Triangles of the Neck & Larynx Flashcards
What are the boundaries of the posterior triangle?
Anterior - sternocleidomastoid M
Posterior - trapezius M.
Inferior - clavicle
Floor - splenius capitis M.; levator scapulae M.; posterior, middle, and anterior scalene M.
What are the arteries within the posterior triangle?
vertebral A.,
internal thoracic A.
thyrocervical trunk [suprascapular A., transverse cervical A. (deep and superficial), inferior thyroid A.]
costocervical trunk
What are the veins within the posterior triangle?
external jugular V.
subclavian V.
What are the nerves within the posterior triangle?
spinal accessory N. cervical plexus (lesser occipital N., great auricular N., transverse cervical N., supraclavicular N.)
What are the boundaries of the anterior triangle?
superior - inferior border of the mandible
anterior - midline of the neck
posterior - sternocleidomastoid M.
What are the muscles within the anterior triangle?
digastric M. mylohyoid M. sternohyoid M. omohyoid M. stylohyoid M. thryohyoid M. sternothyroid M.
What are the arteries within the anterior triangle?
common carotid A. and internal carotid A.
external carotid A.
-superior thyroid A., superior laryngeal A., ascending pharyngeal A., lingual A., facial A., occipital A.,
superficial temporal A.,
What other triangles are within the anterior triangle?
submandibular
submental
carotid
muscular
What other triangles are within the posterior triangle?
occipital
subclavian
What are the neurovascular and lymphatic contents of the submandibular triangle?
submandibular gland
submandibular lymph nodes
hypoglossal N. and mylohyoid N.
facial A. and facial V.
What are the boundaries of the submandibular triangle?
superior - inferior border of the mandible
posterior - posterior belly of the digastric M.
anterior - anterior belly of the digastric M.
What are the boundaries of the submental triangle?
posterior - hyoid
lateral - medial border of the anterior belly of the digastric M.
What are the lymphatic contents of the submental triangle?
submental lymph nodes
What are the boundaries of the muscular triangle?
medial - midline of the neck
superolateral - superior belly of the omohyoid M.
inferolateral - anterior border of the sternocleidomastoid M.
What are the muscular contents of the muscular triangle?
sternohyoid M.
sternothyroid M.
thyrohyoid M.
What are the boundaries of the carotid triangle?
anterior - superior belly of the omohyoid M.
posterior - anterior border of the sternocleidomastoid M.
superior - posterior belly of the digastric M.
What are the neurovascular and lymphatic contents of the carotid triangle?
common carotid A. internal & external carotid A. carotid sinus and carotid body glossopharyngeal N. vagus N. carotid sinus N. internal jugular V. deep cervical lymph nodes
What are the fascial layers in the neck?
superficial fascia
deep cervical fascia
carotid sheath
retropharyngeal space
What is the superficial fascia of the neck?
thin connective tissue layer that lies b/w the dermis and investing layer of deep cervical fascia
What are the contents of the superficial fascia of the neck?
cutaneous nerves, arteries and veins
superficial lymph nodes and lymphatic vessels
fat
platysma M. = muscle of facial expression (innervated by facial N.)
What are the layers of the deep cervical fascia?
Investing Layer
Pretracheal Layer
Prevertebral Layer
What is the investing layer of the deep cervical fascia?
surrounds entire neck
encloses sternocleidomastoid M. and trapezius M.
encloses parotid and submandibular glands
What is the pretracheal layer of the deep cervical fascia?
located only in anterior region of the neck
blends with pericardium of the heart
muscular layer (infrahyoid muscles), buccopharyngeal fascia, and visceral layer
What is the prevertebral layer of the deep cervical fascia?
encloses vertebral column and associated muscles
extends laterally as the axillary sheath into the arm
What are the neurovascular contents of the carotid sheath?
vagus N.
internal jugular V.
common carotid A.
What are the boundaries of the retropharyngeal space?
anterior - buccopharyngeal fascia posterior - prevertebral fascia lateral - carotid sheaths superior - base of skull inferior - mediastinum
What is a retropharyngeal abscess and what are the symptoms?
develops secondary to lymphatic drainage or spread of oral or upper respiratory infections
can cause difficulty swallowing/speaking
can be life-threatening
What nerves exit the jugular foramen?
Glossopharyngeal N. (CN IX)
Vagus N. (CN X)
Spinal Accessory N. (CN XI)
What is the nerve most commonly injured during lateral cervical neck surgery?
Spinal Accessory Nerve (XI), b/c of its superficial location
What are the nerve roots to the phrenic N.?
C3, C4, C5
What does the phrenic N. innervate?
diaphragm
What nerve relays information from the carotid body?
Carotid sinus N.
branch of glossopharyngeal N CNIX and vagus N CNX
Does the external jugular V lie deep or superficial to the SCM?
superficial
What does the carotid body do?
Chemoreceptor that detects oxygen levels
What does the carotid sinus do?
Baroreceptor that detects BP
What the branches of the external carotid A.?
Superior thyroid A. Ascending pharyngeal A. Lingual A. Occipital A. Superficial Temporal A. Facial A.
What nerve root supplies the geniohyoid branch and the thyrohyoid branch of the cervical plexus?
C1
What nerve roots supply the Great Auricular N?
C2 and C3
What does the Great Auricular N. innervate?
Skin over parotid gland
Skin over posterior auricle
Skin over the region b/w mandible and mastoid
What nerve root supplies the Lesser Occipital N.?
C2
What does the Lesser Occipital N. innervate?
Skin of the neck and scalp posterior to auricle
What nerve roots supply the Transverse Cervical N?
C2 and C3
What does the Transverse Cervical N. innervate?
Skin over the anterior triangle
What nerve roots supply the superior and inferior branches of the ansa cervicalis?
Superior - C1
Inferior - C2 and C3
What does the ansa cervicalis innervate?
Sternohyoid M.
Omohyoid M.
Sternothyroid M.
What nerve roots supply the supraclavicular N.?
C3 and C4
What does the supraclavicular N. innervate?
Skin over lateral neck and shoulder
What are the major branches of the vagus N (CN X)?
pharyngeal branch and plexus superior laryngeal N. -internal and external laryngeal N's. superior and middle cardiac branches recurrent laryngeal N. (becomes inferior laryngeal N.)
What does the pharyngeal branch of the vagus N. innervate?
pharyngeal constrictor M.
What does the internal laryngeal N. innervate?
laryngeal mucosa, everything in the superior compartment of the larynx
What does the external laryngeal N. innervate?
cricothyroid M.
What path does the left recurrent laryngeal N. take before it becomes the inferior laryngeal N.?
loops around the aortic arch
What does the inferior laryngeal N. innervate?
thyroarytenoid M oblique arytenoid M. transverse arytenoid M. lateral cricoarytenoid M. posterior cricoartytenoid M. vocalis M.
What does the spinal accessory N. (CN XI) innervate?
SCM
Trapezius M.
In what specific triangle is the thyroid gland?
muscular
Where is the thyroid located?
Superficial to the trachea
Medial to the carotid sheaths
Spans C5-T1 vertebral levels
What is the central part of the thyroid called?
Isthmus
At what tracheal levels is the isthmus located?
Rings 2 and 3
Does the thyroid gland move during speech/swallowing?
Yes
Where are the parathyroid glands located?
On the posterior aspect of the thyroid gland
- superior
- inferior
What is the blood supply to the thyroid?
superior thyroid A. (from external carotid A.)
inferior thyroid A. (from thyrocervical trunk)
What innervates the thyroid?
parasympathetic fibers of the vagus N. (CN X)
What is the pyramidal lobe of the thyroid?
remnant of embryonic development
During a tracheostomy, what must a surgeon beware of?
a potential thyroid ima A., located in 10% of the population … could cause hemorrhage
At what vertebral level is the thyroid cartilage located?
C4
At what vertebral level is the cricoid cartilage located?
C6
What is the action of the thyroarytenoid M.?
- relax vocal L.
- lower pitch
What is the action of the oblique and transverse arytenoid M’s?
adduct arytenoid cartilage
What is the action of vocalis M.?
relax posterior vocal L. while increasing/maintaining tension of the anterior part
What is the action of the lateral cricoarytenoid M.?
aDduct vocal folds
What is the action of the posterior cricoarytenoid M.?
aBduct vocal folds
What is the anatomical relationship b/w the oblique and transverse arytenoid muscles?
Oblique arytenoid M. is superficial to the transverse arytenoid M.
What is the action of the cricothyroid M.?
- stretch/tense vocal L.
- increase pitch
What are the neurovascular and lymph components of the superior laryngeal compartment?
Sensory: internal laryngeal N.
Blood: superior laryngeal A.
Lymph: travels with superior laryngeal A. into the superior deep cervical LN
What are the neurovascular and lymph components of the inferior laryngeal compartment?
Sensory: inferior laryngeal N.
Blood: inferior laryngeal A.
Lymph: pretracheal and prevertebral LN into the inferior deep cervical LN
What vein do the superficial cervical LN’s follow?
external jugular V.
What vein do the deep cervical LN follow?
internal jugular V.
What are the jugulo-digastric LN’s?
Deep cervical LN located ~C4, deep to the posterior belly of the digastric M.
drain fluids from throat and tonsils
What are the jugulo-omohyoid LN’s?
Deep cervical LN located ~C6, deep to the omohyoid M.
What does the right lymphatic duct drain?
R side of the head
R side of the neck
R side of the chest
R upper extremity
What does the thoracic duct drain?
everything on the L side of the body
abdomen
pelvic/perineal area
R lower extremity
Blue Box: Fx of Hyoid B.
- manual strangulation
- cannot elevate hyoid or move it anteriorly
- aspiration pneumonia
Blue Box: Cervical Fascia
- injury to cervical branch of facial N. (CN VII)
- skin falls away from neck in slack folds
- careful w/ platysma and skin when suturing
- disfiguring scars
Blue Box: Congenital Torticollis
- fibrous tumor in infancy
- head tilts toward, face tilts away from affected side
- injury to SCM during birth = hematoma and CN XI injury
Blue Box: Spasmodic Torticollis
- abnormal tonicity of SCM or trapezius M.
- agonist and antagonist actions
- sustained tilting/turning/flexing/extending neck
- involuntary shifting of head
Blue Box: Subclavian V. Puncture
- central line placement
- may accidentally puncture lung … pneumothorax
- may puncture subclavian A. if too far posterior
Blue Box: R Cardiac Catheterization
- puncture of IJV
- into brachiocephalic V.
- into superior vena cava
- into R side of heart
- EJV not idea b/c of junction angle
Blue Box: Prominence of EJV
- internal barometer
- prominent when venous pressure rises (heart failure)
Blue Box: Severance of EJV
- investing layer of deep cervical fascia opens lumen
- negative pressure sucks in air
- churning noise in thorax
- cyanosis
- venous air embolism = froth stops blood flow = SOA
Blue Box: Lesions of Spinal Accessory N.
- penetrating trauma
- tumors at cranial base
- Fx of jugular foramen
- weakness in turning head against resistance
- drooping shoulder
Blue Box: Severance/Block/Crush of Phrenic N.
- paralysis in corresponding 1/2 of diaphragm
- block for short term lung operation
- crush for long term healing of diaphragm hernia repair
- sometimes there’s an accessory phrenic N.
Blue Box: Nerve Block of Cervical Plexus
- injection along posterior border of SCM
- Nerve Point of the Neck
- half of diaphragm is usually paralyzed
- cannot do in pt.’s w/lung or heart disease
Blue Box: Nerve Block of Upper Extremity
- supraclavicular brachial plexus
- superior to midpoint of the clavicle
Blue Box: Injury to Suprascapular N.
- loss of lateral rotation of humerus
- waiter’s tip position
- cannot initiate abduction of limb
Blue Box: Ligation of External Carotid A.
- control bleeding from inaccessible branch
- doesn’t stop flow b/c of retrograde flow
- external carotid A. on other side across midline of face
- occipital A. provides collateral circulation
- anastamose w/vertebral and deep cervical A.
Blue Box: Sugical Dissection of Carotid Triangle
- IJV
- carotid system of arteries
- CN X and CN XII
- cervical sympathetic trunk
- damage to X or recurrent laryngeal = voice altered
Blue Box: Carotid Occlusion and Endarterectomy
Partial occlusion may cause TIA (less than 24 hrs)
Full Occlusion may cause minor stroke
-symptoms last b/w 24 hrs and 3 wks
Endarterectomy = open A., strip off plaque
Risk injury to CN IX-CNXII
Blue Box: Carotid Pulse
- checked during CPR
- absence = cardiac arrest
- shouldn’t check in pt.’s with cardiac/vascular disease
Blue Box: Carotid Sinus Hypersensitivity
- external pressure slows HR, drops BP, cause fainting
- shouldn’t check carotid pulse
Blue Box: Internal Jugular Pulse
- can provide information about heart activity
- R atrial pressure by an ECG
- pulsations visible in Trendelenburg position
- pulsations increase w/mitral valve disease
- R IJV runs a straighter/direct path to R atrium
Blue Box: IJV Puncture
- diagnostic/therapeutic
- R side usually straighter and larger
- insert at 30 degrees, just lateral to common carotid A.
- aim between sternal and clavicular heads of SCM
- then direct inferolaterally to ipsilateral nipple