The Anatomy Coloring Book Wynn Kapit Lawrence M. Elson Fourth Edition

The Anatomy Coloring Book Wynn Kapit Lawrence M. Elson Fourth Edition

Pearson Education Limited Edinburgh Gate Harlow Essex CM20 2JE England and Associated Companies throughout the world Visit us on the World Wide Web at: www.pearsoned.co.uk Pearson Education Limited 2014 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without either the prior written permission of the publisher or a licence permitting restricted copying in the United Kingdom issued by the Copyright Licensing Agency Ltd, Saffron House, 6 10 Kirby Street, London EC1N 8TS. All trademarks used herein are the property of their respective owners. The use of any trademark in this text does not vest in the author or publisher any trademark ownership rights in such trademarks, nor does the use of such trademarks imply any affiliation with or endorsement of this book by such owners. ISBN 10: 1-292-02636-7 ISBN 13: 978-1-292-02636-7 British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library Printed in the United States of America

The neck is a complex tubular region of muscles, viscera, vessels, and nerves surrounding the cervical vertebrae. The muscles of the neck are arranged in superficial and deep groups. Here we will concentrate on the superficial muscles. The trapezius is not to be colored as it is not in the anterior and lateral regions of the neck; it is, however, the most superficial posterior and posterolateral muscle of the neck. The platysma is the most superficial anterior muscle of the neck. The sternocleidomastoid muscle divides the anterior and lateral muscle groups into triangular areas. The anterior region of the neck is divided in the midline; each half forms an anterior triangle. The borders of the anterior triangle of superficial neck muscles are illustrated. The hyoid bone, suspended from the styloid processes of the skull by the stylohyoid ligaments, divides each anterior triangle into upper suprahyoid and lower infrahyoid regions. The suprahyoid muscles arise from the tongue (glossus), mandible (mylo-, genio-, anterior digastric), and skull (stylo-, posterior digastric) and insert on the hyoid bone. They elevate the hyoid bone, influencing the movements of the floor of the mouth and the tongue, especially during swallowing. With a fixed hyoid, the suprahyoid muscles, especially the digastrics, depress the mandible. The infrahyoid muscles generally arise from the sternum, thyroid cartilage of the larynx, or the scapula (omo-) and insert on the hyoid bone. These muscles partially resist elevation of the hyoid bone during swallowing. The thyrohyoid elevates the larynx during production of high-pitched sounds; the sternohyoid depresses the larynx to assist in production of low-pitched sounds. The posterior triangle consists of an array of muscles covered by a layer of deep (investing) cervical fascia just under the skin between the sternocleidomastoid and trapezius. The borders of the triangle are illustrated. Muscles of this region arise from the skull and cervical vertebrae; they descend to and insert upon the upper two ribs (scalenes), the upper scapula (omohyoid, levator scapulae), and the cervical/thoracic vertebral spines (splenius capitis, semispinalis capitis). These muscles function becomes clear when you visualize their attachments. The sternocleidomastoid muscle, acting unilaterally, tilts the head laterally on the same side while simultaneously rotating the head and pulling the back of the head downward, lifting the chin, and rotating the front of the head to the opposite side. Both muscle bellies acting together move the head forward (anteriorly) while extending the upper cervical vertebrae, lifting the chin upward. 116

muscular SyStem / neck anterior & lateral muscles CN: Except for the hyoid bone, E, use your lightest colors throughout the plate. (1) Begin with the diagrams of the triangles of the neck, A and C, and the sternocleidomastoid, B. Color over all the muscles within the triangles. (2) Then work top and bottom illustrations simultaneously, coloring each muscle in as many views as you can find it. Note the relationship between muscle name and attachment. 117

The deep muscles of the back and posterior neck extend, rotate, or laterally flex one or more of the 24 paired facet joints and the 22 intervertebral disc joints of the vertebral column. The long muscles move several motion segments with one contraction, while the short muscles can move one or two motion segments at a time (see intrinsic movers). The splenius muscles extend and rotate the neck and head in concert with the opposite sternocleidomastoid muscle. The splenius capitis covers the deeper muscles of the upper spine. The erector spinae group comprises the principal extensors of the vertebral motion segments. Oriented vertically along the longitudinal axis of the back, they are thick, quadrilateral muscles in the lumbar region, splitting into smaller, thinner separate bundles attaching to the ribs (iliocostalis), and upper vertebrae and head (longissimus, spinalis). The erector spinae muscles arise from the lower thoracic and lumbar spines, the sacrum, ilium, and intervening ligaments. The transversospinalis group extends the motion segments of the back, and rotates the thoracic and cervical vertebral joints. These muscles generally run from the transverse processes of one vertebra to the spine of the vertebra above, spanning three or more vertebrae. The semispinales are the largest muscles of this group, reaching from mid-thorax to the posterior skull; the multifidi consist of deep fasciculi spanning 1 3 motion segments from sacrum to C2; the rotatores are well defined only in the thoracic region (the lumbar vertebrae, for the most part, do not rotate). These small, deep-lying (deepest) muscles cross the joints of only one motion segment. They are collectively important for making small adjustments among the cervical and lumbar vertebrae. Electromyographic evidence has shown that these short muscles remain in sustained contraction for long periods of time during movement and standing/sitting postures. They are most prominent in the cervical and lumbar regions. The small muscles set deep in the posterior, suboccipital region (deep to semispinalis and erector spinae) rotate and extend the joints between the skull and C1 and C2 vertebrae. Intrinsic movers are the small muscles that cross the joints of one motion segment, and include the deepest muscles noted above. These function in stabilization and facilitate getting proprioceptive information to the spinal cord and brain. 118

muscular SyStem / torso deep muscles of the Back & posterior neck CN: Use very light colors on the vertical, B B3, and oblique, C C3, muscle groups. Note that the splenius, A, and semispinalis, C, each have more than one part (e.g., cervicis, capitis); each is identified in the illustration. (1) Color the muscles of the main figure one group at a time. The function of these muscles is related to their orientation (vertical, oblique). (2) Color the suboccipital muscle group, F, in the upper boxed inset along with the sites of origin of the overlying muscles. (3) Color the intrinsic movers and their names below. 119

The thoracic diaphragm is a broad, thin muscle spanning the thoracoabdominal cavity, arising posteriorly from the lumbar vertebrae as muscular crura and aponeurotic arches (lumbar part), from the internal surfaces of the lower six ribs and costal cartilages (costal part), and from the internal surface of the xiphoid process (sternal part); these muscular fibers converge toward the center forming a great musculotendinous oval dome of which the top is the tendinous insertion known as the central tendon. At the level of T12, the descending thoracic aorta courses posterior to the diaphragm through the aortic hiatus (foramen) to become the abdominal aorta. The azygos vein and the thoracic duct have been known to pass through this hiatus as well. The esophageal hiatus can be found at the level of T10 among the fibers of the right crus as it joins the central tendon. It transmits the right and left vagal nerves as well as the esophagus. The inferior vena passes through a tendinous hiatus/foramen in the central tendon. The diaphragm is innervated by the phrenic nerve (C3 C5). How is it that the thoracic diaphragm is supplied by branches of the cervical plexus (of the neck)? Hint: look to embryology. The intercostal muscles, primarily the external and internal intercostals, alter the dimensions of the thoracic cavity by collectively moving the ribs, resulting in 25% of the total respiratory effort. The innermost intercostals are an inconstant layer and here include the transversus thoracis and subcostal muscles. Below the level of the 12th rib, the quadratus lumborum and the psoas (so-az) major and minor muscles of the posterior abdominal wall span the posterior lumbar gap from the diaphragm to the iliac crests bilaterally. The psoas major and minor are muscles of the lower limb. The major arises from the transverse processes of T12 and the lumbar vertebrae as well as the bodies of the lumbar vertebrae; it passes under the inguinal ligament to join with the fibers of the iliacus, converging to a single insertion (iliopsoas) on the lesser trochanter of the femur. The iliacus primarily arises from the iliac fossa. The iliopsoas, a strong flexor of the hip joint, is a powerful flexor of the lumbar vertebrae; a weak psoas may contribute to low back pain. The quadratus lumborum arises from the posterior iliac crest and inserts on the lower part of the 12th rib and the transverse processes of the upper four lumbar vertebrae. It is an extensor of the lumbar vertebrae bilaterally and a lateral flexor unilaterally. 120