Organization of the Neck Flashcards Preview

Medical Anatomy > Organization of the Neck > Flashcards

Flashcards in Organization of the Neck Deck (105)

What muscle divides the anterior and posterior triangles?

The sternocleidomastoid muscle


What is the nerve supply of the sternocleidomastoid muscle?

The spinal accessory nerve (XI) provides motor output
Ventral rami of C2, C3 for proprioception


What are the actions of the sternocleidomastoid muscle?

Flex at the atlantooccipital joint and flex cervical column. One muscle alone tilts the head towards ipsilateral shoulder and turns face toward the opposite side.


What divides the posterior triangle into two parts? What are those parts?

The inferior belly of the omohyoid muscle divides the posterior triangle into two triangles called the occipital triangle and the subclavian triangle


What is the most important nerve crossing the occipital triangle?

The accessory nerve


What is included in the subclavian triangle?

The subclavian vein and the third part of the subclavian artery


What 5 muscles make up the muscular floor of the posterior triangle?

Splenius capitus, levator scapulae, scalenus posterior, scalenus medius, scalenus anterior


What are the nerves of the posterior triangle?

1. Accessory nerve (CN XI)
2. Cutaneous branch of the cervical plexus
3. Phrenic nerve
4. Roots of the brachial plexus


Where does the accessory nerve exit the skull?

Jugular foramen (9, 10, 11 pass through here)


Where does the accessory nerve run respective to the sternocleidomastoid muscle?

It runs either deep to the SCM or through it to supply it


What are the cutaneous branches of the cervical plexus? From which cervical segments do they emerge?

Lesser occipital nerve (C2)
Great auricular nerve (C2 and C3)
Transverse cervical nerve (C2 and C3)
Supraclavicular nerves (C3 and C4)


What is supplied by the lesser occipital nerve (Branch of cervical plexus)?

Ascends on posterior border of SCM and supplies skin on neck and scalp behind the ear


What is supplied by the great auricular nerve (branch of cervical plexus)?

Runs upward across SCM toward the parotid gland w/ ext. jugular vein

Supplies external ear, skin of parotid gland, and area of skin extending from mandible to mastoid process


What is supplied b the transverse cervical nerves (branch of cervical plexus)?

Curves around posterior border of SCM near midpoint

Supplies most of skin of anterior cervical region (sensory of skin of neck)


What is supplied by the supraclavicular nerves?

Emerge from common trunk at posterior border of SCM
-branches distribute as far inferiorly as the sternal angle and second rib and as far laterally and posteriorly as the skin over the spine of scapula
Also supply sternoclavicular joint


On top of which muscle does the phrenic nerve course?

Courses inferiorly on the anterior surface of scalenus anterior muscle


What two arteries cross the phrenic superficially?

Transverse cervical and suprascapular arteries


Between which two muscles do the roots of the brachial plexus emerge?

Appear between the anterior and middle scalene muscles


What 3 arteries are in the posterior triangle?

The third part of the subclavian artery

Branches of the thyrocervical trunk (from first part of subclavian): transverse cervical artery and the suprascapular artery


What are veins in the posterior triangle?

External jugular vein and the subclavian vein


What two veins join to form the external jugular vein?

The posterior auricular vein and the posterior division of the retromandibular vein


What vein does the external jugular vein drain into?

Drains into the subclavian vein


What two muscles subdivide the anterior triangle?

The digastric muscle and the omohyoid muscles


What is the nerve supply of the digastric muscle? What are its actions?

The mandibular division of the trigeminal (V) nerve supplies anterior belly
Facial nerve (VII) supplies the posterior belly

It acts to elevate the hyoid or depress the mandible (e.g. in swallowing)


What nerves supply the omohyoid muscle? What are its actions?

Supplied by the ansa cervicalis
Depresses and fixes the hyoid bone


What are the 4 subdivisions of the anterior triangle?

1. Submental triangle
2. Digastric triangle
3. Carotid triangle
4. Muscular triangle


What is contained in the submental triangle division of the anterior triangle?

Submental lymph nodes
Anterior jugular vein


What is contained in the digastric triangle division of the anterior triangle?

Submandibular gland
Submandibular lymph nodes
Facial artery and vein
Hypoglossal nerve
Mylohyoid nerve


What is contained in the carotid triangle division of the anterior triangle (9)?

Common carotid artery
Internal and external carotid arteries
Internal jugular vein
Branches of external carotid artery (superior thyroid, lingual, facial, ascending pharyngeal, occipital arteries)
Vagus nerve and laryngeal branches
Accessory nerve
Hypoglossal nerve
Ansa cervicalis
Deep cervical lymph nodes


What is contained in the muscular triangle?

Sternohyoid muscle
Sternothyroid muscle
Cricothyroid muscle
Larynx and trachea
Thyroid and parathyroid glands


What two divisions of the hyoid muscles exist? What muscles are in each (4 in each)?

Suprahyoid muscles (above hyoid bone)

Infrahyoid muscles (below hyoid bone)


What nerves supply the digastric muscle? What is its action?

Anterior belly of digastric is supplied by mandibular branch of trigeminal (V)
Posterior belly of digastric is supplied by facial nerve (VII)
Acts to elevate hyoid or depresses mandible


What nerves supply the mylohyoid? What is its action?

Mylohyoid nerve from the inferior alveolar branch of the mandibular nerve of the trigeminal (V) nerve
Acts to raise the hyoid, floor of the mouth, and the tongue during swallowing or depresses the mandible


What nerves supply the geniohyoid? What is its action?

Nerve supply is from C1 that hitchhikes on the hypoglossal nerve (not innervated by the hypoglossal)**
Acts to raise the hyoid or depress the mandible


What nerves supply the stylohyoid? What is its action?

Supplied by the facial nerve (VII)
Acts to raise the hyoid and pull it posteriorly


What are the infrahyoid muscles (4)? Which 3 make up the 'strap muscles' and what are these muscles innervated by?

1. Sternohyoid
2. Omohyoid
3. Sternothyroid
4. Thyrohyoid

Sternohyoid, omohyoid, and sternothyroid are the strap muscles and are innervated by the ansa cervicalis


What are the suprahyoid muscles (4)?

1. Myolohyoid
2. Stylohyoid
3. Geniohyoid
4. Digastric


What nerve supplies the sternohyoid, and what is its action?

Supplied by ansa cervicalis
Acts to depress the hyoid bone after elevation during swallowing


What nerve supplies the omohyoid, and what is its action?

Supplied by ansa cervicalis
Depresses and fixes the hyoid bone


What nerve supplies the sternothyroid, and what is its action?

Supplied by the ansa cervicalis
Draws larynx and hyoid downward


What nerve supplies the thyrohyoid, and what is its action?

Supplied by C1 (Carried via the hypoglossal nerve)
Acts to depress hyoid bone, as well as raise the larynx when the hyoid bone is fixed


What are the four distinct layers of deep fascia (underneath the superficial fascia)?

Investing layer
Prevertebral layer
Pretracheal layer
Carotid sheath


What two muscles does the investing fascia split to enclose?

Sternocleidomastoid and the trapezius muscles


What gland is enclosed by investing fascia?

Parotid gland


What is the name of the thickening on deep surface of parotid between the styloid process and mandible?

Stylomandibular ligament


What structures pierce through the investing layer of deep cervical fascia?

The external and anterior jugular veins
Cutaneous branches of the cervical plexus (lesser occipital, great auricular, transverse cervical, and supraclavicular)


What is formed when the deep investing fascia separates above the maubrium, and what is contained there?

The suprasternal space of Burns is formed there; contains the jugular arch (venous connection between two anterior jugular veins)


What is enclosed by the pretracheal fascia?

Encloses the thyroid gland, trachea, esophagus, pharynx, and larynx in a visceral compartment


What is formed by the posterior portion of pretracheal fascia separating the esophagus from the prevertebral fascia?

The buccopharyngeal (visceral) fascia


What muscles are surrounded by the prevertebral fascia (muscles are associated with the vertebral column)?

Prevertebral muscles
Deep muscles of the back of the neck


What forms the fascial floor of the posterior triangle of the neck?

The prevertebral fascia


What is the extension of the prevertebral fascia surrounding the subclavian artery and brachial plexus as they emerge from between the scalenus anterior scalenus medius?

The axillary sheath (is a specialization of the prevertebral fascia


When does the prevertebral fascia split, and what does it split into?

It splits when it attaches to the transverse processes (on the vertebrae) and splits into the anterior lamina (aka the alar fascia) and the posterior lamina


When does the anterior lamina (alar fascia) blend with the fascia on the posterior wall of the esophagus?

At the level of T2


When does the posterior lamina blend with another structure?

The posterior lamina continues down along the thoracic portion of the vertebral column to the diaphragm


What forms the retropharyngeal (anterior) space?

Space behind the pharynx and esophagus, limited inferiorly by the blending of the alar fascia to esophagus at T2. Space between the alar fascia and esophagus


What is the posterior space also called?

Danger space; is a space between the two layers of prevertebral fascia in front of vertebral column, called the danger space because infection of pharynx leads to erosion of this fascia and the infection reaches the superior mediastinum


What is the name of the condensation of fascia around the great vessels of the neck?

Carotid sheath


What fascial layers contribute to the carotid sheath?

Receives contributions from the investing, pretracheal, and prevertebral layers


What is contained in the carotid sheath?

Internal jugular vein
Common and internal carotid arteries
Vagus nerve
Deep cervical lymph nodes
Ansa cervicalis (may be on the surface of, embedded in, or within the carotid sheath)


What divides the three parts of the subclavian artery?

The anterior scalene muscle
1st part is medial to the muscle
2nd part is behind the muscle
3rd part is lateral to the muscle


Where is the third part of the subclavian artery with regard to the brachial plexus and the subclavian vein?

The 3rd part of the subclavian is in front of the inferior trunk of brachial plexus and behind the subclavian vein (subclavian vein is in front of the anterior scalene muscle)


What are the typical branches of the subclavian artery, from medial to lateral? Which part of the subclavian are they usually derived from?

1. Vertebral artery
2. Thyrocervical trunk
3. Internal thoracic
4. Costocervical

Usually derived from the first part of the subclavian


Which vertebrae does the vertebral artery enter its transverse foramen?



Other than from the left subclavian artery, where else may the vertebral artery arise from on the left?

May arise from the aortic arch (so 4 branches off of aortic arch in this case)


What are the 3 branches of the thyrocervical trunk?

1. Inferior thyroid artery
2. Transverse cervical artery
3. Suprascapula artery


What are the two branches of the inferior thyroid artery of the thyrocervical trunk of the subclavian artery?

Inferior laryngeal artery and the ascending cervical artery


Describe the relationship of the phrenic nerve to the anterior scalene muscle and the suprascapular and transverse cervical artery.***

The phrenic nerve runs anterior to the anterior scalene muscle
The transverse cervical artery and suprascapular artery run anterior to the phrenic nerve


What are the two branches of the costocerical trunk?

Supreme intercostal artery (the posterior intercostal arteries for the upper two intercostal spaces)
Deep cervical artery (ascends on back of eck and anastomoses with the descending branch of the occipital artery


At what level does the common carotid artery bifurcate? Into what two arteries?

Bifurcates at the level of the superior border of the thyroid cartilage
Divides into the internal and external carotid arteries


Where does the right common carotid artery begin?
Where does the left common carotid artery begin?

Right common carotid begins at bifurcation of brachiocephalic trunk behind right sternoclavicular joint
Left common carotid begins as a branch off of arch of aorta and ascends into neck behind the left sternoclavicular joint


Does the carotid sinus carry baroreceptors or chemoreceptors, and what CN carry that information?

Carotid sinus carries baroreceptors, and is carried by CN IX and X (glossopharyngeal and vagus)


Does the carotid body carry baroreceptors or chemoreceptors, and what CN carry that information?

Carries chemoreceptors, and carried by CN IX and X (glossopharyngeal and vagus)


What canal does the internal carotid enter the skull through?

Enters through the carotid canal in the skull, and doesn't give off any branches in the neck


What are the eight branches of the external carotid artery?

1. Superior thyroid artery
2. Lingual artery
3. Facial artery
4. Ascending pharyngeal
5. Occipital artery
6. Posterior auricular artery
7. Maxillary artery
8. Superficial temporal artery


What branch is given off by the superior thyroid artery? By which nerve does it run parallel to? What does the branch of the superior thyroid artery pierce and with what nerve?

The superior laryngeal artery is given off by the superior thyroid artery
The superior thyroid artery passes downward and parallel to the external laryngeal nerve
The superior laryngeal artery pierces the thyrohyoid membrane with the internal laryngeal nerve


What branch of the external carotid artery supplies the submandibular gland?

The facial artery (this artery hooks around mandible)


Which side of the external carotid does the ascending pharyngeal branch off of? What does this branch supply?

The medial side. Supplies the pharynx


Which branch of the external carotid is given off at the same level of the facial artery?

The occipital artery


What nerve hooks around the occipital artery close to its origin?

the hypoglossal nerve


Which branch of the external carotid artery ascends behind the ear?

The posterior auricular artery, which supplies it.


What are the 2 terminal branches of the external carotid artery?

The maxillary artery and the superficial temporal artery


The ventral rami of which cervical segments form the cervical plexus? What kind of nerve plexus is it?

Formed by the ventral rami of cervical nerves C1-C4.
Is a somatic nerve plexus


What are the 3 main branches of the cervical plexus?

Cutaneous branches
Ansa cervicalis
Phrenic nerve


What are the 4 main cutaneous branches of the cervical plexus?

Lesser occipital
Greater auricular
Transverse cervical


What muscles are supplied by the ansa cervicalis?

Sternohyoid, sternothyroid, omohyoid (strap muscles)


After giving off the branch for the superior root of the ansa cervicalis, what does the C1 fiber continue as?

Leave as nerve to the thyrohyoid and nerve to the geniohyoid


What forms the ansa cervicalis?

The superior root, a branch off of the C1 that hitches a ride with the hypoglossal, and the inferior root, a branch of C2, C3


What unites the thyroid gland across the front of the trachea below the larynx?

The isthmus


What is the pointed process that points upward from the isthmus along the anterior midline?

The pyramidal lobe


What two sets of arteries supply the thyroid gland?

Superior thyroid artery (divides into anterior and posterior branches)
Inferior thyroid artery


What is the superior thyroid artery a branch of?

The external carotid artery (1st branch of external carotid)


What part of the thyroid gland is supplied by the anterior branch of the superior thyroid artery? What part is supplied by the posterior branch?

Anterior branch supplies the anterior and superior surfaces of the gland and anastomoses with the other side's anterior branch
Posterior branch supplies posterior/inferior part of thyroid and may anastomose with the inferior thyroid artery


What branches are given off by the inferior thyroid artery?

Ascending cervical branch and inferior laryngeal


Which nerve accompanies the inferior laryngeal branch of the inferior thyroid artery of the thyrocervical trunk?

Accompanies the recurrent laryngeal nerve


What is the inferior thyroid artery a branch of?

The thyrocervical trunk


What is the clinical significance of the close association of which artery and which nerve during thyroid gland removal?

Before the thyroid is removed, the thyroid arteries are ligated, so the recurrent laryngeal nerve is in danger of being severed


What else does the inferior thyroid artery send branches to?

Parathyroid glands


What artery may also supply the thyroid aside from the superior and inferior thyroid artery that is present in 2-12% of the population? Where does it ascend?

Thyroid ima artery, may arise from brachiocephalic trunk or arch of aorta, ascends on anterior surface of neck


What are the 3 sets of veins supplying the thyroid?

Superior (accompanies superior thyroid artery)


What do each of the thyroid veins drain into?

Superior - into the internal jugular vein
Middle - into the internal jugular vein
Inferior - drain to the brachiocephalic veins


What artery mainly supplies the parathyroid glands?

Inferior thyroid artery


Name the 6 veins of the head and neck.

Facial vein
Superficial temporal vein
Maxillary vein
Retromandibular vein
External jugular vein
Anterior jugular vein


The union of which 2 veins give rise to the external jugular vein?

Posterior auricular vein and the posterior division of the retromandibular vein


When does the retromandibular vein split into 2 branches?

After leaving the inferior pole of the parotid gland, divides into anterior and posterior divisions