2: Anterior Cervical Triangle Flashcards
ACT boundaries
anterior=midline of neck
posterior=SCM
superior=inf border of mandible
suprahyoid mm.
stylohyoid m.
digastric m.
mylohyoid m.
geniohyoid m.
infrahyoid mm.
omohyoid m.
sternohyoid m.
thyrohyoid m.
sternothyroid m.
(sternothyroid m. and thyrohyoid m. are deep to the sternohyoid m.)
stylohyoid m.
a: pulls hyoid bone upward in posterosuperior direction
inn: facial n. (CN VII)
(this is an arch 2 m.)
digastric m.
a: supports & elevated floor of mouth; elevates hyoid
inn: V3 (mylohyoid branch coming off the inf alveolar branch of V3)
geniohyoid m.
a: if mandible is fixed, it elevates & pulls hyoid forward. if hyoid is fixed, it pulls mandible downward & inward
inn: branch from ant ramus of C1 carried via hypoglossal n. (CN XII)
sternohyoid m.
a: depresses hyoid after swallowing
inn: ant ramus of C1-C3 via ansa cervicalis
omohyoid m.
a: depresses & fixes hyoid
inn: ant ramus of C1-C3 via ansa cervicalis
thyrohyoid m.
a: depresses hyoid. when hyoid is fixed, it raises pharynx to get it out of the way when swallowing
inn: fibers from ant ramus of C1 carried via the hypoglossal n. (CN XII) (n. to thyrohyoid m.)
sternothyroid m.
a: draws larynx (thyroid cartilage) downward
inn: ant ramus of C1-C3 via ansa cervicalis
veins of the neck
facial v. retromandibular v. anterior jugular v. communicating branch internal jugular v. external jugular v.
which two veins form external jugular v.
facial v. and posterior auricular v.
what is found in between internal and external jugular veins
SCM and superior belly of omohyoid
draining of head & neck
ipsilateral, right drains right and left drains left
retromandibular v.
formed by superficial temporal v. & maxillary v.
have anterior and posterior divisions
ant div + facial v. = common facial v. (which drains into internal jugular v.)
post div + post auricular v. = external jugular v.
ACT arteries
internal carotid a.
external carotid a.
common carotid a.
(bifurcation at C3-C4)
external carotid a. branches
3 anterior:
superior thyroid a.
lingual a.
facial a.
3 posterior:
ascending pharyngeal a.
occipital a.
posterior auricular a.
terminates as: superficial temporal a. & maxillary a.
superior thyroid a.
1st anterior branch of external carotid a.
arises from anterior surface near bifurcation
gives off superior laryngeal a.
supplies superior portion of thyroid gland
lingual a.
2nd anterior branch of external carotid a.
arises just above superior thyroid a. at level of greater horn of hyoid
passes deeply into mm. of tongue
facial a.
3rd anterior branch of external carotid a.
arises just superior to lingual a.
crosses inf border of mandible to supply face
ascending pharyngeal a.
1st posterior branch of external carotid a.
arises close to bifurcation
ascends to supply pharynx & tonsils
occipital a.
2nd posterior branch of external carotid a.
arises near level and posteriorly to the origin of facial a.
passes deep to posterior belly of digastric m.
ascends to supply neck & scalp
sends off muscular branch to SCM (hooks over CN XII)
posterior auricular a.
3rd posterior branch of external carotid a.
arises superior to origin of occipital a.
superior to posterior belly of digastric m.
passes upward & posteriorly to supply scalp posterior to ear
(sometimes too deep and high to find it)
spinal nerve branches
transverse cervical n. (C2-C3) ansa cervicalis (C1-C3)
cranial nerves
facial n. (CN VII) glossopharyngeal n. (CN IX) vagus n. (CN X) accessory n. (CN XI) hypoglossal n. (CN XII)
transverse cervical n.
(C2-C3)
runs transversely across middle of SCM
supplies skin of ACT & lateral neck
ansa cervicalis
n. loop from ant rami (C1-C3)
inn. infrahyoid mm.
superior root: mainly of C1 fibers from ant rami
inferior root: ant rami of C2 & C3
ACT subdivisions
submental triangle
submandibular triangle
muscular triangle
carotid triangle
submental triangle borders
inferior=hyoid bone
lateral (right)=ant. belly of digastric m.
lateral (left)=ant. belly of digastric m.
submental triangle contents
mylohyoid m.
submental lymph nodes
some small veins
submandibular (digastric) triangle borders
superior=inf border of mandible
anterior/inferior=ant. belly of digastric m.
posterior/inferior=post. belly of digastric m.
submandibular (digastric) triangle contents
submandibular gland
submandibular lymph nodes
marginal mandibular branch of facial n. (CN VII) (supplies mm. of facial exp)
hypoglossal n. (CN XII)
mylohyoid n. (of CN V3) (supplies mylohyoid m. & ant. belly of digastric m.)
facial a. & v.
muscular triangle borders
superior=hyoid bone
lateral=sup belly of omohyoid m. & ant border of SCM m.
medial=midline of neck
muscular triangle muscle contents
omohyoid m.
sternohyoid m.
sternothyroid m.
thyrohyoid m.
muscular triangle viscera contents
thyroid gland parathyroid glands trachea esophagus common carotid a. internal jugular v.
carotid triangle borders
superior=stylohyoid m. & post belly of digastric m.
posterior=ant border of SCM m.
anteroinferior=superior belly of omohyoid m.
carotid triangle nn.
accessory n. (CN XI) vagus n. (CN X) hypoglossal n. (CN XII) ansa cervicalis (C1-C3) laryngeal nn. (CN X branches)
carotid triangle aa.
common carotid a.
internal carotid a.
external carotid a.
6 branches of external carotid a.
carotid triangle vv.
all branches have accompanying vv. draining into the IJV
carotid sheath
carotid a. (common carotid a. & internal carotid a.) carotid sinus (baroreceptors are here!) internal jugular v. vagus n. (CN X)
subclavian a.
vertebral a.
thyrocervical trunk=inf thyroid a.+transverse cervical a.
ascending cervical a. branches off inf thyroid a.
transverse cervical a. goes posteriorly
lymphatics of root of the neck
right lymphatic duct
thoracic (left lymphatic) duct
nn. of root of the neck
phrenic n. (C3-C5) (“C3, 4, 5, keep you breathing and alive”
vagus n. (CN X)
recurrent laryngeal n. (asymmetrical in neck)
sympathetics
sympathetic trunk (chain) and ganglia
superior cervical ganglion
middle cervical ganglion
inferior cervical ganglion (combines with 1st thoracic ganglion & forms cervicothoracic (stellate) ganglion)
cervical viscera
thyroid & parathyroid glands (anterior)
larynx & trachea
pharynx & esophagus (posteriorly)
vasculature of thyroid & parathyroid glands
superior & inferior thyroid aa.
superior, middle & inferior thyroid vv.
prevertebral mm.
lie directly posterior to retropharyngeal space
