Neck: Area Under the SCM Flashcards
contents of carotid sheath
common and internal carotid arteries internal jugular vein vagus nerve ansa cervicalis deep cervical lymph nodes
relationships in carotid sheath
artery - medial and anterior
vein - lateral and posterior
vagus - posterior groove between vessels
ansa cervicalis location
lateral to arteries
crosses internal jugular vein anteriorly and courses superiorly and medial on its surface
common carotid artery
left side longer than right
- right from brachiocephalic split
- left from arch of aorta
bifurcation of common carotid artery
level of CV3
carotid sinus
dilated distal common carotid and proximal internal carotid artery
pressure receptor
increased pressure, decreased HR
carotid body
at carotid bifurcation
chemoreceptor
decreased O2 - increased rate and depth of breathing
afferents from carotid body and sinus
carotid sinus nerve (CN IX)
internal carotid artery
enters carotid canal
- no branches prior to entering canal
- supplies orbit and brain
external carotid artery
not in sheath
branches in carotid triangle
-has lots of branches
surgery in carotid triangle
access to carotid bifurcation, internal jugular vein, vagus/hypoglossal nerves, sympathetic trunk
can affect voice - vagus and recurrent laryngeal nn.
carotid endarterectomy
often at bifurcation
access via carotid triangle
superior thyroid artery
1st branch external carotid artery
branches of superior thyroid artery
superior laryngeal artery - pierces thyrohyoid membrane with internal laryngea nerve to interior of larynx
anterior branch - to gland - anastomose with opposite counterpart
posterior branch - posterior gland - anastomose with inferior thyroid artery
ascending pharyngeal artery
arises medially off of external carotid artery
-close to bifurcation
courses straight to base of skull
lingual artery
branch of external carotid artery
deep to posterior border of hypoglossus muscle to enter tongue
facial artery
branch of external carotid artery - either common trunk or just above lingual artery branch
courses to deep surface of submandibular gland
goes around mandible and comes around anterior edge of masseter muscle to enter face
occipital artery
branch of external carotid artery
posterior to external carotid at border of posterior belly of digastric
passes between transverse process of atlas and mastoid process
pierces cervical fascia where trapezius and SCM come together
enters scalp and courses with great occipital nerve
mnemonic for external carotid artery branches
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superior thyroid ascending pharyngeal lingual facial occipital posterior auricular maxillary superficial temporal
posterior auricular artery
branch of external carotid artery
passes posteriorly
to ear and external acoustic meatus and anterior to mastoid process
final branches of external carotid artery
maxillary artery
superficial temporal artery
external carotid ligation
needed to stem flow of blood from deeper branches which are not surgically accessible without damaging their major structures
ex/ carotid endarterectomy
internal jugular veins
begins as dilation - superior jugular bulb
-at jugular foramen
ends at dilation - inferior bulb
- joins subclavian vein
- forms brachiocephalic vein
tributaries to internal jugular vein
occipital vein pharyngeal vein lingual vein facial and common facial veins superior and middle thyroid veins
right internal jugular access
insert needle inferiorly at apex of triangle between clavicular and sternal heads of SCM
-inserted finger width lateral to carotid pulse at 30 degree angle inferiorly toward ipsilateral nipple
branches of vagus and fiber type
meningeal - to dura sensory (GSA)
auricular - to pinna, auditory canal, external tympanic membrane (GSA)
pharyngeal - muscles of arch 4 (SVE)
nerve to carotid body (GVA)
superior laryngeal nerve - internal and external branches
cervical cardiac branches
recurrent laryngeal nerve
internal branch of superior laryngeal nerve
pierces thyrohyoid membrane
-with superior laryngeal branch of superior thyroid artery
sensory - taste and general sense
parasympathetic - to base of tongue (glands), epiglottis, internal larynx (above vocal fold)
fiber types of superior laryngeal nerve
SVA, GVA, GVE-P
external branch of superior laryngeal nerve
innervates cricothyroid muscle
SVE
recurrent laryngeal nerve
SVE, GVE-P, GVA
right - around subclavian artery
left - around aortic arch
both reach larynx
motor to intrinsic muscles of larynx
sensory to mucosa inferior to vocal folds
above vocal folds
internal branch of superior laryngeal nerve
below vocal folds
recurrent laryngeal nerve
laryngeal nerve fibers
SVA, GVA, GVE-P
for recurrent and superior laryngeal nerves
inferior laryngeal nerves
once recurrent passes into larynx
-becomes inferior
deep cervical lymph nodes
associated with carotid sheath
- superior and inferior groups
- split by omohyoid
superior deep cervical lymph nodes
receive from superificial of face and neck
inferior deep cervical lymph nodes
get lymph
jugular lymph trunks
left - to thoracic duct
right - to right lymphatic duct
radical neck dissection
remove all deep cervical lymph nodes and surrounding tissue
hypoglossal canal
near carotid sheath
-descends to submandibular triangle
cervical plexus
ventral rami of C1-4
branches of cervical plexus
greater auricular lesser occipital transverse cervical supraclavicular phrenic ansa cervicalis
ansa cervicalis
C1 and C2 - superior root
C2 and C3 - inferior root
branches to infrahyoid muscles
