BMS100 Back and Anterior Neck Muscles Review Notes PDF

BACK AND ANTERIOR NECK MUSCLES BACK MUSCLES MUSCLE ATTACHMENT/LOCATION Superficial extrinsic back muscles a. b. c. d. Intermediate extrinsic back muscles (Serratus posterior) a. Serratus posterior superior – deep to rhomboid; vertebral column to ribs Trapezius Latissimus dorsi Levator scapula...

BACK AND ANTERIOR NECK MUSCLES BACK MUSCLES MUSCLE ATTACHMENT/LOCATION Superficial extrinsic back muscles a. b. c. d. Intermediate extrinsic back muscles (Serratus posterior) a. Serratus posterior superior – deep to rhomboid; vertebral column to ribs Trapezius Latissimus dorsi Levator scapulae Rhomboids INNERVATION EXTRINSIC BACK MUSCLES Anterior rami of cervical nerves *Trapezius receives motor fibers from a cranial nerve (spinal accessory nerve CN XI) Intercostal nerves (rib cage) MAIN ACTION/ROLE • • Produce and control limb movements Connect vertebral column with upper limb (axial skeleton to superior appendicular skeleton) • • Proprioception Superficial respiratory muscles – some function in respiration but weak b. Serratus posterior inferior – deep to latissimus dorsi; vertebral column to ribs Splenius Capitis Splenius Cervicis INTRINSIC BACK MUSCLES Superficial Layer – Spinotransverse Group' Vertical on lateral aspects of Posterior rami of spinal • the neck nerves • • Ligamentum nuchae and SP C7-T6 à mastoid process and occipital bone Vertical on lateral aspects of the neck SP T3-T6 à TVP of C1-C3 Extension of neck (bilateral) Lateral flexion of neck (unilateral) Ipsilateral rotation of neck (same side) Erector Spinae (3) Groove - between SP (centrally) and angles of ribs (laterally) Each have three parts according to superior attachments – lumborum, thoracis, cervicis All arise by a broad tendon from iliac crest, sacrum, sacro-iliac ligaments, lumbar SP and supraspinous ligament Semispinalis Intermediate Layer – Sacrospinalis Group Iliocostalis – lateral Posterior rami of spinal • - Fibers run superiorly and nerves • slightly laterally • - Attach to: angle of ribs and cervical TVPs Longissimus – intermediate - Fibers run superiorly - Attach to: TVP’s in thoracic and cervical regions and mastoid process of occiput Spinalis – medial - Fibers run superiorly in laminar groove - Attach to: SP’s in thoracic and cervical regions Deep Layer – Transversospinalis Group TVP à SP of superior Posterior rami of spinal • vertebrae; attached to nerves processes, laminae and • ligaments Superficial member: a. Semispinalis capitis b. Semispinalis thoracis c. Semispinalis cervicis Chief extensors of the vertebral column Extension of trunk (bilateral; straighten) Flexion of trunk (unilateral) Extension of head, cervical spine and thoracic spine Rotation (contralateral) Multifidus TVP à SP of superior vertebrae; attached to processes, laminae and ligaments • Stabilization of vertebral column • • • Stabilization of vertebral column Proprioception of vertebral column Small rotary movements of thoracic spine Middle member – short triangular muscles; thickest in lumbar region Rotatores TVP à SP of superior vertebrae; attached to processes, laminae and ligaments Deep member – best developed in thoracic region Interspinales Minor Deep Muscles – Segmental Muscle of the Back Connect adjacent SP’s Posterior rami of spinal • Extension – hold SP’s up nerves • Rotation • Proprioception Intertransversarii Connect adjacent TVP’s Posterior and anterior rami • of spinal nerves • • Stabilization – hold TVP’s stable Lateral flexion Proprioception Levatores costarum Rib to TVPs Posterior rami of spinal nerves Respiration in elevation of ribs – rib to TVP and vice versa Lateral flexion of column – TVP closer to rib Proprioception • • • Thoracolumbar fascia: deep fascia that encloses the intrinsic muscles of the spine which extend from the pelvis to the cranium Ø Extends laterally from spinous processes and forms thin covering over thoracic region and thick covering over lumbar region Ø Helps provide anchor and protection NECK MUSCLES MUSCLE Rectus capitis posterior (2) - Major - Minor Obliquus muscles (2) - Inferior - Superior Platysma Sternocleidomastoid ATTACHMENT/LOCATION Lie deep (anterior) to the semispinalis capitis muscle INNERVATION SUBOCCIPITAL REGION Posterior ramus of C1 – the suboccipital nerve MAIN ACTION/ROLE • • Extension of atlanto-occipital joint (nod yes) Rotation of atlanto-axial joint (nod no) ANTERIOR NECK MUSCLES Superficial Anterior Neck Muscles Fascia over deltoid and CN VII – facial nerve pectoralis major muscles à mandible and skin of the lower face • • Depresses and draws lower lip inferiorly Depresses mandible at TMJ Medial 1/3 of clavicle and manubrium of sternum à mastoid process of temporal bone and lateral ½ of superior nuchal line of occipital bone Unilateral contraction: • Lateral flexion of head/neck • Contralateral rotation of head/neck Bilateral contraction: • Extension of head/upper neck • Flexion of lower neck CN XI – spinal accessory nerve Longus capitis Longus coli Rectus capitis anterior Rectus capitis lateralis Anterior scalene Middle scalene Deep Anterior Neck Muscles Base of occipital à anterior Ventral (anterior) rami of tubercles of TVPs C3-C6 cervical spinal nerves at corresponding levels Anterior tubercle of C1, bodies of C1-C3 and TVPs of C3-C6 à bodies of C5-T3 and TVPs of C3-C5 Base of cranium à anterior surface of lateral mass of atlas Jugular process of occipital bone à TVP of atlas TVP of C3-C6 à 1st rib • Elevation of sternum and clavicle (during forced inhalation – not normal) • • Flexion of cervical spine (chin to chest) Contralateral rotation (a little) • Flexion of joint • Stabilization – holds atlas against occiput • Flexes neck laterally to the same side Posterior scalene TVPs of C5-C7 à 1st rib (middle) and 2nd rib (posterior) • • Anterior/middle – elevates 1st rib during forced inspiration Posterior – elevates 2nd rib during forced inspiration