Triangles of the Neck (4/10)

true or false: fascial planes divide the neck into 4 main fascial compartments—this has implications for migration of infection

true

name the 4 fascial planes of the neck

investing fascia

pretracheal fascia

carotid sheath

prevertebral fascia

what does the investing fascia surround?

encircles the neck as a whole

surrounds superficial muscles (trapezius and SCM)

(not a Q) investing fascia

(not a Q) investing fascia

name the 2 heads of the SCM

clavicular head

sternal head

what does pretracheal fascia surround?

viscera

(thyroid, pharynx, larynx, esophagus, trachea)

what is the buccopharyngeal fascia?

the part of the pretracheal fascia that covers the posterior surface of the pharyngeal muscles

true or false: the trachea is an entirely cartilaginous structure

false

the trachea is a C-shaped cartilaginous structure closed off posteriorly by muscle

(not a Q) pretracheal fascia

(not a Q) pretracheal fascia

what does the carotid sheath surround?

neurovascular bundle

(contains carotid arteries, internal jugular vein, vagus nerve)

what do the common carotid arteries branch off of?

the R carotid artery branches off of the brachiocephalic trunk

the L carotid artery branches off of the aortic arch

(not a Q) carotid sheath

*there is a L and R carotid sheath, one on either side

(not a Q) carotid sheath

what does prevertebral fascia surround?

epaxial muscles

prevertebral muscles

scalene muscles

vertebra

(prevertebral fascia surrounds all these structures in a continuous sheath)

what do prevertebral muscles include?

longus capitis

longus colli (reference structure on axial images)

(not a Q) prevertebral fascia

(not a Q) prevertebral fascia

where is the retropharyngeal space (AKA danger space) located?

between prevertebral fascia and the buccopharyngeal fascia

(not to be confused with the “danger zone,” which is on the face)

what does the retropharyngeal space contain?

loose areolar tissue

what does the retropharyngeal space communicate with, and what is its clinical significance?

it communicates with the superior mediastinum

provides a route for infection to spread from the neck to the thorax

(not a Q) retropharyngeal/danger space

*green = buccopharyngeal fascia; purple = prevertebral fascia

what are the attachments of the SCM?

the SCM passes obliquely from the sternum and clavicle to attach to the mastoid process and occipital bone

what structure divides the neck into anterior and posterior triangles?

SCM

(not a Q) triangles of the neck

what is the anterior boundary of the posterior triangle of the neck?

posterior border of SCM

what is the posterior boundary of the posterior triangle of the neck?

anterior border of trapezius

what is the base of the posterior triangle of the neck?

superior border of clavicle

what is the roof of the posterior triangle of the neck?

investing layer of deep cervical fascia

what is the floor of the posterior triangle of the neck?

prevertebral fascia covering the splenius capitis, levator scapulae, and scalene muscles

what structure divides the posterior triangle of the neck into 2 smaller triangles?

inferior belly of the omohyoid

the posterior triangle of the neck is subdivided into what named smaller triangles?

occipital triangle

supraclavicular triangle

name the contents of the posterior triangle of the neck

spinal accessory nerve (CN XI)

cutaneous branches of the cervical plexus

inferior belly of the omohyoid

thyrocervical trunk

subclavian artery and vein

name the most specific triangle of the neck in which the subclavian artery and vein are located

supraclavicular triangle

(not a Q) posterior triangle of the neck

name the boundaries of the anterior triangle of the neck

anterior border of SCM

inferior border of the mandible

median plane of the neck

(not a Q) anterior triangle of the neck

*there is a L and R anterior triangle of the neck, separated by the median plane of the neck

name the subdivisions of the anterior triangle of the neck

submental triangle

digastric triangle

muscular triangle

carotid triangle

is the submental triangle paired or unpaired?

unpaired

name the apex of the submental triangle

chin

name the base of the submental triangle

hyoid bone

name the L/R borders of the submental triangle

R and L anterior belly of digastric muscles

name the floor of the submental triangle

mylohyoid muscles

what are the contents of the submental triangle?

submental lymph nodes

what is unique about the hyoid bone?

it does not articulate with another bone

(not a Q) submental triangle

is the digastric triangle paired or unpaired?

paired

what is the superior boundary of the digastric triangle?

mandible

what is the inferior boundary of the digastric triangle?

posterior belly of digastric

what is the medial boundary of the digastric triangle?

anterior belly of digastric

what is the floor of the digastric triangle?

mylohyoid

name the contents of the digastric triangle?

stylohyoid muscle

facial artery and vein

submandibular gland

submandibular lymph nodes

the stylohyoid muscle is parallel to what muscle?

posterior belly of digastric

(not a Q) digastric triangle

name the boundaries of the muscular triangle of the neck

median plane of neck

superior belly of omohyoid

SCM

name the contents of the muscular triangle

infrahyoid muscles

thyroid gland

parathyroid glands

larynx

trachea

esophagus

(not a Q) muscular triangle

name the boundaries of the carotid triangle

superior belly of omohyoid

posterior belly of digastric

anterior border of SCM

name the contents of the carotid triangle

bifurcation of the common carotid into external/internal carotid arteries

carotid sinus

carotid body

vagus nerve

hypoglossal nerve (CN XII)

internal jugular vein

(not a Q) carotid triangle

what bone do the suprahyoid muscles have a relationship with?

the suprahyoid muscles are attached or related to the superior aspect of the hyoid bone

true or false: the suprahyoid muscles are paired muscles

true

name the suprahyoid muscles

anterior belly of digastric

posterior belly of digastric

stylohyoid

mylohyoid

geniohyoid

which 2 suprahyoid muscles are continuous?

anterior and posterior bellies of digastric

what are the attachments of posterior belly of digastric?

mastoid process

hyoid bone

what is the innervation of posterior belly of digastric and stylohyoid?

CN VII

(facial nerve)

what are the actions of posterior belly of digastric and stylohyoid?

elevate, retract, and fix in place the hyoid

what is the innervation of anterior belly of digastric and mylohyoid?

CN V₃

(3rd division of trigeminal nerve)

what are the actions of anterior belly of digastric and mylohyoid?

depress (poorly) the mandible

elevate and fix in place the hyoid

geniohyoid is located deep to which muscle?

mylohyoid

(if you put a pin through mylohyoid, geniohyoid is the 2nd structure pierced)

true or false: geniohyoid is a suprahyoid muscle in the submental triangle

geniohyoid is a suprahyoid muscle

it is not in the submental triangle

what is the innervation of geniohyoid?

a branch of C1

(cervical nerve 1, NOT CN I)

(not a Q) suprahyoid muscles

where do the infrahyoid muscles attach?

inferior side of hyoid bone

what are the infrahyoid muscles collectively known as?

strap muscles

name the infrahyoid muscles

omohyoid (superior and inferior bellies)

sternohyoid

sternothyroid

thyrohyoid

what are the actions of the infrahyoid muscles?

act on the hyoid to either depress it or fix it in place during swallowing

what is the innervation of the infrahyoid muscles?

ansa cervicalis innervates all the infrahyoid muscles except the thyrohyoid (which is innervated by a branch of C1)

(not a Q) infrahyoid muscles

(not a Q) arterial supply of the head and neck

what fascia does the common carotid artery travel in?

carotid sheath

what does the external carotid artery supply?

primary supply of blood to neck and face

what does the internal carotid artery supply?

primary supply of blood to brain and orbit

what is the carotid sinus and where is it located?

the swelling that occurs at the branching of the internal carotid artery from the common carotid artery

it is a baroreceptor that regulates the blood pressure of the cerebral arteries

what is the carotid body and where is it located?

a small mass of tissue located at the bifurcation of the common carotid artery (lies in close relation with the carotid sinus)

it is a chemoreceptor responding to changes in blood CO₂ levels

(not a Q) arterial supply of the head and neck

*can’t really see carotid sinus and body in lab, but must know their approximate locations

name the branches of the external carotid artery

superior thyroid artery

lingual artery

facial artery

maxillary artery

superficial temporal artery

ascending pharyngeal artery

occipital artery

posterior auricular artery

name the 3 branches of the external carotid artery that are generally easy to find in the neck

superior thyroid artery

lingual artery

facial artery

what does the superior thyroid artery supply?

it is one of the arteries to the thyroid gland

what branches off of the superior thyroid artery?

superior laryngeal artery

what does the superior laryngeal artery supply?

larynx

what structure does the superior laryngeal artery pierce through?

thyrohyoid membrane

what does the lingual artery supply?

tongue

parts of oral cavity

what does the facial artery supply?

passes deep to the submandibular gland to supply the external face and oral cavity

(may arise in common with lingual artery)

name the branches of the facial artery

inferior labial artery

superior labial artery

(supplies upper and lower lips)

what is the terminal branch of the facial artery?

angular artery

(this is a renaming of the facial artery by the nose)

(not a Q) branches of the external carotid artery

what does the maxillary artery supply?

infratemporal fossa

nasal cavity

teeth

what does the superficial temporal artery supply?

temporal region of the scalp

side of the head