the neck by: lina abdullah & rahaf jreisat · lingual artery (deep to mylohyoid m.) facial...
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The Neck
BY: Lina Abdullah & Rahaf Jreisat
Boundaries of the Neck: generally from base of the skull to root of the neck
From superior nuchal line of occipital bone up to mastoid process down to margin of the mandible : Superior
margin
inferior margin: inlet of thoracic cavity , the clavicle and root of the neck
cervical vertebral muscles
subocciptal(part of deep muscles posteriorly and they form
triangular-like space ) and deep neck muscles
mainly extends head and neck
-rectus capitis posterior major m
-rectus capitis posterior minor m
-oblique capitis inferior m
-oblique capitis superior m
Action of these muscles is extension the head -
Recti muscles insert in inferior nuchal line of the occipital bones -
Anterior vertebral muscles
flexes head and
neck
•Longus coli m.
Capitis mean occipital bone so it attach from occipital to transverse processes of cervical vertebra: Longus capitis m.
Rectus capitis anterior m :anteriorly to cranium and vertebra of cervical
Remember that superior nuchal line
lines posterior of the occipital bone
from transverse
processes o middle cerviacal vertebrae to first rib and anteriorly to groove for subclavian artery: Anterior scalene m.
:Lateral vertebral muscles
laterally flex head
and neck
anterolateral to occipital condyle: Rectus capitis lateralis m.
•Splenius capitis m.
Lateral flexion of the head on one side of scapula up to cervical: Levator scapulae m.
: sup. attachment of transverse processes to first rib and posteriorly to groove for subclavian artery Middle scalene
m.
: also sup. Attachment of transverse processes of cervical vertebra to second rib Posterior scalene m.
So anterior to groove for subclavicn artery is anterior scalene
But posteriorly to this groove is middle scalene and between middle and anterior scalene is brachial plexus
all of lateral and anterior vertebra muscles are innervated by cervical nerves directly except levator scapulae ,which
is innervated by cervical nerves and brachial plexus
Superficial fascia: (externally) is layer of connective tissue that lies deeper to skin and part of hypodermis, it
contains the platysma
Deep fascia 3layers
The most superifical layer envelopes the trapezius and sternocleidomastoid muscles: Investing layer*
The middle layer has 2 parts: : Pretracheal layer**
Visceral part: it surrounds the thyroid , trachea ,parathyroid ,pharynx ,larynx and esophagus 1-
the fascia surrounds the pharynx and down to esophagus ( in some references) known as buccopharyngeal fascia ‐
2- muscular part :it surrounds the all anterior muscles of the neck (infrahyoid and suprahyoid muscles)
Prevertebral layer: the deepest one ,it surrounds all vertebral muscles and vertebrae***.
Posterior to pharynx(posterior to pretracheal layer)
Continue as axillary sheath
Carotid sheath
,it is surrounded by all layers of deep fascia Thickening of the other layers
: contents
Common & internal carotid
aa.
Intrnal jugular v.
Vagus n.
Deep cervical lymph nodes
Cervical Fascia extensions
Alar fascia:
Division from prevertebral fascia-
From skull to T2 that means in superior mediastinum region (merge with-
buccopharyngeal fascia anteriorly))
: Buccopharyngeal fascia
That surrounds the pharynx and esophagus Superior & posterior continuation of the pretracheal fascia
The Merging between alar fascia and buccopharyngeal fascia forms space in sup.mediastinum known as real
retropharyngeal space
Cervical Fascia: Spaces
: Retropharyngeal space
Prevertebral fascia Between buccopharyngeal fascia and
•Spread of infections
(Real) Retropharyngeal space:
ngealbuccophary Between the alar fascia and
Allow movement of pharynx, larynx, and trachea during swallowing-
Continuous with superior mediastinum toT2-
the spread of infection in real space stops at t2 where fusion of alar and buccopharyngeal
Prevertebral fascia posteriorly to alar Between the alar fascia and the
Continuous with mediastinum
The risk that an infection in this space can spread directly to the thorax ,because it continuous with mediastinum
Slide 12: (Bear with me)
Neck Triangles: Boundaries
• Anterior triangle: Anterior to SCM
• Carotid triangle • Digastric triangle • Submental triangle • Muscular triangle • Posterior triangle:
Posterior to SCM Anterior to trapezius
• Occipital triangle • Supraclavicular triangle
*Sternocleidomastoid (SCM)
seperates the neck into
anterior and posterior
triangles.
*Anterior triangle:
- Digastric (submandibular)
triangle: between the anterior
and posterior bellies of digastrics muscle, floor of digastrics: mylohyoid m.
The rest of the triangles are separated by hyoid bone and sup&inf bellies of
omohyoid m.
carotid triangle : anterior to SCM, posteriosuperior to sup belly of omohyoid, and
inferior to posterior belly of digastrics.
- Submental: superior to hyoid bone, between anterior bellies of digastrics.
Floor of submental triangle is made of mylohyoid muscles.
- Muscular triangle: inferior to hyoid bone and posterior to superior belly of
omohyoid.
*Posterior triangle:
Inferior belly of omohyoid divides it into two subtriangles
- Occipital triangle: superficial, superior to inf. belly of omohyoid, its floor is made
of muscles (scalenius medius, levator scapulae, splenius capitis)
- Supraclavicular triangle: superior to clavicle, inferior to inf. belly of omohyoid
and lateral to SCM.
Neck Triangles: Content
Anterior Triangle:
*Muscular triangle:
-Infrahyoid muscles (sternohyoid, sternothyoid, thyrohyoid, omohyoid)
-Viscera (thyroid cartilage, cricoid cartilage, trachea, thyroid gland isthmus
and connections btw these structures)
* Submental triangle:
-Lymph nodes in submental groove that can be felt is they swell.
* Digastric triangle:
- Submandibular lymph nodes: drain nasal&oral cavity, pharynx
- Submandibular salivary gland (superficial part)
- Facial artery: pass deep to submandibular gland then transverse the lower
edge of mandible (become superficial), you can feel it pulsing just inferior
to masseteric muscle.
Importance of this triangle:
1.injuries damage facial artery
2. Swelling of lymph nodes in common cold, sinusitis,…
*Carotid triangle:
-Carotid sheath and its contents
- Hypoglossal nerve before it goes deep to mylohyoid
- Cervical part of sympathetic trunk (posterior)
Posterior Triangle:
*Occipital triangle:
- accessory nerve which innervates SCM and trapezius
accessory nerve exits through jugular foramen(which is deep) then passes
deep towards SCM, it exits through posterior edge of SCM and transverses
occipital triangle where it becomes superficial (separated from skin by
investing deep fascia only) which makes it more susceptible to injury.
Any injury in this triangle can affect accessory nerve and leads to paralysis
in trapezius muscle – one can’t lift his shoulder.
*Supraclavicular triangle:
-External jugular vein
معلش
Sensory Innervations of the Neck
*cervical plexus:
-motor and sensory branches
sensory branches exit posterior to SCM muscle and spread all over cervical region.
-Deep: ansa cervicalis (part of carotid triangle) = hypoglossal nerve& C2& C3 –
innervate infrahyoid muscles.
*Well be taken in another lecture
Root of the Neck
*Boundries:
Ant: suprasternal angle
Lateral: first rib
Pos: body of T1
*Contents (from ant to pos):
Veins (Right and left brachiocephalic), vagus and phrenic nerves, arteries, trachea,
esophagus, thoracic duct & left lymphatic duct.
Arteries of the Head and Neck Branches of external carorid artery:
Superior thyroid artery
Ascending pharyngeal artery
Lingual artery (deep to mylohyoid m.)
Facial artery
occipital artery (hypoglossal nerve exit just
inferior to it)
Posterior auricular artery
Superficial temporal artery (pass
superficial to zygomatic arch anterior to
ear, you can feel its pulse)
Maxillary artery (Enter pteygopalatine fossa, pass with maxillary nerve)
Mneumonic:
Some American Ladies Find Our Pyramids Most Satisfactory
Veins of the Head and Neck
*Internal Jugular vein drain all cranial cavity and a lot of superficial veins (facial, retromandiular,
external jugular)
*Retromandibular vein = union of maxillary vein and superficial temporal veins
* External jugular can be drained in internal jugular or subclavian vein.
Principal groups of lymph nodes
Lymph drainage of Head and neck
• Regional lymph nodes: • Occipital
• Retroauricular • Parotid • Buccal • Submandibular • Submental • Anterior cervical • Laryngeal • Tracheal • Superficial cervical • Deep cervical: • Jugular trunk
*occipitaland & retroauricular are posterior.
*The fate of all lymph all over head and neck: Deep Cervical
*Deep cervical drain all superficial and ant group (pretracheal, paratracheal,
retrotracheal, retropharyngeal) and submandibular lymph nodes.
*Importance: knowing the sequence for tracing metastasis.
Occipital Triangle
• Above the inferior belly of omohyoid m. • Spinal accessory nerve (XI): -Junction of the superior & middle thirds of the posterior border of SCM → junction between middle & lower thirds of the anterior border of trapezius -Injury
Anterior Triangle
• Carotid triangle: -Carotid sheath: Between sternocalvicular joint and the mid point between mastoid and angle of mandible - Hypoglossal nerve - Cervical sympathetic trunk • Submandibular (digastric) triangle - Submandibular gland - Submandibular lymph nodes
Surface Anatomy of the Neck • Hyoid bone – C3:
- Posterior to the mandible • Laryngeal prominence (Adma’s apple)‐ tip (C4): - Vocal cords – at the middle • Cricoid cartilage – C6: - Cricothyroid ligament - Cricothyrotomy • First tracheal cartilage: - Tracheostomy • Thyroid gland: - Isthmus – 2nd – 4th tracheal Rings
Tracheostomy