Anatomy Block I*- Introduction to the Neck, Cervical Fascia, Posterior Neck, CN XI
suprasternal (jugular) notch of manubrium
clavicle and acromion
What are the palpable bondy prominences in/near the neck/cervix/cervical region anteriorly
external occipital protuberance
mastoid processes of temporal bones
spinous process of C7 vertebra
What are the palpable bondy prominences in/near the neck/cervix/cervical region posteriorly
L and R platysma muscle
thyroid cartilage (forms part of larynx/voice box) with laryngeal prominence (Adam's apple)
What is some main surface anatomy of the neck anteriorly
external jugular vein- runs vertically over SCM to angle of mandible
submandibular gland- palpate in submandibular triangle
pulse of common carotid artery- may be taken between the trachea and medial border of the superior 1/2 of the SCM muscle
accessory nerve (CN XI)- travels deep to SCM from jugular foramen to trapezius
what is some main surface anatomy of the neck laterally
What are the superficial muscles of the neck
- runs in subcutaneous layer, from mandible/lower face to upper thorax
- actions: tense skin of neck, pull lower lip inferioly (pouting)
- innervation (CN VII)
- formed from
where does the platysma run? what does it do? what innervates it and what pharyngeal arch is it formed from
-sternum and proximal part of clavicle to mastoid process
-uni- turns head to opposite side
-bi- together they flex the neck
-innervation- accessory nerve (XI)
where does SCM run? what are its unilateral and bilateral action? what is the innervation of the SCM
- caused by spasm or contraction of SCM, resulting in neck to be flexed and bent on side of injury
--acute- usually resolves itself after a period of days
--congenital muscular torticollis- SCM is injured either during birth or due to uterine malposition; typically treated with physical therapy over a period of months/years, and may never completely resolve
--inflammatory- due to respiratory infection or other head/neck infection
what is torticollis? what causes it?
-single muscle innervated by L and R accessory muscle (XI)
- in posterior cervical region, NOT posterior triangle of neck/lateral cervical region
- superficial back muscle, helps move upper limb especially scapula
--other parts of trapezius move scapulae in other ways
is the trapezius single or bilateral? what innervates it and where is it found?
posterior: anterior SCM border
anterior: midline of neck
what are the boundaries of the anterior cervical region (anterior triangle)
what are the smaller subdivisions of anterior cervical region
post: border of trapezius
ant: posterior border of scm
what are the boundaries of the lateral cervical region (posterior triangle)
occipital and supraclavicular
what are the two smaller triangles into which the posterior triangle is divided?
borders of trapezius in neck and up to its attachment on skull
what are the boundaries of the posterior cervical region?
trapezius, parts of splenius muscles, semispinalis capitis
what is contained within the posterior triangle?
all of the nerves come from the cervical plexus, which are anterior rami of C1-C4; these all originate from the middle of the posterior border of the SCM, called the nerve point of the neck
what constitutes the cutaneous innervation of the anterior and lateral neck? where do these nerves originate?
regional anasthesia for a cervical plexus block is placed near the nerve point of the neck, so it numbs the branches of the plexus.
this is done for neck and some proximal limb surgeries
why is the nerve point of the neck clinically important?
skin over parotid gland, auricle, upper part of anterior cervical region and skin over upper SCM
where does the greater auricular nerve originate from? what does it innervate
most of anterior cervical region, skin over lower SCM
where does the transverse cervical nerve originate from? what does it innervate?
lower part of lateral region
where does the supraclavicular nerve originate from? what does it innervate
skin/scalp behind ear, upper part of lateral cervical region
where does the lesser occipital nerve originate from? what does it innervate?
posterior rami of C2-C4 or C2-C5
what innervates the posterior neck?
compartmentalize the structures and muscles of neck, allow neck organs and structures to move without difficulty during swallowing speech and turning the head etc
what do they fascial layers (deep cervical fascia) of the neck do? what do they allow to happen?
fascial layers provide natural cleavage planes which are useful for surgery
infection, blood, and other material may be limited or assisted in its spread due to these layers
why are the fascial layers of the neck surgically important?
surrounds common/internal carotid artery, itnernal jugular vein, vagus nerve, deep cervical lymphatics
if you were going to operate on any of these structures you would have to open the sheath
the sheath could limit blood spread
what does the carotid sheath cover?
what are the layers of the deep cervical fascia?
surrounds trapezius, SCM, strap muscles (suprahyoid and infrahyoid in anterior neck region)
what is the most superficial layer of the deep fascia? what does it surround?
with fascia of head forming part of the scalp
manubrium, clavicles, part of scapulae
what does the investing layer of DCF blend with? what does it attach to inferiorly
from hyoid to sternum and blends with pericardium
surrounds the trachea, esophagus and thyroid gland
where does the pretracheal layer run? what does it surround?
deep muscles near vertebral column like longus colli, capitis, and scalenes
what does the prevertebral layer of fascia surround?
brachial plexus and 3rd part of subclavian artery, which becomes the axillary sheath in the upper limb
what does the prevertebral layer form a covering around?
from cranial base to about T3, where it fuses with ligaments on anterior surface of T3
where does the prevertebral run?
cranial base to root of neck
where does the carotid sheath run?
cranial cavity and mediastinum
internal jugular vein, common and internal carotid arteries, CN X, deep cervical LNs
what does the carotid sheath link? what does it enclose?
potential space filled with areolar CT that runs posterior to pharynx and esophagus
what is the retropharyngeal space?
vertically oriented space posterior to esophagus and pharynx
post: prevert fascia
lat: L and R carotid sheaths
ant: pretracheal layer in neck and buccopharyngeal fascia around pharynx: the pretracheal layer is continuous with the buccopharyngeal fascia
where is the retropharyngeal space located and what are its boundaries?
allows viscera of neck to move during swallowing/speech
danger space because infection can spread through this space and travel inferiorly to mediastinum or superiorly to cranial base
what is the function of the retropharyngeal space
material enters retropharyngeal space from trauma/perforation of the pharynx, esophagus, or trachea (accidentally swallow chicken bone)
clinical indication of perforation: streaks of air in retropharyngeal space viewed radiograph
what is a retropharyngeal perforation
abscess in general: collection of pus that accumulates in space/tissue as a result of an infection, typically painful and swollen
usually pus must be drained
retropharyngeal abscess develops in the space, most commonly in kids due to infection
infection can spread from pharyngeal region to mediastinum could impinge on neck viscera
what is a retropharyngeal abscess
ant: posterior edge of SCM
post: edge of trapezius
inf: middle 1/3 of clavicle
roof: investing layer of deep cervical fascia
floor: msucles covered by prevertebral layer of deep cervical fascia
what are the borders of the lateral cervical regino (posterior triangle of the neck)
occipital triangle (more superior and larger of 2 triangles, branches of cervical plexus originate here)
supraclavicular (omoclavicular, subclavian) triange
what are the subdivisions of the lateral cervical region (posterior triangel of neck)
inferior body of omohyoid muscle
what divides the lateral cervical region (posterior triangle of neck)
inferior belly of omohyoid
muscles covered by prevertebral layer of deep cervical fascia (splenius capitis, levator scapulae, scalenes
what are the muscles in the lateral cervical region?
external jugular vein
what is the most superficial neurovascular structure in the lateral cervical region?
cutaneous branches of cervical plexus
what neurovascular structures are in the posterior border of the SCM
subclavian artery (3rd part)
roots (rami) of brachial plexus (anterior rami of C5-T1)
what are the neurovascular structures emergy between the middle and anterior scalene
transverse cervical artery
what are the neurovascular structures found anterior to the anterior scalene muscle
thyrocervial trunk, which comes off 1st part of subclavian
where does the suprascapular artery branch off of?
somatic motor functions only
what type of nerve is the accessory nerve
foramen magnum; the spinal root and CN merge and then leave skull via jugular foramen
where does the accessory nerve's spinal root enter the skull? what happens after it enters?
deep to SCM
where does the accessory nerve travel/
SCM and trapezius
what does the accessory nerve innervate