Posterior Triangle of the Neck - RCSI Year 2, Semester 1 PDF

11/1/2023 Posterior Triangle of the neck Class Year 2, Semester 1 Lecturer DR. VIJAYALAKSHMI S B Department of Anatomy Email id: [email protected] Date 30-10-2023 1 1...

11/1/2023 Posterior Triangle of the neck Class Year 2, Semester 1 Lecturer DR. VIJAYALAKSHMI S B Department of Anatomy Email id: [email protected] Date 30-10-2023 1 1 POSTERIOR TRIANGLE OF THE NECK 2 1  11/1/2023 LEARNING OUTCOMES ▪ Demonstrate the posterior triangle and its contents, including the location and course of major vessels and nerves ▪ Outline the boundaries, roof and floor of the posterior triangle ▪ Define the surface anatomy of the accessory nerve ▪ Identify the jugular veins and their surface anatomy ▪ Describe the cervical and brachial plexus 3 THE NECK 4 2  11/1/2023 BONES AND CARTILAGES OF NECK 5 SUPERFICIAL CERVICAL FASCIA Contents : Platysma Superficial veins – External jugular vein, Anterior jugular vein Superficial cervical lymph nodes Cutaneous nerves 6 3  11/1/2023 CERVICAL FASCIA Deep cervical fascia Investing layer of fascia Superficial fascia Pretracheal fascia Prevertebral fascia Carotid sheath 7 Deep cervical fascia Prevertebral layer Subcutaneous (superficial fascia) Investing layer Skin Outermost layer of the Platysma Deep Cervical Carotid sheath Fascia) Alar fascia Pretracheal layer 8 4  11/1/2023 9 STERNOCLEIDOMASTOID MUSCLE mastoid Sternum Cleido (Clavicle) 10 10 5  11/1/2023 CONT. Action ▪ Individually ▪ Turns the chin to the opposite shoulder (Contralateral head rotation) ▪ Acting together ▪ Head flexion 11 11 CLINICAL APPLICATION A 40-year-old woman presented to An 18-month-old baby presented to the Neurology outpatient clinic for an pediatric clinic by his mother. Mother said evaluation of her neck. On examination, that the baby was born with small mass there was marked torticollis with tilting of on the left side of his neck and head head to the left and chin facing upwards turned to the right side. and to the right Which structure is affected in both the case? Which side of the neck is abnormal in both the case? 12 6  11/1/2023 13 TRAPEZIUS ▪ Action: ▪ Assist in rotating the scapula during abduction of humerus above horizontal ▪ Shrugs the shoulders ▪ Nerve supply: ▪ Accessory nerve (CN XI) 14 14 7  11/1/2023 CLINICAL APPLICATION 28-year-old man inability to shrug his shoulder after surgery in the neck 15 THE ACCESSORY NERVE (CN XI) Surface marking ▪ Passes deep to the sternocleidomastoid muscle ▪ Emerges at the junction of the superior and middle thirds (upper third) of the posterior border of Sternocleidomastoid ▪ Passes deep to the investing layer of deep cervical fascia ▪ Descends & enters the posterior triangle ▪ Enters lower -third of anterior border of Trapezius 16 16 8  11/1/2023 HOW DO YOU TEST THE FUNCTION OF ACCESSORY NERVE? 17 17 Physiotutors - https://www.youtube.com/watch?v=cVuH6wL1GU0 18 9  11/1/2023 MUSCULAR TRIANGLES OF NECK 19 20 10  11/1/2023 occipitalbonejustposteriortomastoid process 21 Posterior triangle Splenius capitis Levator scapulae Scalenus posterior Scalenus medius Scalenus anterior Prevertebral fascia overlies the muscles 22 11  11/1/2023 Middle and Anterior Scalene Passage of Brachial Plexus + Subclavian Artery Passage of Subclavian Vein 23 Anterior Scalene- Phrenic nerve 24 12  11/1/2023 POSTERIOR TRIANGLE OF THE NECK Divided into upper large occipital triangle and lower small supra-clavicular/ omoclavicular/ subclavian Inferior belly of triangle by inferior belly of Omohyoid omohyoid 25 Two structures within the chest cavity extends up into the posterior triangle: Apex of the lung - extend 2 cm above middle third of the clavicle Cervical Pleura 26 13  11/1/2023 27 CERVICAL PLEXUS 28 28 14  11/1/2023 CUTANEOUS BRANCHES OF THE CERVICALPLEXUS Form from posterior branches of anterior rami of cervical plexus Branches: Lesser occipital C2: upper triangle, behind ear Great Auricular C2,3: skin over parotid Transverse Cervical C2,3: chin to sternum Supraclavicular C3,4: skin over the shoulder 29 29 MUSCULAR BRANCHES OF THE CERVICALPLEXUS Anterior rami of the upper cervical nerves form the motor branches Branches: Ansa cervicalis: C1,2,3 travel with cranial nerve XII (descendens hypoglossi) - supplies the strap muscles Phrenic nerve: C3,4,5: supplies diaphragm 30 30 15  11/1/2023 BRACHIAL PLEXUS IN THE POSTERIOR TRIANGLE OF NECK 31 31 ANTERIOR AND MIDDLE SCALENE Passage of Brachial Plexus+ Subclavian Art Passage of Subclavian Vein 32 16  11/1/2023 BLOOD VESSELS IN THE POSTERIOR TRIANGLE OF THE NECK 33 33 ARTERIES IN THE POSTERIOR TRIANGLE OF THE NECK 34 34 17  11/1/2023 VEINS IN THE POSTERIOR TRIANGLE OF THE NECK External jugular vein Subclavian vein Angle of the mandible to 3cm above middle third of the clavicle where it Crosses the base of pierces the investing fascia to join the posterior triangle 35 subclavian vein 35 POSTERIOR TRIANGLE – LYMPH NODES Superficial cervical nodes Occipital nodes Nuchal nodes Transverse cervical nodes Supraclavicular nodes 36 18  11/1/2023 Post. Triangle - Summary of Content Accessory nerve (XI) The cervical plexus - cutaneous branches Upper trunk of the brachial plexus (C5 & C6 roots) passing through the scalene space between anterior and middle Remember, the phrenic nerve travels on anterior scalene Subclavian artery (3rd part) emerging from the space between Anterior & Middle Scalene flanking brachial plexus roots Suprascapular and transverse cervical arteries (arising from Thyrocervical trunk, a branch of the the 1st part of subclavian) Subclavian vein (passing anterior to Anterior Scalene) Apex of the lung with pleural space extending up to just inferior to the subclavian vessels Occipital and supraclavicular lymph nodes 37 CLINICAL APPLICATION ▪ Torticollis ▪ Lesions of spinal accessory nerve (CN XI) – Drooping of shoulder ▪ Nerve block (Cervical plexus block) ▪ Injury to phrenic nerve ▪ Injury to cervical pleura – Pneumothorax ▪ Injury to the subclavian vessels – haemothorax ▪ Upper trunk of brachial plexus injury - Erb Duchenne Palsy 38 19  11/1/2023 39 References Gray’s Anatomy for Students Snell’s Clinical Anatomy by Regions Acknowledgement Google images http://teachmeanatomy.info/ Practice questions 40 20