(BQ) Part 1 book Essential clinical anatomy presents the following contents: Introduction to clinical anatomy, thorax (surface anatomy of thoracic wall, surface anatomy of heart, surface anatomy of pleurae and lungs), abdomen, pelvis and perineum, back.
Fifth Edition Moore_FM.indd i 1/15/14 2:45 AM Moore_FM.indd ii 1/15/14 2:45 AM Fifth Edition Keith L Moore, MSc, PhD, DSc, FIAC, FRSM, FAAA Professor Emeritus, Division of Anatomy, Department of Surgery Former Chair of Anatomy and Associate Dean for Basic Medical Sciences Faculty of Medicine University of Toronto Toronto, Ontario, Canada Anne M.R Agur, BSc(OT), MSc, PhD Professor, Division of Anatomy, Department of Surgery, Faculty of Medicine Division of Physiatry, Department of Medicine Department of Physical Therapy Department of Occupational Science & Occupational Therapy Division of Biomedical Communications, Institute of Medical Science Graduate Department of Rehabilitation Science Graduate Department of Dentistry University of Toronto Toronto, Ontario, Canada Arthur F Dalley II, PhD Professor, Department of Cell and Developmental Biology Adjunct Professor, Department of Orthopaedic Surgery and Rehabilitation Vanderbilt University School of Medicine Adjunct Professor for Anatomy Belmont University School of Physical Therapy Nashville, Tennessee, U.S.A Moore_FM.indd iii 1/15/14 2:45 AM Not authorised for sale in United States, Canada, Australia, New Zealand, Puerto Rico, and U.S Virgin Islands Acquisitions Editor: Crystal Taylor Product Manager: Julie Montalbano/Lauren Pecarich Marketing Manager: Joy Fisher Williams Art Director: Jennifer Clements Artist: Imagineeringart.com, lead artist Natalie Intven, MSc, BMC Compositor: Absolute Service, Inc 5th Edition Copyright © 2015, 2011, 2007, 2002, 1995 Lippincott Williams & Wilkins, a Wolters Kluwer business 351 West Camden Street Baltimore, MD 21201 Two Commerce Square 2001 Market Street Philadelphia, PA 19106 Printed in China All rights reserved This book is protected by copyright No part of this book may be reproduced or transmitted in any form or by any means, including as photocopies or scanned-in or other electronic copies, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews Materials appearing in this book prepared by individuals as part of their official duties as U.S government employees are not covered by the above-mentioned copyright To request permission, please contact Lippincott Williams & Wilkins at Two Commerce Square, 2001 Market Street, Philadelphia, PA 19106, via email at permissions@lww.com, or via website at lww.com (products and services) Library of Congress Cataloging-in-Publication Data Moore, Keith L., author Essential clinical anatomy / Keith L Moore, Anne M.R Agur, Arthur F Dalley II — Fifth edition p ; cm Parent text: Clinically oriented anatomy / Keith L Moore, Arthur F Dalley, Anne M.R Agur 7th ed c2014 Includes bibliographical references and index ISBN 978-1-4511-8749-6 (paperback) I Agur, A M R., author II Dalley, Arthur F., II, author III Moore, Keith L Clinically oriented anatomy Digest of (work): IV Title [DNLM: Anatomy—Handbooks QS 39] QM23.2 611—dc23 2013049982 DISCLAIMER Care has been taken to confirm the accuracy of the information present and to describe generally accepted practices However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of the publication Application of this information in a particular situation remains the professional responsibility of the practitioner; the clinical treatments described and recommended may not be considered absolute and universal recommendations The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accordance with the current recommendations and practice at the time of publication However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions This is particularly important when the recommended agent is a new or infrequently employed drug Some drugs and medical devices presented in this publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings It is the responsibility of the health care provider to ascertain the FDA status of each drug or device planned for use in their clinical practice To purchase additional copies of this book, call our customer service department at (800) 638-3030 or fax orders to (301) 223-2320 International customers should call (301) 223-2300 Visit Lippincott Williams & Wilkins on the Internet: http://www.lww.com Lippincott Williams & Wilkins customer service representatives are available from 8:30 am to 6:00 pm, EST Moore_Intl-CPY.indd iv 1/10/14 4:59 AM In Loving Memory of Marion My best friend, wife, colleague, mother of our five children, and grandmother of our nine grandchildren for her love, unconditional support, and understanding Wonderful memories keep you in our hearts and minds —Keith L Moore To my husband, Enno, and my children, Erik and Kristina, for their support and encouragement —Anne M.R Agur To Muriel, my bride, best friend, counselor, and mother of our sons; and to our family—Tristan, Lana, Elijah, Finley, and Sawyer; Denver and Skyler—with love and great appreciation for their support, understanding, good humor, and—most of all—patience —Arthur F Dalley And with sincere appreciation for the anatomical donors without whom our studies would not be possible Moore_FM.indd v 1/15/14 2:45 AM KEITH L MOORE, MSc, PhD, DSc, FIAC, FRSM, FAAA Moore_FM.indd vi ANNE M.R AGUR, ARTHUR F DALLEY II, BSc (OT), MSc, PhD PhD 1/15/14 2:45 AM PREFACE Nineteen years have passed since the first edition of Essential Clinical Anatomy was published The main aim of the fifth edition is to provide a compact yet thorough textbook of clinical anatomy for students and practitioners in the health care professions and related disciplines We have made the book even more student friendly The presentations • Provide a basic text of human clinical anatomy for use in current health sciences curricula • Present an appropriate amount of clinically relevant anatomical material in a readable and interesting form • Place emphasis on clinical anatomy that is important for practice • Provide a concise clinically oriented anatomical overview for clinical courses in subsequent years • Serve as a rapid review when preparing for examinations, particularly those prepared by the National Board of Medical Examiners • Offer enough information for those wishing to refresh their knowledge of clinical anatomy This edition has been thoroughly revised, keeping in mind the many invaluable comments received from students, colleagues, and reviewers The key features include • An extensively revised art program, giving the book an entirely new streamlined and fresh appearance All of the illustrations are now in full color and designed to highlight important facts and show their relationship to clinical medicine and surgery Each illustration has been reworked, whether for the seventh edition of Clinically Oriented Anatomy (COA7) or specifically for this book, to create a uniform and user-friendly product A great effort has been made to further improve clarity of labeling and to place illustrations on the pages being viewed as the illustrations are cited in the text • Revised text with a stronger clinical orientation • More illustrated clinical correlations, known as “blue boxes,” have been included to help with the understanding of the practical value of anatomy In response to our readers’ suggestions, the blue boxes have been grouped They are also classified by the following icons to indicate the type of clinical information covered: Anatomical variations icon These blue boxes feature anatomical variations that may be encountered in the dissection lab or in practice, emphasizing the clinical importance of awareness of such variations Life cycle icon These blue boxes emphasize prenatal developmental factors that affect postnatal anatomy and anatomical phenomena specifically associated with stages of life—childhood, adolescence, adult, and advanced age Trauma icon The effect of traumatic events— such as fractures of bones or dislocations of joints— on normal anatomy and the clinical manifestations and dysfunction resulting from such injuries are featured in these blue boxes Diagnostic procedures icon Anatomical features and observations that play a role in physical diagnosis are targeted in these blue boxes Surgical procedures icon These blue boxes address such topics as the anatomical basis of surgical procedures, such as the planning of incisions and the anatomical basis of regional anesthesia Pathology icon The effect of disease on normal anatomy, such as cancer of the breast, and anatomical structures or principles involved in the confinement or dissemination of disease within the body are the types of topics covered in these blue boxes • Surface anatomy is integrated into the chapter at the time each region is being discussed to demonstrate the relationship between anatomy and physical examination, diagnosis, and clinical procedures • Medical images (radiographic, CT, MRI, and ultrasonography studies) have been included, often with correlative illustrations Current diagnostic imaging techniques demonstrate anatomy as it is often viewed clinically • Case studies accompanied by clinico-anatomical problems and USMLE-style multiple-choice questions Interactive case studies and multiple-choice questions are available to our readers online at http://thePoint.lww.com/ECA5e, providing a convenient and comprehensive means of selftesting and review • Instructor’s resources and supplemental materials, including images exportable for PowerPoint presentation, are available through http://thePoint.lww.com/ ECA5e The terminology adheres to the Terminologica Anatomica (1998) approved by the International Federation of Associations of Anatomists (IFAA) The official Englishequivalent terms are used throughout the present edition vii Moore_FM.indd vii 1/15/14 2:45 AM viii PREFACE When new terms are introduced, however, the Latin forms as used in Europe, Asia, and other parts of the world appear in parentheses The roots and derivation of terms are included to help students understand the meaning of the terminology Eponyms, although not endorsed by the IFAA, appear in parentheses to assist students during their clinical studies The parent of this book, Clinically Oriented Anatomy (COA), is recommended as a resource for more detailed descriptions of human anatomy and its relationship and importance to medicine and surgery Essential Clinical Anatomy, in addition to its own unique illustrations and manuscript, has utilized from the outset materials from Clinically Oriented Anatomy and Grant’s Atlas Moore_FM.indd viii We again welcome your comments and suggestions for improvements in future editions Keith L Moore University of Toronto Faculty of Medicine Anne M.R Agur University of Toronto Faculty of Medicine Arthur F Dalley II Vanderbilt University School of Medicine 1/15/14 2:45 AM ACKNOWLEDGMENTS We wish to thank the following colleagues who were invited by the publisher to assist with the development of this fifth edition Volodymyr Mavrych, MD, PhD, DSc Professor St Matthew’s University Cayman Islands List of Reviewers Kacie Bhushan Nova Southeastern University Fort Lauderdale, Florida Leonard J Cleary, PhD Professor The University of Texas Health Science Center Medical School Houston, Texas Alan Crandall, MS Idaho State University Pocatello, Idaho Bertha Escobar-Poni, MD Loma Linda University Loma Linda, California Thomas Gillingwater, PhD Professor of Neuroanatomy University of Edinburgh Edinburgh, United Kingdom William Huber, PhD Professor St Louis Community College at Forest Park St Louis, Missouri Lorraine Jadeski, PhD Associate Professor University of Guelph Ontario, Canada Marta Lopez, LM, CPM, RMA Program Coordinator/Professor Medical Assisting Program Miami Dade College Miami, Florida Yogesh Malam University College London London, United Kingdom Karen McLaren Monica Oblinger, MS, PhD Professor Rosalind Franklin University of Medicine and Science North Chicago, Illinois Onyekwere Onwumere, MA, MPhil Adjunct Faculty The College of New Rochelle New Rochelle, New York Simon Parson, BSc, PhD Professor University of Edinburgh Edinburgh, United Kingdom Gaurav Patel Windsor University School of Medicine Cayon, Saint Kitts Ryan Splittgerber, PhD Assistant Professor University of Nebraska Medical Center Omaha, Nebraska Christy Tomkins-Lane, PhD Assistant Professor Mount Royal University Calgary, Alberta, Canada Victor Emmanuel Usen Medical University of Lublin Lublin, Poland Edward Wolfe, DC Instructor Central Piedmont Community College Charlotte, North Carolina Andrzej Zeglen Lincoln Memorial University-DeBusk College of Osteopathic Medicine Harrogate, Tennessee ix Moore_FM.indd ix 1/15/14 2:45 AM 294 CHAPTER • BACK Clinical Box Lumbar Spinal Puncture To obtain a sample of CSF from the lumbar cistern, a lumbar puncture needle, fitted with a stylet, is inserted into the subarachnoid space Lumbar spinal puncture (spinal tap) is performed with the patient leaning forward or lying on the side with the back flexed Flexion of the vertebral column facilitates insertion of the needle by spreading the laminae and spinous processes apart, stretching the ligament flava (Fig B4.8) Under aseptic conditions, the needle is inserted in the midline between the spinous processes of the L3 and L4 (or the L4 and L5) vertebrae At these levels in adults, there is reduced danger of damaging the spinal cord Subarachnoid space Ligamentum flavum Skin Supraspinous ligament Conus medullaris Epidural Anesthesia (Blocks) Interspinous ligament An anesthetic agent can be injected into the extradural (epidural) space using the position described for lumbar spinal puncture The anesthetic has a direct effect on the spinal nerve roots of the cauda equina after they exit from the dural sac (Fig B4.8) The patient loses sensation inferior to the level of the block An anesthetic agent can also be injected into the extradural space in the sacral canal through the sacral hiatus (caudal epidural anesthesia) or through the posterior sacral foramina (trans-sacral epidural anesthesia) (Fig B4.9) The distance the agent ascends (and hence the number of nerves affected) depends on the amount injected and on the position assumed by the patient Epidural space CSF in lumbar cistern Lumbar spinal puncture for spinal anesthesia Filum terminale internum L2 Spinous process of L4 Lumbar injection for epidural anesthesia S2 Spinal dural sac Sacrum Epidural space in sacral canal Filum terminale externum Sacral hiatus FIGURE B4.8 Lumbar spinal puncture and epidural anesthesia Lumbar cistern of subarachnoid space Epidural space Pia mater (transparent, covering nerve roots of cauda equina) Arachnoid mater (purple) Dura mater (gray) of dural sac Cauda equina in CSF S1 vertebral level S1 spinal nerve S2 vertebral level Sacral foramina Trans-sacral (epidural) anesthesia S5 spinal nerve Sacral cornua Filum terminale internum Dural sac Subarachnoid space Dura mater Filum terminale externum Epidural space Sacral canal Filum terminale externum (A) Posterior view Caudal (epidural) anesthesia (B) Median section FIGURE B4.9 Trans-sacral and caudal anesthesia Moore_Ch04.indd 294 1/10/14 4:22 AM CHAPTER • BACK MUSCLES OF BACK Most body weight is anterior to the vertebral column, especially in obese people For this reason, the many strong muscles attached to the spinous and transverse processes of vertebrae are necessary to support and move the vertebral column There are two major groups of muscles in the back The extrinsic back muscles include superficial and intermediate muscles that produce and control limb and respiratory movements, respectively The intrinsic back muscles include muscles that specifically act on the vertebral column, producing its movements and maintaining posture Extrinsic Back Muscles The superficial extrinsic back muscles (trapezius, latissimus dorsi, levator scapulae, and rhomboids) connect the upper limbs to the trunk (see Chapter 6).These muscles, although located in the back region, for the most part, receive their nerve supply from the anterior rami of cervical nerves and act on the upper limb The trapezius receives its motor fibers from a cranial nerve, the spinal accessory nerve (CN XI) The intermediate extrinsic back muscles (serratus posterior superior and inferior) are thin muscles and are commonly designated superficial respiratory muscles but are more likely proprioceptive rather than motor in function They are described with muscles of the thoracic wall (see Chapter 1) 295 of the vertebral column These muscles, extending from the pelvis to the cranium, are enclosed by deep fascia that attaches medially to the nuchal ligament, the tips of the spinous processes of the vertebrae, the supraspinous ligament, and the median crest of the sacrum The fascia attaches laterally to the cervical and lumbar transverse processes and to the angles of the ribs The thoracic and lumbar parts of the deep fascia constitute the thoracolumbar fascia (Fig 4.21) The deep back muscles are grouped into superficial, intermediate, and deep layers according to their relationship to the surface (Table 4.6) SUPERFICIAL LAYER OF INTRINSIC BACK MUSCLES The splenius muscles (L musculi splenii) are thick and flat and lie on the lateral and posterior aspects of the neck, covering the vertical muscles somewhat like a bandage, which explains their name (L splenion, bandage) The splenii arise from the midline and extend superolaterally to the cervical vertebrae (splenius cervicis) and cranium (splenius capitis) These muscles cover the deep neck muscles (Fig 4.22B; Table 4.6) INTERMEDIATE LAYER OF INTRINSIC BACK MUSCLES Intrinsic Back Muscles The erector spinae muscles (sacrospinalis) lie in a “groove” on each side of the vertebral column between the spinous processes and the angles of the ribs (Fig 4.22) The massive erector spinae, the chief extensor of the vertebral column, divides into three muscle columns: The intrinsic back muscles (muscles of back proper, deep back muscles) are innervated by the posterior rami of spinal nerves and act to maintain posture and control movements • Iliocostalis: lateral column • Longissimus: intermediate column • Spinalis: medial column Psoas major muscle Quadratus lumborum Thoracolumbar fascia: Anterior layer Middle layer Posterior layer Origin of (2) & (3) from lateral part of thoracolumbar fascia Layers of anterolateral abdominal wall muscle: (1) External oblique (2) Internal oblique (3) Transversus abdominis Free posterior border of external oblique (1) Latissimus dorsi Deep muscles of back Inferior view of transverse section of posterolateral abdominal wall FIGURE 4.21 Transverse section of the intrinsic back muscles and layers of thoracolumbar fascia Moore_Ch04.indd 295 1/10/14 4:22 AM 296 CHAPTER • BACK TABLE 4.6 SUPERFICIAL AND INTERMEDIATE LAYERS OF INTRINSIC BACK MUSCLES Muscle Origin Insertion Nerve Supply Main Action(s) Splenius capitis: fibers run superolaterally to mastoid process of temporal bone and lateral third of superior nuchal line of occipital bone Splenius cervicis: tubercles of transverse processes of C1–C3 or C4 vertebrae Posterior rami of spinal nerves Acting alone: laterally flex neck and rotate head to side of active muscles Acting together: extend head and neck Posterior rami of spinal nerves Acting bilaterally: extend vertebral column and head; as back is flexed, control movement by gradually lengthening their fibers Acting unilaterally: laterally flex vertebral column Superficial layer of intrinsic back muscles Splenius Arises from nuchal ligament and spinous processes of C7–T6 vertebrae Intermediate layer of intrinsic back muscles (erector spinae) Iliocostalis Longissimus Spinalis Arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes, and supraspinous ligament Iliocostalis (lumborum, thoracis, and cervicis): fibers run superiorly to angles of lower ribs and cervical transverse processes Longissimus (thoracis, cervicis, and capitis): fibers run superiorly to ribs between tubercles and angles to transverse processes in thoracic and cervical regions and to mastoid process of temporal bone Spinalis (thoracis, cervicis, and capitis): fibers run superiorly to spinous processes in upper thoracic region and to cranium Each column is divided regionally into three parts according to its superior attachments (e.g., iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis) The common origin of the three erector spinae columns is through a broad tendon that attaches inferiorly to the posterior part of the iliac crest, the posterior aspect of the sacrum, the sacro-iliac ligaments, and the sacral and inferior lumbar spinous processes (Fig 4.22) Although the muscle columns are generally identified as isolated muscles, each column is actually composed of many overlapping shorter fibers—a design that provides stability, localized action, and segmental vascular and neural supply The attachments, nerve supply, and actions of the erector spinae are described in Table 4.6 Surface Anatomy Back Muscles In the midline of the erect back, there is a posterior median furrow that overlies the tips of the spinous processes of the vertebrae (Fig SA4.3) The furrow is continuous superiorly with the nuchal groove in the neck and ends in the flattened triangular area covering the sacrum superior to the intergluteal cleft The erector spinae muscles produce prominent vertical bulges on each side of the furrow When the upper limbs are elevated, the scapulae move laterally on the thoracic wall, making the rhomboid and teres major muscles visible The superficially located trapezius (D, descending [superior] part; T, transverse [middle] part; A, ascending [inferior] part) and latissimus dorsi muscles connecting the upper limbs to the vertebral column are also clearly visible in lean individuals or when the muscles are well developed Note the dimples indicating the site of the posterior superior iliac spines Nuchal groove (site of nuchal ligament) D Vertebra prominens (spinous process of C7) Medial border of scapulae T Rhomboid A Posterior median furrow Latissimus dorsi Erector spinae Dimples indicating posterior superior iliac spines Posterior site of sacrum Intergluteal cleft Posterior view FIGURE SA4.3 Moore_Ch04.indd 296 1/10/14 4:22 AM 297 CHAPTER • BACK Transverse process of C4 Angle of 2nd rib Semispinalis capitis Sternocleidomastoid Sternocleidomastoid Splenius capitis Levator scapulae Levator scapulae Iliocostalis cervicis Splenius cervicis Iliocostalis cervicis Iliocostalis thoracis Spinalis thoracis Longissimus thoracis Iliocostalis lumborum Longissimus Superficial layer of intrinsic back muscles—erector spinae Iliocostalis thoracis Iliocostalis Iliac crest Iliocostalis Posterior rami Posterior superior iliac spine 10th rib Iliocostalis lumborum Aponeurosis of transversus abdominis (B) Mastoid process Gluteus medius Longissimus capitis Gluteus maximus (A) Nuchal ligament Angle of rib Mastoid process Longissimus thoracis Spinalis cervicis Nuchal ligament Splenius capitis Longissimus Spinous process (T1) Splenius cervicis Spinalis thoracis Spinous process (T4) Spinalis Spinous process (T6) (C) (D) Spinous process (L2) (E) FIGURE 4.22 Superficial and intermediate layers of intrinsic back muscles A Overview B Iliocostalis C Splenius capitis and splenius cervicis D Spinalis E Longissimus Moore_Ch04.indd 297 1/10/14 4:22 AM 298 CHAPTER • BACK DEEP LAYER OF INTRINSIC BACK MUSCLES Deep to the erector spinae muscles is an obliquely disposed group of muscles—the transversospinales muscle group, which is composed of the semispinalis, multifidus, and rotatores These muscles originate from transverse processes of vertebrae and pass to spinous processes of more superior vertebrae They occupy the “gutter” between the transverse and spinous processes (Fig 4.23; Table 4.7) • The semispinalis is superficial, spanning four to six segments • The multifidus is deeper, spanning two to four segments • The rotatores are deepest, spanning one to two segments The semispinalis, as its name indicates, arises from approximately half of the vertebral column It is divided into three parts according to the vertebral level of its superior attachments: semispinalis capitis, semispinalis cervicis, and semispinalis thoracis The semispinalis capitis is responsible for the longitudinal bulge on each side in the back of the neck near the median plane It ascends from the cervical and thoracic transverse processes to the occipital bone The semispinalis thoracis and cervicis pass superomedially from the transverse processes to the thoracic and cervical spinous processes of more superior vertebrae The multifidus consists of short, triangular muscular bundles that are thickest in the lumbar region Each bundle passes obliquely, superiorly, and medially and attaches along the whole length of the spinous process of the adjacent superior vertebra The rotatores—best developed in the thoracic region—are the deepest of the three layers of transversospinales muscles They arise from the transverse process of one vertebra and insert into the root of the spinous processes of the next one or two vertebrae superiorly The interspinales, intertransversarii, and levatores costarum are the smallest of the deep back muscles The interspinales and intertransversarii muscles connect spinous and transverse processes, respectively TABLE 4.7 DEEP LAYERS OF INTRINSIC BACK MUSCLES Muscle Origin Insertion Nerve Supply Main Action(s) Posterior rami of spinal nerves Extends head and thoracic and cervical regions of vertebral column and rotates them contralaterally Deep layer of intrinsic back muscles (transversospinales) Semispinalis (thoracis, cervicis, and capitis) Arises from transverse processes of C4–T10 vertebrae Fibers run superomedially to occipital bone and spinous processes in upper thoracic and cervical regions, spanning four to six segments Multifidus Arises from posterior sacrum, posterior superior iliac spine of ilium, aponeurosis of erector spinae, sacro-iliac ligaments, mammillary processes of lumbar vertebrae, transverse processes of thoracic vertebrae, and articular processes of C4–C7 Thickest in lumbar region, fibers pass obliquely superomedially to entire length of spinous processes of vertebrae located two to four segments superior to origin Unilateral contraction rotates to contralateral side; stabilizes vertebrae during local movements of vertebral column Rotatores (brevis and longus) Arise from transverse processes of vertebrae; are best developed in thoracic region Fibers pass superomedially to attach to junction of lamina and transverse process or spinous process of vertebra immediately (brevis) or two segments (longus) superior to vertebra of origin May function as organs of proprioception; possibly stabilize vertebrae and assist with local extension and rotatory movements of vertebral column Minor deep layer of intrinsic back muscles a Interspinales Superior surfaces of spinous processes of cervical and lumbar vertebrae Inferior surfaces of spinous processes of vertebrae superior to vertebrae of origin Posterior rami of spinal nerves Aid in extension and rotation of vertebral column Intertransversarii Transverse processes of cervical and lumbar vertebrae Transverse processes of adjacent vertebrae Posterior and anterior rami of spinal nervesa Aid in lateral flexion of vertebral column; acting bilaterally, stabilize vertebral column Levatores costarum Tips of transverse processes of C7 and T1–T11 vertebrae Pass inferolaterally and insert on rib between its tubercle and angle Posterior rami of C8–T11 spinal nerves Elevate ribs, assisting respiration; assist with lateral flexion of vertebral column Most back muscles are innervated by posterior rami of the spinal nerves, but a few are innervated by anterior rami Moore_Ch04.indd 298 1/10/14 4:22 AM CHAPTER • BACK Superior nuchal line External occipital protuberance Mastoid process Obliquus capitis superior Rotatores Semispinalis Spinalis Longissimus Obliquus capitis inferior Semispinalis thoracis Transversospinalis Multifidus Rectus capitis posterior major Semispinalis capitis 299 Erector spinae Iliocostalis Rotatores Serratus posterior Levatores costarum Latissimus dorsi Thoracic spinous process Trapezius (B) Transverse section Back muscles Lumbar intertransversarii Multifidus Superficial extrinsic Intermediate extrinsic Erector spinae (intermediate intrinsic) Transversospinales (deep intrinsic) Cervical interspinales Multifidus Cervical intertransversarii (A) Posterior view Semispinalis capitis Rotatores Spinalis cervicis Levatores costorum Lumbar interspinales Lumbar intertransversarii Spinalis thoracis (C) Multifidus (D) (E) Posterior views FIGURE 4.23 Deep layer of intrinsic back muscles A Overview B Transverse section The erector spinae consists of three columns and the transversospinales consists of three layers: semispinalis (C), multifidus (D), and rotatores (A) E Interspinales, intertransversarii, and levatores costarum Moore_Ch04.indd 299 1/10/14 4:22 AM 300 CHAPTER • BACK Occipital region Suboccipital region (deep) Suboccipital triangles Posterior cervical region Occipital bone Trapezius Semispinalis capitis Rectus capitis posterior minor Suboccipital nerve (C1) Inferior nuchal line Sternocleidomastoid Rectus capitis posterior major Obliquus capitis superior Posterior atlanto-occipital membrane Longissimus capitis Posterior arch (C1) Suboccipital nerve (C1) Transverse process (C1) Obliquus capitis inferior Spinal ganglion (C2) Transverse process (C2) Greater occipital nerve (C2) Semispinalis capitis Vertebral artery Splenius Semispinalis cervicis Trapezius Interspinales FIGURE 4.24 Suboccipital muscles and suboccipital triangle Suboccipital and Deep Neck Muscles The suboccipital region—superior part of the back of the neck—is the triangular area (suboccipital triangle) inferior to the occipital region of the head, including the posterior aspects of the C1 and C2 vertebrae The suboccipital triangle lies deep to the trapezius and semispinalis capitis muscles (Fig 4.24) The four small muscles in the suboccipital region—rectus capitis posterior major and minor and obliquus capitis superior and inferior—are innervated by the posterior ramus of C1, the suboccipital nerve These muscles are mainly postural muscles, but they act on the head—directly or indirectly—as indicated by capitis in their name • Rectus capitis posterior major arises from the spinous process of the C2 vertebra and inserts into the lateral part of the inferior nuchal line of the occipital bone • Rectus capitis posterior minor arises from the posterior tubercle on the posterior arch of the C1 vertebra and inserts into the medial third of the inferior nuchal line • Obliquus capitis inferior arises from the spinous process of the C2 vertebra and inserts into the transverse process of the C1 vertebra The name of this muscle is somewhat misleading because it is the Moore_Ch04.indd 300 only “capitis” muscle that has no attachment to the cranium • Obliquus capitis superior arises from the transverse process of C1 and inserts into the occipital bone between the superior and the inferior nuchal lines The boundaries and contents of the suboccipital triangle are • • • • Superomedially, rectus capitis posterior major Superolaterally, obliquus capitis superior Inferolaterally, obliquus capitis inferior Floor, posterior atlanto-occipital membrane and posterior arch of C1 • Roof, semispinalis capitis • Contents, vertebral artery and suboccipital nerve (C1) MUSCLES PRODUCING MOVEMENTS OF INTERVERTEBRAL JOINTS The principal muscles producing movements of the cervical, thoracic, and lumbar IV joints and structures limiting these movements are summarized in Tables 4.8 and 4.9 The back muscles are relatively inactive in the stand-easy position It is actually the interaction of anterior (abdominal) and posterior (back) muscles that provides the stability and produces motion of the axial skeleton 1/10/14 4:22 AM CHAPTER • BACK 301 TABLE 4.8 PRINCIPAL MUSCLES PRODUCING MOVEMENT OF CERVICAL INTERVERTEBRAL JOINTS Key Sternocleidomastoid (SCM) Longus colli Scalenes Intertransversarii Splenius capitis Splenius cervicis and levator scapulae Semispinalis cervicis and iliocostalis cervicis Longissimus capitis Multifidus Semispinalis capitis Trapezius (A) Muscles producing flexion (C) (B) Muscles producing lateral flexion (E) (D) C–E, Muscles producing extension Flexion Extension Lateral Bending Rotation Bilateral action of • Longus colli • Scalene • Sternocleidomastoid Bilateral action of deep neck muscles • Semispinalis cervicis and iliocostalis cervicis • Splenius cervicis and levator scapulae • Splenius capitis • Multifidus • Longissimus capitis • Semispinalis capitis • Trapezius Unilateral action of • Iliocostalis cervicis • Longissimus capitis and cervicis • Splenius capitis • Splenius cervicis • Intertransversarii and scalenes Ipsilateral action of • Rotatores • Semispinalis capitis and cervicis • Multifidus • Splenius cervicis Contralateral action of • Sternocleidomastoid Limiting structures • Ligaments: posterior atlanto-axial, posterior longitudinal, flavum, tectorial membrane • Posterior neck muscles • Anulus fibrosus (tension posteriorly) • Ligaments: anterior longitudinal, anterior atlanto-axial • Anterior neck muscles • Anulus fibrosus (tension anteriorly) • Spinous processes (contact between adjacent processes) • Ligaments: alar ligament tension limits movement to contralateral side • Anulus fibrosus (tension anteriorly) • Zygapophysial (facet) joints • Ligaments: alar ligament tension limits movement to ipsilateral side • Anulus fibrosus Moore_Ch04.indd 301 1/10/14 4:22 AM 302 CHAPTER • BACK TABLE 4.9 PRINCIPAL MUSCLES PRODUCING MOVEMENTS OF THORACIC AND LUMBAR INTERVERTEBRAL JOINTS Rectus abdominis Erector spinae Multifidus Semispinalis thoracis Psoas major Gluteus maximus (A) Flexion (starting from extended position) (B) Neutral (C) Extension (starting from flexed position) Splenius* Sternocleidomastoid* Sternocleidomastoid Rhomboids Splenius Serratus anterior Transversospinalis External oblique (anterior part) Internal and external obliques (lateral part) Iliocostalis and longissimus External oblique Quadratus lumborum Internal oblique Gluteus medius* Gluteus maximus* Internal oblique (anterior part) * Involved in overall Adductor longus* movement but not produce movement at IV joints of Table 4.8 (D) Lateral flexion (E) Rotation (Muscles shown contract to bend to opposite [left] side) (Muscles shown contract to rotate to the right) continued Smaller muscles generally have higher densities of muscle spindles (sensors of proprioception—the sense of one’s position—that are interdigitated among the muscle’s fibers) than large muscles It has been presumed that this is because small muscles are used for the most precise movements, such as fine postural movements or manipulation, and therefore require more proprioceptive feedback The movements described for small muscles are assumed from the location of their attachments, from the direction of the muscle fibers, and from activity measured by Moore_Ch04.indd 302 electromyography Muscles such as the rotatores, however, are so small and are placed in positions of such relatively poor mechanical advantage that their ability to produce the movements described is somewhat questionable Furthermore, such small muscles often are redundant to other larger muscles having superior mechanical advantage Hence, it has been proposed that the smaller muscles of small–large muscle pairs function more as “kinesiological monitors” (organs of proprioception) and that the larger muscles are the producers of motion 1/10/14 4:22 AM CHAPTER • BACK 303 TABLE 4.9 PRINCIPAL MUSCLES PRODUCING MOVEMENTS OF THORACIC AND LUMBAR INTERVERTEBRAL JOINTS (continued) Flexion Extension Lateral Bending Rotation Bilateral action of • Rectus abdominis • Psoas major • Gravity Bilateral action of • Erector spinae • Multifidus • Semispinalis thoracis Unilateral action of • Iliocostalis thoracis and lumborum • Longissimus thoracis • Multifidus • External and internal oblique • Quadratus lumborum • Rhomboids • Serratus anterior Unilateral action of • Rotatores • Multifidus • Iliocostalis • Longissimus • External oblique acting synchronously with opposite internal oblique • Splenius thoracis • Ligaments: supraspinous, interspinous, flavum • Capsules of zygapophysial (facet) joints • Extensor muscles • Vertebral bodies (apposition anteriorly) • IV disc (compression anteriorly) • Anulus fibrosus (tension posteriorly) • • • • • Ligaments: contralateral side • Contralateral muscles that laterally bend trunk • Contact between iliac crest and thorax • Anulus fibrosus (tension of contralateral fibers) • IV disc (compression ipsilaterally) • Ligaments: costovertebral • Ipsilateral external oblique, contralateral internal oblique • Articular facets (apposition) • Anulus fibrosus Ligaments: anterior longitudinal Capsules of zygapophysial joints Abdominal muscles Spinous processes (contact between adjacent processes) • Anulus fibrosus (tension anteriorly) • IV discs (compression posteriorly) TABLE 4.10 PRINCIPAL MUSCLES PRODUCING MOVEMENT OF ATLANTO-OCCIPITAL JOINTS (A) (B) Flexion (C) (D) Extension Key Suprahyoid muscles Infrahyoid muscles Rectus capitis anterior Flexion Longus capitis Sternocleidomastoid Trapezius Rectus capitis posterior major Rectus capitis posterior minor Obliquus capitis superior Extension Lateral Bending (not shown) Longus capitis Rectus capitis posterior major and minor Sternocleidomastoid Rectus capitis anterior Obliquus capitis superior Anterior fibers of sternocleidomastoid Splenius capitis Rectus capitis lateralis Suprahyoid and infrahyoid muscles Longissimus capitis Longissimus capitis Trapezius (ascending part) Splenius capitis Moore_Ch04.indd 303 1/10/14 4:22 AM 304 CHAPTER • BACK The actions of the suboccipital group of muscles are to extend the head on C1 and rotate the head and the C1 on C2 vertebrae The principal muscles producing movements of the craniovertebral joints are summarized in Tables 4.10 and 4.11 The motor innervation of the muscles and the cutaneous innervation of the posterior aspect of the head and neck are summarized in Figure 4.25 and Table 4.12 TABLE 4.11 PRINCIPAL MUSCLES PRODUCING MOVEMENT OF ATLANTO-AXIAL JOINTSa Head rotates to left by contraction of: Right: Sternocleidomastoid Semispinalis capitis Left: Obliquus capitis inferior Rectus capitis posterior, major and minor Longissimus capitis Splenius capitis a Rotation is the specialized movement at these joints Movement of one joint involves the other Clinical Box Back Sprains and Strains Back sprain is an injury in which only ligamentous tissue, or the attachment of ligament to bone, is involved without dislocation or fracture It results from excessively strong contractions related to movements of the vertebral column, such as excessive extension or rotation Back strain involves some degree of stretching or microscopic tearing of muscle fibers The muscles usually involved are those producing movements of the lumbar IV joints, especially the erector spinae If the weight is not properly balanced on the vertebral column, strain is exerted on the muscles This is the most common cause of low back pain Moore_Ch04.indd 304 As a protective mechanism, the back muscles go into spasm after an injury or in response to inflammation (e.g., of ligaments) A spasm is a sudden involuntary contraction of one or more muscle groups Spasms result in cramps, pain, and interference with function, producing involuntary movement and distortion of the vertebral column Using the back as a lever when lifting puts an enormous strain on the vertebral column and its ligaments and muscles These strains can be minimized if the lifter crouches, holds the back as straight as possible, and uses the muscles of the buttocks and lower limbs to assist with the lifting 1/10/14 4:22 AM CHAPTER • BACK 305 Trigeminal nerve (CN V) Spinal ne rve s Supra-orbital Lacrimal Supratrochlear CN V Infratrochlear External nasal C2 C3 Lesser occipital (C2,C3) Great auricular (C2,C3) C5 C4 C6 C4 T2 T3 Zygomaticotemporal Infra-orbital CN V2 Zygomaticofacial Greater occipital (C2) Third occipital (C3) T2 C4 Posterior Anterior rami rami C5 (A) Posterior view Auriculotemporal CN V3 Mental Buccal (B) Lateral view FIGURE 4.25 Sensory innervation of suboccipital region and head A Dermatomes B Cutaneous innervation TABLE 4.12 NERVE SUPPLY OF POSTERIOR ASPECT OF HEAD AND NECK Nerve Origin Course Distribution Suboccipital Posterior ramus of C1 spinal nerve Runs between cranium and C1 vertebra to reach suboccipital triangle Muscles of suboccipital triangle Greater occipital Posterior ramus of C2 spinal nerve Emerges inferior to obliquus capitis inferior and ascends to posterior scalp Skin over neck and occipital bone Lesser occipital Anterior rami of spinal nerves C2–C3 Pass directly to skin Skin of superior posterolateral neck and scalp posterior to ear Posterior rami, nerves C3–C7 Posterior rami of spinal nerves C3–C7 Pass segmentally to muscles and skin Intrinsic muscles of back and overlying skin adjacent to vertebral column Moore_Ch04.indd 305 1/10/14 4:22 AM 306 CHAPTER • BACK Medical Imaging Back Conventional radiographs are very good for high-contrast structures such as bone (Fig 4.26A) The advent of digital radiography allows improved contrast resolution Myelography is a radiopaque contrast study that allows visualization of the spinal cord and spinal nerve roots (Fig 4.26B) In this procedure, largely replaced by MRI, contrast material is injected into the spinal subarachnoid space This technique shows the extent of the subarachnoid space and its extensions around the spinal nerve roots within the dural sheaths Computerized tomography (CT) differentiates between the white and the gray matter of the brain and spinal cord It has also improved the radiological assessment of fractures of the vertebral column, particularly in determining the degree of compression of the spinal cord The dense vertebrae attenuate much of the X-ray beam Left common iliac artery Intervertebral disc L2 F Psoas major Disc space (DS) IA L3 Superior articular process of L5 Zygapophysial (facet) joint Cauda equina in lumbar cistern Inferior articular process of L4 Lamina Transverse process (TP) P DS TP Zygapophysial (facet) joint (F) Superior articular process Spinous process (A) Oblique view: P, pedicle; IA, inferior articular process (B) Transverse CT Dural sac Pedicle T10 L3 vertebral body T11 Ligamentum flavum Spinous process Spinal cord Dye in dural root sheaths (extensions of subarachnoid space around spinal nerve roots) T12 L1 Cauda equina L2 Nerve roots of cauda equina CSF in lumbar cistern Anulus fibrosus Lumbar cistern within dural sac L3 Nucleus pulposus (C) Anteroposterior view (D) Sagittal MRI FIGURE 4.26 Imaging of the vertebral column A Oblique radiograph of lumbar spine B Transverse (axial) CT scan of L4–L5 IV disc C Myelogram of lumbar region D Sagittal MRI scan of vertebral column Moore_Ch04.indd 306 1/10/14 4:22 AM CHAPTER • BACK and therefore appear white on the scans (Figs 4.26B and 4.27) The IV discs have a higher density than the surrounding adipose tissue in the extradural space and the CSF in the subarachnoid space Threedimensional reconstruction of CT images is shown in Figure 4.27C Magnetic resonance imaging, like CT, is a computer-assisted imaging procedure, but X-rays are not used as with CT MRI 307 produces extremely good images of the vertebral column, spinal cord, and CSF (Fig 4.26C) MRI clearly demonstrates the components of IV discs and shows their relationship to the vertebral bodies and longitudinal ligaments Herniations of the nucleus pulposus and its relationship to the spinal nerve roots also are well defined MRI is the imaging procedure of choice for evaluating IV disc disorders 1 2 18 18 15 14 19 17 11 16 19 543 18 14 19 15 17 12 16 11 13 10 12 10 13 (A) Inferior view (B) Inferior view Key for A and B Linea alba Rectus abdominis External oblique Internal oblique Transversus abdominis Latissimus dorsi 11 Descending aorta 12 Inferior vena cava 13 14 Spinalis 15 Longissimus 10 Multifidus Rotatores Iliocostalis 4th lumbar vertebra Transverse process 16 17 18 19 Spinous process Cauda equina Psoas major Quadratus lumborum AT MP C1 D AA D C2 St AA MP C1 T IV C3 St C1 T SF VC PA VA PA PT C4 C5 C2 La C6 La C3 C4 Sc FJ C7 Lu SP T1 Lu (D) Posterior view (C) Coronal MRI Key for C and D AA AT C1–T1 D FJ La Anterior arch of C1 Anterior tubercle of C1 Vertebrae Dens (odontoid process) of C2 Zygapophysial (facet) joint Lamina Lu MP PA PT Sc SF Lungs Mastoid process Posterior arch of C1 Posterior tubercle of C1 Scalenes Superior articular facet of C1 SP St T VA VC Spinous process Sternocleidomastoid Foramen transversarium Vertebral artery Vertebral canal FIGURE 4.27 Computed tomographic (CT) imaging A Transverse section of cadaveric specimen at L4 vertebra B Transverse (axial) CT scan at L4 vertebra C Coronal MRI scan of cervical region D Three-dimensional reconstructed CT image of cervical spine Go to http://thePoint.lww.com for helpful study tools, including USMLE-style questions, case studies, images, and more! Moore_Ch04.indd 307 1/10/14 4:22 AM Moore_Ch04.indd 308 1/10/14 4:22 AM ... Cavity 13 2 Abdominal Viscera 13 5 Esophagus 13 7 Stomach 13 7 Small Intestine 14 1 xiii Moore_FM.indd xiii 1/ 15 /14 2:45 AM xiv CONTENTS Surface Anatomy of Stomach 14 2 Large Intestine 14 8 Spleen 15 4... Vessels 81 Surface Anatomy of Heart 88 Superior Mediastinum 98 Posterior Mediastinum 10 3 Medical Imaging of Thorax 10 9 Abdomen 11 1 Abdominal Cavity 11 2 Anterolateral Abdominal Wall 11 2 Fascia... xiv Back Lower Limb 309 Bones of Lower Limb 311 Hip Bone 311 Femur 311 Patella 315 Tibia 315 Fibula 315 Tarsus, Metatarsus, and Phalanges 315 Surface Anatomy of Lower Limb Bones 320 Fascia, Vessels,