1. Triangles of the Neck and The Larynx (KEIM) Flashcards
Landmarks of vertebral level C3-4
Body of Hyoid bone
Upper margin of thyroid cartilage
Bifurcation of common carotid A.
Landmarks of vertebral level C5-6
Arch of cricoid cartilage
superior end of esophagus
superior end of trachea
What are the borders of the posterior triangle of the neck?
SCM (anterior border)
Trapezius (posterior border)
Clavicle (Base)
What are the borders of the anterior triangle of the neck?
Midline of the neck (anterior border)
SCM (posterior border)
Lower border of mandible (base)
it’s an upside-down triangle
What are the borders of the submandibular subdivision/triangle of the anterior triangle?
anterior belly of digastric M. (anterior border)
posterior belly of digastric M. (posterior border)
inferior mandible (base)
What are the borders of the submental subdivision/triangle of the anterior triangle?
Midline of neck (anterior border)
anterior belly of digastric (posterior border, kind of)
Body of hyoid bone (base)
Floor: Mylohyoid M.
What are the borders of the carotid subdivision/triangle of the anterior triangle?
Posterior belly of digastric M. (post. border)
Superior belly of omohyoid M. (ant. border)
SCM (base)
What are the borders of the Muscular subdivision/triangle of the anterior triangle?
Body of hyoid (anterior border)
superior belly of omohyoid (posterior border)
SCM (base)
What muscles make up the floor of the posterior triangle?
semispinalis capitis M.
Splenius capitis M.
Levator Scapulae M.
Posterior, middle and anterior scalene M.
All covered by prevertebral layer of deep fascia
The triangles are superficially covered by what structures? (superficial to deep)
skin
superficial facia
Platysma M.
investing deep fascia
What are the major arteries running through the neck within the posterior triangle? (overview)
subclavian a.
thyrocervical trunk
transverse cervical a.
dorsal scapular a.
suprascapular a.
part of occipital a.
Where is the transverse cervical artery specifically going? (thru posterior triangle)
it runs superficially and laterally across the phrenic nerve and anterior scalene muscle
Where is the suprascapular artery going, specifcially? (thru posterior triangle)
passes inferolaterally across the anterior scalene muscle and phrenic nerve, traveling with the suprascapular N.
Veins within the posterior triangle
external jugular vein starts below the angle of the mandible, after it joins with the posterior retromandibular vein and posterior auricular vein anterior to SCM.
Drains into subclavian
Subclavian V. is anterior to anterior scalene M. and joins with internal jugular vein to form the brachiocephalic vein.
Cutaneous branches of the cervical plexus within the posterior triangle include:
Lesser occipital, C2: neck and scalp behind ear
Great Auricular, C2-3: skin over parotid gland, mastoid process, auricle and angle of mandible
Transverse Cervical, C2-3: skin of anterior neck
Supraclavicular, C3-4: skin over clavicle and shoulder
Other nerves in the posterior triangle of the neck include:
Spinal Accessory Nerve: deep to SCM, lies in deep fascia, enters trapezius
Phrenic N. diaphragm (C3, 4, 5)
Roots of brachial plexus (C5, 6, 7, 8, T1); located between anterior and mid scalene
Ansa Cervicalis: found in fascia of carotid sheath (superior and inferior roots)
Clinical Note on Spinal Accessory Nerve
Torticollis
contraction or shortening of the SCM that causes the head to tilt forward and the face to turn away from the affected side. Can be nerve related (lesion), or muscle related.
Also most commonly cut nerve, easy to damage during procedures.
If severed, only Trap is affected, SCM is okay
Travels through anterior and posterior triangle
Posterior Triangle subdivisions include:
Occipital triangle-contains External Jugular V., branches of cervical plexus, spinal accessory N., cervicodorsal trunk, cervical lymph nodes
Omoclavicular Triangle: Subclavian A, part of subclavian V, Suprascapular A, Supraclavicular Lymph nodes
Muscle groups of the anterior triangle-one set elevates hyoid and larynx, one set depresses
Suprahyoid muscles-elevate hyoid and larynx during speech and swallowing
Infrahyoid muscles-depress hyoid and larynx during speech and swallowing
What are the suprahyoid muscles?
Mylohyoid
Stylohyoid
Digastric (anterior and posterior bellies)
Geniohyoid
My Stylish, Dynamic Girlfriend “Raises” her voice. (larynx)
What are the infrahyoid muscles?
Sternohyoid
Omohyoid
Sternothyroid
Thyrohyoid
Remeber that the sternum and thyroid are lower on the body and that these muscles are also low, so they will pull down on the hyoid/layrnx
What are the arteries of the anterior triangle?
- Common carotid A. which splits at C3-4 and becomes Internal Carotid (ICA) and External Carotid Arteries (ECA)
- Carotid sinus in proximal part of ICA
- Carotid body in between ICA and ECA
- External Carotid and all it’s branches
The External Carotid A. branches into what arteries?
Superior thyroid A
Ascending pharyngeal A.
Lingual A.
Fascial A.
Occipital A.
Posterior auricular A.
Maxillary A.
Superficial temporal a.
Some Anatomists Like Freaking Out Poor Med Students
What makes up the floor of the submandibular triangle
mylohyoid
hyoglossus
middle pharyngeal constrictor
What are the contents of the submandibular triangle?
submandibular gland
submandibular lymph nodes
hypoglossal N.
nerve to mylohyoid
parts of fascial a. and v.
What are the contents of the submental triangle?
Submental lymph nodes
small veins that come together to form the anterior jugular vein
What are the muscles/floor of Muscular triangle?
sternohyoid
sternothyroid
thyrohyoid
What are the contents of the muscular triangle?
Viscera: thyroid, parathyroid, larynx, trachea, esophagus
Arteries: common carotid, superior thyroid, inferior thyroid
Veins: anterior jugular v, thyroid veins (superior, middle, inferior)
Nerves: ansa cervicalis, external laryngeal, recurrent laryngeal
What makes up the floor of the carotid triangle?
thyroidhyoid, hyoglossus, middle and inferior constrictor muscles of the pharynx
What are the contents of the carotid triangle
Carotid Sheath: common and internal carotid arteries, internal jugular v, vagus n, deep cervical lymph nodes, carotid sinus n, sympathetic nerve fibers
Arteries: branches of external carotid a.
Nerves: internal and external laryngeal N, hypoglossal N, spinal accesory N. and Ansa Cervicalis
What does the Superior Thyroid Artery give rise to?
Superior Laryngeal A. to the thyroid
The Ascending Pharyngeal A. is the only _____ branch and is found where?
Medial; medial to ICA
Where does the Lingual A. go?
anterior to middle pharyngeal constrictor, deep to hypoglossal nerve, stylohyoid M and posterior belly of digastric.
Disappears deep to hyoglossus M.
The facial A. gives rise to what and is found where?
gives rise to the ascending palatine artery and tonsillar a.
is found deep to submandibular gland, angle of mandible (pulse point)
Where does the occipital A. go?
passes superficial to ICA and hypoglossal N.
Where does the posterior auricular A. go?
ascends between teh external auditory meatus and mastoid process
The external carotid A. terminates as what?
maxillary artery and superficial temporal artery in the face
Functions of the Carotid Body and Carotid Sinus
Carotid Sinus: Baroreceptor (BP)
“Pressure in my sinuses”
Carotid Body: Chemoreceptor (O2)
“You put chemo in a body”
Carotid sinus nerve comes from Glossopharyngeal and Vagus N.
Structures within the carotid sheath (medial to lateral)
carotid arteries (anterior and medial)
internal jugular v. (lateral)
vagus N (posterior)
Ansa Cervicalis (embedded in sheath)
Lymph, Phrenic N. and Sympathetics also found in the sheath
Branches of the Vagus N.
Pharyngeal branch
Superior Laryngeal branch: internal and external branches of superior laryneal n.
Carotid body branch
Carotid Triangle Nerves include?
Carotid Sheath (neurovascular, contains vagus)
Vagus N.
Spinal accesory N.
Hypogossal N.
Thoracic Inlet and Thoracic Outlet
(Not the syndrome)
Thoracic Inlet: superior thoracic aperture where food and air may enter
Thoracic Outlet: superior thoracic aperture where arteries and nerves emerge
Contents: apex of lung, subclavian artery and vein, brachial pelxus, vagus n., phrenic n., thoracic duct, right lymphatic duct, sympathetic chain, trachea, esophagus
Clinical Note
Subclavian Steal Syndrome
Vertebrobasilar Insufficiency
(Add from Moore’s?)
Add from Moore’s?
Clinical Note on the Phrenic N.
Only motor supply to diaphragm, C3, 4, 5
must be ID’ed and preserved during thoracic surgery
Neck injuries can compromise. Injuries of spinal cord below neck, may lead to lower limb paralysis but ability to breath is preserved.
The cervical plexus is made up of anterior rami from
C1-C4
Superficial branches: sensory
Deep branches: motor
What is significant about the Sympathetic Trunk?
It extends superiorly to C1 or base of skull
consists of three ganlgions
Sympathetic Trunk: Superior Cervical Ganglion
located at C1-2
Sympathetic Trunk: Middle Cervical Ganglion
located at C6 at the level of the circoid cartilage
smallest of the three and may be absent
Sympathetic Cercival Ganglion: Inferior Cervical Ganglion
in 80% of people, the inferior cervical ganglion fuses with the 1st thoracic ganglion and is termed the stellate (cervicothoracic) ganglion
Located anterior to TP of C7
What are the contents of the superficial layer of the neck?
Subcutaneous layer between dermis and investing layer of deep fascia
contents: cutaneous nerves, blood, lymph nodes and vessesls, fat, Platysma M.
Platysma does some facial expression, innervated by facial nerve.
Deep Fascia: Investing Layer
Most Superficial Layer
- Surrounds SCM and Trap.
- Encloses Parotid and Submandibular glands
- Attaches to occiptal and temporal bones, Zyg. arches, mandible, hyoid, and SP of Cerv. Vert.
- Extends to manubrium, clavicles, acromions, and scapular spine
Deep Facia: Pretracheal Layer
- Located only in anterior region of neck
- blends with pericardium
- contains muscular layer (infrahyoid muscles), buccopharyngeal fascia, and a visceral layer
Deep Fascia: Prevertebral Layer
- Encloses vertebral column and muscles
- extends laterally as the axillary sheath
- extends from cranial base to mediastinum
Carotid Sheath is made of Deep cervical fascia
What are the borders of the retropharyngeal space?
Anterior: buccopharyngeal fascia (alar)
Posterior: prevertebral gascia
Laterally: Carotid sheaths
space is located behind the pharynx and extends superiorly to the base of the skull and inferiorly to the mediastinum
Clinical Note
Retropharyngeal Abscess
develop secondary to lymph drainage or spread of URI/oral infections
swelling can cause dysphasia and dysphagia and can be life-threatening
Where is the thyroid located?
- deep to sternothyroid and sternohyoid muscles
- levels C5-T1
- Isthmus anterior to 2nd-3rd tracheal rings
- May or may not have pyramidal lobe
What arteries supply the Thyroid?
Superior Thyroid: Supplies anterior-superior aspects of the gland
Inferior Thyroid: Supplies posterior-inferior aspects of the gland and parathyroid gland
Thyroid Ima artery: found in 10% of people, anterior to trachea
Veins: Superior, middle and inferior thyroid form the thyroid plexus of veins
how does the thyroid relate to other nearby structures?
Recurrent laynrgeal nerves ascend in a groove between trachea and esophagus, passing deeply to posteromedial surface of lateral lobes
ligaments bind thyroid gland to trachea and cricoid cartilage of larynx
What is the organization of the Larynx?
Located at vertebral levels C3-6
Connected to the pharynx and trachea
Functions: Phonation and patent airway
Thyroid Cartilage Anatomy
Located at C4
Laminae
Laryngeal prominence (adam’s apple)
Superior thyroid notch
superior and inferior thyroid horn
Cricoid Cartilage Anatomy
Located at C6
Signet ring shaped
Laminae
Arch
Also know where these cartilages are: epiglottic, arytenoid, corniculate, cuneiform
What is the thyrohyoid membrane?
aperture for teh internal branch of the superior laryngeal n and superior laryngeal a.
What is the cricothyroid membrane?
lateral and medial cricothyroid membranes
where cricothyrotomies are done
also be able to ID thyroepiglottic ligament, vocal ligament, cricothyroid joint
Where is the Laryngeal Cavity?
Extends from the laryngeal inlet, through which it communicates with the laryngopharynx, to the inferior border of the cricoid cartilage. It is continuous with the trachea
Where is the Laryngeal Vestibule?
between the laryngeal inlet and the vestibular folds
Where is the laryngeal ventricle?
between the vestibular and vocal folds
Where is the infraglottic cavity?
between vocal folds and the inferior borer of teh cricoid cartilage
Where is the Rima Glottidis?
Space between the vocal folds
Cricothyroid M. OIAN
O: cricocartilage
I: thyroid cartilage
A: stretches/tenses vocal L.
IN: External Laryngeal N (from CN X)
high pitch sound
Thyro-arytenoid M. OIAN
O: Thyroid Lamina and cricothyroid L.
I: Arytenoid Surface
A: Relaxes vocal L.
N: Inferior Laryngeal N. (from CN X)
low pitch sound
Posterior Crico-arytenoid M. OIAN
O: Lamina and cricoid cartilage
I: arytenoid cartilage
A: Abducts vocal folds
N: Inferior laryngeal N. (from CN X)
room to breath
Lateral Crico-Arytenoid M. OIAN
O: cricoid cartilage
I: Arytenoid cartilage
A: Adducts vocal folds
N: Inferior laryngeal N. (From CN X)
phonation
Transverse and oblique arytenoid M. OIAN
O: One arytenoid cartilage
I: arytenoid cartilage
A: adduct arytenoid cartilage
N: Inferior laryngeal N. (from CN X)
phonation
Vocalis M. OIAN
O: Arytenoid cartilage
I: vocal L.
A: relaxes posterior vocal L. while keeping tension on anteiror part
N: Inferior laryngeal N. ( from CN X)
What arteries supply the larynx?
Superior laryngeal A: travels with internal branch of superior laryngeal n. and supplies larynx above vocal folds
inferior laryngeal A: travels with inferior laryngeaal n. and supplies inferior larynx below the vocal folds
What innervates the larynx?
Superior laryngeal n. branches into internal and external
- Internal branch:* sensory above vocal cords
- external branch*: motor to cricothyroid muscle
Internal laryngeal N. is the terminal branch of the recurrent laryngeal nerve
Sensory below the vocal cords
What are the functions of the superficial lymph nodes of the head?
five groups that form a ring around the head
drain the face and scalp
Drainage from occipital and mastoid nodes passes to superficial cervical nodes along the external jugular vein
Drainage from pre-auricular, parotid, submanibular, submental nodes passes to the deep cervical nodes
List the superificial lymph nodes of the head:
Occipital: drain posterior scalp and neck
Mastoid: drain posterolateral half of scalp
Pre-auricular and parotid: drain anterior auricle, anterlateral scalp, upper half of face
Submandibular: follows facial artery, drains gums, teeth, tongue, upper lip and lateral lower lip
Submental: drains center lower lip, chin, floor, mouth, tip of tongue, and lower incisors
Superficial cervical lymph nodes lie along
the external jugular vein
receive lymph from posterior and posterolateral regions of scalp
will eventually drain into deep cervical nodes
Deep cervical lymph nodes lie along the
internal jugular vein
divideded into upper and lower
Jugulodigastric: Most superior node in the upper deep cervical region, located at C3-4 near posterior belly of diagastric M. (drains throat and tonsils)
Jugulo-omohyoid M: Associated with lower deep cervical nodes, located at C6, inferior to tendon of omohyoid
THESE WILL NOT MOVE WHEN YOU SWALLOW!
What does a prominent EJV indicate?
increased venous pressure possibly due to heart failure or obstruction of the vena cava
What’s relevant about subclavian vein?
central line/port placement
Facial and Lingual A. may
come off common trunk in lab
Hypoglossal N. wraps around which artery?
occipital A.
What can happen if you get stabbed/shot/injured in the neck above the first rib or clavicle?
What are some things that can go wrong in a Subclavian Central Line placement?
Can injure the lung and cause a PTX
Can puncture the subclavian A. or the lung causing a PTX. Better get an Xray after each placement.
What is posterior to the carotid sheath?
Phrenic N. (superficial to anterior scalene)
KNOW
Draw Cervical Plexus and Know Horner’s Syndrome
Clinical Note on Deep Cervical Fascia
Mumps
Swelling ins painful because the glands swell which causes the investing fascia to tighten
When you swallow, ______ moves while ____ remain stationary
Thyroid; Lymph Nodes
What structure allows phonation?
What structure provides flexibility for ranges of sound?
Vocal Ligament
Conus Elasticus
Dr Keim said this 3x within 30sec so you should know that the
internal branch of the superior laryngeal N. does this:
SENSORY INNERVATION ABOVE THE VOCAL FOLDS
Above the vocal folds:
N: Internal branch of superior laryngeal N. (sensory)
B: Superior Laryngeal A.
L: runs with superior laryngial A. and goes to deep cervical LNs
If you swallow water with your trachea, the internal branch of the superior laryngeal N. will sense it.
Below the vocal folds:
N: inferior laryngeal N.
B: Inferior Laryngeal A.
L: goes to prelaryngeal Deep Cervical LNs.
The right lymphatic duct will drain
right head
right UE
right chest wall
Left does everything else
