Anatomy: Head and Neck Flashcards
where does the hyoid bone lie?
anterior to the neck around C3 level
how is the hyoid bone attached to the skeleton
there are no articulations, it is suspended by muscles that connect to the mandible, styloid process of temporal bone, thyroid cartilage, manubrium of the sternum and the scapula
what does the hyoid bone contain
a body and 2 greater and 2 lesser horns
what does the hyoid bone do?
provides a moveable base for the tongue and helps keep the pharynx patent (needed for swallowing and respiration)
what 2 ligaments support the hyoid in place?
stylohyoid ligament and thyrohyoid membrane
stylohyoid ligaments
attach to the lesser horns of the hyoid bone and suspend the hyoid from the styloid processes
thyrohyoid membrane
acts as a strong anchor to the hyoid bone to the thyroid cartilage
subcutaneous fascia is found?
below the skin of the neck
what part of the subcutaneous fascia contains the platysma muscle?
the anterolateral part
the fibers of the platysma diverge and leave a gap anterior to what two structures?
the larynx and trachea
name the 3 layers of deep cervical fascia
- investing fascia
- pretracheal fascia
- prevertebral fascia
where is the investing cervical fascia found?
immediately deep to the subcutaneous fascia.
It is the most superficial deep layer of fascia that surrounds the entire neck
what muscles are enclosed by the investing cervical fascia?
the trapezius and the sternocleidomastoid muscles
what is the investing cervical fascia continuous with?
the nuchal ligament
what does the investing cervical fascia connect to superiorly?
the superior nuchal lines of the occipital bone, mastoid processes of the temporal bone, zygomatic arches, inferior border of the mandible, the hyoid bone and the spinous processes of the cervical processes
what does the investing cervical fascia connect to inferiorly?
it remains divided in two layers to enclose the SCM. One layer attaches to the anterior and the other to the posterior surface of the manubrium
what is the space called formed by the two inferior layers of the investing cervical fascia?
the suprasternal space
what is enclosed in the suprasternal space
the inferior ends of tha anterior jugular veins, the jugular venous arch, fat, and lymph nodes
what is the most superior landmark on the sternum?
the jugular notch
where is the pretracheal fascia found?
lies in the anterior part of the neck, deep to the inesting fascia
what does the pretracheal fascia blend with inferiorly?
the fibrous pericardium of the heart in the thorax
what is enclosed in the muscular part of the pretracheal fascia?
the infrahyoid muscles
what is enclosed in the visceral part of the pretracheal fascia?
the thyroid gland, trachea, and esophagus
what is the visceral part of the pretrachael fascia continuous with posteriorly and superiorly?
buccopharyngeal fascia of the pharynx
what does the pretrachael fascia blend with laterally?
the carotid sheaths
superior to the hyoid what forms a pulley through the intermediate tendon of the digastric muscle passes suspending the hyoid bone?
a thickening of pretrachael fascia
what is tethered to the two bellied omohyoid muscles?
pretrachael fascia
where is the prevertebral layer of deep cervical fascia?
fixed to the cranial base superiorly.
what does the prevertebral fascia form?
a tubular sheath for the vertebral column and the muscles associated with it (longus colli, longus capitis, scalenes, and deep cervical muscles)
what does the prevertebral fascia blend with inferiorly?
endothoracic fascia peripherally and fuses with the ALL centrally around T3
what does the prevertebral fascia extend with laterally?
the axillary sheath to then form the axillary fascia
what is surrounded by the axillary sheath?
axillary artery, axillary vein, and the brachial plexus
where are the prevertebral muscles contained?
directly within the prevertebral fascia attaching to the cervical vertebrae
prevertebral muscles:
longus colli, longus capitis, rectus capitis anterior, rectus capitis lateralis, anterior scalenes, middle scalenes, and posterior scalenes
what is horner syndrome?
upper thoracic neck masses can compress the sympathetic chain resulting in miosis, ptosis, anhidrosis and vasodilation of the ipsilateral face
where does the carotid sheath extend from?
it is a fascial tube that extends from the cranial base to the root of the neck
what does the carotid sheath blend with anteriorly?
the investing and pretrachael layers of fascia
what does the carotid sheath blend with posteriorly?
the prevertebral fascia
what is contained in the carotid sheath?
the common and internal carotid arteries, the internal jugular vein, the vagus nerve, some deep cervical lymph nodes, the carotid sinus nerve, and sympathetic nerve fibers
which is the largest and most important space in the neck?
the retropharyngeal space
where is the retropharyngeal space?
behind the pharynx
what is the retropharyngeal space?
a space filled with loose connective tissue between the pretrachael and prevertebral layers just posterior to the esophagus
what is the retropharyngeal space continuous with?
the superior mediastinum
if there was an abscess in the pharynx and it eroded where could it potentially go?
in the retropharyngeal space
an abscess in the retropharyngeal space may make what two activities difficult?
swallowing (dysphagia) and speaking (dysarthria)
what does the sternocleidomastoid region divide?
the neck into anterior and lateral regions
what are the contents of the sternocleidomastoid region?
the sternocleidomastoid, the superior part of the external jugular vein, the greater auricular nerve, and the transverse cervical nerve
what space do the two heads of the sternocleidomastoid separate inferiorly?
lesser supraclavicular fossa
what vein resides deep in the supraclavicular fossa?
the internal jugular vein
name the cutaneous and superficial muscles of neck
platysma muscle, sternocleidomastoid, and trapezius
what are the boundaries of the posterior cervical region?
the anterior edge of the trapezius, the midline of the body, and the horizontal fibers of the trapezius
what are the contents of the posterior cervical region?
the trapezius muscle, the cutaneous branches of the posterior rami of cervical spinal nerves and the suboccipital triangle (lies deep)
lateral cervical region (aka posterior triangle) anterior boundary
posterior border of SCM
lateral cervical region posterior boundary
posterior border of trapezius
lateral cervical region inferior boundary
middle 1/3 of of clavicle (between trap and SCM)
lateral cervical region apex
where the SCM and trap meet on superior nuchal line of occipital bone
lateral cervical region roof
formed by the investing layer of the deep cervical fascia
lateral cervical region floor
formed by the muscles covered by the prevertebral layer of fascia (spelnius muscles, levator scap, posterior and middle scalenes
what two triangles can the the lateral cervical region be split into but the inferior belly of the omohyoid?
superiorly: occipital triangle
inferiorly: omoclavicular triangle
what are the contents of the occipital triangle?
occipital artery. spinal accessory nerve is not a content but does cross over the traingle
what are the contents of the omoclavicular (subclavian) triangle?
the inferior external jugular vein crosses superficial and the subclavian artery lies deep within
arteries of the lateral cervical region
occipital artery, subclavian artery
what does the occipital artery branch off of
external carotid artery
what is the course of the occipital artery?
enters the lateral cervical region at its apex and goes up over the head to supply the posterior part of the scalp
what does the subclavian artery supply?
the upper limb as well as the neck and brain
Where does the right subclavian artery arise from?
the brachiocephalic trunk
where does the left subclavian artery arise from?
directly off the arch of the aorta (to the left of the left common carotid artery)
where do both the left and right subclavian arteries enter?
the sternoclavicular joint
what muscle divides the subclavian artery into 3 parts?
the anterior scalene
how does the subclavian artery divide?
a medial, posterior and lateral part
what is contained in the medial part of the subclavian artery division?
the vertebral artery, internal thoracic artery, and the thyrocervical trunk
what is contained in the posterior part of the subclavian artery division?
costocervical trunk
what is contained in the lateral part of the subclavian artery division?
dorsal scapular artery
where does the right part of the vertebral artery arise from?
the first part of the subclavian artery rises up through the pyramidal space formed by the scalene and longus colli muscles
where does the vertebral artery enter?
the transverse forearm of the transverse processes of C6-C1
what does the suboccipital part of the vertebral artery course over?
the groove for the vertebral artery on the arch of C1
where does the suboccipital part of the vertebral artery enter?
the cranium through the foramen magnum
when does the suboccipital part of the vertebral artery become the cranial part of the vertebral artery?
when it passes through the foramen magnum into the cranium
what does the cranial part of the vertebral artery supply?
branches to the medulla, spinal cord, parts of the cerebellum, and the dura of the posterior cranial fossa
when do the vertebral arteries come together?
at the inferior order of the pons of the brainstem
what do the vertebral arteries form when they come together?
the basilar artery
where does the internal thoracic artery arise from
the anterior superior aspect of the first part of the subclavian artery
where does the internal thoracic artery pass?
inferomedially to the thorax
what does the thyrocervical trunk give rise to?
suprascapular artery, ascending cervical artery, and inferior thyroid arteries
what is the course of the suprascapular artery?
passes inferolaterally across the anterior scalene and the phrenic nerve, then crosses the third part of the subclavian artery and the cords of the brachial plexus to pass posterior to the clavicle to supply muscles on the scapula
which is the largest and most important artery from the thyrocervical trunk?
inferior thyroid arteries
what do the inferior thyroid arteries supply?
larynx, trachea, esophagus, and thyroid and parathyroid glands
what does the costocervical trunk bifurcate into?
the supreme costal artery and deep cervical artery
where does the dorsal scapular artery run?
along the dorsal scapular nerve
what does the dorsal scapular artery supply?
the levator scapulae and rhomboid muscles
where does thoracic outlet syndrom usually occur?
outside the aperture in the root of the neck (subclavian artery and transverse cervical nerve)
*this is why the manifestations of symptoms involve the upper extremity
what are the nerves of the lateral cervical region?
spinal accessory nerve, roots of the brachial plexus (C5-T1), suprascapular nerve, and the cervical plexus,
where does the spinal accessory nerve enter the lateral cervical region?
deep to the SCM
which muscle does the spinal accessory nerve run on but does not innervate?
levator scapulae
what is the course of the spinal accessory nerve?
passes deep to the SCM, then passes posteroinferiorly within or deep to the investing layer of fascia, running on the levator scapulae then separated by the prevertebral fascia and terminates to final destination- trap
what is a sign of spinal accessory nerve damage?
unilateral paralysis to the trapezius muscle and drooping of the shoulder
where do the roots of the brachial plexus appear?
between the anterior and middle scalene muscles and descend down through the axilla
where does the suprascapular nerve arise from?
the superior trunk of the brachial plexus
where does the suprascapular nerve run?
laterally across the lateral cervical region to innervate the supraspinatus and infraspinatus on the backside of the scapula
what is the result of suprascapular nerve injury from fracture of the middle third of clavicle?
loss of lateral rotation and abduction of the humerus at the GH joint
*result: relaxed limb in waiter’s tip position
what are the roots for the cervical plexus?
C1-C4 anterior rami
what does the cervical plexus consist of?
irregular series of nerve loops and branches that arise from these loops
where is the cervical plexus found?
lying anteromedially to levator scapulae muscle, posterior to the middle scalenes deep to the SCM
what are the nerves of the cervical plexus?
lesser occipital nerve (C2), greater auricular nerve (C2, C3), Transverse cervical nerve (C2,C3), supraclvaicular nerve (C3,C4), phrenic nerve (C3,C4,C5) ansa cervicalis
what does the lesser occipital nerve innervate?
the skin of the neck and the scalp
where is the lesser occipital nerve found?
posterosuperior to the ear
where does the greater auricular nerve travel?
superficial to the SCM
what does the greater auricular nerve supply?
skin over the parotid gland, angle of the mandible, and ear surfaces.
what does the transverse cervical nerve innervates
the skin of the anterior neck
where does the supraclavicular nerve emerge from?
the cervical plexus as a trunk containing 3 branch
what does the supraclavicular nerve innervate?
the skin over the clavicle and the shoulder
what nerve is the sole motor innervation to the diaphragm and sensation to the middle part
phrenic nerve
where does the phrenic nerve cross on the left?
anterior to the first part of the subclavian artery
where does the phrenic nerve lie on the right?
on the anterior scalene muscle and crosses anterior to the second part of the subclavian artery
_______ ____________ is a secondary loop of motor fibers emerging off the cervical plexus
ansa cervicalis
fibers from ansa cervicalis join and travel with which cranial nerve?
hypoglossal nerve
is the hypoglossal nerve a part of the cervical plexus?
NO
which infrahyoid muscle is NOT innervated by ansa cervicalis
thyrohyoid
what is the anterior boundary of the anterior cervical region?
median line of the neck
what is the posterior boundary of the anterior cervical region?
anterior border of the SCM
what is the superior boundary of the anterior cervical region?
inferior border of the mandible
what is the apex of the anterior cervical region?
jugular notch of the manubrium
what is the roof of the anterior cervical region?
subcutaneous tissue containing the platysma muscle
what is the floor of the anterior cervical region?
pharynx, larynx, and the thyroid gland
how many triangles is the anterior cervical region divided into?
4 (3 of them are paired- one on each side)
what are the triangles of the anterior cervical region?
submental, submandibular, carotid, and muscular
Where is the submental trianglelocated?
inferior to the chin
what are the contents of the submental triangle?
submental veins that unite to form the anterior jugular vein
what is the inferior border of the submental triangle?
body of the hyoid bone
what is the lateral border of the submental triangle?
left and right anterior bellies of the digastric muscles
what is the floor of the submental triangle?
formed by the two mylohyoid muscles which meet together in a median fibrous raphe
what is the apex of the submental triangle?
mandibular symphysis, which is the site of union of the halves of the mandible during infancy
what is the base of the submental triangle?
formed by the rest of the hyoid bone
where is the submandibular triangle located?
between the inferior border of the mandible and the anterior and posterior bellies of the digastric muscle
what is the floor of the submandibular triangle formed by?
the mylohyoid muscles, the hypoglossal muscles, and the middle pharyngeal constrictor muscle of the pharynx
what fills the majority of the space of the submandibular triangle?
the submandibular gland
what does the duct of the submandibular gland do?
empties salivary secretions inferior to the tongue in the floor of the mouth
what else is contained in the submandibular triangle?
submandibular lymph nodes
which arteries travel through the submandibular triangle?
the facial artery and a brach of it as well as the submental artery
what are the borders of the carotid triangle?
the superior belly of the omohyoid muscle, the posterior belly of the digastric muscle, and the anterior border of the SCM
what is the carotid triangle a common site for?
palpating pulse and auscultating for bruits sounds
what is contained in the carotid triangle?
common carotid artery it travels up and through
what are bruits sounds a result of?
turbulent blood flow due to obstruction and interruption of laminar flow by plaques of atherosclerosis
what level does the common carotid artery divide at? and what are the divisions?
thyroid cartilage into internal and external carotid artery
the carotid body is a what kind of structure?
neural
what is the carotid sinus and what does it do and where is it located?
a large portion of the internal of the carotid artery. it senses the oxygen content via chemoreceptors and blood pressure via baroreceptors. located on the internal carotid artery at the bifurcation of the common carotid
what are the carotid body and carotid sinus innervated by?
glossopharyngeal and vagus nerve
what are the contents of the carotid sheath?
the common carotid artery into the internal carotid artery, the vagus nerve runs between and then the internal jugular vein
T/F the ansa cervicalis is a part of the carotid sheath
false it is in the region but superficial to the sheath
what is the muscular triangle made up of?
the superior belly of the omohyoid muscle, the anterior border of the SCM, and the medial plane of the neck
what are the contents of the muscular triangle?
the infrhyoid muscles and the viscera (thyroid and parathyroid glands) and the thyroid cartilage
what does the thyroid gland do?
secretes hormones that regulate rate of metabolism of cells
what does the parathyroid gland do?
secretes hormones that control calcium levels in the body
name the suprahyoid muscles
mylohyoid, geniohyoid, stylohyoid, anterior and posterior belly of the digastric msucle
name the infrahyoid muscles
sternohyoid, omohyoid, sternothyroid, thryohyoid
where does the right common carotid artery begin?
at the bifurcation of the brachiocephalic trunk into the subclavian and right common carotid artery
where does the left common carotid artery begin?
as a branch off the aorta
where do the carotid arteries enter the cranium and what are the two terminal branches?
enter the cranium through the carotid canal and terminal branches are anterior and middle cerebral arteries
which artery supplies almost all the external cranium?
external carotid artery
the orbit and scalp are supplied but what arteries?
supraorbital and supratrochlear
what are the two terminal branches of the external carotid artery?
maxillary and superficial temporal artery
what are the six side branches of the external carotid artery and how do they arise?
one branch arises medially: ascending pharyngeal artery
two branches arise posteriorly: occipital and posterior auricular arteries
three branches arise anteriorly: superior thyroid, lingual, and facial arteries
how does the ascending pharyngeal artery ascend?
on the pharynx medial to the internal carotid artery and travels to the pharynx, prevertebral muscles, middle ear, and cranial meninges
where is the occipital artery?
it is superior to the origin of the facial artery. it passes posteriorly and medially and parallel to the posterior belly of the digastric muscle in the occipital groove in the temporal bone to the posterior part of the scalp
where does the posterior auricular artery ascend?
posteriorly between the external auditory meatus and mastoid process to supply the adjacent muscles, parotid gland, facial nerve, and structures on the temporal bone, auricle, and scalp
where does the superior thyroid artery run?
anteroinferiorly deep to the infrahyoid muscles to reach the thyroid gland. it gives off branches to the infrahyoid muscles and the SCM and a branch called superior laryngeal artery to supply the larynx
where is the lingual artery?
it lies on the middle pharyngeal constrictor muscle. it passes deep to the hypoglossal nerve, the stylohyoid muscle, and the posterior belly of the digastric muscle. it gives branches to the posterior tongue then bifurcates into the deep lingual and sublingual arteries
where is the fascial artery and what does it supply?
it gives off the ascending palatine artery and tonsillar artery, then passes superior under the digastric and stylohyoid muscles and the angle of the mandible. it supplies the submandibular gland and gives off the submental artery and then hooks around the middle of the inferior border of the mandible to enter the face
where does the external jugular vein begin?
near the angle of the mandible just inferior to the auricle bu the union of the posterior division of the retromandibular vein with the posterior auricular vein
where does the external jugular vein run?
crosses the SCM obliquely, deep to the platysma and enters the anteroinferior part of the lateral cervical region, then it pokes through the investing layer of fascia then down the inferior part of the lateral cervical region
what does the external jugular vein terminate into?
subclavian vein
where do the two parts of the internal jugular vein run?
superior- descends into the carotid sheath towards subclavian vein then merge with subclavian into brachiocephalic vein
inferior- dilates to form the inferior bulb of the internal jugular vein.
what does the inferior bulb of the internal jugular vein have?
a bicuspid valve that permits blood flow toward the heart while preventing backflow through the vein
which is the smallest of the jugular veins?
anterior jugular vein
where does the anterior jugular vein run?
arises near the hyoid bone and the right and left anterior jugular veins typically unite together near the jugular arch near the manubrium in the suprasternal space dumping their venous blood into the subclavian veins
where does the subclavian vein run?
it curves through the inferior part of the lateral cervical region. then passes anterior to the anterior scalene and phrenic nerve and then unites at the medial border of the muscle with the internal jugular vein to form the brachiocephalic vein
what does the brachiocephalic vein dump into?
superior vena cava
what is the venous angle?
it is when the subclavian and internal jugular vein combine to form the brachiocephalic vein
what is the venous angle a common site for?
lymphatic drainage
which brachiocephalic vein is longer and why?
left because it has to cross the superior mediastinum
what are the 3 parts of the pharynx?
nasopharynx, oropharynx, laryngopharynx
describe the nasopharynx:
posterior to the nose and superior to the soft palate. there are 2 openings into the nasal cavity called the choanae. the roof is composed of the body of the sphenoid bone and the basilar part of the occipital bone. the openings of the pharyngotympanic tubes are found on the lateral aspects of the nasopharynx
what is a single pharyngeal tonsil (adenoid)
a mass of lymphoid tissue
describe the oropharynx:
posterior to the mouth. primary role is deglutition (swallowing). the chewed bolus of food is mixed with salvia and is then pushed into the oropharynx. involuntarily the soft palate elevates and the suprahyoid muscles contract, elevating the larynx. the involuntary sequential contraction of the 3 constrictor muscles pushes the bolus into the esophagus
where are the paired palatine tonsils?
in the tonsillar fossa between the palatal folds
describe the laryngopharynx:
posterior to the larynx, extending from the superior border of the epiglottis to the inferior border of the cricoid cartilage. it is continuous with the esophagus. the piriform recesses are the grooves at the lateral borders of the laryngeal inlet where the mucosa is reflected along the posterior surface of the thyroid cartilage back to the layngopharynx
what are the layers of the constrictor muscles of the pharynx? and are they voluntary or involuntary?
voluntary. external circular layer and an internal longitudinal layer
is the first or second part of swallowing voluntary?
the first is voluntary the second is involuntary
what are the external circular layers of the pharyngeal constrictor muscles?
superior pharyngeal constrictor, middle pharyngeal constrictor, inferior pharyngeal constrictor, palatopharyngeus muscle (innervated by CN X), salpingopharyngeus muscle (innervated by CN X) stylopharyngeus muscle (innervated by CN IX)
how are the internal smooth muscles arranged in the pharynx and what are they important for?
internal circular and external longitudinal. they elevate the pharynx which is important for phase 2 of swallowing
what is the superior border of the larynx?
the laryngeal inlet (a ring bounded anteriorly by the superior border of the epiglottis)
what is the posterior border of the larynx?
the arytenoids/corniculate cartilages
what is the lateral border of the larynx?
the aryepiglottic folds and superior ends of the cuneiform cartilages
what is the inferior border of the larynx?
cricoid cartilage
what do the vocal folds consist of?
the vocal ligament and the vocalis muscle
what are the vocal folds?
the true vocal cords
what is the glottis?
the vocal apparatus of the larynx
what does the glottis consist of?
vocal folds and the opening between them called the rima glottidis
what are the vestibular folds also known as?
the false vocal cords
where do the vestibular folds extend from?
arytenoid cartilages to the thyroid cartilage superior to the glottis
what is the point of the two thick folds of mucous membrane covering the vestibular ligaments?
protection in function for the glottis
what is the space between the vestibular folds and the glottis?
ventricle
how many cartilages is the laryngeal skeleton composed of?
9 total 3 unpaired and 3 paired
what are the 3 unpaired cartilages in the laryngeal skeleton?
epiglottis, thyroid cartilage, and cricoid cartilage
which unpaired cartilage in the laryngeal skeleton is the largest?
thyroid cartilage
how is the thyroid cartilage connected to the hyoid bone?
thyrohyoid membrane
where does cricoid cartilage articulate with thyroid cartilage and what does it allow for?
laterally at the cricothyroid joints. allows for movements of gliding and rotation to change the lengths of the vocal cords
how does the cricoid attach to the thyroid?
via median crocothyroid ligament and to the first trachael ring via the cricotrachael ligament
what are the 3 paired cartilages of the laryngeal skeleton?
arytenoid, corniculate, and cuneiform cartilages
what are the arytenoid cartilages?
paired pyramidal shaped cartilages articulating with the superior border of the cricoid. the articulation is called the cricoarytenoid joint allowing for many movements between the two cartilages. the apex of each has a corniculate cartilage attached
what are the cuneiform cartilages of the laryngeal skeleton?
they flank the inferior epiglottis projecting superiorly on the posterolateral wall of thyroid cartilages
