Triangles of the Neck and Larynx Flashcards
What structures are found at the C3-C4 level?
1)Body of hyoid bone 2)Upper margin of thyroid cartilage 3)Bifurcation of common carotid artery
What structures are found at vertebral level C5-C6
1)Arch of cricoid cartilage 2)Superior end of esophagus 3)Superior end of trachea
What are the structures that make up the boundaries of the posterior triangle of the neck?
Sternocleidomastoid Trapezius Clavicle
What are the structures that make up the boundaries of the Anterior triangle of the neck?
Midline of the neck
Sternocleidomastoid
Lower border of mandible
List the subdivisions of the anterior triangle
Submandibular, Submental, Carotid, Muscular
What are the structures that form the boundaries of the submandibular triangle?
- Anterior belly of digastric
- Posterior belly of digastric
- Inferior border of mandible
*Located in the anterior triangle
What are the structures that form the boundaries of the submental triangle?
- Midline of neck
- Anterior belly of digastric
- Body of hyoid
*Subdivision of the anterior neck
What are the structures that form the boundaries of the carotid triangle?
- Posterior belly of digastric
- Superior belly of omohyoid
- Sternocleidomastoid
*Subdivision of the Anterior Triangle of neck
What are the structures that form the boundaries of the muscular triangle?
- Body of hyoid
- Superior belly of omohyoid
- Sternocleidomastoid
What muscles form the floor of the posterior triangle of the neck? *What kind of fascia covers it?
Semispinalis capitis
Splenius capitis
Levator scapula
Posterior, middle and anterior scalene
*Prevertebral layer of deep fascia
The posterior triangle is covered by…
Hint: 4 things
Covered by skin, superficial fascia, platysma and
investing layer of deep fascia
List the arteries of the posterior triangle.
subclavian, thyrocervical trunk, transverse cervical, dorsal scapular and suprascapular, and part of
occipital a.
Describe the course of the transverse cervical a. in posterior triangle of neck; which trunk does it branch off of?
It runs superficially and laterally across the phrenic nerve and anterior scalene muscle and is a branch of the thyrocervical trunk.
Describe the course of the suprascapular a in the posterior triangle; which trunk does it branch off of?
…a branch of the
thyrocervical trunk, passes inferolaterally across
the anterior scalene muscle and phrenic nerve.
Travels with the suprascapular n.
Which muscle does the external jugular V run anteriorly to?
Which vein does it drain into?
What is the significance of seeing EJV pulsating in a patient?
In which triangle is it located?
1) SCM
2) Subclavian
3) Indicates increased venous pressure, possible heart failure or obstruction
4) Posterior
Which muscle does the subclavian v. run anteriorly to?
Which v does it join with?
Which trunk does it ultimately help form?
Clinical relevance?
Which triangle is it located?
1) Anterior scalene M.
2) Internal jugular V
3) Brachiocephalic V
4) Where central lines can be placed to administer parenteral fluids and medications. If inserted improperly, can puncture lung and lead to pneumothorax.
5) Posterior
What are the cutaneous nerves of the posterior triangle of the neck? Which areas of skin do they give sensation to?
1) Lesser occipital: skin of neck and scalp posterior
to auricle
2) Great Auricular: skin and sheath over parotid
gland, mastoid process, auricle and angle of
mandible
3) Transverse cervical: skin of anterior cervical
region
4) Supraclavicular: skin over the clavicle and over the
shoulder
*emerge from cervical plexus
Where does the cervical plexus emerge in the . posterior triangle of the neck?
Cutaneous branches of cervical plexus emerge around the middle of the posterior SCM (Nerve point of
the neck or Erb’s point)
What are the functions and locations of the spinal accessory, phrenic, and ansa cervicalis nerves?
Spinal accessory: deep to SCM, lies in deep fascia, enters
trapezius
Phrenic: anterior to anterior scalene, supplies diaphragm
Ansa cervicalis: in fascia of carotid sheath
Which nerve is affected in torticollis?
What are the clinical features?
1) Spinal accessory nerve can be compressed by a hematoma/fibrotic mass which entraps a branch of the spinal accessory n. Part of the SCM becomes denervated
2) Shortening of the SCM that causes the head to tilt toward and the face to turn away from the affected side.
Which muscle forms a division in the posterior triangle?
Which triangles are subsequently formed?
1) Inferior belly of the omohyoid
2) Occipital triangle (superior) & omoclavicular triangle (inferior)
What are the main contents and underlying structures of the occipital triangle?
EJV
posterior branches of cervical plexus of nerves
CN XI
Trunks of brachial plexus
Cervical lymph
*Posterior triangle division
What are the main contents and underlying structures of the omoclavicular triangle?
Subclavian A (3rd div)
Subclavian V (sometimes)
Suprascapular A
Supraclavicular lymph nodes
List the suprahyoid muscles.
Which compartment do they reside?
General Function?
1) Mylohyoid
Stylohyoid
Digastric (anterior and posterior bellies)
Geniohyoid (not seen)
2) Found in Anterior Triangle
3) Elevate hyoid and larynx
List the infrahyoid muscles?
Which compartment do they reside in?
General function?
1)Sternohyoid
Omohyoid
Sternothyroid
Thyrohyoid
2) Anterior Triangle of the Neck
3) Depress Hyoid and Larynx
Which division of the common carotid A. branches in the neck?
What are its branches?
1) External Carotid A
2)
Superior thyroid a.
Lingual
Facial a.
Ascending pharyngeal a.
Occipital a.
Posterior auricular a.
Maxillary a. (located in the face)
Superficial temporal a. (located in the
face)
Borders of Submandibular triangle.
What forms the floor of this triangle?
What are its contents?
- *Borders:** inferior border of mandible, and anterior and posterior bellies of digastric m.
- *Floor:** mylohyoid, hyoglossus and middle pharyngeal constrictor
- *Contents:** submandibular gland, submandibular lymph nodes, hypoglossal n., nerve to mylohyoid,
parts of facial a. and v.
Borders of the submental triangle
What forms the floor of this triangle?
What are its contents?
- *Borders:** body of hyoid, right and left anterior belly of digastric
- *Floor:** mylohyoid muscles
- *Contents**: submental lymph nodes and small veins that unite to form anterior jugular v.
Borders of the muscular compartment
What muscles make up this triangle?
What are its contents?
Borders: superior belly of omohyoid, SCM, and median plane of neck
Muscles: Sternohyoid, sternothyroid, thyrohyoid
Contents:
Viscera: thyroid gland, parathyroid glands, larynx, trachea, and 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 are the borders of the carotid triangle?
What makes up the floor of this triangle?
What are its contents?
- *Borders**: superior belly omohyoid, posterior belly of digastric, SCM
- *Floor**: thyrohyoid, hyoglossus, middle and inferior constrictor muscles of the pharynx
Contents: 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 the external carotid a.,
- Nerves: internal and external laryngeal nerves, hypoglossal nerve, spinal accessory n.,
ansa cervicalis
What are the branches of the ECA?
Which triangle do they reside?
1)
Superior thyroid, Ascending pharyngeal, Lingual, Facial, Occipital, Posterior auricular, and terminates into Maxillary, and Superficial temporal in the face
2) Carotid triangle
What parts of the common carotid contain baroreceptors and chemoreceptors, respectively?
Carotid sinus, carotid body
What are the contents of the carotid sheath?
Which triangle is this structure located?
1) Carotid arteries medial
Internal jugular v. lateral
Vagus posterior
Ansa cervicalis anterior or
embedded in the sheath
2) Carotid triangle of the anterior triangle
What are the branches of the vagus nerve in the neck?
Where is the vagus nerve found in the neck?
1) Pharyngeal branch
Superior laryngeal
- Internal branch of superior laryngeal n.
- External branch of superior laryngeal n.
Carotid body branch
2) Posterior to the carotid sheath in the carotid triangle
What are the nerve structures in the carotid sheath?
Vagus (Pharyngeal branch, sup/inf laryngeal branch, carotid body branch), Ansa Cervicalis, Spinal accessory, and Hypoglossal
Describe….
Thoracic inlet?
Thoracic outlet?
Contents of the outlet?
1) Superior thoracic aperture where food and air may enter (anatomists use this term)
2) Superior thoracic aperture where nerves and arteries emerge (clinicians use this term)
3) Apex of lung, Subclavian A/V, Brachial plexus, Vagus N, Phrenic N, thoracic duct, right lymphatic duct, sympethetic chain, trachea, esophagus
Describe the importance of the phrenic nerve (dr Keim repeated this like 50x in lecture)
- Sole motor supply to the diaphragm
- Must be identified during thoracic surgery and preserved
- Because it arises in the next, patients who suffer spinal cord injuries below the neck are still able to breathe
C3, 4, 5 KEEP THE DIAPHRAGM ALIVE
What is the basic outline of the cervical plexus?
What are its spinal roots?
1) Superficial branches = sensory
Deep branches = motor
2) Anterior rami of C1-4
Where does the sympathetic trunk extend in the neck?
What are its ganglion and where they tend to reside?
1) Extends superiorly to C1 or base of skull
2) Superior cervical ganglion:
* Located at C1-C2
Middle cervical ganglion:
- Located at C6 at the level of the cricoid cartilage
- Smallest of the three and may be absent
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 transverse process of C7
What innervates the platysma? Which layer of fascia does it reside?
1) Facial Nerve (CN VII)
2) Superficial
What are the 4 layers of the deep cervial fascia?
Generally where do they reside?
1) Investing layer: surrounds entire neck
2) Pretracheal Layer: Only in anterior region of neck
3) Prevertebral layer: Encloses vertebral column
4) Carotid sheath
Describe the location/surrounding fascial structures of retropharyngeal space.
Clinical significance?
1) Posterior to the pharynx
2) Bound by buccopharyngeal fascia anteriorly, Prevertebral fascia posteriorly, and carotid sheaths laterally
3) Retropharyngeal abscess develops secondary to lymphatic drainage or contiguous spread of upper respiratory or oral infections. The swelling can cause difficulty in swallowing and speaking and can be life threatening.
Which muscles is the thyroid deep to?
Which vertebral level is this?
1) Sternothyroid and sternohyoid muscles
2) C5-T1
What arteries supply the thyroid? Which aspects of the thyroid do they supply?
Veins of thyroid?
1) Arteries : Superior thyroid: supplies anterior-superior aspects of the gland
Inferior thyroid: supplies posterior-inferior aspects of the gland
Thyroid ima artery: found in 10% of people, located anterior to the trachea •
2) Veins: Superior, middle and inferior thyroid veins form the thyroid plexus of veins
Where do the recurrent laryngeal nerves reside?
Recurrent laryngeal nerves ascend in a groove between trachea and esophagus. They pass deep to the
posteromedial surface of the lateral lobes of the thyroid gland.
What vertebral levels is the larynx located?
What other structures is it connected to?
1) C3-C6
2) Pharync and trachea
What are the 2 most prominent cartilaginous structures of the larynx? What vertebral levels are they located?
Which of these cartilages cartilages contains the laryngeal prominence (Adam’s Apple)?
1) Thyroid, C4
2) Cricoid Cartilage, C6
3) Thyroid
List the cartilaginous structures of the larynx
Thyroid, cricoid, epiglottic, arytenoid, corniculate, and cuneiform
What are the 2 membranes of the larynx? Give general descriptions and possible clinical correlations.
Thyrohyoid membrane: Aperture for the internal branch of superior laryngeal n. and superior laryngeal artery
Cricothyroid membrane: Lateral and medial cricothyroid membranes, where tracheotomy is performed (aka cricothyrotomy)
Which Artery (ies) and nerve cross over the Anterior scalene muscle?
Phrenic nerve, Transverse cervical artery, and suprscapular artery more inferiorly
