Triangles of Neck/ Larynx Flashcards
Anterior Triangle Boundaries
midline of neck, SCM, lower mandible
Posterior Triangle Boundaries
SCM, trapezius and clavicle
Floor: splenius capitis, semispinalis capitis, levator scapulae, scalenes
Carotid sinus vs carotid body
Sinus in ICA->baroreceptor (increased BP)
Body at bifurcation–> chemoreceptor O (oxygen)
Anterior Triangle Arteries
Common carotid bifurcates @ C3-C4 into ICA and ECA
ECA branches
Superior thyroid A
Superior
laryngeal A
Ascending pharyngeal
A b/t bifurcation
(medial pharynx)
Lingual A
Facial A
Occipital A (bone)
Posterior Auricular A
Maxillary A
Superficial temporal AAnterior Triangle muscles
Suprahyoid: elevate hyoid and larynx in phonation and swallowing, form floor of oral cavity and stabilize tongue and hyoid
Infrahyoid: depress hyoid and larynx
Suprahyoid Ms
Mylohyoid
Stylohyoid (straddles posterior digastric)
Digastric
Geniohyoid (oral cavity)
Infrahyoid Ms
Sternohyoid
Omohyoid
Sternothyroid
Thyrohyoid
Posterior Triangle Arteries
Transverse cervical A lateral and superficial to anterior scalene and phrenic N Suprascapular A inferior and lateral "
both off of thyrocervical trunk
Posterior Triangle Veins
External jugular vein: union of posterior auricular and retromandibular veins
anterior to SCM
drains into subclavian
Subclavian Vein
anterior to anterior
scalene, joins IJV–>
Brachiocephalic vein
What does it mean if you can see EJV externally
heart failure, superior vena cava obstruction
Where do you place central lines?
Subclavian vein (R mostly b/c more straight)
Poke too deep, you can hit subclavian A or lung–> pneumothorax
Posterior Triangle Nerves
cutaneous, CN XI, brachial plexus roots/trunks, phrenic N
Erb’s point
middle of posterior SCM
Cutaneous branches of cervical plexus:
Lesser occipital
Greater auricular
Transverse cervical
Supraclavicular
Lesser Occipital N
C2, skin of neck and scalp posterior to ear
Great auricular N
C2-C3, skin and sheath over parotid gland, mastoid process, ear and angle of mandible
Transverse Cervical N
C2-C3, skin of anterior cervical region
Supraclavicular N
C3-C4, skin over clavicle and shoulder
Spinal accessory (CN XI)
Exits skull via jugular foramen to anterior triangle–>deep to SCM (innervates it) –> posterior triangle–> (where susceptible to accidental cutting) trapezius
most common accidentally cut nerve
torticollis if damaged–> head moves toward damage, face away
Phrenic N
C3, C4, C5 keep the diaphragm alive
anterior to anterior scalene, immediately posterior to carotid sheath
Submandibular contents
both bellies of digastric, interior mandible
submandibular gland and lymph nodes, CN XII, N to mylohyoid, parts of facial A and V along mandible
Submental contents
midline of neck, anterior digastric x2, body of hyoid
submental lymph nodes
small veins that make
anterior jugular V
Muscular contents
body of hyoid, midline of neck, superior belly of omohyoid, SCM
sternohyoid
sternothyroid
thyrohyoid
thyroid and parathyroid
glands, larynx,
trachea, esophagus
common carotid A,
superior thyroid A,
inferior thyroid A
anterior jugular V,
thyroid veins
ansa cervicalis, external
laryngeal N, recurrent
laryngeal N
Carotid contents
posterior belly of digastric, superior belly of omohyoid, SCM
branches of ECA internal and external laryngeal nerves, CN XII, CN XI, ansa cervicalis carotid sheath
Carotid Sheath
Ansa cervicalis anterior
or embedded in sheath
Common carotid A
anterior medial
Internal jugular vein
anterior lateral
Vagus nerve posterior
Vagus nerve branches
Pharyngeal branch
Superior laryngeal N
internal branch of "
sensory above vocal
cord, pierces
thyrohyoid membrane
with superior
laryngeal A
external branch of "
innervates cricothyroid
Carotid body branch
Recurrent laryngeal N
Inferior laryngeal N
All intrinsic laryngeal
muscles with sensory
below vocal cord
Occipital triangle contents
Part of EJV
Posterior branches of cervical plexus
CN XI
Trunks of brachial plexus
Cervical lymph nodes
Subclavian triangle contents
dorsal scapular A (via subclavian A)
part of subclavian V
suprascapular A and lymph nodes
Superficial Fascia
Between dermis and investing layer of deep fascia
contain SubQ tissue, cutaneous nerves, blood, lymph, fat and PLATYSMA
Deep Fascia
Investing layer
Pretracheal
Prevertebral
Carotid Sheath
Investing layer of deep fascia
most superficial of deep fasica
surrounds entire neck, encloses SCM, trap and glands (parotid and submandibular)
attaches to manubrium, clavicals, scapula, occipital, temporal, zyg arch, mandible, hyoid and vertebrae
–>mumps d/t expanding parotid glands held by this tight fascia
Pretracheal layer of deep fascia
only in anterior neck, blends with pericardium
makes up muscular layer over infrahyoid muscles, buccopharyngeal fascia and a visceral layer
Prevertebral layer of deep fascia
encloses vertebral column and muscles, extends laterally into axillary sheath of arm
base of head to mediastinum
Carotid Sheath (fascia wise)
blends with prevertebral and pretracheal fascia
common carotid A anterior and medial
internal jugular vein anterior and lateral
vagus nerve most posterior
Retropharyngeal Space
it is posterior to pharynx
buccopharyngeal fascia (pretracheal) anterior
prevertebral fascia posterior
carotid sheaths lateral
–>abscess causes swelling, makes difficult swallowing or breathing
Venous drainage of neck and head
EJV formed via posterior auricular and retromandibular veins
Anterior to SCM
Drains external face–>
Subclavian V
IJV begins in cranial cavity as continuation of sigmoid sinus exits via jugular foramen in carotid sheath combines with subclavian V to form brachiocephalic vein has inferior bulb to stop backflow of blood
AJV
paired veins in anterior
neck drains this area to
subclavian V
Dural venous sinuses drain blood in head superior and inferior sagittal sinuses meet in confluence of sinus--> transverse sinus--> sigmoid sinus-->IJV
