaxillary fissure, covered by the lateral pterygoid muscle, larger of the two terminal branches of the external carotid artery, arises posterior to the neck of the mandible, divides into three parts
first (mandibular) part of the maxillary artery
proximal (posterior) to lateral pterygoid muscle, runs horizontally, deep (medial) to neck of condylar process of mandible and lateral to stylomandibular ligament, gives of the deep auricular, anterior tympanic, middle meningeal, accessory meningeal and inferior alveolar artery branches
deep auricular artery
supplies external acoustic meatus, external tympanic membrane and TMJ
anterior tympanic artery
supplies internal aspect of tympanic membrane
middle meningeal artery
branch of the maxillary artery, enters the foramen spinosum and has a very characteristic feature (nerve has fibers that go around the artery on both sides), enters the skull next to V3, leaves a depression where it travels between the periosteum and meningeal dura, supplies the dura and periosteum and can be easily torn following head trauma to the region of the temporal bone, supplies trigeminal ganglion, facial nerve and geniculate ganglion, tympanic cavity and tensor tympani muscle
accessory meningeal artery
enters cranial cavity via foramen ovale, its distribution is mainly extracranial to muscles of infratemporal fossa, sphenoid bone, mandibular nerve and otic ganglion
inferior alveolar branch
branch of the maxillary artery, enters through the mandibular foramen to the lower jaw and supplies the teeth, mental nerve, chin and mylohyoid
second (pterygoid) part of the maxillary artery
adjacent (superficial or deep) to lateral pterygoid muscle, ascends obliquely anterosuperiorly, medial to temporal muscle, gibes off masseteric, deep temporal, pterygoid branch and buccal artery branches
masseteric artery
traverses mandibular notch, supplying TMJ and massetere
deep temporal artery
branch of the maxillary artery, there is an anterior and posterior one, the artery to the temporalis muscle, ascend between temporal muscle and bone of temporal fossa
pterygoid branches of the maxillary artery
irregular in number and origin, supply pterygoid muscles
buccal artery
runs anterioinferiorly with buccal nerve to supply buccal fat-pad, buccinators and buccal oral mucosa
third (pterygoid-palatine) part of the maxillary artery
distal (anteromedial) to lateral pterygoid muscle, passes between heads of lateral pterygoid and through pterygomaxillary fissure into pterygopalatine fossa, gives off posterior superior alveolar artery, infraorbital artery, artery of ptergoid canal, pharyngeal branch, descending palatine artery and sphenopalatine artery
otic ganglion
parasympathetic, located in the infratemporal fossa, inferior to foramen oval, medial to CN V3 and posterior to the medial pterygoid muscle, presynaptic parasympathetic fibers from the glossopharyngeal nerve synapse here, postsynaptic parasympathetic pass through here and go to the parotid gland via the auriculotemporal nerve
buccal nerve of V3
innervation of mucous linings of oral cavity and the tongue
lingual nerve
innervation to the anterior 2/3 of the tongue
tongue taste receptors
special sense, carried out of the brainstem by CN VII (via chorda tympani), then jumps onto CN V (via lingual nerve) just like the parasympathetics do
salivary gland innervation
all of the glands of the head except for the parotid are innervated by CN VII, parotid gland is innervated by CN IX (which gives presynaptic parasympathetic to the otic ganglion which is then picked up by CN V (via auriculotemporal nerve))
CN nerves and the brain stem
where the cells are located in the brain stem determine where the CN are, CN V, VI, VII, VIII who do we appreciate Pons, nuclei for CN V, VI, VII, VIII are in the pons, CN III and IV are form the midbrain and CN IX-XII are from the medulla
pons
three divisions, the ophthalmic goes into the orbit via the superior orbital fissure, maxillary dives into the deepest area of the skull where the pterygoid fissure is, mandibular goes through the foramen ovale
terminal ganglion
where the three branches of CN V comes off, have sensory ganglion cells similar to DRG
mandibular nerve
V3, through the foramen ovale into the infratemporal fossa and divides into sensory and motor branches, is distal to the trigeminal ganglion, enters the submandibular ganglion which is the ganglion for the submandibular and sublingual glands
branches of V3
1. undivided trunk-Meningeal, Medial pterygoid, Tensor veli palatine, Tensor tympani
2. Anterior division-(mostly motor, one sensory) Buccal (sensory branch), Lateral pterygoid, Masseter, Anterior and Posterior deep temporals
3. Posterior division-(mostly sensory one motor), Auriculotemporal, Lingual, Inferior alveolar, mylohyoid (floor of the mouth) is motor off the inferior alveolar
mylohyoid
sling, holds up floor of mouth, attached to the hyoid bone, pulls up the hyoid bone when swallowing, if pull down on the hyoid bone with inferior muscles may help in opening the mouth
parasympathetics to the head
parasympathetics to the head leave the brainstem with CN III, VII and IX (X too but not for the head), these fibers travel with their respective cranial nerve for a short distance and then hitchhike on a branch of CN V to their target (they must synapse along the way, either before or after), used to supply the submandibular and sublingual glands as well as the parotid gland
lingual nerve branch of CN V
carries the parasympathetics to the glands except the parotid
auriculotemporal nerve branch of CN V3
supplies the parotid gland with parasympathetic secretomotor fibers, encircles the middle meningeal artery, sends some articular fibers to the TMJ
inferior alveolar nerve brance of CN V3
enters the mandibular foramen and passes through the mandibular canal forming the inferior dental plexus
somatosensory fibers and the glands
supply the submandibular and sublingual gland off the lingual nerve
parasympathetic fibers and the glands
supply the submandibular and sublingual gland by first coming of the chorda tympani branch of VII, then joining with the lingual nerve to supply the glands
taste fibers and the tongue
supplies the anterior 2/3 of the tongue by coming off the chorda tympani and going to the lingual nerve onto the tongue, its sensory ganglia is next to the CNS
chorda tympani
important for giving face parasympathetic and taste sensation, leaves the cranium via the petrotympanic fissure, branch of CN VII, carries taste fibers to the anterior 2/3 of the tongue, joins the lingual nerve in the infratemporal fossa, carries secretomotor fibers for the submandibular and sublingual salivary glands
parotid gland innervation
innervated by preganglionic parasympathetics from CN IX to the otic ganglion, postganglionics then hitchhike with the auriculotemporal nerve from V3
lesser petrosal nerve
comes from CN IX, goes to the otic ganglion and synapses, jumps onto CN V and goes to the parotid gland giving off postganglionic parasympathetics
purpose of saliva
1. keeps the mucous membrane of the mouth moist
2. lubricates the food during mastication
3. begins the digestion of starches
4. serves as an intrinsic mouthwash
5. plays significant roles in the prevention of tooth decay and in the ability to taste
accessory salivary glands
small, scattered over the palate, lips, cheeks, tonsils and tongue
submandibular gland
lie along the body of the mandible, partly superior and partly inferior to the posterior half of the mandible and partly superficial and partyl deep to the nylohyoid muscle
submandibular duct
arises from the portion of the gland that lies between the mylohyoid and the hyoglossus muscles
lingual nerve and the submandibular gland
loops under the duct that runs anteriorly
arterial supply of the submandibular gland
submental arteries, veins accompany the arteries
innervation of the submandibular gland
supplied by presynaptic parasympathetic secretomotor fibers conveyed from the facial nerve to the lingual nerve by the chorda tympani nerve which synapse with postsynaptic neurons in the submandibular ganglion (accompany arteries to reach the gland)
lymphatic drainage of the submandibular gland
end in the deep cervical lymph nodes, particularly the jugulo-omohyoid node
sublingual gland
smallest and most deeply situated of the salivary glands, almond shaped, lies in the floor of the mouth between the mandible and the genioglossus muscle, glands from each side unite to form a horseshoe shaped structure around the lingual frenulum
sublingual ducts
open into the floor of the mouth along the sublingual folds
arterial supply to the sublingual glands
from the sublingual and submental arteries, branches of the lingual and facial arteries respectively
nerves of the sublingual gland
accompany those of the submandibular gland, presynaptic parasympathetic secretomotor fibers are conveyed by the facial, chroda tympani and lingual nerves to synapse in the submandibular ganglion
What is the location of the hyoid bone?
lies in the anterior part of the neck at the level of the C3 vertebra in the angle between the mandible and the thyroid cartilage, isolated form the rest of the skeleton because it does not articulate with any other bone
How does the hyoid bone attach to the rest of the body?
it is suspended from the styloid process of the temporal bone by the stylohyoid ligament, it is also bound to the thyroid cartilage
What are the components of the hyoid bone?
composed of a body (faces anteriorly), greater horn and lesser horn (projection where the body meets the greater horn), greater horn on one side is palpable only when steadied on the other side
What is the function of the hyoid bone?
it acts as an attachment for anterior neck muscles and a prop to keep the airway open, the wide variety of muscles attaching to the hyoid bone allow it to elevate and depress in vocalization and swallowing
What is the importance of the fascial planes in the neck?
they help determine the direction in which an infection in the neck may spread
Describe the subcutaneous tissue of the neck.
it is the superficial cervical fascia, a layer of fatty CT that lies between the dermis of the skin and the investing layer of deep cervical fascia, contains cuteaneous nerves, blood and lymphatic vessels, superficial lymph nodes and variable amounts of fat
Where does the platysma attach to and where is it located?
1. superior attachment-inferior border of mandible, skin and subQ tissues of lower face
2. inferior attachment-fascia covering superior parts of pectoralis major and deltoid muscles
3. location-in the subQ tissue of the neck, on the left and right side, inferiorly the fibers diverge leaving a gap anterior to the larynx and trachea,
What is the innervation to the platysma?
it is innervated by the cervical branch of facial nerve (CN VII)
what is the main action of the platysma
draws corners of mouth inferiorly and widens it as in expressions of sadness and fright, draws skin of neck superiorly when teeth are clenched, tenses the skin (as in shaving the neck or easing tight colors)
Where does the platysma derive from?
from the 2nd pharyngeal arch
What are the 3 (or 4) fascial compartments that make up the deep cervical fascia?
cervical investing fascia, prevertebral fascia, pretracheal fascia and carotid sheath, these support the viscera, muscles, vessels and deep lymph nodes
what is the purpose of these multiple fascial layers?
form natural cleavage planes through which tissues may be separated during surgery and limit the spread of abscesses resulting from infections, also allow for movement of structures over one another without difficulty
Describe the cervical investing fascial layer.
most superficial deep fascial layer, surrounds the entire neck deep to the skin and subQ tissue, at the 4 corners of the neck it splits into superficial and deep layers that enclose the trapezius and SCM
What does the cervical investing fascial layer attach to superficially (its boundaries)?
1. superior nucahl line of the occipital bone
2. mastoid processes of the temporal bones
3. zygomatic arches
4. inferior border of the mandible
5. hyoid bone
6. spinous processes of the cervical vertebrae
7. also surrounds the submandibular gland inferiorly and parotid gland posteriorly
what does the cervical investing fascial layer attach to inferiorly, posteriorly?
1. inferior-manubrium, clavicle and acromions and spines of the scapula
2. posterior-periosteum covering the C7 spinous process and with the nuchal ligament
Describe the suprasternal space.
space that forms between the anterior and posterior portion of the investing fascial layer that covers the anterior and posterior aspects of the manubrium, houses the anterior jugular veins, the jugular venous arch, fat and a few deep lymph nodes
Describe the pretracheal layer of the deep cervical fascia.
thin layer, limited to the anterior neck, visceral compartment that surrounds the thyroid gland, larynx, trachea and esophagus, muscular compartment that covers the infrahyoid muscles, in continuation with the bucco-pharyngeal fascia posteriorly and superiorly, blends laterally with the carotid sheaths
What are the boundaries of the pretracheal layer?
extends inferiorly from the hyoid into the thorax where it blends with the fibrous pericardium
How are the pretracheal fascia and the digastric muscle related?
the pretracheal fascia forms a pully through which the intermediate tendon of the digastric muscle passes suspending the hyoid, also tethers the omohyoid muscle
Where is the buco-pharyngeal fascia located?
it is posterior to the larynx and esophagus
Describe the pre-vertebral layer of deep cervical fascia.
surrounds all the muscles associated with the vertebral body, covers the longus colli and longus capitis anteriorly, the scalenes laterally and the deep cervical muscles posteriorly, also houses the cervical parts of the sympathetic chain
What are the attachments for the pre-vertebral layer?
fixed to the cranial base superiorly, inferiorly it blends with the endothoracic fascia and fuses with the anterior longitudinal ligament at T3
Describe the carotid sheath.
is composed from a combination of the three previous fascia in the deep cervical fascia, a tubular fascia that extends from the cranial base to the root of the neck, has free communication with the pretracheal fascia (which communicates with the thorax and cranial cavity)
what structures does the carotid sheath enclose?
1. the common and internal carotid arteries
2. internal jugular vein
3. vagus nerve
4. some deep cervical lymph nodes
5. carotid sinus nerve
6. sympathetic nerve fibers (carotid periarterial plexuses)
Describe the retropharyngeal space
is considered the DANGER SPACE, is most susceptible to infection, between the bucco-pharyngeal fascia and prevertebral fascia, allows for communication from the oral cavity to the thorax, permits movement of the pharynx, esophagus, larynx and treachea during swallowing, superior limit is the sphenoid bone, can become iatrogenic when removing tonsils
What does the sternoclediomastoid (SCM) attach to?
1. superior attachment-lateral surface of mastoid process of temporal bone and lateral half of superior nuchal line
2. inferior attachment-the sternal head attaches to the anterior surface of manubrium of the sternum while the clavicular head attaches to the superior surface of the medial third of the clavicle
what is the innervation of the SCM?
spinal accessory nerve (CN XI, motor), C2 and C3 nerves (pain and propioception), surrounded by deep cervical fascia
what is the main action of the SCM?
1. unilateral contraction-tilts the head to same side and rotates is so face is turned superiorly toward opposite side
2. bilateral contraction-estends neck at atlanto-occipital joint, flexes cervical vertebrae so that chin approaches manubrium, or extends superior cervical vertebrae while flexing inferior vertebrae so chin is thrust forward with head kept level
3. with cervical vertebrae fixed-may elevate manubrium and medial ends of clavicles, assisting pump-handle action of deep respiration
what does the trapezius attach to?
1. superior attachment-medial third of superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes of C7-T12 vertebrae, and lumbar and sacral spinous processes
2. inferior attachment-lateral third of clavicle, acromion and spine of scapula
what is the innervation of the trapezius?
spinal accessory nerve (CN XI, motor), C2 and C3 nerves (pain and propioception)
what is the main action of the trapezius?
1. elevates, retracts, and rotates scapula
2. superior fibers-elevate pectoral girdle, maintain level of shoulders against gravity or resistance
3. middle fibers-retract scapula
4. inferior fibers-depress shoulders
5. superior and inferior fibers together-rotate scapular upward
6. fixed shoulders-extends neck (bilateral contraction), produces lateral flexion to same side (unilateral contraction)
Define the SCM region.
the region between the anterior and lateral triangles of the neck, corresponding to the area of the SCM
What structures are associated with the SCM region?
superior part of the external jugular vein (superficial to SCM), greater auricular nerve (superficial to SCM, run with the external jugular vein), transverse cervical nerve (superficial to SCM)
what structure runs through the lesser supraclavicular fossa (space between the clavicular and sternal head of SCM)?
the inferior part of the internal jugular vein
how do you test for the integrity of the SCM?
turning the head to the opposite side against resistance, can see and feel muscle when doing this
What are the boundaries of the posterior cervical region
the region posterior to the anterior borders of the trapezius
what structures are associated with the posterior cervical region?
trapezius muscle, cutaneous branches of posterior rami of cervical spinal nerves, suboccipital region lies deep to superior part of this region
how do you test for the integrity of the trapezius?
shrug shoulders against resistance
what are the boundaries of the posterior triangle of the neck (AKA lateral cervical region)?
1. anteriorly by the posterior border of the SCM
2. posteriorly by the anterior border of the trapezius
3. inferiorly by the middle third of the clavicle between the trapezius and SCM
4. by an apex where the SCM and trapezius meet on the superior nuchal line of the occipital bone
5. by a roof, formed by the investing layer of deep cervical fascia
6. by a floor formed by muscles (splenius capitis, levator scapulae, anterior, middle and posterior scalene, inferior belly of omohyoid) covered by the prevertebral layer of deep cervical fascia
what are the subcomponents of the posterior triangle?
the occipital triangle and the omoclavicular (subclavian, separated from the occipital triangle from the inferior belly of the omohyoid) triangle
what strucuters are found in the occipital triangle branch of the posterior triangle?
part of the external jugular vein, posterior branches of cervical plexus of nerves, spinal accessory nerve, trunks of brachial plexus (between the anterior and middle scalenes), transverse cervical artery, cervical lymph node, occipital artery (branch of the external carotid, supplies the posterior half of the scalp)
what structures are found in the omoclavicular triangle of the posterior triangle?
subclavian artery (third part), part of subclavian vein, suprascapular artery, supraclavicular lymph nodes, EJV crosses superficially, these vessels all separated by the investing layer of deep cervical fascia
Describe the scalene muscles that make up the floor of the posterior triangle.
must attach to the first and second ribs, main job is to position the upper ribs so that the intercostal muscles work, the ribs can be held tight in a superior position, are accessory respiratory muscles
Describe scalenus anticus syndrome
the subclavian artery and brachial plexus pass between the anterior and middle scalene and can be compressed causing numbness and ischemia, the vein is not involved, brachial plexus is compressed between the clavicle and first rib, most commonly seen in people w/ an extra cervical rib
What are the branches of the subclavian artery (a branch of the brachiocephalic w/ the common carotid?
vertebral, internal thoracic, thyrocervial trunk, costocervical trunk
What arteries are located in the posterior triangle?
transverse cervical, suprascapular, occipital artery, third part of subclavian artery
What veins are located in the posterior triangle of the neck?
the external jugular vein and subclavian vein
what nerves are located in the posterior triangle of the neck?
spinal accessory, roots of the brachial plexus, suprascapular nerve, roots and branches of the cervical plexus, ansa cervicalis, phrenic
What are the branches of the thryocervical artery?
suprascapular, transverse cervical, inferior thyroid, ascending cervical
What is the course of the transverse cervical artery?
in the posterior triangle, originates from the thyrocervical trunk (a branch of the subclavian artery), runs superficially across the phrenic nerve and anterior scalene, then crosses the trunks of the brachial plexus, supplying branches to their vasa nervorsum, then passes deep to trapezius, then gives off branches
What are the branches of the transverse cervical artery?
1. superficial branch-accompoanies the spinal accessory nerve along the anterior (deep) surface of the trapezius
2. deep branch-runs anterior to the rhomboid muscles as the dorsal scapular artery accompanying the nerve of the same name, may also arise directly from the third part of the subclavian artery
What is the course of the suprascapular artery?
in the posterior triangle, originates from the thyrocervical trunk (or may arise from the third part of the subclavian artery), passes inferolaterally across the anterior scalene muscle and phrenic nerve, then crosses the third part of the subclavian artery and the cords of the brachial plexus, passes posterior to the clavicle to supply muscles on the posterior aspect of the scapula
What is the course of the third part of the subclavian artery?
in the posterior triangle, begins superior to the clavicle opposite the lateral border of the anterior scalene, lies on the 1st rib, passes posterior to the anterior scalene muscle, lies anterior to the inferior trunk of the brachial plexus where it supplies blood to the upper limb
Describe the course of the external jugular vein.
begins near the angle of the mandible by the union of the retromandibular vein with the posterior auricular vein where it drains most of the scalp and side of the face, crosses the SCM deep to the platysma and enters the anteroinferior part of the posterior triangle, then pierces the investing layer leaving the triangle, descends, receives the transverse cervical, suprascapular and anterior jugular veins, and terminates in the subclavian vein
Describe the course of the subclavian vein with respect to the posterior triangle of the neck.
curves through the inferior part of the posterior triangle, passes anterior to the anterior scalene and phrenic nerve and unites at the medial border of the muscle with IJV to form brachiocephalic vein
What is the course of the spinal accessory nerve
passes deep to the SCM (supplying it) before entering the posterior triangle, passes posteroinferiorly (within or deep to the investing layer) running on the levator scapulae from which it is separated by the prevertebral layer of fascia, disappears deep to the anterior border of the trapezius
what is the course of the roots of the brachial plexus (anterior rami of C5-C8 and T1)?
these roots appear between the anterior and middle scalene muscles (the five rami unite to form three trunks of the brachial plexus) and descend through the posterior triangle, then passes between the 1st rib, clavicle and superior border of the scapula to enter the axilla providing innervation for most of the upper limb
describe the course of the suprascapular nerve
arises form the superior trunk of the brachial plexus, runs laterally across the posterior triangle to supply the suprasinatus and infraspinatus muscles on the posterior aspect of the scapula, also has articular branches to the glenohumeral joint
describe the composition of the roots of the cervical plexus.
comes from anterior rami of C1-C4, each ramus (excep the first), divide into ascending and descending branches that unite with the branches of the adjacent spinal nerve to form loops
what is the location of the cervical plexus?
lies anteromedial to the levator scapulae and middle scalene muscles deep to the SCM
Describe the branches of the cervical plexus.
its cutaneous branches are superifical branches that pass posteriorly, its deep branches (roots of the phrenic and ansa cervicalis) pass anteromedially, are motor branches
Describe the course, composition and innervation of the ansa cervicalis.
its superior root joins and descends from the hypoglossal nerve as it traverses the posterior triangle, ansa cervicalis consists of fibers from C1-C3, supply the infrahyoid muscles
What is the course of the cutaneous branches of the cervical plexus.
emerge around the middle of the posterior border of the SCM (nerve point of the neck), supply the skin of the neck, superolateral thoracic wall, and scalp
Describe the lesser occipital nerve.
comes from the anterior rami of C2 from the nerve loop of the cervical plexus, supplies the skin of the neck and scalp posterosuperior to the auricle
describe the origin of the great auricular nerve.
comes from the anterior rami of C2 and C3 form the nerve loop of the cervical plexus
what is the course of the great auricular nerve.
ascends vertically across the oblique SCM to the inferior pole of the parotid gland, supplies the skin over the glan, mastoid process and both surfaces of the auricle
describe the origin of the transverse cervical nerve.
comes from the anterior rami of C2 and C3 from the nerve loop of the cervical plexus
what is the course and innervation of the transverse cervical nerve.
curves around the middle of the posterior border of the SCM inferior to the great auricular nerve and passes anteriorly and horizontally across it deep to the EJV and platysma, divides into superior and inferior branches, innervates the skin covering the anterior triangle of the neck
describe the origin of the supraclavicular nerve.
comes from the anterior rami of C3 and C4 from the nerve loop of the cervical plexus
what is the course and innervation of the supraclavicular nerve?
it emerges as a common trunk under cover of the SCM, sends small branches to the skin of the neck that cross the clavicle and supply the skin over the shoulder
What nerves do the deep motor branches of the cervical plexus give rise to?
dorsal scapular nerve (C4-C5, innervate rhomboids), long thoracic nerve (C5-C7, innervate serratus anterior) and nearby prevertebral muscles
What is the origin of the phrenic nerve?
originates from C4 but receives contribution from the C3 and C5 nerves, contains motor, sensory and sympathetic nerve fibers, supplies diaphragm, mediastinal pleura and pericardium
What is the course of the phrenic nerve
forms at the superior part of the lateral border of the anterior scalene, descends obliquely with the IJV across the anterior scalene, deep to the prevertebral layer and the transverse cervical and suprascapular arteries, on the left, crosses anterior to the first part of the subclavian artery, on the right, it crosses anterior to the second part of the subclavian artery, posterior to the subclavian vein and anterior to the internal thoracic artery
Describe the lymph nodes in the posterior triangle of the neck.
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lymph enters the superficial cervical lymph nodes along the EJV superficial to the SCM, then drain into the deep cervical lymph nodes, which form a chin along the IJV
What are the boundaries of the anterior triangle of the neck
1. anterior boundary formed by the median line of the neck
2. posterior boundary formed by the anterior border of the SCM
3. superior boundary formed by the inferior border of the mandible
4. apex located at the jugular notch of the manubrium
5. roof formed by the subQ tissue containing platysma
6. floor formed by the pharynx, larynx, and thyroid gland
what are the subdivisions of the anterior triangle of the neck?
the submandibular (digastric) triangle, submental triangle, carotid triangle, and muscular triangle
describe the boundaries of the submandibular triangle.
between the inferior border of the mandible and the anterior and posterior bellies of the digastric muscle, floor is formed by mylohyoid and hypoglossus
what are the contents of the submandibular triangle?
submandibular gland (which almost fills the triangle, submandibular lymph nodes, hypoglossal nerve, mylohyoid nerve, parts of facial artery and vein
Describe the boundaries of the submental triangle.
inferior to the chin, unpaired, bounded inferiorly by the body of the hyoid and laterally by the right and left anterior bellies of the digastric muscles, floor formed by the fibrous raphe formed by the mylohyoid muscles, apex is mandible, base is hyoid
what are the contents of the submental triangle?
submental lymph nodes and small veins that unite to form anterior jugular vein
describe the boundaries of the carotid triangle.
bounded by the superior belly of the omohyoid, posterior belly of the digastric and the anterior border of the SCM
what are the contents of the carotid triangle?
carotid sheath and its contents, external carotid artery and some of its branches, hypoglossal nerve and superior root of ansa cervicalis, spinal accessory nerve, thyroid gland, larynx, and pharynx, deep cervical lymph nodes, branches of cervical plexus
what are the boundaries of the muscular triangle?
bounded by the superior belly of the omohyoid muscle, the anterior border of the SCM and the median plane of the neck
what are the contents of the muscular triangle?
sternothyroid and sternohyoid muscles, thyroid and parathyroid glands
describe the carotid sinus.
a slight dilation of the proximal part of the internal carotid artery, innervated by the glossopharyngeal nerve through the carotid sinus nerve as well as by vagus, a baroreceptor that reacts to changes in arterial blood pressure, innervated by CN IX
describe the carotid body.
a small ovoid mass that lies on the medial (deep) side of the bifurcation of the common carotid artery in close relation to the carotid sinus, supplied by the carotid sinus and vagus nerve, a chemoreceptor that monitors the level of O2 in blood, stimulate by low O2 and initiates reflex that INC rate and depth of respiration, cardiac rate and blood pressure, innervated by CN IX
What are the muscles in the anterior triangle in the neck?
are suprahyoid (mylohyoid, geniohyoid, stylohyoid, digastric) and infrahyoid (AKA strap muscles, sternohyoid and omohyoid (part of the superficial plane) and sternothryoid and thryohyoid (part of the deep plane)) muscles, hyoids steady or move the hyoid and larynx
what is the purpose of the suprahyoid muscles?
they form the floor of the mouth, supporting the hyoid in providing a base form which the tongue functions and elevating the hyoid and larynx in relation to swallowing and tone production
what is the origin, insertion, innervation, and main action of the mylohyoid?
1. origin-mylohyoid line of mandible
2. insertion-mylohyoid raphe and body of hyoid
3. innervation-nerve to mylohyoid, a branch of inferior alveolar nerve (from CN V3)
4. main action-elevates hyoid, floor of mouth, and tongue during swallowing and speaking
what is the origin, insertion, innervation and main action of the geniohyoid?
1. origin-inferior mental spine of mandible
2. insertion-body of hyoid
3. innervation-C1 via hypoglossal nerve
4. main action-pulls hyoid anterosuperiorly, shortens floor of mouth, widens pharynx
what is the origin, insertion, innervation and main action of the stylohyoid?
1. origin-styloid process of temporal bone
2. insertion-body of hyoid
3. innervation-stylohyoid branch of facial nerve
4. main action-elevates and retraces hyoid, thus elongating floor of mouth
what is the origin, insertion, innervation and main action of the digastric?
1. origin-digastirc fossa of mandible (anterior belly) and mastoid notch of temporal bone (posterior belly)
2. insertion-intermediate tendone to body and greater horn of hyoid
3. inneravtion-nerve to mylohyoid, a branch of inferior alveolar nerve (anterior belly, derived from pharyngeal arch 1, so innervated by CN V) and digastric branch of facial nerve (posterior belly, derived from pharyngeal arch 2, so innervated by CN VII)
4. main action-working with infrahyoid muscles, depresses mandible against resistance, elevates and steadies hyoid during swallowing and speaking
what is the origin, insertion, innervation and main action of the sternohyoid
1. origin-manubrium of sternum and medial end of clavicle
2. insertion-body of hyoid
3. innervation-C1-C3 by a branch of ansa cervicalis
4. main action-depresses hyoid after elevation during swallowing
what is the origin, insertion, innervation and main action of the omohyoid
1. origin-superior border of scapula near suprascapular notch
2. insertion-inferior border of hyoid
3. inneravtion-C1-C3 by a branch of ansa cervicalis
4. main action-depresses, retracts and steadies hyoid
what is the origin, insertion, innervation and main action of the sternothyroid
1. origin-posterior surface of manubrium of sternum
2. insertion-oblique line of thyroid cartilage
3. innervation-C2 and C3 by a branch of ansa cervicalis
4. main action-depresses hyoid and larynx
what is the origin, insertion, innervation and main action of the thyrohyoid
1. origin-oblique line of thyroid cartilage
2. insertion-inferior border of body and greater horn of hyoid
3. innervation-C1 via hypoglossal nerve
4. main action-depresses hyoid and elevates larynx
What is the importance of the carotid triangle of the anterior triangle of the neck?
it contains the carotid system of arteries, housing the common carotid, its branches (internal and external carotids), the IJV and its tributaries, and the anterior jugular vein
What is the course of the common carotid artery?
common carotid ascends within the carotid sheath (along with the IJV and vagus) to the level of the superior border of the thyroid cartilage where it bifurcates into the internal and external carotid arteries, internal carotid has no branches in the neck, the right common carotid begins at the bifurcation of the brachiocephalic trunk, the left is a branch from the arch of the aorta
Describe the internal carotid artery.
superior to the origin of the external carotid, at the level of the superior border of the thyroid cartilage, proximal part houses the carotid sinus, carotid body is in the cleft between the internal and external carotids
what is the course of the internal carotid artery?
once it bifurcates it enters the cranium through the carotid canals in the petrous parts of the temporal bones and become the main arteries of the brain and structures in the orbit
Describe the external carotid arteries.
supplies most structures external to the cranium, each branch runs posterosuperiorly to the region between the neck of the mandible and the lobule of the auricle, terminates at the parotid gland where it bifurcates into the maxillary artery and the superficial temporal artery
What are the branches of the external carotid arteries?
Superior thyroid, Ascending pharyngeal, Lingual, Facial, Occipital, Posterior auricular, Maxillary, Superficial temporal
describe the course and innervation of the superior thyroid artery
most inferior of the three anterior branches, runs anteroinferiorly deep to the infrahyoid muscles to reach the thyroid gland, supplies this gland as well as giving off branches to the infrahyoid muscles and the SCM and gives rise to the superior laryngeal artery, supplying the larynx
Describe course and innervation of the ascending pharyngeal artery.
the only medial branch of the external carotid, ascends on the pharynx deep to the internal carotid artery, sends branches to the pharynx, prevertebral muscles, middle ear and cranial meninges
describe the course and innervation of the lingual artery
arises from the anterior aspect of the external carotid, lies on the middle constrictor muscle of the pharynx, arches superoanteriorly and passes deep to the hypoglossal nerve, the stylohyoid muscle and the posterior belly of the digastric muscle, disappears deep to the hyoglossus where it gives branches to the posterior tongue, then turns superiorly at the anterior border of this muscle, bifurcating into deep lingual and sublingual arteries
describe the course and innervation of the facial artery
arises anteriorly from the external carotid (either in common with the lingual or immediately superior to it, gives off ascending palatine artery and tonsillar branch, passes superiorly under cover of the digastric and stylohyoid muscles and the angle of the mandible, loops anteriorly and enters a deep groove in and supplies the submandibular gland, then gives rise to submental artery to the floor of the mouth and hooks around the middle of the inferior border of the mandible to enter the face
Describe course and innervation of occipital artery.
arises from the posterior aspect of the external carotid, superior to the origin of the facial artery, passes posteriorly immediately medial and parallel to the attachment of the posterior belly of the diagastric muscle, in the occipital groove in the temporal bone and ends by diving into numerous branches in the posterior part of the scalp, passes superficial to the internal carotid and CN IX-XI
Describe the course and innervation of the posterior auricular artery.
it is a small posterior branch of the external carotid, ascends posteriorly between the external acoustic meatus and the mastoid process to supply the adjacent muscles, parotid gland, facial nerve, and structures in the temporal bone, auricle and scalp
what is a pneumonic to remember the branches of the carotid artery?
SALFOPMS, or know 1-2-3, there is one branch that arises medially (ascending pharyngeal), two that arise posteriorly (occipital and posterior auricular) and three that arise anteriorly (superior thyroid, lingual and facial)
What veins are in the anterior triangle?
most veins in the anterior triangle are tributaries of the IJV
what purpose does the IJV have?
drains blood from the brain, anterior face, cervical viscera and deep muscles of the neck
what is the course of the IJV
originates from a dilation (superior bulb of the IJV) and descends in the carotid sheath (where it lies laterally), it runs anterior to the cervical sympathetic truck, leaves the anterior triangle by passing deep to the SCM through the lesser supraclavicular fossa, it then merges with the subclavian vein to form the brachiocephalic vein
what are the tributaries of the IJV?
the inferior petrosal sinus and the facial and lingual, pharyngeal and superior and middle thyroid veins, may also drain the occipital vein (which usually drains into the suboccipital venous plexus which is subsequently drained by the deep cervical vein and the vertebral vein
Describe the inferior petrosal sinus and its course.
leaves the cranium through the jugular foramen and enters the superior bulb of the IJV
describe the course of the facial vein to the IJV
empties into the IJV opposite or just inferior to the level of the hyoid
describe the course of the lingual vein to the IJV
forms a single vein from the tongue which empties into the IJV at the level of origin of the lingual artery
describe the course of the pharyngeal vein to the IJV
arise form the venous plexus on the pharyngeal wall and empty into the IJV at the level of the angle of the mandible
describe the course of the superior and middle thyroid veins to the IJV
leave the thyroid gland and drain into the IJV
What nerves are found in the anterior triangle?
transverse cervical nerve, hypoglossal nerve, branches of the glossopharyngeal and vagus nerves
What is the course of the Hypoglossal nerve?
enters the submandibular triangle deep to the posterior belly of the digastric, passes between the external carotid and the jugular vessels and gives off the superior root of the ansa cervicalis and then a branch to the geniohyoid, conveys only fibers from C1 spinal nerve
What are the branches that are given off by the glossopharyngeal and vagus nerves in the anterior triangle?
glossopharyngeal gives off branches to the tongue and pharynx while the vagus gives off branches to the pharyngeal, laryngeal and cardiac branches
What are the classes of prevertebral muscles?
the prevertebral muscles are the muscles that are deep to the prevertebral layer of deep cervical fascia, classes are the anterior (lie directly posterior to the retropharyngeal space) and lateral (form the floor of the posterior triangle) vertebral muscles
what muscles make up the anterior vertebral muscles?
longus coli, longus capitis, rectus capitis anterior, anterior scalene
what muscles make up the posterior vertebral muscles?
rectus capitis lateralis, splenius capitis, levator scapulae, middle scalene, posterior scalene
what are the attachments, innervation and main action of the longus colli
1. superior attachment-anterior tubercle of C1 vertebrae, bodies of C1-C3 and transverse processes of C3-C6
2. inferior attachment-bodies of C5-T3 vertebrae, transverse processes of C3-C5 vertebrae
3. innervation-anterior rami of C2-C6 spinal nerves
4. main action-flexes neck with rotation (torsion) to opposite side if acting unilaterally
what are the attachments, innervation and main action of longus capitis
1. superior attachment-basilar part of occipital bone
2. inferior attachment-anterior tubercles of C3-C6 transverse processes
3. innervation-anterior rami of C1-C3 spinal nerves
4. main action-flex head
what are the attachments, innervation and main action of rectus capitis anterior?
1. superior attachment-base of skull, just anterior to occipital condyle
2. inferior attachment-anterior surface of lateral mass of atlas (C1 vertebrae)
3. innervation-branches from loop between C1 and C2 spinal nerve
4. main action-flex head
what are the attachments, inneravtion and main action of the anterior scalene?
1. superior attachment-transverse processes of C4-C6 vertebrae
2. inferior attachment-1st rib
3. innervation-cervical spinal nerves (C4-C6)
4. main action-flex head
what are the attachments, innervation and main action of the rectus capitis lateralis
1. superior attachment-jugular process of occipital bone
2. inferior attachment-transverse process of atlas (C1 vertebrae)
3. inneravtion-branches from loop between C1 and C2 spinal nerves
4. main action-flexes head and helps stabilize it
what are the attachments, innervation and main action of the splenius capitis?
1. superior attachment-inferior half of nuchal ligament and spinous processes of superior six thoracic vertebrae
2. inferior attachment-lateral aspecte of mastoid process and lateral third of superior nuchal line
3. innervation-posterior rami of middle cervical spinal nerves
4. main action-laterally flexes and rotates head and neck to same side, acting bilaterally, extend head and neck
what are the attachments, innervation and main action of the levator scapulae
1. superior attachment-posterior tubercles of transverse processes C1-C4 vertebrae
2. inferior attachment-superior part of medial border of scapula
3. innervation-dorsal scapular nerve C5 and cervical spinal nerves C3 and C4
4. main action-elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula
what are the attachments, innervation and main action of the middle scalene
1. superior attachment-posterior tubercles of transverse processes of C4-C6 vertebrae
2. inferior attachments-superior surface of 1st rib, posterior groove for subclavian artery
3. innervation-anterior rami of cervical spinal nerves
4. main action-flexes neck laterally, elevates 1st rib during forced inspiration
what are the attachments, innervation and main action of the posterior scalene?
1. superior attachment-posterior tubercles of transverse processes of C4-C6 vertebrae
2. inferior attachment-external border of 2nd rib
3. innervation-anterior rami of cervical spinal nerves C7-C8
4. main action-flexes neck laterally, elevates 2nd rib during forced inspiration
What are the boundaries of the root of the neck?
1. inferiorly the superior thoracic aperture
2. laterally by the 1st pair of ribs and their costal cartilages
3. anteriorly by the manubrium of the sternum
4. posteriorly by the body of T1 vertebra
Describe the course of the brachiocephalic trunk.
it is covered anteriorly by the right sternohyoid and sternothryoid muscles, arises posterior to the manubrium then superolaterally to the right where it divides into the right common carotid and right subclavian
When does the subclavian artery become the axillary artery?
when the artery crosses the outer margin of the first rib
How is the subclavian artery divided into parts?
divided relative to the anterior scalene, 1st part is medial to muscle, 2nd part is posterior to it, 3rd part is lateral
What are the branches of the subclavian artery associated with the root of the neck?
1. vertebral artery, internal thoracic and thyrocervical trunk-from the 1st part
2. costocervical trunk-from the 2nd part
3. dorsal scapular artery-from the 3rd part
What are the branches of the thyrocervical trunk
inferior thyroid, suprascapular (supplying muscles of the posterior scapular) and transverse cervical artery (supplying muscles in the posterior triangle, trapezius and medial scapular muscle), terminal branches are the inferior thyroid and ascending cervical arteries
Describe the inferior thyroid artery
branch of the thyrocervical trunk, the primary visceral artery of the neck
What is the origin and course of the costocervical trunk?
arises from the posterior aspect of the 2nd part of the subclavian artery, passes posterosuperiorly and divides into the superior intercostal and deep cervical arteries which supply the first two intercostal spaces and the posterior deep cervical muscles, respectively
Describe the course of the anterior jugular vein
smallest of the jugular veins, typically arises near the hyoid from the confluence of superficial submandibular veins, descends in the subQ tissure or deep to the investing layer of deep cervical fascia between the anterior median line and the anterior border of the SCM, at the root of the neck, the AJV turns laterally, posterior to the SCM and opens into the termination of the EJV or into the subclavian
What is the jugular venous arch?
it is in the suprasternal space, where the right and left AJV’s commonly unite across the midline
What is the course of the subclavian vein
the continuation of the axillary vein and ends when it joins the IJV and forms the brachiocephalic vein, passes over the 1st rib anterior to the scalene tubercle parallel to the subclavian artery
what is the venous angle?
where the IJV and subclavian meet, also the site where the thoracic duct and the right lymphatic trunk drain lymph collected through the body into the venous circulation
what are the three paired nerves in the root of the neck?
vagus nerve, phrenic nerve and sympathetic chain
Describe the course of the right and left vagus nerve
they both leave through the jugular foramen, then pass inferiorly in the neck within the posterior part of the carotid sheath in the angle between the IJV and the common carotid artery, the right passes anterior to the first part of the subclavian and posterior to the brachiocephalic vein and SC joint to enter the thorax, the left descends between the left common cartodi and the left subcalvian and postieror to the SC joint to enter the thorax
Describe the course of the recurrent laryngeal nerve
arise from the vagus in the inferior part of the neck, right loops inferior to the right subclavian (T1-2) and the left loops inferior to the arch of the aorta (T4-5), then ascend to the thyroid gland, supplying both trachea and esophagus and all the muscles of the larynx except the cricothyroid
Describe the cervical portion of the sympathetic trunk
lie anterolateral to the vertebral column, extending superiorly to the level of the C1 vertebra, receives no white communicating rami in the neck, includes three cervical sympathetic ganglia (superior, middle and inferior) that receive presynaptic fibers conveyed to the trunk by the superior thoracic spinal nerves, after synapsing, postsynaptic neurons send fibers to the cervical spinal nerves (via gray communicating branches), thoracic viscera (via cardiopulmonary splanchnic nerves) and head and viscera of the neck (via cephalic arterial branches)
What is the location of the inferior cervical ganglion?
in 80% of people, it fuses with the first thoracic ganglion to form the large cervicothoracic ganglion (stellate ganglion), this lies anterior to the transverse process of the C7 vertebra
what purpose does the inferior cervical ganglion have?
postsynaptic fibers from this ganglion pass via gray communicating branches to the anterior rami of the C7 and C8 spinal nerves and others pass to the heart via the inferior cervical cardiac nerve
what is the location of the middle cervical ganglion?
smallest of the three ganglia, lies on the anterior aspect of the inferior thyroid artery at the level of the cricoid cartilage and the transverse process of C6 vertebra
what purpose does the middle cervical ganglion have?
postsynaptic fibers pass form the ganglion to the anterior rami of C5 and C6 spinal nerves to the heart to form the periarterial plexuses to the thyroid gland
what is the location of the superior cervical ganglion?
at the level of C1 and C2 vertebrae, used as a landmark for locating the sympathetic chain
what is the purpose of the superior cervical ganglion?
postsynaptic fibers form the internal carotid sympathetic plexus, also sends arterial branches to the external carotid artery
what is the location of the thyroid gland?
lies deep to the sternothyroid and sternohyoid muscles, located anteriorly in the neck at the level of the C5-T1 vertebrae
what is the arterial supply to the thyroid?
supplied by the superior and inferior thyroid arteries, superior thyroid artery is the first branch of the external carotid and normally branches into anterior and posterior branches that supply the anterosuperior aspect of the thyroid gland, inferior thyroid artery comes form the thyrocervical trunks and supply the posterior aspect of the thyroid, lots of anastomoses between the arteries
what is the venous drainage of the thyroid gland?
three pairs of thyroid veins usually form a thyroid plexus of veins on the anterior surface of the thyroid, the superior thyroid veins accompany the superior thyroid arteries and drain the superior poles of the thyroid, middle thyroid veins run parallel to the inferior thyroid arteries and drain the middle of the lobes, the inferior thyroid vein drain the inferior poles, the superior and middle drain into the IJVs and the inferior drains into the brachiocephalic vein
what is the lymphatic drainage of the thyroid gland?
lymphatic vessels run in the interlobular CT, pass to prelaryngeal, pretracheal and paratraceal lymph nodes which then drain into the superior and inferior deep cervical nodes
what is the nerve supply to the thyroid gland?
derived from the superior, middle and inferior cervical sympathetic ganglia, reach the gland through the cardiac, superior and inferior thyroid periatrial plexuses, are vasomotor not secretomotor
Where is the referred pain go from the gall bladder?
inflamed gallbladder can irritate peritoneum on undersurface of the diaphragm, phrenic nerve provides somatosensory innervation to diaphragm, including the peritoneum, pain from diaphragm enters dorsal horns of cervical nerve C3-5, supraclavicular nerves arise from C3 and C4 and innervate skin over shoulder
What are the muscles of the styloid process?
1. stylohyoid-splits around the digastric muscle, is from branchial arch 2, is innervated by CN VII
2. styloglossus-derived from postotic somites, innervated by CN XII, pulls the tongue up and back
3. sytlopharyngeus-derived from branchial arch 3, innervated by CN IX, the most medial of the three muscles
What does the chorda tympani do?
it gives preganglionic parasympathetics to the submandibular gland where it synapses then innervates the submandibular and sublingual gland
what is the course of the vertebral artery?
1. branch of the subclavian vein
2. C6-C1 transverse foramina
3. foramen magnum
4. basilar artery
what are some branches of the vagus nerve?
1. superior laryngeal nerve-internal branch is sensory above the vocal cords, external branch is motor to cricothyroid
2. recurrent laryngeal nerve-is sensory below the vocal cords, is motor to all other muscles of the larynx, recurs around either the subclavian artery or the aortic arch
What is Horner’s Syndrome?
it is disruption of the sympathetic chain due to injury to the neck or spinal cord or head, leads to ptosis (droopy eyelid), flushed face (due to vasodilation), anhydrosis (dry face) and constricted pupil
What is the course of the thoracic duct?
it enters the junction of the subclavian and internal jugular veins, courses posterior to the junction
What is the lymphatic drainage of the lips and tongue?
lymph from the median part of the tongue drains to the right and left sides