Triangles of the neck and larynx Flashcards
What is found in vertebral level c3-c4?
Body of hyoid bone
Upper margin of the thyroid cartilage
Bifurcation of common carotid artery
What is found in vertebral level C5-c6?
Arch of cricoid cartilage
Superior end of esophagus
Superior end of trachea
Draw the anterior and posterior triangles:
Refer to your drawings
Anterior triangle borders
Midline of the neck
Sternoclediomastoid
Lower border of the mandible
Posterior triangle/lateral cervical borders
Sternocleidomastoid
Trapezius
Clavicle
What divides the anterior and posterior triangles?
SCM (sternocleidomastoid m.)
Divisions of the Anterior triangle:
Submandibular triangle borders
Anterior belly of digastric
Posterior belly of digastric
Inferior border of mandible
*Divisions of the anterior triangle:
Carotid triangle borders:
Posterior belly of digastric
Superior belly of omohyoid
Sternocleidomastoid
Divisions of the anterior triangle:
Submental triangle borders:
Midline of the neck
Anterior belly of digastric
Body of hyoid
*Divisions of the anterior triangle:
muscular triangle borders
Body of hyoid
Superior belly of omohyoid
Sternocleidomastoid
Draw the anatomical relationships of the different divisions of the anterior triangle:
Refer to your drawings
What makes up the floor of the posterior triangle?
Splenius capitis Levator scapulae Omohyoid Posterior scalene Middle scalene Anterior scalene
Arteries in the posterior triangle:
Transverse Cervical A.
Thyrocervical Trunk
Suprascapular A.
Draw the arteries of the neck including:
Vertebral artery Transverse Cervical A. (deep and superficial) Inferior thyroid Suprascapular Thyrocervical trunk Costocervical trunk Internal thoracic
Refer to your drawings
*What forms the external jugular vein?
Retromandibular v. and posterior auricular v. coming together
*The subclavian vein meets the () to form the …
What drains into the venous system in this part of the body?
- Internal jugular vein … brachiocephalic vein
- Lymphatic ducts (right lymphatic and thoracic ducts on the left draining into the venous system)
*If you External Jugular vein is visible on a patient, what does it mean?
Increased venous pressure - possible heart failure or obstruction of superior vena cava
Draw the relevant veins of the posterior triangle:
Refer to your drawings
Cutaneous nerves of the posterior triangle (coming off the cervical plexus):
Lesser Occipital N.
Greater Auricular N.
Transverse Cervical N.
Supraclavicular N.
*all come from the cervical plexus
What do you call the point behind the sternocleidomastoid where the cutaneous nerves of the posterior triangle exit?
Erb’s point/Nerve point of the neck. Relevant in Erb’s palsy
*Lesser occipital N.
Origin
Cutaneous innervation
C2
Skin to scalp and posterior neck
*Great auricular N.
Origin
Cutaneous innervation
C2-C3
Parts of the ear, part of the carotid area, angle of the mandible, mastoid process, bit of the neck
*Transverse Cervical N.
Origin
Cutaneous innervation
C2-C3
Anterior triangle area
*Supraclavicular N.
Origin
Cutaneous innervation
C3-C4
Skin over clavicle and shoulder
Draw the innervations of the posterior triangle:
Refer to your drawings
Spinal Accessory N.
Aka CN XI
Most common nerve that is accidentally cut, usually resulting in trap paralysis (sternocleidomastoid is innervated proximal to this area of common trauma so it is intact)
Phrenic N.
Responsible for diaphragm
C3-C5
Anterior to the anterior scalene
Where does the Brachial plexus come out?
Between the anterior and middle scalene m.
Torticollis:
Cause
Clinical
SCM shortening/contraction. Could also be caused by Spinal Accessory N. issue
Head tilt toward and face to turn away from affected side
Course of the spinal accessory n.
Cervical region of spinal cord > foramen magnum > enters cranial cavity > exits jugular foramen with CN IX and XI (glossopharyngeal and vagus) > appears in Anterior triangle > innervates SCM > appears in posterior triangle (area of common damage) > through the fascia > trapezius
Occipital triangle and omoclavicular (subclavian) triangle are divided by….
Inferior belly of the omohyoid
What are the suprahyoid muscles?
What do they form?
Function?
Anterior and posterior belly of the digastric m.
Myologhyoid M.
Stylohyoid M.
Geniohyoid M. (in the oral cavity)
- form- the floor of the oral cavity
- elevate the hyoid and larynx during swallowing and talking
What are the infrahyoid muscles?
Sternohyoid
Omohyoid
Sternothryoid
Thyrohyoid
What are the branches of the external carotid a.
What branches are seen in the anterior triangle?
Posterior Auricular A. Occipital A. Facial A. Lingual A. Ascending pharyngeal A. Superior Thyroid A. External Carotid A. Internal Carotid A. Common Carotid A.
Draw the branches of the ECA
Refer to your drawings
*Floor of the submandibular triangle:
Mylohyoid
Hyoglossus
Mid constrictor m.
*Contents of the submandibular triangle:
Facial A. and V Hypoglossal N. Nerve to Mylohyoid M. Submandibular gland Lingual A.
Draw the submandibular triangle
Refer to your drawings
*Contents of the submental triangle:
Mylohyoid M. (floor)
Submental lymph nodes
Veins forming the anterior jugular v.
*Contents of the muscular triangle:
Thyroid gland and parathyroid
Thyroid cartilage
Larynx
Trachea
Esophagus
Common carotid, inferior and superior thyroid a.
Anterior jugular v., thyroid v. (superior, middle, inferior)
Ansa cervicalis n., external laryngeal n., recurrent laryngeal n.
*Contents of the carotid triangle
Carotid sheath
Branches of the common carotid a.
External and internal laryngeal n.
Hypoglossal n. and spinal accessory n.
*Carotid sheath contents
Internal jugular v. Common carotid a. Vagus N. Deep cervical lymph nodes Carotid sinus n. Sympathetic n. fibers Ansa cervicalis
*Relationship between occipital a. and hypoglossal n.
Hypoglossal N. wraps around the Occipital A.
Which nerve dives into the larynx in the Carotid triangle?
Internal laryngeal N.
What is the carotid sinus?
*Innervation?
Dilation in the proximal part of the internal carotid a.
Acts as a baroreceptor (blood pressure)
Innervation: cartoid sinus nerve (branching from the glossopharyngeal N. and vagus N. (IX and X))
What is the carotid body?
Innervation?
Located at the bifurcation of the carotid artery.
Tissue that acts as chemoreceptor and senses oxygen levels
Innervation: carotid sinus nerve (branching from the glossopharyngeal N. and vagus N (IX and X))
Draw the carotid triangle innervation:
Refer to your drawings
Thoracic inlet/outlet clinical correlations: Lungs Central Line *Nerves *Esophagus and Trachea
- superior thoracic/inferior thoracic aperture (diaphragm area)
- Lungs extend about 2 inches into the root of the neck. Trauma above the collar (e.g. stabbing) affects the lung and results in pneumothorax.
- Subclavian V. (most superficial) is site for central line. Could puncture the subclavian a. if you got too deep. Can puncture lung if you go too posterior. XR done after central line to ensure lung was not punctured/collapsed
- Brachial plexus, esophagus, trachea, vagus and phrenic are also in this region. So trauma to these structures can affect things further away due to continuity between respiratory and digestive systems
Thoracic outlet syndrome
Compressing the nerves and arteries leading to the upper limb = upper limb issues
Anatomical position and importance of the phrenic nerve:
-Lies superficial to the anterior scalene m.
Sole motor supply to the diaphragm. Phrenic nerve needs to be preserved during surgery.
Arises at the neck level, so spinal cord damage below the neck preserves breathing despite paralysis of limbs
Cervical plexus goes from … to…
C1 - C4
Motor nerves coming off of the cervical plexus
Draw this innervation
Hypoglossal (CN XII, not cervical plexus) - tongue
Superior root of the ansa cervicalis (C1-C2) - geniohyoid, thyrohyoid
Inferior root of the ansa cervicalis (C2-C3) - infrahyoid muscles
Phrenic N. (C3-C5) - diaphragm
*Sympathetic trunk origins:
Superior Cervical Ganglion
Middle Cervical Ganglion
Inferior Cervical Ganglion
What is located close to the sympathetic ganglion and what is the significance of this?
C2-C3
C6
C7-T1
-Arteries. The sympathetic fibers follow these vessels to get to their target areas
Superficial fascia:
- Subcutaneous layer lies between dermis and investing layer of the deep cervical fascia
- contains platysma muscle, cutaneous n., blood and lymphatic vessels, superficial lymph nodes and fat
Platysma muscle
Muscle of facial expression
Innervated by the facial N. (CN VII)
Deep cervical fascia: 3 layers (superficial to deep)
Investing
Pretracheal
Prevertebral
Investing layer
Encloses the SCM and the trapezius
Forms the sheath around the carotid and submandibular glands
Mumps and investing layer:
Parotid gland swelling against unrelenting investing layer causing pain during mumps
Pretracheal layer
Goes around the thyroid, trachea and esophagus (only on anterior side)
Extends to the mediastinum where the heart is
Prevertebral layer
Encircles the prevertebral muscles
Carotid sheath blends with which fascia?
All layers, depending on location
Anatomical relationships of the carotid sheath
Draw the fascia of the neck
- Common carotid artery (most anterior and medial)
- Internal jugular vein (most anterior and lateral)
- Vagus N. ( most posterior structure)
- Sympathetic trunk and phrenic n. are located medial and posterior to the carotid sheath respectively
Retropharyngeal space anatomical position and borders:
-posterior to the pharynx
Anterior border: buccopharyngeal fascia
Posterior border: prevertebral fascia
Lateral border: carotid sheaths
Retropharyngeal abscess:
Develops secondary to lymphatic drainage or contiguous spread of upper respiratory or oral infections
Swelling can cause difficulty in swallowing/speaking and can be life threatening
Anatomical position of the thyroid gland:
Deep to the sternohyoid and sternothyroid muscles
Extends from C5 - T1
Isthmus is located anterior to the trachea and found on tracheal rings 2 and 3
Draw the thyroid gland and neurovasculature
Refer to your drawings
Blood supply of the thyroid gland:
Superior thyroid artery (from external cartoid a.) - superior and anterior portions of the gland
Inferior thyroid artery (from thyrocervical trunk) - inferior and posterior portions of the gland
Parathyroids
What is the blood supply of the parathyroid?
Embedded in the posterior lateral lobes of the thyroid
Usually supplied by the inferior thyroid artery
Thyroid ima artery
Where does it branch from?
Present in 10% of patients
Usually branches from thyrocervical trunk or subclavian
Need to be careful not to puncture during tracheostomies
Thyroid veins
Where do they drain?
Superior thyroid v. and middle thyroid v.
Drain to the Internal jugular v.
Inferior thyroid v.
Drain to the brachiocephalic trunk
Right recurrent laryngeal and left recurrent laryngeal nerves
RCLN branches from Right vagus N. and wraps around the subclavian a.
LRLN branches from the left vagus N. and wraps around the aortic arch
Thyroid movement during swallowing due to ….
Do lymph nodes move with swallowing?
Connections to fascia.
Lymphatics do not move however
Draw the anatomical organization of the larynx relative to other throat structures:
Refer to drawings
Vertebral level of the thyroid cartilage?
Vertebral level of the cricoid cartilage?
C4
C6
Function of the vocal ligament
Produces sound and speech
Laryngeal cavity anatomical position
Extends from the laryngeal inlet to the inferior boundary of the cricoid cartilage
Laryngeal vestibule anatomical position
Laryngeal inlet to vestibular fold
What is the conus elasticus made of?
Cricothyroid membrane and vocal ligament
Internal branch of the SLN is ()
External branch of the SLN is ()
Sensory
Motor (cricothyroid m.)
Inferior laryngeal n. does (sensory or motor) innervation?
both
Sensory innervation above the vocal fold is the …
Sensory innervation below the vocal fold is the …
Internal branch of the superior laryngeal nerve
Inferior laryngeal nerve (terminal branch of the left recurrent laryngeal N.)
Blood supply above the vocal fold is the …
Blood supply below the vocal fold is the …
Superior laryngeal a.
Inferior laryngeal a.
Lymphatics above the vocal fold go …
Lymphatics below the vocal fold go …
With the superior laryngeal a. and to the superior deep cervical nodes
To the pretracheal/prelaryngeal and to the inferior deep cervical nodes
Superficial Cervical Lymph nodes are located …
They follow which vessel?
On the superficial face/neck area
External Jugular Vein
Deep Cervical Lymph nodes are located ….
They follow which vessel?
On the deeper face/neck area
Internal Jugular vein
Two types of deep cervical lymph nodes:
Jugulo-digastric
Location?
Drains from?
C4, deep to posterior belly of digastric m.
Lymph from throat and tonsils
Two types of deep cervical lymph nodes:
Jugulo-omohyoid
Location?
C6, deep to the omohyoid muscle
What are the major lymphatic ducts of the head and neck?
Where are these located?
Left: Thoracic Duct
RIght: lymphatic duct
Located at the junction of IJV and SV
right Lymphatic duct drains…
Right side of the head, neck, chest and right upper extremity
Left thoracic duct drains…
(everything else) Left side of the head, neck, chest, left upper extremity, abdomen, pelvis and perineum, both lower extremities
