Exam III: Neck I Flashcards Preview

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Flashcards in Exam III: Neck I Deck (54):

Neck Boundaries

Superior boundaries: investing fascia: trapezius muscle, sternocleidomastoid (attaches along mandible); border the mandible, to base of skull; mastoid process to back of the skull; follows of attachments of sternocleidomastoid and trapezius

Inferior boundaries: goes down clavicle and back along the spine of scapula; find the superior thoracic aperture- space bound by first thoracic vertebrae and first rib; all arteries, lymphatics, veins, and nerves follow it; muscles that cross the structure; transition area

Laryngeal structures: hyoid bone connected by the ligaments to rest of structures; hyoid anchors everything; use muscles in swallowing


Deep Fascia

1. Investing Fascia - completely surrounds the neck; arises from skull and mandible and extends inferiorly to the sternum, clavicles, manubrium...

2. Infrahyoid fascia - begins at hyoid bone, forms an investing fascia for the infrahyoid muscles; superficial and deep layers; continuous across the midline

3. Pretracheal - a continuous fascial tube that surrounds the viscera in the neck:
a. Pre-tracheal proper – attaches to the hyoid bone above and fibrous pericardium below
b. Buccopharyngeal – attaches to base of the skull, covering the buccinator and pharyngeal constrictors, fuses with pre-tracheal, fuses with adventitia of esophagus

4. Prevertebral fascia - attaches to base of skull and vertebrae and encloses the deep muscles, has specializations: alar fascia, axillary sheath and Sibson’s fascia

5. Carotid Sheath: is a column of fascia that surrounds the common and internal carotid artery, internal jugular vein, and the vagus nerve as these structures pass through the neck


Superficial Cervical Fascia

subcutaneous CT; superficial fatty layer and deeper fibrous layer; contains superficial nerves, vessels, lymph nodes and the platysma muscle


Cervical Subcutaneous Tissue and Platysma

Platysma: very thin muscle; extends over the mandible and all the way down the pectoral major muscle; changes the tension of the skin on your neck
Does not attach to bone, only attaches to superficial tissue
Action: moves bottom lip down, tighten fascia in neck
Innervation: facial nerve (CN 7)
Extension of muscle on face
Muscles in the superficial fascia; most attachments and insertions are in the fascia


Platysma Paralysis

Paralysis of the platysma: will be unable to move the lower lip and corners of the mouth down

With age the platysma loosens

Face Lift: is a surgical procedure which involves removing the localized fat deposits under the chin. It also tightens the platysma muscle further defining the neckline. Fat deep to the platysma muscle may also require removal as well as weakening of some of the deeper muscles (anterior belly of the digastric muscle). The procedure is performed through a small incision under the chin. This procedure significantly improves the neck and jawline.


Attachments of the Investing Fascia

Completely surrounds the neck attaching anteriorly to the ligamentum nuchae and spinous process of C7. It splits as it passes forward to enclose the trapezius and then reunites into a single layer as it forms the roof of the posterior triangle, splits again as it surrounds the sternocleidomastoid and reunites again to join on the other side
Anteriorly: surrounds the infrahyoid muscles
Superiorly: attaches to mandible, mastoid, trapezius; external occipital protuberance and superior nuchal line
Laterally: mastoid process, and zygomatic arch
Inferiorly: manubrium of the sternum, clavicle, spine of scapula and blend across midline, acromion


Specializations of the Pre-Vertebral Fascia

Axillary sheath: follows all big arteries, nerves, veins; is a fibrous sheath that encloses the first portion of the axillary artery, together with the axillary vein and the brachial plexus. It is an extension of the prevertebral fascia of the deep cervical fascia

Sibson’s fascia: sits on top of first rib (apex of lung pokes above the first rib) and protects things under; sits deep to subclavian artery to cover gray mass underneath it (apex of lung); protects the lung/a little extra protection


Specializations of the Infrahyoid and Pre-Tracheal Fascia

Two Slings:
1. Posterior digastric belly
2. Omohyoid
Sling: loops of fascia that changes orientation and direction; in this case it goes down the posterior digastric belly anteriorly then goes forward along the omohyoid


Pre-Tracheal Space

Between the investing layer of the cervical fascia (covering the posterior surface of the infrahyoid muscles) and the pretracheal fascia (covering the anterior surface of trachea and the thyroid gland), which passes between the neck and the anterior part of the superior mediastinum; infections can spread inferiorly to the mediastinum


Fascial Space Deep to Pre-Vertebral Layer

Infections deep to the prevertebral layer (yellow) can extend laterally, protruding along the posterior border of the SCM


Between Buccopharyngeal Fascia and Alar Fascia

Can spread inferiorly to lower cervical levels (this space extends superiorly to the base of the skull)


Between Alar/Buccopharyngeal Fascia and Pre-Verterbal Layer

Posterior layer of pre-vertebral fascia = buccopharyngeal
Alar fascia blends in and joins the buccopharyngeal fascia
"Retropharyngeal Abscess"
Extend inferiorly to the diaphragm
Air from a ruptured airway/esophagus can result in pneumomediastinum via this fascial space


Retropharyngeal Abscess

Refers to an infection between the cervical vertebrae and the pharyngeal wall

Most common in children under 6 and immunocompromised adults

Reach the retropharyngeal space via the oral cavity (dental abscess), nasopharynx (tonsillitis, peritonsillar abscess)

Signs and symptoms include: fever, sore throat, dysphagia, odynophagia, neck, and back pain

Complications include airway obstruction, sepsis, mediastinitis, pneumonia, empyema, jugular vein thrombosis, and carotid artery erosion


Masticatory Space

Oral cavity space
Paired suprahyoid cervical spaces on each side of the face
Each space is enveloped by the superficial layer of the deep cervical fascia containing muscles of mastication, ramus and body of mandible, inferior alveolar nerve, inferior alveolar vein and artery, mandibular division of the trigeminal nerve (V3) which enters the masticator space via the foramen ovale
Common for dental infections to spread


Spread of Infections: Spaces A-D

Space A: pericardium/ thorax; only up to thyroid bone (neck to thyroid)

Space B: vertebral compartment/pre-vertebral fascia can bulge to sternocleidomastoid; between SCM and trapezius in neck; not up and down, only bulges outwards

Space C: between buccopharyngeal and alar: all the way to base of skull to middle of the neck

Space D: is most important; goes up to base of skull, down to posterior mediastinum and down to diaphragm- easy space for infections to spread through; can affect many things during an infection like the heart



Superior: mastoid process
Inferior: clavicle

Origin: upper part of anterior surface of manubrium of sternum

Insertion: lateral one half of superior nuchal line

Innervation: accessory nerve XI and branches from anterior rami of C2 to C3 (C4)

Action: individually will tilt head toward shoulder on same side rotating head to turn face to opposite side; acting together, draw head forward; right SCM turns head to left and vice versa



Origin: superior nuchal line; external occipital protuberance; ligamentum nuchae; spinous processes of vertebrae C7 to T12

Insertion: lateral one third of clavicle; acromion; spine of scapula

Innervation: motor- accessory nerve 11; proprioception C3 and C4

Action: assists in rotating the scapula during abduction of humerus above horizontal; upper fibers elevate, middle fibers adduct, lower fibers depress scapula


Suprahyoid: Stylohyoid

Action: pulls hyoid bone upward in a posterosuperior direction

Innervation: facial nerve/ CN VII



Infrahyoid: strap muscles inferior to hyoid including omohyoid, sternohyoid, thyrohyoid, and sternothyroid (TOSS)

Needed for stabilize hyoid and larynx and reposition after swallowing
Innervations: cervical plexus (anterior rami between C1-4)


Suprahyoid: Posterior Digastric

Action: pulls hyoid bone upward and back

Innervation: facial nerve 7/ CN VII


Suprahyoid: Anterior Digastric

Action: opens mouth by lowering mandible; raises hyoid bone

Innervation: mylohyoid nerve from inferior alveolar branch of mandibular nerve


Suprahyoid: Mylohyoid

Action: upper and elevation of floor of mouth; elevation of hyoid

Innervation: mylohyoid nerve from inferior alveolar branch of mandibular nerve/ CN V


Suprahyoid: Geniohyoid

Action: fixed mandible elevates and pulls hyoid bone forward; fixed hyoid bone pulls mandible downward and inward

Innervation: branch from anterior ramus of C1 (carried along the hypoglossal nerve 12)/ CN V


Pre-Vertebral and Lateral Neck Muscles

A. Rectus capitis lateralis
B. Rectus capitis anterior
C. Longus capitis
D. Longus colli
E. Anterior Scalene
F. Middle Scalene
G. Posterior Scalene

Innervation of all these muscles: cervical plexus
If longus colli was paralyzed: wouldn’t notice because have other muscles that will do the jobs of that muscle… muscles in thumb though you do notice


Actions of Rectus Capitis Lateralis and Rectus Capitis Anterior

Rectus capitis lateralis: flexes head laterally to same side; attach to lateral mass of C1

Rectus capitis anterior: flexes head at atlanto-occipital joint


Actions of Longus Capitis and Longus Colli

Longus capitis: flexes the head; rotation and side bending individually

Longus colli: flexes neck anteriorly and laterally and slight rotation to opposite side

cervical column flexion together


Actions of Anterior, Middle, and Posterior Scalene Muscles

Anterior Scalene: elevation of rib I; attaches to lateral transverse processes of cervical vertebrae

Middle Scalene: elevation of rib I

Posterior Scalene: elevation of rib II

All Three: scalene must contract to elevate the rib, and are accessory respiratory muscles


Scalene Triangle

Scalene triangle is interval between anterior and middle scalene and 1st rib (borders of the triangle)
Can put traction (pressure) on the nerves and artery going through that triangle

Subclavian artery, nerves forming brachial plexus (controls upper limbs) – goes through triangle

Anterior scalene: subclavian vein and phrenic nerve are in front of it; phrenic nerve extends through spinal cord levels 3 4 and 5 and innervates the diaphragm
If you paralyze whole diaphragm is death, half is trouble breathing


Scalene Muscle Dysfunction

Muscles Dysfunction: all muscles have normal resting tone, but when a muscle is dysfunctional it contracts/shortens

If scalene is too short what happens? Since it lifts the first rib, it would be out of place causing impingement of nerves and blood vessels causing pain, tingling in upper extremities, coldness in fingers/hands
Can fix this in the office by relaxing the anterior scalene muscle


Arteries in the Neck

1. Brachiocephalic Trunk (on R only!)

2. Common Carotids: External Carotid and Internal Carotid

3. Subclavian: Vertebral, Internal thoracic, Thyrocervical trunk, Costocervical trunk, and Descending (Dorsal) Scapular – 50%


Subclavian Artery: 3 Parts

Divide the subclavian artery into 3 parts based on relation to anterior scalene muscles
1. Medial
2. Directly behind anterior scalene
3. Lateral to anterior scalene (very short)
As soon as it passes the border of anterior scalene it becomes brachial artery


Variations of the Thyrocervical Trunk

Gives rise to three branches, but the second branch varies
Always gives rise to the first and third (inferior thyroid and suprascapular respectively)
Second branch varies: either transverse cervical OR superficial cervical

If gives rise to the transverse cervical, the rhomboids are supplied by the deep branch of the transverse cervical
If gives rise to the superficial cervical, then the rhomboids are supplied by the descending (dorsal) scapular, which directly branches off the subclavian artery


Descending (Dorsal) Scapular Artery

characteristically pierces the brachial plexus


Subclavian Artery: 4 Branches In Order

1. Vertebral Artery: Supplies the brainstem, sends nerves to spinal cord, gives rise to anterior spinal artery

2. Thyrocervical Trunk: divides into three branches- the inferior thyroid, transverse cervical OR superficial cervical, and suprascapular arteries; suprascapular damaged easily when clavicle is fractured

3. Internal Thoracic Artery

4. Costocervical Trunk: divides into two branches- deep cervical and supreme intercostal arteries


Contents of the Carotid Sheath

Common and Internal Carotid
Internal jugular vein
Superior root of ansa cervicalis
Deep cervical lymph nodes


Common Carotid Artery

Right side has brachiocephalic trunk that gives rise to common carotid
Left comes past aortic arch and is a little longer
Carotid divides around thyroid cartilage (C5 ish) into internal and external carotid (common to internal and external)
If you look at a arteriograms: easy way to distinguish is that all the branches is the external and the one with no branches is internal


External Carotid Branches

Immediately after bifurcation with common carotid give off to branches (in order):
Superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular arteries
Terminal branches: superficial temporal and maxillary arteries


Relations of Branches from External Carotid

Come out below digastric muscle: occipital and lingual arteries
Come out above digastric muscle: facial and posterior auricular arteries
Come out backward: facial and lingual
Come out forward: posterior auricular and occipital


Branches from the Lingual and Facial Arteries

Lingual: Dorsal lingual, Deep lingual, Sublingual

Facial: Tonsillar, Ascending palatine, Glandular, Muscular, Submental
Tonsillar and ascending palatine: supply the oral cavity
Glandular: for submandibular gland that sits in the submandibular triangle


Braches from Occipital and Posterior Auricular

Occipital: SCM, Mastoid, Stylomastoid (~66%), Auricular, Muscular, Descending, Meningeal, Occipital

Posterior Auricular: Stylomastoid, Auricular, Occipital

Relation to Hypoglossal Nerve XII: as it descends, it passes outward between the internal jugular vein and the internal carotid artery. At this point it passes forward hooking around the occipital artery, across the lateral surfaces of the internal and external carotid and the lingual arteries, then continues deep to the posterior belly of the digastric and stylohyoid muscles. Passes over the surface of the hypoglossus muscle and disappears deep to the mylohyoid muscle


Carotid Sinus

functions as a baroreceptor
consists of a dilation of the lower end of the internal carotid artery
the tunica intima is thinner
the adventitia is thicker and includes sensory nerve endings, mainly from CN IX


Carotid Body

is a small reddish-brown, vascular arterial chemoreceptor found at the “carotid crotch”
is innervation by CN IX >> CN X and pre-ganglionic sympathetic axons (post-ganglionics are in the carotid body!)


Anastomoses of Occipital Branch: Collateral Circulation

Descending branch of occipital branch forms an anastomosis where two arteries connect to each other to permit collateral circulation without using capillary beds so structures can survive if one of them is cut off


Veins of Head and Neck

Veins are highly variable in their course and anastomoses

There are SUPERFICIAL and DEEP venous networks
a. Deep veins travel with the main arteries (branches from carotid system)
b. Superficial veins are outside the deep fascia
c. Superficial and Deep veins anastomose
There are 3 JUGULAR veins: Internal, External, Anterior


Internal Jugular Vein

begins in jugular foramen and runs in the carotid sheath
ends by joining the subclavian vein to form the brachiocephalic vein
Receives: Inferior petrosal sinus (skull), occipital, pharyngeal, lingual, facial (joins the anterior division of the retromandibular vein), thyroid veins
Big veins have valves, but most of them don’t have valves so can get backflow (branches above listed)
Internal is deep to investing fascia and infrahyoid fascia and carotid sheath


Superficial Veins: Anterior Jugular, External Jugular, Communicating Veins

Facial vein and retromandibular vein to form a external jugular vein which runs superficial to the SCM and outside the investing fascia
Anterior Jugular Vein: that drain the submental region
Variably, there is a communicating vein that connects the external and anterior jugular veins


Brachiocephalic Veins and the Jugulovenous Angle

Dumping into venous angle… all blood needs to get back to superior vena cava and into the heart
Internal jugular into subclavian to form right venous angle


Superior Vena Cava

It divides into the right and left brachiocephalic veins, which both divide further into the subclavian and internal jugular veins on both sides of the neck


Subclavian Venipuncture

Enter the venous system via subclavian vein puncture
Sibson's fascia: if you puncture it.. dangerous for the lung causing pneumothorax



Mastoid drain scalp
Submental drain face/oral cavity
Submandibular drain face/oral cavity

Where does lymph come from? Blood plasma from capillary beds which are leaky now called interstitial fluid then pressure takes the fluid into the lymphatics now called lymph fluid
Where does it go? Through channels of lymph nodes to meet up with macrophages and monocytes to clean out things, and then back into the heart eventually

Superficial nodes: are within the skin, and basically drain superficial fascia: scalp, face, skin
Submental, submandibular, external jugular, anterior jugular, pre-auricular/parotid, mastoid, occipital nodes
Run down and back to the thorax
Superior border of the neck
External jugular vein has nodes surrounding it


Deep Cervical Nodes

Deep Cervical Nodes: situated around the internal jugular vein
1. Superior Deep Cervical= jugulodigastric node
2. Inferior Deep Cervical= jugulo-omohyoid node

1. Accessory Nodes- on CN XI
2. Transverse Cervical Nodes

All lymph from the head and neck ends in DEEP CERVICAL NODES!


Cervical Lymph Nodes Levels

Used to determine spread of cancers

Level I – submental, submandibular
Level II – superior deep cervical; from skull base to hyoid
Level III – nodes along the middle 1/3 of the internal jugular
Level IV – inferior deep cervical; lower 1/3 of the internal jugular to clavicle
Level V – posterior triangle
Level VI – prelaryngeal and pretracheal; midline between hyoid and sternal notch
Level VII – superior mediastinal; below sternal notch and between common carotid a


Lymphatic Drainage of Head and Neck

Right Lympathic Duct: right arm, 5th rib (inferior border)

Thoracic Duct: Left arm, both legs, rest of torso
All deep nodes drain into lymphatic trunks and drain into the jugulovenous system
Tumor cells can spread in many ways: through the lymphatic system, goes through lymph nodes so knowing the pathways of drainage we know where the cancer could be spreading
Say someone has submandibular cancer and goes into jugular trunk and goes into the venous system… look for capillary beds.. Next bed is into lungs so spreads there; if past the lungs can use arteries to spread as well


Dissemination of Cancer

1. Direct seeding of body cavities or surfaces: peritoneum and pleura
2. Lymphatic spread: pattern of lymph involvement follows lymphatic drainage of affected organ
3. Hematogenous spread: arterial spread may occur AFTER passage through capillary beds of the lung
Tumor cells tend to leave the vasculature at the next capillary bed encountered

There are some exceptions, for example:
bronchogenic carcinomas tend to involve the adrenals and the brain
skeletal muscle (despite have dense capillary beds) is rarely affected by metastasis