Axial Muscles PDF

Axial Muscles  Introduction Both attachments on parts of axial skeleton (or under skin) Functions of axial muscles include: Support and move the head and spinal column Used in facial expression and chewing...

Axial Muscles  Introduction Both attachments on parts of axial skeleton (or under skin) Functions of axial muscles include: Support and move the head and spinal column Used in facial expression and chewing Aid in breathing Support and protect organs Unilateral vs Bilateral action © McGraw Hill, LLC 2  Learning target: Identify and describe major muscles involved in facial expression Head and Neck oFacial Expression o Attach subcutaneous layer or skull bones o Move skin around face Muscles of Facial Expression Region/Muscle Action(s) Bony Attachment(s) (pp. 317-324) (B)/Soft Tissue Attachment(s) (S)1 MOUTH Depressor anguli Draws corners of B: Body of mandible oris mouth inferiorly and S: Skin at inferior (dĕ-pres’ǒr ang’gyū-lī laterally (“frown” corner (angle) of ōr’ǔs) muscle) mouth depressor = depresses angul = angel or = mouth Depressor labii Draws lower lip B: Body of mandible inferioris (lā’bē-ī in- inferiorly (“grimace” lateral to midline fēr’ē-ōr-is) muscle) S: Skin at inferior lip labi = lip infer = below Levator anguli oris Draws corners of B: Lateral maxilla (le-vā’tōr, le-vā’tǒr) mouth superiorly and S: Skin at superior leva = raise laterally (“smile” corner of mouth muscle) Levator labii Opens lips; raises and B: Zygomatic bone; superioris furrows the upper lip maxilla (sū-pēr’ē-ōr-is) (“Elvis” lip snarl) S: Skin and muscle of superior lip Mentalis (men-tā’lis) Protrudes lower lip B: Central mandible ment = chin (“pout”); S: Skin of chin wrinkles chin Table 11.1 Risorius (rē-sōr’ē-ǔs) Retracts corners of B: Deep fascia Muscles of Facial Expression Region/Muscle Action(s) Bony Attachment(s) (B)/Soft Tissue Attachment(s) (S)1 Buccinator Compresses B: Alveolar (buk’si-nā’tēr) cheek; holds food processes of bucco = cheek between teeth mandible and during chewing maxillae (“trumpet- S: Orbicularis oris blowing” muscle) Orbicularis oris Compresses and B: Maxilla and (ōr-bik’yū-lā’ris purses lips (“kiss” mandible; ōr’is) muscle) blend with orb = circular fibers from or = mouth other facial muscles S: Encircling mouth; skin and muscles at angles to mouth Zygomaticus Elevates corner B: Zygomatic major (zī-gō- of the mouth bone mat’i-kǔs) (“smile” muscle) S: Skin at zygomatic- = superolateral cheekbone edge of mouth major = greater Zygomaticus Elevates corner B: Zygomatic minor Table 11.1 of the mouth bone  Learning target: Identify muscles of mastication and explain how each affects movement of mandible Head and Neck oFacial Expression o Attach subcutaneous layer or skull bones o Move skin around face oMastication (chewing) o Move mandible at temporomandibular joint (TMJ)  Muscle Action(s) Superior Muscles of Mastication Attachment(s) (S)/ Inferior (pp. 3226-327) Attachments(s) Temporalis Elevates and S: Superior and (tem’pǒ-rā’lis) retracts mandible inferior tempora = temporal lines pertaining to I: Coronoid temporal bone process of mandible Masseter (mas’ĕ- Elevates and S: Zygomatic arch tĕr) protracts I: Ramus (lateral maseter = chewer mandible; prime surface) and angle mover of jaws of mandible closure Medial Elevates and S: Maxilla, pterygoid protracts palatine, and (ter’i-goyd) mandible; medial surface produces side-to- of lateral side movement of pterygoid plate mandible I: Medial surface of mandibular ramus Lateral Protracts S: Greater wing of pterygoid mandible; sphenoid and pterygoid = produces side-to- lateral surface winglike side movement of of lateral mandible pterygoid plate I: Condylar process of mandible Table 11.3  Learning target: Identify and describe the muscles involved in major movements of head and neck Head and Neck oFacial Expression o Attach subcutaneous layer or skull bones o Move skin around face oMastication (chewing) o Move mandible at temporomandibular joint (TMJ) oMove H&N o Anterolateral neck muscles: flexion o Posterior neck muscles: extension o From vertebrae, ribs, pec girdle to cranial bones Muscles that Move the Head and Neck (pp. 331-334) Muscle Action(s) Superior Attachment(s) (S)/ Inferior Attachment(s) Sternocleidom Unilateral S: Mastoid astoid (ster’nō- action1: Lateral process of klī’dō-mas’toyd) flexion, rotation temporal bone sterno = sternum of head to I: Manubrium cleido = clavicle opposite side and sternal masto = mastoid Bilateral action2: end of clavicle process Flexes neck Scalene Flex neck (when S: Transverse muscles 1st rib is fixed); processes of (anterior, middle, elevate 1st and cervical posterior) (see 2nd ribs during vertebrae also table 11.9) forced inhalation I: Superior (skā’lēnz) when neck is surface of 1st scalene = fixed and 2nd ribs uneven Table 11.7 Muscle Action(s) Superior Attachment(s) (S)/ Inferior Attachment(s) Muscles that Move the Head Splenius capitis and cervicis Unilateral action: Turns head to same S: Occipital bone and mastoid and Neck(pp. 331-334) (splē’nē-ǔs ka’pī-tis) side process of (ser’vī’sis) Bilateral action: temporal bone splenion = bandage Extends head/neck I: Ligamentum nuchae Longissimus Unilateral action: S: Mastoid process capitis (lon-gis’i- Turns (rotates) head of temporal bone mǔs) toward same side I: Transverse longissimus = Bilateral action: process of and longest Extends head/neck articular caput = head processes of vertebrae Obliquus capitis Turns head to same S: Occipital bone superior (ob- side I: Transverse lī’kwǔs) process of atlas obliquus = slanting Obliquus capitis Turns head to same S: Transverse inferior side process of atlas I: Spinous process of axis Rectus capitis Extends head/neck S: Occipital bone posterior major I: Spinous process of axis Rectus capitis Extends head/neck S: Occipital bone posterior minor I: Posterior tubercle of atlas Table 11.7  Learning target: Identify and describe muscles involved in movements of vertebral column Vertebral Column (pp. 334-335) oVertebral Column o Erector spinae – posture; ext./lat. flex vert. o Transversospinalis – stability o Quadratus lumborum – ext./lat. flex lumbar vert. Muscles of Respiration (pp. 335-339) oInhale – incr. thoracic cavity space oExhale – decr. thoracic cavity space oDiaphragm o Most important o Divides thoracic cavity from abdomen o Relaxed – dome shaped o Contracted – flattened Muscles of Respiration Muscle Action(s) Superior Attachment(s) (S)/ Inferior Attachment(s) Serratus Elevates ribs S: Spinous posterior during forced processes of superior (sĕr- inhalation vertebrae ā’tǔs) I: Lateral serratus = a borders of ribs 2- saw 5 Serratus Depresses S: Inferior posterior ribs during borders of ribs 8- inferior forced 12 exhalation I: Spinous processes of vertebrae Table 11.9; Figure 11.13 ©McGraw-Hill Education/Photo and Dissection by Christine Eckel Muscles of Respiration Muscle Action(s) Superior Attachment(s) (S)/ Inferior Attachment(s) External Elevates ribs during S: Superior border of intercostals inhalation inferior rib (in’tĕr-kos’tălz) I: Inferior border of inter = between superior rib cost = rib Internal Depresses ribs during S: Superior border of intercostals forced exhalation; inferior rib (in’ter-kos’talz) antagonistic to external I: Inferior border of intercostals superior rib Table 11.9; Figure 11.13 ©McGraw-Hill Education/Photo and Dissection by Christine Eckel  Learning target: Identify and describe organization and actions of abdominal wall muscles Muscles of Abdominal Wall (pp. 339-341) oHold organs in place oFlex/Lat. Flex/stabilize vert. Muscles of Abdominal Wall Muscle Action(s) Superior Attachment(s) (S)/ Inferior Attachment(s) (I) External oblique Unilateral action: Lateral S: External and inferior flexion of vertebral borders of the inferior column; rotation of 8 ribs vertebral column I: Linea alba by a broad Bilateral action: Flexes aponeurosis; some to vertebral column and iliac crest compresses abdominal wall; used in forced exhalation Internal oblique Unilateral action: Lateral S: Lumbar fascia, flexion of vertebral inguinal ligament, and column; rotation of iliac crest vertebral column I: Linea alba, public Bilateral action: Flexes crest, inferior rib vertebral column and surfaces (last 4 ribs); compresses abdominal costal cartilages of wall ribs 8-10 Transversus abdominis Unilateral action: Lateral S: Iliac crest, cartilages (ab-dom’i-nis) flexion of vertebral of inferior 6 ribs; column lumbar fascia; inguinal Bilateral action: ligament Compresses abdominal I: Linea alba and pubic wall crest Rectus abdominis Flexes vertebral column; S: Xiphoid process of compresses abdominal sternum; inferior wall surfaces of ribs 5-7 Table 11.10 I: Superior surface of  Muscle Actions on the Axial Skeleton Extend the Head, Flex the Head, Laterally Flex Rotate Head and/or Elevate the Ribs Depress the Neck, and/or Neck, and/or the Vertebral Neck to One Side Ribs Vertebral Column Vertebral Column Column Splenius Sternocleidomastoid Quadratus Sternocleidomastoid Serratus Serratus muscles2 2 lumborum1 1 posterior posterior superior inferior Erector spinae2 Scalenes2 External Splenius muscles1 External Internal (iliocostalis, oblique1 intercostals intercostals longissimus, spinalis) Quadratus External oblique2 Internal Longissimus capitis1 Scalene muscles Transversus lumborum2 oblique1 (ribs 1 and 2 thoracis only) Transversospinali Internal oblique2 Transversus Obliquus capitis s group2 abdominis1 inferior1 Minor deep back Transversus Obliquus capitis muscles2 abdominis2 superior1 Rectus capitis Rectus abdominis2 posterior major and minor2 1. Unilateral action 2. Bilateral action Table 11.11