Neck 1-3 Flashcards
Functions of Neck (4)
- Supporting + moves head, moves VC
- Move + support larynx for swallowing/speaking,
- Connect upper + lower respiratory digestive tract via pharynx + larynx w/esophagus + trachea
- Communication – sounds from larynx -> pharynx + oral cavity = speech
Neck Superior Boundary (2)
- inferior mandible, skull base, MP, trap attachments
- Post neck higher than ant neck to connect cervical viscera w/post opening of nasal + oral cavities
Neck Inferior boundary (base of neck) (1)
top of sternum, spine of scapula + clavicle, to SP C7 + adjacent acromion
Superior thoracic aperature (2)
- thoracic inlet or outlet: Space btwn T1 + rib 1 (all that travels to/from thorax)
- transitional area btwn thorax + neck
Traits of CV (1)
Transverse foramen, Bifid SPs, Square VB, triangular vertebral foramen, sloped APs
Joints of Cervical Column (4)
- AO – synovial condyloid
- AA – synovial (2 Articular facet – plane, 1 dens – pivot)
- ZP – synovial plane
- IV disc – secondary cartilaginous
Superficial Cervical Fascia (3)
- subcutaneous CT;
- superficial fatty layer + deep thin fibrous layer
- superficial nerves, vessels, lymph nodes and platysma muscle
Investing fascia (2)
- tube (cont across midline), whole body, surrounds SCM+ traps in neck
- fuses w/periosteum at tendon
Infrahyoid fascia (3)
- sheet, continuous across midline
- begins at hyoid bone, forms investing fascia for infrahyoid (strap) muscles (attach to hyoid bone)
- superficial + deep layers due to diff muscle layers
Pretracheal fascia (3)
- tube, continuous across midline, posterior to infrahyoid muscles
- surrounds viscera in neck (thyroid gland, trachea, pharynx, esophagus), + vocal cords
- Pre-tracheal + Buccopharyngeal
Prevertebral Fascia (4)
- tube, attaches to skull base
- in front of vert, encloses deep prevertebral + back muscles
- specializations: alar fascia, axillary sheath and Sibson’s fascia
- Wraps around VC/SPs + muscles attached to it (lateral cervical muscles)
Carotid Sheath (6)
tube that wraps common + internal carotid arteries, cervical lymph nodes, IJV, vagus nerve, superior root of ansa cervicalis
Fascial Layers
BIG PICTURE: spaces btwn layers = spread of infection, etc. Some contained, some large + spread out.
Platysma (4)
- thin muscle, over mandible, down neck past clavicle, limited connection to bone, mostly to superficial fascia
- Changes tension of skin in neck, depresses mandible (makes sad face)
- innervated by CN VII (facial nerve)
- Gap in btwn platysma muscle on left + right side of neck
Investing Fascia Attachments (4)
- Follows attachments for/surrounds traps
- Superiorly to external occipital protuberance + superior nuchal line
- Laterally to MP and zygomastic arch
- Inferiorly to spine of scapula, acromion, clavicle, manubrium of sternum
Vessels + Nerves that pierce investing fascia (2)
- vessels = external and anterior jugular veins
- nerves = lesser occipital, great auricular, transverse cervical, and supraclavicular nerves (all branches of cervical plexus)
Pre-tracheal proper of Pre-tracheal Fascia
- in front of airway – attaches to hyoid bone above + fibrous pericardium (upper thoracic cavtiy) below
Buccopharyngeal layer of Pre-tracheal fascia (3)
- behind pharynx, separates it from prevert layer, attaches to skull base
- covers buccinator and pharyngeal constrictors
- fuses w/pre-tracheal + CT of esophagus
Sibson’s Fascia (2)
- from prevertebral fascia, deep to subclavian artery, closes superior aperature of lung -> Forms CT roof
- protects lung apex in subclavian puncture (if go through it = pneumothorax)
Axillary Sheath (2)
- from pre-vertebral fascia
- follows nerves + vessels to upper limb (brachial plexus, subclavian artery, etc)
Digastric Muscle (3)
- down to hyoid
- tendon in middle where sling changes muscle direction
- anterior + posterior belly
omohyoid muscle (3)
- 2 bellied, deep to SCM
- scapula -> neck -> hyoid
- tendon in middle where sling fascia loop changes muscle direction, angles it back to hyoid bone
Infection btwn investing/infrahyoid fascia + pretracheal fasica (2)
- spread inferiorly to pericardium (superior mediastinum)
- up to hyoid bone (neck to thorax)
Deep to prevertebral layer (space) infection (2)
- infection contained by prevertebral layer
- extend laterally, bulge out in neck by posterior border of SCM
Infection in space btwn buccopharygeal fascia and alar fascia (2)
- go up to skull base
- down to lower neck/cervical areas since alar fascia blends w/buccopharyngeal fascia
Infection in space btwn alar/buccopharyngeal fascia and prevertebral layer (3)
- up to skull base thru posterior mediastinum down to diaphragm
- most imp, wide open space for spreading infection
- air from ruptured airway/esophagus = pneumomediastinum via fascial space
SCM (3)
- Attachment = MP, sternum, clavicle
- action = contralateral rotation of head (opp side)
- innervation = spinal accessory CN XI, C3 + C4(sensory)
Trapezius (3)
- attachment = spine of scapula, clavicle, acromion, SP C7-T12, ligamentum nuchae
- Action = elevates/retract scapula, abduction of humerus above shoulder
- Innervation = spinal accessory CN XI, C3 + C4 (sensory)
Congenital Torticollis (4)
- SCM scarred + shortened (act like its contracted)
- damaged during birth (no mastoid process)
- head always tilted to side of damage
- spasmodic - from disease in basal nuclei
Suprahyoid (2)
- above hyoid bone, connections to skull + mandible
- actions = swallowing
Suprahyoid Innervations (3)
- Stylohyoid + Post digastric = CN VII
- Ant digastric + mylohyoid = CN V
- geniohyoid = cervical plexus
Infrahyoid (3)
- strap muscles
- actions = stabilize hyoid bone + larynx, reposition after swallowing
- omohyoid, sternohyoid (most anterior), sternothyroid (middle), thyrohyoid (deepest)
Scalene triangle (2)
- btwn anterior + middle scalene, base = rib 1
- subclavian art + nerves of brachial plexus pass thru triangle
Anterior to scalene triangle (2)
- subclavian vein + phrenic nerve
- phrenic nerve (C3-5) -> innervates diaphragm (paralysis = death)
Anterior Scalene Muscle dysfunction
If muscle too short (dysfunction)-> rib 1 out of place -> impinges on nerves + BVs = numbness, pain, tingling in upper extremity, cold hands
4 compartments of neck
visceral - parts of digestive/resp systems, endocrine glands
vertebral - cervical vert, SC, cervical nerves
2 vascular components - major BVs + vagus nerve
Hyoid Bone (2)
- tethered to skull, connected to larynx via ligs
- anchors airway, muscles aid in swallowing
Prevertebral + Lateral Neck muscles (3)
- actions = flex head
- innervation = cervical plexus
- rectus capitis muscles, longus muscles, scalene muscles
Rectus Capitis Muscles (2)
- Rectus Capitis Anterior = flexs head at AO joint, side bending
- Rectus Capitis Lateralis - flex head laterally to same side, side bending
Longus Muscles (3)
Longus Capitis - flexes head
Longus Colli - bilaterally flexes neck anteriorly, unilaterally rotation/side bending to opp side
if longus colli paralyzed on one side, won’t notice because other muscles to flex head
Scalene Muscles (3)
Anterior Scalene - CV TPs -> elevation of rib 1
Middle Scalene - CV TPs -> elevation of rib 1
Posterior Scalene - CV TPs -> elevation of rib 2
3 parts of subclavian artery (3)
- part 1 = in front of anterior scalene
- part 2 = behind anterior scalene, in scalene triangle
- part 3 = outside of scalene triangle (sometimes branch off here)
4 branches of Subclavian artery (4)
- Costocervical trunk – ascending branch (deep cervical artery)
- Vertebral artery – in transverse foramen of C1-C6
- Thyrocervical trunk - 1 branch to thyroid gland, 1 branch to neck/shoulder
- Internal thoracic artery
Suprascapular Artery (2)
- under deep of clavicle
- clavicle = most commonly fractured -> suprascapular art at risk of damage
Thyrocervical trunk branches (3)
- inferior thyroid art (and ascending cervical art)
- TCA (superficial br + deep br) OR superficial cervical art (50% of time)
- suprascapular art
Rhomboids blood supply
deep br of TCA OR descending (dorsal) scapular art (off subclavian art, goes thru brachial plexus)
Vertebral Artery (2)
- goes to skull, supplies brainstem, muscles
- sends feeder arts to spinal cord -> gives rise to spinal artery
Common carotid artery (3)
- right common carotid shorter than left
- divides into internal + external carotid at lvl of thyrocartilage (adam’s apple)
- no branches from internal carotid artery
1-3 Branches of External Carotid
- Superior thyroid art - down to thyroid (dbl blood supply from above/below)
- Occipital - first off, goes post under MP + back of head
- Ascending pharyngeal art - off crotch region, up to skull base, supplies meninges
4-6 branches of external carotid
- posterior auricular artery - goes posterior behind external ear
- lingual (oral cavity, tongue) + facial branch - separate or together (10% of ppl, lingual-facial trunk)
Terminal Branches of External Carotid (2)
Internal maxillary artery (temple) + superficial temporal artery (up side of head)
External Carotid Branches related to digastric muscles (2)
- occipital art (posterior) + lingual art (anterior) = below posterior digastric
- posterior radicular art (posterior) + facial art (anterior) = above posterior digastric
Lingual Branches (2)
Dorsal Lingual
Deep Lingual
Sublingual
Facial Branches (5)
Tonsillar (tonsils) Ascending palantine (oral cavity) Glandular (submandibular glands) Muscular Submental
Occipital Branches (7)
- Relation to CN XII
- muscular to SCM
- Mastoid
- Stylomastoid
- Aurical
- descending
- meningeal
Posterior Auricular Branches (4)
- relations to CN XII
- stylomastoid
- auricular
- occipital
Carotid Sinus (4)
- baroreceptor
- dilation at lower internal carotid artery
- tunica intima thinner, adventitia thicker
- sensory nerve endings from CN IX (glossopharyngeal)
Carotid Body (2)
- reddish-brown vascular chemoreceptor at carotid crotch
- innervation by CN IX (mostly), CN X, pre-gang symp axons (post-gangs in carotid body)
Collateral circualtion (2)
- descending branch of occipital art forms anastomoses
- if something closed off (plaques, etc.), upper limb/facial structures still survive
Ligation of Subclavian Artery (3)
- tie off artery in surgery, but main supply to upper limbs
- limbs live from collateral circulation from int. thoracic art + scapular vessels
- thyrocervical trunk forms anastomosis, bypasses subclavian
block in common carotid (2)
- overcome by anastomosis btwn thyrocervical trunk, costocervical trunk w/descending branch
- backfill occipital + ext. carotid
Carotid Endartectomy (2)
- clean out plaque in carotid artery
- not an issue in external carotid, but huge issue in internal carotid = 1/2 brain dead
Superficial + Deep Venous Networks (4)
- deep veins travel w/main arteries (branches from carotid)
- superficial veins outside deep fascia
- superficial + deep veins anastomoses
- 3 jugular veins: Internal, External, Anterior
Internal Jugular Vein
- skull base in int. jugular foramen -> carotid sheath (deep to pre-tracheal fascia)
- tributaries in neck = vessels that dump into it, follow arteries
- joins subclavian vein = venous angle, forms brachiocephalic vein (becomes superior vena cava)
IJV tributaries
- inferior petrosal sinus (skull)
- occipital
- pharyngeal
- lingual
- facial (joins anterior division of retromandibular vein)
- thryoid veins
Superficial Veins
- external jugular vein = superficial to SCM + investing fascia
- anterior jugular vein = drains submental region, in carotid sheath
- communicating vein = connects branches of external to anterior vein
Draining Anterior + External Jugular Veins
- dump out to side, near venous angle
- blood has to get back to superior vena cava + heart
Brachiocephalic Vein
- IJV, subclavian vein + venous angle joining
- left brachiocephalic longer than right
- venous blood shifts to right of body, forms superior vena cava
Subclavian Venipuncture
- get into venous system via subclav puncture
- if miss vein/puncture it thru, can damage lung (protected by Sibson’s Fascia) = pneumothorax, hemothorax
- watch for rib 1, subclavian art, phrenic nerve (paralysis of diaphragm)
Lymph
- superficial nodes of head, superficial cervical nodes in EJV, deep cervical nodes along IJV
- Accessory nodes (on CN XI), transverse cervical nodes
- blood plasma -> cap beds -> lymph vessels + nodes -> venous system
Superficial Nodes
- in skin/superficial fascia
- submental
- submandibular
- external + anterior jug
- pre-auricular/parotid
- mastoid
- occipital
Deep Cervical Nodes
- around IJV, get lymph from head + neck
- superior deep cervical = jugulodigastric node
- inferior deep cervical = jugulo-omohyoid node
Cervical Lymph Node Level 1
- submental, submandibular
- drains mainly oral cavity (oral cancer spreads here first)
Cervical Lymph Node Level 2
- along IJV, deep to SCM
- superior deep cervical, from skull base to hyoid
- jugulogastric nodes
Cervical Lymph Node Level 3
- along middle 1/3 of IJV, deep to SCM
Cervical Lymph Node Level 4
- along lower 1/3 of IJV to clavicle, deep to SCM
- inferior deep cervical
- jugularo-omohyoid nodes - everything converges here
Cervical Lymph Node Level 5
- posterior triangle
Cervical Lymph Node Level 6
- pre-laryngeal + pretracheal midline btwn hyoid and sternal notch
Cervical Lymph Node Level 7
- superior mediastinal, below sternal notch, btwn common carotid
Submandibular cancer
- deep cervical nodes, tumor cells -> lymph trunks -> venous system
- look for capillary bed b/c leaky
dissemination of cancer
1) direct seeding of body cavities/surfaces (peritoneum/pleura)
2) lymphatic spread - follows lymph drainage of affected organ
3) hematogenous spread - after passage thru lung cap beds, tumor cells leave at next encountered cap bed
Exceptions to cancer dissemination
- bronchogenic carcinomas involve adremals + brain
- skeletal muscle (despite dense cap beds) rarely affected by metastasis
Alar Fascia
divides space into 2 compartments (small + big), ends at T2
