Triangles of the Neck Flashcards
Fascia of the neck
Contents of superficial fascia
Platysma m.
Cutaneous nn.
Contents of the superficial cervical (investing) fascia
Sternocleidomastoid m.
Trapezius m.
Contents of the infrahydoid fascia
The strap muscles:
Sternohyoid m.
Omohyoid m.
Sternothyroid m.
Thyrohyoid m.
Contents of the pretracheal fascia
Thyroid and parathyroid glands
Contents of the carotid sheath
Internal jugular vein
CN X (vagus)
Common carotid aa
Contents of the prevertebral fascia
Deep neck muscles
Roots of brachial/cervical plexuses
Phrenic n.
Sympathetic trunk
Triangles of the neck
Surface anatomy
The nerve point
2/3 of the way up the sternocleidomastoid muscle
Supraclavicular nerve
Transverse cervical nerve
Great auricular nerve
Lesser occipital nerve
CN XI
Carefree zone
Careful zone
External jugular vein
Surface anatomy
Subclavian triangle
Subdivision of careful zone
Submental triangle
Anterior belly of digastric m. (CN V-3)
Mylohyoid (CN V-3)
Sumental lymphnode (lymph from tongue)
Submandibular triangle
Posterior belly of digastric (CN VII)
Mylohyoid/stylohyoid muscles (CN VII)
CN XII
Mylohyoid n.
Genioglossus (C1)
Facial artery and vein
Carotid triangle
Lots of nerves
CN IX
CN XII
Ansa cervicalis (C1-3)
Thyrohyoid n
Laryngeal n.
Deep cervical nodes
Jugulodigastric nodes
Jugulo-omohyoid nodes
Thyroid artery
Superior belly of omohyoid m. (ansa cervicalis innervates)
Muscular triangles
Sternohyoid+omohyoid+sternothyroid (ansa cervicalis innervates these) and thyrohyoid (innervated by C1)
Prelaryngeal nodes
Pretracheal nodes
Anterior jugular and communicating veins
Posterior triangle
Anterior triangle
CN XII is just anterior to the superior aspect of external jugular (image on left - lateral view)
CN XII pierces the carotid sheath
Submental triangle (center of image)
Branches of the external carotid artery
Anastomoses between the internal and external carotid arteries
The facial a./lingual a./ and ascending pharyngeal artery also anastomose at the palantine tonsil bed
Major branches off of the right subclavian
Transverse cervical a.
Inferior thyroid a.
Suprascapular a.
Dorsal scapular a. (sometimes off transverse cervical)
Branches of the external carotid a.
Branches of the right subclavian a.
Superior laryngeal nerve
Superior laryngeal nerve (CN X) branches to form the external superior laryngeal nerve
Innervates the cricothyroid muscle
The nerve point
Contains part of the C2-3 loop (common place to anesthetize)
Contains:
Lesser occipital n.
Greater auricular n.
Transverse cervical n.
The ansa cervicalis
The descending hypoglossi
The descending cervicalis
The phrenic nerve (C3-5)
Nerve to the thyrohyoid muscle
The cervical plexus
C1-2 loop
C2-3 loop
C4
C1-2 loop of the cervical plexus
Contains the nerve to the thyrohyoid muscle (tongue)
and the descending hypoglossi nerve
C2-3 loop of the cervical plexus
Contains the descending cervicalis nerve, lesser occipital nerve, greater auricular nerve, transverse cervical nerve (also contains fibers from C4), supraclavicular nerve (also contains fibers from C4), and the phrenic nerve
Anterior carotid triangle
Cartilage/Bone landmarks
What innervates the sternocleido mastoid muscle?
CN XI (spinal acessory nerve) - delineates the carefree and careful zone
Anterior digastric innervation
CN V-3 (the mandibular branch)
Specifically by the nerve to the mylohyoid muscle
Posterior digastric innervation
CN VII
Vertebral level of bifurcation of the common carotid
CV4
Ansa cervicalis
Loop from the cervical plexus carrying fibers from the descending hypoglossi n
C1-3
Motor to the muscles in the muscular triangle
Ansa - means loop
Motor innervation of the muscle that tenses the vocal cords
Cricothyroid muscle is innervated by the external laryngeal nerve
Travels right with the superior thyroid artery (commonly damaged during thyroid surgery)
Muscle innervation and action of the sternohyoid
Ansa cervicalis innervates the sternohyoid muscle which pulls down on the hyoid when contracted (during swallowing)
What is superficial to the thyroid gland (and location)
The thyroid is deep to the sternothroid and sternohyoid muscles
2nd and 3rd tracheal rings of the larynx
The lateral region
Forms the posterior triangle (Home of the careful and carefree zones)
Borders:
Posterior - trapezius m
Inferior - clavicle
Anterior - sternocleidomastoid
The anterior cervical region
Borders:
Posterior - sternocleidomastoid
Inferior - manubrium
superior - mandible
Four sub divisions (triangles) - submental, submandibular, carotid, and muscular
Congenital torticollis
Sternocleidomastoid m. is damaged due to a tumor or tearing
Zones of cutaneous innervation
Virchow’s node
swelling indicative of infection or cancer in head, neck or chest
Deep to investing fascia
Where is an emergency cricothyrotomy incision made?
Between the thyroid and cricoid cartilages
A - great auricular n.
C - lessor occipital n.
D - spinal accessory n. (CN XI)
Zone A - carefree zone
Zone B - careful zone
Careful zone contents
Muscles - Levator scapulae, anterior/middle/posterior scalene muscles
Nerves - Roots and trunks of cervical and brachial plexuses, phrenic nerve, dorsal scapular nerve
Blood vessels - subclavian artery and vein, transverse cervical artery, dorsoscapular artery, and suprascapular arteries, and the internal jugular vein
What separates the border between the careful and carefree zones of the posterior triangle (lateral region)
CN XI (spinal acessory nerve) - pierces the sternocleidomastoid m. on its way to the trapezius, picks up branches of C2-3 en route.
Thoracic outlet syndrome cause
Suffieicient muscle tension can build up in the scalenes to compress the C5-6 roots giving rise to nuerogenic symptoms
A - mylohyoid
B - anterior belly of the digastric
C - hyoid bone
A - Posterior belly of the digastric
B - Common facial v.
C - Hypoglossal n. (CN XII)
D - Submandibular gland
E - Anterior belly of digastric muscle
A - Superior belly of the omohyoid m.
B - Ansa cervicalis
C - Facial artery
D - Carotid sheath
A - CN XII (hypoglossal n.)
B - Omohyoid m.
C - CN X (vagus)
D - Internal carotid artery
E - External carotid artery
F - Common carotid a.
G - Phrenic nerve (anterior to the anterior scalene)
A - Internal jugular
B - superior belly of omohyoid muscle
C - subclavian triangle
D - CN XI (spinal accessory n.)
E - transverse cervical a
F - prevertebral fascia
A - sternohyoid muscle (innervated by ansa cervicalis)
B - Sternothyroid (also innervated by ansa cervicalis)
C - Superior belly of omohyoid m.
D - Thyrohyoid muscle
A - Great auricular n.m (C2-3)
B - Lesser occipital n. ()
C - Transverse cervical (C2-3)
D - CN XI (spinal accessory n.)
E - Superficial cervical lymph node (deep are at the level of internal jugular vein)
F - Supraclavicular n. (C3-4)
A - Sympathetic trunk (posterior to common carotid artery)
B - Anterior scalene m.
C - Phrenic n.
D - Vagus n.
A - CN XI (spinal accessory n.)
B - CN X (vagus n.)
C - Cervical sympathetic trunk
A - CN XII
B - C1 - nerve to the thyrohyoid
C - Interal laryngeal n.
D - External laryngeal n.
E - Ansa cervicalis
Cricothyroid m.
A - Maxillary atery
B - Facial artery
C - Lingual artery
D - Superior thyroid artery
E - Superificial temporal artery
F - Posterior auricular artery
G - CN XI (spinal accessory nerve - under occipital artery)
H - Internal carotid a.
I - Carotid sinus
A - Occipital artery
B - CN XI
C - CN IX (nerve to the carotid sinus)
D - CN X (vagus between common carotid a. and internal jugular vein)
Nerves that emerge from the jugular foramen
CN IX, X, and XI
A - External carotid a.
B - Superior thyroid a.
C - Inferior thyroid a.
D - Transverse cervical a.
A - Transverse cervical (superior to suprascapular, both run over anterior scalene m.)
B - Dorsal scapular a.
C - Suprascapular a. (inferior to transverse cervical, both run over the anterior scalene m.)
D - Anterior scalene (phrenic nerve runs over it)
E - Vertebral a.
Boundaries of the submental triangle
Anterior bellies of the digastric muscle and anterior aspect of the hyoid bone
Functions of the hypoglossal nerve
Somatic motor innervation of the intrinsic and some extrinisic muscles of the tongue
Which muscles are not innervated by the
ansa cervicalis?
A. Omohyoid muscles.
B. Sternohyoid muscle.
C. Sternothyroid muscle.
D. Thyrohyoid muscle.
The thyrohyoid muscle is innervated by a branch of the ansa cervicalis (C1) called the nerve to the thyrohyoid muscle
A 59-year-old man complains of numbness
in the anterior cervical triangle.
Therefore, damage has occurred to which
of the following nerves?
A. Greater auricular nerve
B. Lesser occipital nerve
C. Phrenic nerve
D. Supraclavicular nerve
E. Transverse cervical nerve
E. Transverse cervical nerve
.During surgery on a 56-year-old man for a squamous cell carcinoma of the neck, the surgeon notices profuse
bleeding from the deep cervical artery. Which of the following arteries must be ligated immediately to stop
bleeding?
A. Ascending cervical artery
B. Costocervical trunk
C. Inferior thyroid artery
D. Thyrocervical trunk
E. Transverse cervical artery
B. Costocervical trunk
8.Any irritation of the diaphragm (e.g. infection, tumor) may create referred pain that seems (to the patient) to
originate in the area atop the shoulder. This is due to the fact that the phrenic nerve shares spinal segments with
what cutaneous nerve in the shoulder region?
A. Dorsal scapular
B. Lesser occipital nerve
C. Long thoracic nerve
D. Supraclavicular nerve
E. Suprascapular nerve
D. Supraclavicular Nerve
At the superior orbital fissure compressing the oculomotor nerve
