Superficial Back 24.pdf

Superficial Back Questions or Concerns? My personal goals for executing this course: Transparency: your part – ask questions, communicate Support: your part -- we are a team, assess your needs Quality: your part -- work hard, growth mindset Friday: First Lab! Room assignments for pre-lab qui...

Superficial Back Questions or Concerns? My personal goals for executing this course: Transparency: your part – ask questions, communicate Support: your part -- we are a team, assess your needs Quality: your part -- work hard, growth mindset Friday: First Lab! Room assignments for pre-lab quiz: Teams 1 & 2: Micro Lab (2nd floor) Teams 3-6: Alumni-Stukey Classroom (3rd floor) 12:45 -- Arrive at Couts Building in scrubs. Find assigned room and scan QR code for attendance. Don’t forget to bring your gloves and toolkits. 1:00 – Quiz Opens up on Canvas. You have 8 minutes to submit. Quietly leave the room when you are finished and head to your lab table. Check bulletin board for age and COD of donor body. Login on computer and pull up Dissector for LAB 1.  Lecture Outline: Skeletal Anatomy Bones and Joints Muscles and Fascia Layers Superficial Muscles Intermediate Muscles Clinical Application: Scapular dyskinesis Neurovasculature Principles and Set-Up NV Supply to Superficial Back Clinical Application: Nerve Injury Surface Anatomy Skeletal Anatomy Skeletal Anatomy Occipital bone o Superior nuchal line o External occipital protuberance Scapula o Spine o Medial border o Superior angle o Inferior angle o Acromion process Clavicle Humerus o Intertubercular sulcus Ilium o Iliac crest Skeletal Anatomy Scapula, Humerus, & Clavicle R shoulder, posterior view R shoulder, anterior view Glenohumeral Joint Glenoid fossa of scapula + Head of humerus Ball-and-socket joint Movements of the Humerus Flexion/Extension Abduction/Adduction Medial rotation/lateral rotation (Circumduction) not for this lecture Scapulothoracic “Joint” Posterior view Physiological joint Anterior surface of scapula “articulates” with ribs scapula Concave on convex Important contributor to upper limb motion Movements of the Scapula Elevation Protraction Upward Rotation Depression Retraction Downward Rotation (abduction/adduction) Upward Rotation: (above, left) Glenoid cavity of scapula tilts superiorly Muscles and Fascia Soft Tissue Layers posterior view Skin Superficial fascia Deep fascia (invests muscles) (covering these today) Superficial and Intermediate Back muscles: extrinsic Deep Back Muscles: intrinsic Thoracolumbar fascia posterior view Deep fascia of the thoracic and lumbar regions Continuous with nuchal fascia Multiple aponeurotic layers Extends laterally from SP’s Strong, thick covering Function Thoracolumbar fascia Muscles: 7 for this Lecture Superficial Layer: Trapezius Latissimus dorsi Levator scapulae Romboid major Rhomboid minor Intermediate Layer: Serratus posterior superior Serratus posterior inferior Remember these are all bilateral muscles On R side: Trapezius removed Latissimus reflected Rhomboids cut Superficial Layer of Back Muscles Axio-appendicular mm Act upon the upper limb Stabilize scapula Proximal stability is necessary for distal mobility Trapezius Latissimus dorsi Levator scapulae Romboid major Rhomboid minor Trapezius 3 Parts: Note fiber direction Upper Middle (upper) Lower Origin: Superior nuchal line, EOP, nuchal ligament, SP C7-T12 Insertion: Lateral 1/3 clavicle, (lower) acromion, spine of scapula Trapezius Main Function: postural support, stabilize + move the scapula (at STJ) 1. Upper: Elevation and upward rotation of scapula Extension of neck (bilateral activation and scapulae are fixed) 1 1 2 2. Middle: Retraction (adduction) of scapula 3 3 3. Lower: Depression and upward rotation of scapula Latissimus Dorsi Multi-direction fiber orientation Origin: SP’s T7-T12, inferior-most ribs, thoracolumbar fascia, iliac crest Insertion: Intertubercular sulcus of anterior humerus Latissimus Dorsi Main Function: move the humerus (at glenohumeral joint) Medial rotation Adduction Extension With humerus fixed; it pulls the pectoral girdle backward as a whole Levator Scapulae Deep to trapezius Prone to pathology: strain/spasm Origin: Posterior tubercle of TP’s C1-C4 Insertion: Medial border of scapula, (above scapular spine) Levator Scapulae “levator” = lifter Main Function: moves the scapula (at scapulothoracic joint) Elevation of scapula Downward rotation of scapula But with scapula fixed: lateral flexion of the cervical spine (bend neck to same side) Rhomboids: Major + Minor Origin: Nuchal ligament + SP’s C7-T5 Levator Insertion: scapulae Rhomboid Medial border of scapula; minor Spine Minor at spine Rhomboid Major inferior to spine major Rhomboids: Major + Minor Main Function: moves the scapula (at the scapulothoracic joint) Retraction of scapula (adduction) Downward rotation of scapula Intermediate Layer of Back Muscles Serratus Posterior Superior Serratus Posterior Inferior Deep to rhomboids (cut) Deep to latissimus dorsi (cut) On R side: Trapezius removed Latissimus reflected Rhomboids cut Intermediate Back Muscles Serratus Posterior Superior: Origin: nuchal lig., SP’s C7-T3 Insertion: ribs 2-4 Serratus Posterior Inferior: Origin: SP’s T11-L2 Insertion: ribs 8-12 Function: Accessory muscles of respiration (?); proprioception Spatial Relationships Trapezius Latissimus dorsi Levator scapulae Romboid major Rhomboid minor SPS SPI Clinical Application: Scapular Dyskinesis Scapular “winging” Alteration of scapular position or motion May affect shoulder function  Musculature: Check-In Muscle ID 1 2 Thoracolumbar fascia: 4 deep or superficial fascia? 3 Considering the line of pull of rhomboids, they would produce scapular: o Protraction or retraction? 5 o Upward or downward rotation? Levator scapulae and rhomboid major/minor are _________ to trapezius. Neurovasculature Overview: Nerve Supply to Superficial Back Cranial Brain nerves The trapezius is innervated by the accessory nerve (cranial nerve XI (CN XI)) o Cranial nerves interface with Spinal the brain nerves o There are 12 paired CN’s Spinal cord The remaining muscles and skin are innervated by various branches originating from spinal nerves (SN) o From the spinal cord o There are 31 pairs of SN Innervation of Trapezius Motor: via CN XI; (spinal) accessory n. Exits cranium Runs inferiorly thru sternocleidomastoid Reaches deep surface of Accessory n. trapezius (CN XI) Long and superficial Proprioception/sensory: via anterior rami C3 C4 spinal nn What do you notice here? Atrophy of R trapezius mm Depression of R scapula Abduction of R scapula (note inferior angle position) Spinal Accessory N. palsy Innervation of Extrinsic Back Muscles + Skin Branches originating from spinal nerves (SN): formed from spinal cord Contains both: o Motor (efferent) neurons: from CNS to body (muscle movement) o Sensory/afferent neurons: from body to CNS (pain) SN divides into dorsal and ventral rami D (a or ffe sa nt l ro Spinal re en ot /s so le nerve ) ts ry Dorsal Dorsal skin + deep mm of back ramus root Ventral Skin, mm, joints of limbs ramus and anterolateral trunk ot lets ral ro r) Ventral t to Ven rent/mo root fe (ef Key Concept: Spinal Nerves Ventral rami: Skin, mm, joints of limbs and anterolateral trunk Dorsal rami: Skin and deep mm of back (does NOT include the superficial back mm in this lecture) Cross-section Some of the ventral rami go on to form plexuses Some of the ventral rami (T1-T12) continue as individual intercostal nerves The ventral rami of C5-T1 form the brachial plexus Ventral ramus of spinal nerve Ventral rami of C5-T1 form the brachial plexus Individual peripheral nerves are then formed by the BP that innervate the superficial back mm Innervation of the Superficial Back Muscles Latissimus dorsi-> thoracodorsal n. (C6, 7, 8) Levator scapulae Rhomboid major dorsal scapular n. (C5) Rhomboid minor Ventral ramus  Innervation of the Superficial Back Muscles Dorsal scapular n. (C5) From BP then runs deep to: D To levator scapulae, rhomboid mj/mn Thoracodorsal n. (C6-C8) From BP Posterior view To latissimus dorsi Anterior view Clinical Application: Nerve Injury Latissimus dorsi-> thoracodorsal n. (C6, 7, 8) Levator scapulae Rhomboid major dorsal scapular n. (C5) Rhomboid minor Next Step: how is function impacted? x x Ventral ramus x Innervation of Intermediate Back Muscles Intercostal nerves: ventral rami of thoracic spinal nerves Serratus Posterior Superior o T2-T5 intercostal nerves Serratus Posterior Inferior o T9-T12 intercostal and subcostal nerves Dermatomes Area of skin supplied by a particular spinal nerve segment Cutaneous branches (touch, pain, etc.) Variation and overlap Overview: Arterial Supply to Superficial Back Superficial back muscles are supplied by branches from subclavian artery From aorta Becomes axillary artery at lateral border of 1st rib Intermediate back muscles are supplied by branches directly from aorta Posterior intercostal arteries Paired Run with intercostal nerves along ribs  Arterial Supply to Superficial Back Muscles Subclavian Trapezius: superficial branch of transverse cervical a. artery Rhomboids + levator scap.: dorsal scapular a./deep br. of transverse cervical a. Axillary artery Latissimus dorsi: thoracodorsal artery (br. of subscapular a.) Transverse cervical a. Subclavian a. Dorsal scapular artery (typically a branch of subclavian, but known as deep branch of the transverse cervical artery if it arises from the TCA ) Latissimus dorsi Posterior view, R side Key Concept: Supply to Superficial Back Muscles trapezius LS s b o id rhom accessory n. superficial br. of transverse cervical a. dorsal scapular n. dorsal scapular a. Posterior view, trapezius Posterior view, rhomboids reflected to reveal deep surface reflected to reveal deep surface Key Concept: Supply to Superficial Back Muscles latissimus dorsi Posterior view, latissimus dorsi thoracodorsal n. reflected to reveal deep surface thoracodorsal a. Arterial Supply to Intermediate Back Muscles Serratus posterior superior and inferior mm are supplied by posterior intercostal arteries (from aorta) Venous Drainage Veins: Lymph: Posterior intercostal or Vessels & associated regional veins to IVC or SVC nodes parallel veins  Neurovasculature: Check-In Which nerve innervates the trapezius muscle (motor)? Skin of the back is innervated by dorsal or ventral rami of SN? The superficial back muscles (such as rhomboids) are innervated by nerves coming from the _________ plexus? The subclavian artery changes names to the _________ a. Posterior intercostal arteries travel with __________ (bone). Neurovasculature: Summary Table Muscle(s) Innervation Arterial supply Trapezius Accessory nerve (CN XI) Superficial branch of transverse cervical artery Latissimus dorsi Thoracodorsal nerve from Thoracodorsal artery ventral rami of C6-C8 via brachial plexus Rhomboids & Dorsal scapular nerve (rom Deep branch of transverse levator scapulae ventral rami of C5 via brachial cervical artery plexus (aka dorsal scapular artery) Serratus posterior Intercostal nerves from ventral Posterior intercostal arteries superior rami of T2-T5 Serratus posterior Intercostal and subcostal Posterior intercostal arteries inferior nerves from ventral rami of T9- T12 Surface Anatomy Surface Anatomy Triangle of Auscultation: * Just medial to the inferior angle of the scapula at the 6th intercostal space Borders: Trapezius (medially) Latissimus dorsi (inferiorly) Surface Anatomy Palpable features: Reference lines: I: Posterior median line II: Paravertebral line III: Scapular line Thank you! J