Boundaries Landmarks Regions Neck Landmarks Neck Landmarks Organ Projections Subcutaneous Layer

Home , Costocervical trunk, Jugular venous arch, Posterior auricular vein

NECK. REGIONAL ANATOMY Neck

Boundaries Landmarks Regions Neck Landmarks Neck Landmarks Organ projections Subcutaneous layer

Platysma V. jugularis anterior V. jugularis externa • retro mandibular vein posterior division • posterior auricular vein. Pl. cervicalis n. occipitalis minor n. auricularis magnus n. transversus colli nn. supraclaviculares

Cervical plexus

Cutaneous (4 branches) . Great auricular nerve (C2,C3)- skin near auricle, external acoustic meatus . Transverse cervical nerve (C2,C3)- anterior region of neck . Lesser occipital (C2)- skin and scalp posterosuperior to the auricle . Supraclavicular nerves (C3,C4)- skin above and below the clavicle Muscular . Ansa cervicalis (C1-C3)  geniohyoid (C1), thyrohyoid (C1), sternothyroid, sternohyoid, omohyoid) . Phrenic (C3-C5 (primarily C4))- diaphragm and the pericardium . Segmental branches (C1-C4)- anterior and middle scalenes Two branches from the posterior roots of spinal nerves: . Preauricular nerve (from the posterior roots of C2–C3) . Postauricular nerve (from the posterior roots of C3–C4) Neck fascia

Lamina superficialis - Covers entire neck - Fascia masseterica - Fascia parotidea - Fascia gl. submandibularis Lamina pretrachealis - Between os hyoideum, strenum & clavicula, and m. omohyoideus - Linea alba - from os hyoideum to isthmus tracheae - Spatium interaponeuroticum suprasternale - Arcus venosus juguli - Recessus Gruberi - behind m. sternocleidomastoideus Lamina prevertebralis - Skull base - bodies Т3-Т4 (fascia endothoracica) - Fascia mm. longi capitis et cervicis - Fascia mm. scaleni, m. levator scapulae - Spatium prevertebrale – extends to proc. transversi Fascia endocervicalis - Lamina visceralis – covers neck organs - Lamina parietalis – apart from the visceral - Vagina carotica - from lamina parietalis - Spatium pretracheale - between the two layers - Extends to mediastinum superius - Spatium retropharyngeum - between fascia endocervicalis & lamina prevertebralis - Extends to mediastinum posterius Regions of the neck

Trigonum anterior  Tr. submentale  Tr. submandibulare  Tr. musculo-viscerale  Tr. caroticum

Trigonum posterior  Tr. omotrapezoideum  Tr. omoclaviculare Posterior triangle

 Apex: Btwn sternocleidomastoid and trapezius muscles at the superior nuchal line of the occipital bone

 Anterior: Posterior border of sternocleidomastoid muscle

 Posterior: Anterior border of the trapezius

 Base: Middle one third of the clavicle

 Roof: Investing layer of the deep cervical fascia Divisions  Crossed at 2.5 cm above the clavicle by the inferior belly of the omohyoid muscle, which  Divides the region into two triangles: – Upper or occipital triangle – Lower or subclavian triangle (or supraclavicular triangle) Contents

Nerves  Spinal accessory nerve (Cranial Nerve XI)  Branches of cervical plexus  Roots and trunks of brachial plexus  Phrenic nerve (C3,4,5) Vessels  Subclavian artery (Third part)  Transverse cervical artery  Suprascapular artery  Terminal part of external jugular vein Contents

Lymph Nodes  Occipital  Supraclavicular Muscles  Inferior belly of omohyoid muscle  Anterior Scalene  Middle Scalene  Posterior Scalene  Levator Scapulae Muscle  Splenius Regio infrahyoidea Boundaries - Os hyoideum, sternum, m. sternocleidomastoideus Content Lamina pretrachealis Muscles а) depresses os hyoideum and larynx in swallowing: - M. sternohyoideus, m. thyrohyoideus, m. sternothyroideus & m. omohyoideus. b) straightens the vocal folds - M. cricothyroideus

Regio infrahyoidea

Vessels - V. jugularis anterior - Arcus venosus juguli - in the suprasternal space - A.v. thyroidea superior - V. thyroidea inferior

Lymph nodes - Prelaryngeal - Pretracheal - Paratracheal Organs а) Endocrine system - Gl. Thyroidea - Gll. Parathyroideae b) Respiratory system - Larynx - C4-C6 - Trachea - C6-Th4 c) Digestive system - Pharynx - basis cranii - C6 - Esophagus - C6 - Th11 Regio infrahyoidea. Larynx, trachea, gl. thyroidea

Trigonum submandibulare

Boundaries Basis mandibulae M. digastricus – venter anterior et posterior M. mylohyoideus/m.hyoglossus Lamina superficialis Superficial structures

M. platysma V. facialis R. coli nervi facialis Trigonum submandibulare

Gl. submandibularis – in sheath of lamina superficialis - Posterior process - extends to medial pterygoid muscle - Anterior process – extends to sublingual gland - submandibular duct – on the inner surface - lndd. submandibulares – lateral to the capsule Trigonum submandibulare

- A.v. facialis – give off a.v. submentalis - N. mylohyoideus – branch of n. mandibularis - N. hypoglossus - N. lingualis - Gangl. submandibulare - Trigonum Pirogovi – approach to a. lingualis - m. mylohyoideus - tendo m. digastrici - n. hypoglossus Trigonum submandibulare

Boundaries - m. digastricus, venter posterior - m. omohyoideus, venter superior - m. sternocleidomastoideus

Trigonum caroticum

A. carotis communis – at the upper margin of cart. thyroidea divides into: - A. carotis externa - - a. thyroidea superior, a. lingualis, a. facialis - - a. occipitalis, a. sternocleidomastoidea, a. pharyngea ascendens - A. carotis interna V. jugularis interna Ansa cervicalis (С1-С3) - Radix superior (С1,2) – anterior to a. carotis communis - Radix inferior (С2,3) – lateral to v. jugularis interna

Variations in the bifurcation of a. carotis communis Trigonum caroticum - cont. N. vagus – in the groove btw a. carotis comm. & v. jugularis interna - N. laryngeus superior - In the upper part, medial to a. carotis externa et interna - Enters the larynx thru membr. thyrohyoidea with a. laryngea superior N. hypoglossus - beneath venter posterior m. digastrici - Crosses lateral to a. carotis externa et interna - enters trig. submandibulare between vent. post. m. digastrici & m. hyoglossus Plexus cervicalis (С1-С4) – over deep cervical muscles Truncus sympaticus - behind lamina prevertebralis

Truncus sympaticus - behind lamina prevertebralis - behind a. carotis communis/interna close to n. vagus - gangl. cervicale superior - over m. longus colli (C2-3) - ganl. cervicale medius – at the levbel of a. thyroidea inferior (C6) - gangl. сervicale inferior (С7 head of І rib) - Innervates upper limb arteries & a. vertebralis - Contact with cupula pleurae, d. thoracicus (on the left side), a. subclavia, a. vertebralis Midline structures

• Hyoid bone • Thyrohyoid membrane • Thyroid cartilage • Cricothyroid membrane • Cricoid cartilage • Crico-tracheal ligament • Thyroid gland isthmus • Tracheal rings • Important to identify these important midline structures.

Midline structures

• Thymus – upper poles

• Parathyroid glands (inferior)

• Jugular venous arch.

• Inferior thyroideae veins (plexus venosus)

• Esophagus (pars cervicalis)

• Longus coli muscle Midline structures Root of the neck

Transitional area btwn neck and thorax. Opens in the superior thoracic inlet. Bounded:

 First ribs - laterally

 Manubrium sterni - anteriorly

 Body of Т1 - posteriorly

Topographic structures

 Spatium antescalenum

 Spatium interscalenum

 Trigonum scalenovertebrale

Structures at the root of the neck

• Brachio cephalic trunk • Subclavian artery and its branches • Subclavian vein • Termination of internal jugular vein • Thoracic duct • Apex of lung • Phrenic nerve • Vagus nerve

Contents

1)The arteries:

• The brachiocephalic trunk.

• Right common carotid.

• Right subclavian.

• May also give thyroidea ima. Subclavian artery

Divided into 3 parts by scalenus anterior muscle. Part 1: Medial to the muscle and gives 3 branches: • Vertebral artery : Enters foramen transversarium at C6 • Thyrocervical trunk : Inferior thyroid artery, transverse cervical artery and suprascapular artery. • Internal thoracic artery. Part 2: Posterior to the muscle and gives 1 branch, – the costocervical trunk which gives – superior intercostal and deep cervical arteries. Part 3: Lateral to the muscle, usually giving one branch (dorsal scapula). It may also occasionally give the suprascapular artery. 2)The veins:

• External jugular veins. • Anterior jugular veins: – drain into the external jugular or subclavian vein. – joined by the jugular venous arch, but could unite to form a single trunk in the midline of the neck. These veins have no valves. • The subclavian vein: – A continuation of the axillary vein. – has only one named tributary, the external jugular vein. • The internal jugular vein, in the carotid sheath. – The internal jugular vein and subclavian veins unite to from the brachiocephalic vein. Vagus nerve

Btwn common carotid and the internal jugular vein. Branches in the neck: • Meningeal nerve: Recurrent to the dura. • Auricular nerve: – supplies the pinnae and external auditory meatus. • Pharyngeal nerves: Join the pharyngeal plexus. • Superior laryngeal nerve: – Divides into internal laryngeal and external laryngeal. • Recurrent laryngeal nerve • Cardiac branches: Cardiac plexus. Spatium antescalenum

Boundaries - Anteriorly - mm. sternocleidomastoideus, sternohyoideus, sternothyroideus - Posteriorly - m. scalenus anterior. Content - angulus venosus juguli - v. jugularis interna - v. subclavia - ductus thoracicus/ductus lymphaticus dexter - a. suprascapularis - a. cervicalis superficialis - n. phrenicus (C3-5) - ndd. lymphaticae, around - v. jugularis interna - a. transversa cervicis Root of neck Spatium antescalenum Spatium antescalenum (right) Spatium interscalenum Boundaries – three-wall slit btwn m. scalenus anterior anteriorly, m. scalenus medius posteriorly and first rib (sulcus a. subclaviae) below.

Content

- a. subclavia (middle, interscalenous part), gives off - truncus costocervicalis

- a. cervicalis profunda – for neck muscles - a. intercostalis suprema - for І and ІІ costal interspaces

- pl. brachialis - truncus superior, medius and inferior. Trigonum scalenovertebrale Boundaries - m. scalenus anterior laterally, m. longus coli and neck vertebrae medially and cupula pleurae below. The apex coincides with the transverse process of С6. Content - a. subclavia, prescalenous part - a. vertebralis - truncus thyrocervicalis - a. thyroidea inferior - a. cervicalis ascendens - a. cervicalis superficialis - a. suprascapularis - a. thoracica interna - ductus thoracicus - n. vagus - n. laryngeus recurrens - truncus sympaticus - ganglion inferior/stellatum - ansa subclavia Trigonum scalenovertebrale

Ductus thoracicus Trigonum scalenovertebrale

Pl. brachialis, tr. sympathicus, m. scalenus minimus A. subclavia. Branches A. vertebralis. Variations Four major arterial anastomoses btw aorta and head