Anterior Cervical Triangle and Root of Neck Flashcards
What are the boundaries of the anterior cervical triangle?
anterior = midline of neck posterior = SCM superior = inferior border of mandible
What is the main landmark between anterior and posterior cervical triangles?
SCM
What is the floor of the anterior cervical triangle? roof?
muscles, skin and platysma m
What are the muscles of the anterior cervical triangle grouped by?
position relative to hyoid bone
What are the supra hyoid mm?
stylohyoid m, digastric m, mylohyoid m, geniohyoid m
What are the infrahyoid mm?
omohyoid m, sternohyoid m, thyrohyoid m, sternothyroid m
What is the function of the supra hyoid mm?
located superior to hyoid bone, elevate hyoid bone
What is the function of the infrahyoid mm?
inf to hyoid and depress hyoid
What muscle pulls the hyoid bone posterosuperiorly during swallowing?
stylohyoid
What innervates the anterior belly of the digastric m?
mandibular division of trigeminal n (V3) (mylohyoid branch)
What innervates the posterior belly of the digastric m?
facial n (CN VII)
Where does the common tendon between the digastric bellies insert?
on the hyoid bone
Which pharyngeal arch is the anterior belly derived from? posterior?
1st, 2nd
Where does the mylohyoid brach of V3 arise from?
inf alveolar n
What does the mylohyoid m do?
supports and elevates floor of mouth; elevates hyoid
What is the innervation of the mylohyoid m?
mandibular division of trigeminal n (V3) (mylohyoid branch)
What m forms the floor of the mouth?
mylohyoid
What is the function of the geniohyoid m when the mandible is fixed? hyoid fixed?
- elevates and pulls hyoid forward
- pulls mandible downward and inward
What is the innervation of the geniohyoid m?
Branch from anterior rams of C1 carried via hypoglossal n (CN XII)
Is the geniohyoid m part of the ant cervical triangle?
No
What is the function of sternohyoid m?
depresses hyoid bone after swallowing or anchors hyoid bone for infra hyoids to interact
What innervates sternohyoid m?
ant rami of C1-3 via ansa cervicalis
What is the function of omohyoid m?
depresses and fixes hyoid bone
What innervates omohyoid m?
ant rami of C1-3 via ansa cervicalis
What connects the superior and inferior bellies of omohyoid m?
intermediate tendon (attached to clavicle)
What is the function of thyrohyoid m?
depresses hyoid bone
- when hyoid fixed; raises larynx
What innervates thyrohyoid m?
fibers from ant ramps of C1 carried via hypoglossal n
What is the function of sternothyroid m?
draws larynx (thyroid cartilage) downward
What innervates the sternothyroid m?
anterior rami of C1-3 via ansa cervicalis
What are the veins of the neck?
facial, retromandibular, anterior jugular, communicating branch, internal jugular and external jugular
Where does the facial v originate and drain?
angle of eye to internal jugular v
Where is retromandibular v? where do its branches drain?
behind mandible
- post branch and post auricular drain into EJV
- ant branch and facial drain to IJV
Where is ant jugular v and where does it drain?
midline of neck, drains to EJV (drains ant neck)
What does the communicating branch connect?
facial v and AJV
What does the internal jugular v drain?
brain, ant face, cervical viscera
What forms the external jugular v?
posterior auricular and post branches of retromandibular v
What come together to form common facial v?
ant retromandibular and facial v
What forms retromandibular v?
superficial temporal and maxillary vv
Where does the R common carotid arise from?
indirectly from arch of aorta from brachicephalic trunk
Where does the L common carotid come from?
direct branch off arch of aorta
What does the internal carotid a branch to?
no branches
Where does common carotid a bifurcate?
C3-4 vertebra
What are the ant branches of external carotid a?
sup thyroid a, lingual and facial aa
What are the post branches of external carotid a?
ascending pharyngeal, occipital and post auricular a
What does external carotid a terminate as?
superficial temporal a and maxillary a
What is the first ant branch of EC a?
sup thyroid a, arises from ant surface near bifurcation
What does the sup thyroid artery give off? Supply?
sup laryngeal a
supplies superior portion of thyroid gland
What is the 2nd branch of ECA?
lingual a
where does lingual a arise above?
sup thyroid a at level of greater horn of hyoid bone, passes deeply into mm of tongue
What is the 3rd branch of an ECA?
facial
Where does facial a arise?
sup to lingual, crosses inf border of mandible to supply face
What gland does facial a pass through?
submandibular gland
What is the 1st post branch of ECA?
ascending pharyngeal a
where does ascending pharyngeal a arise?
close to bifurcation of common carotid a
What does ascending pharyngeal a supply?
pharynx and tonsils
What is the 2nd branch of post ECA?
occipital a
where does occipital a arise?
near level of origin of facial a, deep to post belly of digastric
What does occipital a supply?
neck and scalp
Where does the branch off occipital a go?
muscular branch to SCM (hooks over CN XII)
What is 3rd post branch of ECA?
post auricular a
Where does post auricular a arise?
sup to origin of occipital a and post belly of digastric m
What does post auricular a supply?
scalp and posterior to ear
What are the spinal n branches in the ant cervical triangle?
transverse cervical n (C2-3) and Ansa cervicalis (C1-3)
What are the cranial nerves of ant cervical triangle?
facial, glossopharyngeal, vagus, accessory, hypoglossal
Where does transverse cervical n (C2-3) run?
transversely across middle of SCM
What does transverse cervical n supply?
skin of ant cervical triangle and lateral neck
What is the nerve loop formed from ant rami of cervical nerves C1-3?
ansa cervicalis
What does ansa cervicalis innervates?
infrahyoid mm except thyrohyoid m
What are the fibers of the superior root of ansa cervicalis?
mainly C1 fibers from ant rami
What are the fibers from inf root of ansa cervicalis?
ant rami of C2 and C3
What are the subdivisions of the anterior cervical triangle?
submental, submandibular, muscular, carotid
What are the borders of the submental triangle?
inferior = hyoid bone
lateral (right) = ant belly of digastric m
lateral (L) = ant belly of digastric
What are the contents of submental triangle?
mylohyoid m, submental lymph nodes, small veins
What are the borders of the submandibular (digastric) triangle?
superior = inf border of mandible ant/inf = ant belly of digastric m post/inf = post belly
What are the contents of submandibular triangle?
- submandibular gland
- sumandibuilar lymph nodes
- marginal mandibular branch of facial n (CN VII)
- hypoglossal n
- mylohyoid n
- facial n
What are the borders of the muscular triangle?
sup = hyoid bone lateral = sup belly of omohyoid and ant border of SCM m medial = midline of neck
What are the muscles of the muscular triangle?
- omohyoid
- sternohyoid
- sternothyroid
- thyrohyoid
What are the viscera in the muscular triangle?
thyroid gland, PTG, trachea, esophagus, common carotid a, internal jugular v
What are the borders of the carotid triangle?
sup = stylohyoid m and post belly of digastric m post = ant border of SCM m anteroinferior = sup belly of omohyoid m
What are the nerves in the carotid triangle?
accessory, vagus, hypoglossal, ansa cervicalis, laryngeal nn
What are the aa in the carotid triangle?
common, internal and external carotid aa, 6 branches of ext carotid a
What are the vv in the carotid triangle?
all branches have accompanying vv draining into IJV
What does the carotid sheath surround?
carotid a (common and internal carotid) internal jugular v and vagus n
What is the dilation of int carotid a near bifurcation of common carotid a, contains receptors that monitor blood pressure changes (baroreceptors)?
carotid sinus
What is the junction between the thorax and neck?
root of neck; includes cervical part of parietal pleura and apical part of sup lobe of lung
What are the major structures of the thoracic inlet (sup thoracic aperture)?
trachea, esophagus, brachiocephalic trunk (R), L common carotid a and L suclavian a, IJV, EJV, AJV, thoracic duct, R and L subclavian vv, phrenic nn and vagus nn and sympathetic trunk
What is the first branch of subclavian a?
vertebral a, medial to ant scalene m
Where does vertebral a enter?
transverse foramen of C6, passes up to C1
What branches does thryocervical trunk divide into?
inf thyroid, transverse cervical, ascending cervical a and suprscapular a
Where does inf thyroid a run?
post to carotid sheath and thyroid gland
What structures do transverse cervical a and suprascapular a cross over?
ant surface of ant scalene m and phrenic n
What is the major lymph channel that drains from L upper limb, head, neck, thorax, abdomen and lower limbs?
thoracic duct
Where does thoracic duct lie?
post to esophagus between azygos v and thoracic aorta
What does thoracic duct drain into?
L venous angle
- junction between L IJV and L subclavian v
Where does R lymphatic duct drain?
right venous angle
- junction b/t R IJV and R subclavian v
What are the nerves in the root of the neck?
phrenic, vagus, sympathetics, recurrent laryngeal and recurrent subclavian
What provides all parasympathetic innervation to neck?
vagus n
What is a branch of the vagus n?
R and L recurrent laryngeal n
What are the 3 sympathetic ganglion in cervical region?
sup, middle and inf
What does inf cervical ganglion coming with to form cervicothoracic ganglion?
first thoracic ganglion
T/F there are white rami communicates in cervical region
F
Where are the thyroid and parathyroid glands found in cervical viscera?
endocrine layer
Where are larynx and trachea found in cervical viscera?
respiratory layer
Where are pharynx and esophagus found in cervical viscera?
alimentary layer
Where does the isthmus of the thyroid gland cover?
2nd - 4th tracheal rings
What is the pyramidal lobe of thyroid gland?
embryologic remnant
What vertebral level is thyroid gland located?
C5-T1
What plays an important role in regulation of calcium metabolism?
PTG, usually 4 glands within post surface of thyroid
T/F thyroid gland is unparied
T
What are the aa of the thyroid gland?
sup thyroid a, inf thyroid a, thyroid ima a
What are the veins of the thyroid gland?
sup thyroid v, middle and inf thyroid vv
What does sup thyroid branch off and supply?
ECA, supplies sup pole of lateral lobe of thyroid
What does inf thyroid a branch off and supply?
thyrocervical trunk, int pole of lateral lobe
What does thyroid ima a branch off of and supply?
wither brachiocephalic trunk or aorta, thyroid
Where does sup thyroid v drain?
drains area supply by sup thyroid a into IJV
Where does middle thyroid v drain?
rest of thyroid not drained by sup into IJV
What does inf thyroid drain?
rest not drained by sup thyroid into brachiocephalic vv
What are the deep structures of the neck? where do they lie?
prevertebral muscles, directly post to retropharyngeal space
