Neck Flashcards
Superficial cervical fascia
. Thin layer subQ that lies btw dermis and investing layer of deep cervical fascia
. Contains cutaneous nn., blood and lymph vessels, superficial lymph nodes, fat, and platysma m. Anterolat.
Layers of deep cervical fascia
. Investing
. Pretracheal
. Prevertebral
. Carotid sheath
Investing cervical fascia
. Superficial layer of deep fascia
. Encloses trap, SCM mm., parotid and submandibular glands
. Stylomandibular ligament is thickened modification of this layer
Pretracheal cervical fascia
. Visceral layer of deep cervical fascia
. Thin and only in ant. Part of neck
. Visceral part: encloses thyroid, trachea, esophagus
. Muscular part: iencloses infrahyoid mm.
. Thickening forms a pulley/trochlea where intermediate tendon of digastric mm. Passes through suspending hyoid
. Tethers omohyoid m. To clavicle, redirecting the course of mm. Btw the bellies
Prevertebral layer of deep cervical fascia
. Forms tubular sheath for vertebral column and mm. Assoc. w/ it
. Fuses w/ ant. Longitudinal ligament lat. as the Axillary sheath
Carotid sheath
. Tubular fascial investment extending from base of skull to root of neck
. Contains common and internal carotid aa., internal jugular v., vagus nn., deep cervical lymph nodes, carotid sinus n. And sympathetic n. Fibers
. Communicates w/ mediastinum inf. And cranial cavity sup. (Creates potential pathways for infections)
Posterior triangle of neck
. Ant: SCM m.
. Post: trap m.
. Inf: middle 1/3 clavicle
. Apex: behind ear to sup. Nuchal line of occipital bone post. To mastoid process
. Roof: investing fascia, platysma, skin
. Floor: prevertebral fascia, splenius capitis, levator scapulae, scalenes
Triangles w/in post. Triangle of neck
. Occipital: CN XI crosses triangle, embedded w/in investing layer of deep cervical fascia
. Subclavian triangle
Boundaries of ant. Triangle in neck
. Post: SCM
. Ant: median line of neck
. sup.: inf margin mandible
. Apex: jugular (suprasternal) notch
. Roof: investing fascia, platysma, skin
. Floor: pharynx, larynx, thyroid covered w/ pretracheal fascia
Triangles w/in ant. Triangle
. Submental
. Submandibular
. Carotid
. Muscular
Scalenus ant. OIAN
. Deep to SCM, ant. To scalenus ant.
O: transverse processes of C4-C6 vertebrae
I: first rib
A: elevates 1st rib; laterally flexes and rotates neck
N: cervical spinal nerves (C4, C5, & C6)
Tightness in scalenes can cause ___
. Compression of subclavian a. And roots of brachial plexus in interscalane triangle
Scalenus medius OIAN
O: transverse processes of C2-C7 vertebrae
I: superior surface of 1st rib
A: flexes neck laterally; elevates 1st rib during forced inspiration
N: ventral rami of cervical spinal nerves
Scalenus post. OIAN
O: transverse processes of C5-C7 vertebrae
I: superior border of 2nd rib
A: flexes neck laterally; elevates 2nd rib during forced inspiration
N: ventral rami of cervical spinal nerves C7 and C8
Omohyoid m. and NA
. 2 bellies united by tendon
. Only inf. Belly cross post. Triangle in anterosup. Portion and courses post. To SCM
. N: Anna cervicalis (C1-3)
. A: depresses, retracts, and steadies hyoid bone
Inferior belly of omohyoid OI
O: superior border of scapula
I: intermediate tendon (held to clavicle by CT loop or sling)
Superior belly of omohyoid m. OI
O: intermediate tendon
I: inferior border of hyoid bone
Suprahyoid mm.
. Digastric m. . Stylohoid m. . Mylohyoid m. . Geniohyoid m. . Hypoglossus m.
Digastric m.
. 2 bellies (ant. And post.)
. Raise hyoid bone, steady during speaking and swallowing
. Acting post. To open mouth and depress mandible
Post. Belly of digastric OIN
O: mastoid notch of temporal bone
I: intermediate tendon (connected to hyoid bone by CT loop or sling)
N: facial nerve (CN VII)
Ant. Belly of digastric m. OIN
O: digastric fossa of mandible
I: intermediate tendon
N: mylohyoid nerve (branch of CN V3)
Stylohyoid OIAN
O: styloid process of temporal bone
I: body of hyoid bone; surrounds tendon of digastric m
A: elevates and retracts hyoid bone
N: facial nerve (CN VII)
Infrahyoid mm.
. Lie inf. To hyoid . Depress hyoid bone during swallowing and speaking . Called strap mm. . Sternohyoid . Thyrohyoid . Sternothyroid . Omohyoid (only sup. Belly)
. Sternohyoid OIAN
O: manubrium sterni and medial end
of clavicle
I: body of hyoid
A: depresses hyoid bone and larynx
N: ansa cervicalis (C1-3)
Thyrohyoid m. OIAN
. Deep to sternohyoid O: oblique line of thyroid cartilage I: body and greater horn of hyoid bone A: depresses hyoid bone; elevates thyroid cartilage N: C1 via hypoglossal n.
Sternothyroid m. OIAN
O: manubrium sterni and 1st costal cartilage
I: oblique line of thyroid cartilage
A: depresses hyoid bone and larynx
N: ansa cervicalis (C1-3)
SCM OIAN
O: sternal head—manubrium sterni;clavicular head—med. 1/3 clavicle
I: mastoid process of temporal bone, occipital bone
A: unilat.—lat. flexes neck, rotates head to opposite side (face is turned sup. towards opposite side). Bilat.—flexes neck
N: accessory nerve (CN XI); sensory fibers from C2 and C3 ventral rami
Cervical plexus
. Formed by ventral rami of spinal nn. C1-4
. Branches seen in post. Triangle include the cutaneous nn.
. Lesser occipital: scalp post. To ear
. Greater auricular: skin post. To ear over parotid
. Transverse cervical: skin on ant. Neck
. Supraclavicular: skin over clavicle and shoulder
Phrenic n.
. Motor innervation to diaphragm (ventral rami C3-5)
. Courses on ant. Surface of ant. Scalene m. In neck
Brachial plexus in neck
. Only parts in neck are roots and trunks and 2 branches (dorsal scapular, suprascapular)
. Roots and trunks emerge btw ant. And middle scalenes
Spinal accessory n. In neck
. Innervates trap and SCM
. W/Nik investing fascia of post. Triangle
Vagus n. In neck
. Travels in carotid sheath in neck btw common carotid a. And internal jugular v. But is post. To both
. Gives off pharyngeal branches, sup. And recurrent laryngeal nn., and cardiac nn. (Preganglionic parasympathetics that terminal in/near heart wall)
Hypoglossal n. In neck
. Courses ant. To supply innervation to tongue musculature
. Lies on superficial surface of hypoglossal m.
. Plays role in course and distribution of fibers on ansa cervicalis
Ansa cervicalis
. Loop of motor fibers from ventral rami C1-3)
. Fibers of C1 go w/ hypoglossal n. And are termed sup. Root of ansa cervicalis once they leave hypoglossal n.
. Sup. Root joins inf. Root (C2-3 fibers) to form loop
. Lies on superficial surface of carotid sheath
. Supplies strap mm.
Sympathetic trunk in neck
. Located anterolat. To vertebral column on ant. Surface longus colli m. (Preganglionic)
. Inf. Cervical ganglia: post. To vertebral a. At origin from subclavian a. (Sometimes fused w/ 1st thoracic ganglion to form stellate ganglion)
. Middle cervial ganglion: ant. Aspect of inf. Thyroid a. Around level of cricoid cartilage of larynx
. Sup. Cervical ganglion: largest, locates at level of atlas/axis
Subclavian a. In neck
. Courses lat. and post. Or scalenus ant. In interscalene triangle
. Gives off branches (Vertebral, internal thoracic, thyrocervical trunk, costocervical trunk) then becomes axillary a.
Vertebral a. In neck
. Ascends through neck to enter transverse foramen of C6
. Then travels through remaining transverse foramina and enters foramen magnum to get to cranial cavity
Thyrocervical trunk in neck
. Divides into 3 branches
. Inf. Thyroid a.: courses sup, and ant. To scalenus ant., post. To carotid sheath to supply thyroid
. Suprascapualr a.: lat. and post. Across root of neck, deep to SCM and trp, ant. To scalenus ant.
. Transverse cervical a.: lat and ant. To scalenus ant., deep to SCM and omohyoid mm., can give deep scapular a. Branch
Costocervical trunk in neck
. Passes post. Over apex of lung, post. To scalenus ant.
. Branches supply 1st intercostal space and deep mm. Of back
Common carotid a.
. R originates off brachiocephalic trunk
. L from arch of aorta
. In carotid sheath
. Bifurcated into internal and external branches at sup. Border thyroid cartilage
Carotid body
. Small brownish mass at bifurcation of common carotid a.
. Blood chemoreceptor
. Innervated by carotid branch of glossopharyngeal (Hering’s n.) and the vagus
Internal carotid a. In neck
. Direct continuation of common carotid a.
. No branches
. Enters carotid canal in petrous portion of temporal bone to gain middle cranial fossa to supply large portion of brain
. Prox. Part has carotid sinus
Carotid sinus
. Baroreceptor stimulated by inc. in bp
. Innervates by carotid branch of CN IX (hering’s) and vagus
External carotid a. Branches
. Sup. Thyroid: inf. To thyroid, SCM, strap mm., larynx via sup. Laryngeal a.
. Ascending pharyngeal a.: btw carotid, ascends to supply pharynx, prevertebral mm., and middle ear
. Lingual a: sup. And ant., deep to hypoglossus m. To tongue
. Facial a.: inf. Border of mandible to supply face, tonsils, palate, submandibular gland
. Occipital a: post. Surface of external carotid, courses post. To supply post. Scalp
. Post. Auricular a.: post. To external auditory meatus
. Maxillary: end branch to infratemporal fossa
. Superficial temporal a.: end branch to scalp and temporalis m.
Internal jugular v. In neck
. Largest v. In neck
. Drains blood from brain and superficial head and neck
. Direct continuation of sigmoid sinus
. Found inc aortic sheath lat. to internal carotid a.
. Passes deep to SCM and unites w/ subclavian v. To form brachiocephalic v.
External jugular v. In neck
. Begins near angle of mandible
. Crosses SCM in superficial fascia
.. empties into subclavian v.
Subclavian v. In neck
. Continuation of axillary v.
. Joints internal jugular to form brachiocephalic v.
. Located ant. To ant. Scalene m.
Thyroid gland
. Bi-loaded endocrine gland connected via isthmus extending across 2-4th tracheal rings
. 40% people have pyramidal lobe extending from isthmus to hyoid bone as persistent thyroglossalduct
. Artery blood supply: sup. And inf. Thyroid aa.
. Vein blood supply: sup. And middle thyroid vv. Drain to internal jugular, inf. Thyroid drains to brachiocephalic
Parathyroid glands
. 2 pairs (sup./inf.) of small endocrine glands
. Embedded in post. Surface thyroid
. Sup.a dm inf. Thyroid aa. Supply blood
Root of neck
. Junction btw neck and thoracic cavity
. Includes thoracic inlet/sup. Thoracic aperture: heart-shaped opening bounded by 1st thoracic vertebra, 1st pair ribs, and manubrium
. Compression causes thoracic outlet syndromes
