10: Anterior Neck Flashcards
separates post triangle from ant triangle
SCM
borders of anterior triangle
mandible, midline of neck, anterior border of SCM
4 triangles of the anterior triangle and what’s in them (general answer)
muscular (lots of muscles), carotid (carotid + internal jugular), submandibular (salivary gland), submental (mental means chin - region below chin)
muscular triangle borders
lateral/superior: superior belly of omohyoid
lateral/inferior: SCM
medial: midline
contents of muscular triangle
“strap muscles” - infrahyoid muscles
infra = below
below the hyoid bone
omohyoid
sternohyoid
sternothyroid
thyrohyoid
superficial strap muscles
omohyoid
sternohyoid
deep strap muscles
sternothyroid - attaches to thyroid cartilage
thyrohyoid
infrahyoid muscles action
depress hyoid and larynx during swallowing and speaking
stabilize tongue with the suprahyoid muscles to provide a stable base for the tongue
inervation to infrahyoid muscles
ansa cervicales of cerival plexus (C1-C3)
muscles of the muscular triangle are all innervated by the ___except for ____
ansa cervicales
thyrohyoid (the short one): C1 (piggybacks with hypoglossal nerve)
contents of the carotid sheath
common carotid artery - medial
internal jugular vein - lateral
vagus nerve - posterior
deep cervical lymph nodes
also associated with the carotid sheath
CN 9, 11, and 12 pierce the sheath at the top
ansa cervicales embedded in anterior wall
C1 fibers piggyback with and innervate
piggyback with hypoglossal nerve
innervate the thyrohyoid m.
“viscera” deep to the strap muscles
from superior to inferior: thyrohyoid membrane thyroid cartilage (adam's apple) cricothyroid membrane cricoid cartilage thyroid gland trachea
vagus nerve: 3 branches to the larynx
recurrent laryngeal
external laryngeal
internal largyngeal
recurrent laryngeal n.
supplies all intrinsic muscles of the larynx EXCEPT for the cricothyroid muscle, which is innervated by the external laryngeal n.
external laryngeal n.
innervates the cricothyroid mucles
internal laryngeal n.
pierces thyrohyoid membrane with superior laryngeal artery (branch of external carotid a.)
THE ONE WE SAW ON THE PRACTICAL!
left recurrent laryngeal n. (review)
wraps around aorta/ligamentum arteriosum
right recurrent laryngeal n.
wraps under the R subclavian a./common carotid a.
carotid triangle borders
posterior belly of the digastric m.
superior belly of omohyoid m.
SCM
carotid triangle contents
carotid sheath - cc, internal jugular, vagus
ansa cervicales - embedded in carotid sheath
hypoglossal nerve XII
branches of external carotid a.
to find the hypoglossal nerve
look under the tendon of the digastric m.
follow the hypoglossal nerve to find
the superior limb of ansa cervicales
superior root of the ansa cervicales
the more medial part of the loop
cervical plexus - sensory and motor components
cutaneous: GA, LO, TC (from C2-C3) and SC (from C3-C4)
motor: ansa cervicales - OH, ST, SH from C1-C3 and TH from C1 only
branches of the external carotid a. in the carotid triangle
superior thyroid a. w superior laryngeal branch
ascending pharyngeal a.
lingual a.
facial a.
occipital a.
“posterior auricular a.” (out of triangle..)
branches of external carotid a. NOT in the carotid triangle
maxillary a.
superficial temporal a.
superior laryngeal artery travels with
the internal recurrent laryngeal n. and pierces through the thyrohyoid membrane
carotid sinus
baroreceptor
bulge in the internal carotid a.
**innervated by CN 9
cartotid body
chemoreceptor
small hard thing in the crotch of the common carotid a.
**innervated by CN 9
what lies deep to the carotid sheath?
anterior scalene muscle
branches of cervical arteries
phrenic nerve (C3, C4, C5)
sympathetic trunk/middle cervical ganglion
phrenic nerve is composed of fibers from
C3, C4, and C5
sympathetic chain
starting from superior to inferior:
superior cervical ganglion - levels C1/C2 - LARGE
middle cervical ganglion - lies on the anterior aspect of the inferior thyroid artery, near the cricothyroid cartilage - ON PRACTICE PRACTICAL
cervicothoracic ganglion - aka stellate ganglion - posterior to the origin of the vertebral artery
submandibular triangle borders
mandible
posterior digastric
anterior digastric
submandibular triangle contents
mylohyoid stylohyoid anterior and posterior bellies of digastric facial artery and vein mylohyoid nerve (trigeminal -5) facial nerve (7) hypoglossal (12) submandibular salivary gland
stylohyoid/posterior belly of digastric relationship
stylohyoid is supposed to run over/superficial to the digastric (but for some reason it’s different on ours)
contraction of the suprahyoid muscles
opens the mouth (moves mandible down)
raphe
center of the mylohyoid, where it inserts on itself
different innervation of the submandibular triangle
trigeminal nerve - mylohyoid nerve (5): ant. belly of digastric, mylohyoid facial nerve (7): post. belly of digastric, stylohyoid
digastric/stylohyoid actions
elevates hyoid in swallowing
opens mandible
mylohyoid actions
tightens and elevates oral floor
draws hyoid forward in swallowing
opens mandible, side to side movement (mastication)
facial artery/vein
vein runs superficial to the submandibular gland, artery runs deep to it
submental artery
from the facial artery
supplies mylohyoid and anterior belly of digastric
submental triangle borders
an unpaired triangle
anterior bellies of digastric
hyoid bone
submental triangle contents
mylohyoid (midline raphe)
small veins from anterior jugular v. (drain into external jugular v.)
