The Neck. BY: Lina Abdullah & Rahaf Jreisat

Transcription

1 The Neck BY: Lina Abdullah & Rahaf Jreisat

2 Boundaries of the Neck: generally from base of the skull to root of the neck Superior margin :From superior nuchal line of occipital bone up to mastoid process down to margin of the mandible 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 Remember that superior nuchal line lines posterior of the occipital bone 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.longus capitis m :Capitis mean occipital bone so it attach from occipital to transverse processes of cervical vertebra Rectus capitis anterior m :anteriorly to cranium and vertebra of cervical

3 from transverse.anterior scalene m :processes o middle cerviacal vertebrae to first rib and anteriorly to groove for subclavian artery Lateral vertebral muscles: and neck laterally flex head.rectus capitis lateralis m :anterolateral to occipital condyle.splenius capitis m.levator scapulae m :Lateral flexion of the head on one side of scapula up to cervical Middle scalene.m : sup. attachment of transverse processes to first rib and posteriorly to groove for subclavian artery.posterior scalene m : also sup. Attachment of transverse processes of cervical vertebra to second rib 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

4 Superficial fascia: (externally) is layer of connective tissue that lies deeper to skin and part of hypodermis, it contains the platysma Deep fascia 3layers *Investing layer :The most superifical layer envelopes the trapezius and sternocleidomastoid muscles **Pretracheal layer :The middle layer has 2 parts: 1- Visceral part: it surrounds the thyroid, trachea,parathyroid,pharynx,larynx and esophagus 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 Thickening of the other layers,it is surrounded by all layers of deep fascia 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 : Superior & posterior continuation of the pretracheal fascia That surrounds the pharynx and esophagus The Merging between alar fascia and buccopharyngeal fascia forms space in sup.mediastinum known as real retropharyngeal space

5 Cervical Fascia: Spaces Retropharyngeal space : Between buccopharyngeal fascia and Prevertebral fascia Spread of infections (Real) Retropharyngeal space: Between the alar fascia and buccopharyngeal -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 posteriorly to alar Between the alar fascia and the Prevertebral fascia Continuous with mediastinum The risk that an infection in this space can spread directly to the thorax,because it continuous with mediastinum

6 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.

7 *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

8 - 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

9 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

10 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

11 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

12 *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

13 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.

14 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:

15 - 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

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