THIEME Atlas of Anatomy General Anatomy and Musculosl<eletal System
Michael Schuenke Erik Schulte Udo Schumacher Consulting f.clitor~
Lawrence M. Ross Edward D. l ampert i 11lus£rc11ions by
Markus Voll l<arJWesker
I
Thieme
@!) Thieme
General Anatomy and Musculoskeletal System
THIEME Atlas of Anatomy Consulting Editors
Lawrence M. Ross, M.D., Ph.D., Department of Neurobiology and Anatomy University ofTexas Medical School at Houston
Edward D. Lamperti, Ph.D., Immune Disease Institute and Harvard Medical School
Authors
Michael Schuenke, M.D., Ph.D., Institute of Anatomy Christian Albrecht University Kiel
Erik Schulte, M.D., Department of Anatomy and Cell Biology johannes Gutenberg University
Udo Schumacher, M.D., FRCPath, CBiol, FIBiol, DSc, Institute of Anatomy II: Experimental Morphology Center for Experimental Medicine University Medical Center Hamburg-Eppendorf
In collaboration with jurgen Rude Illustrations by
Markus Voll Karl Wesker 1694 Illustrations 100Tables
Thieme Stuttgart· New York
l.ibroryof Congress Carologing-in-Publication Daro is available from the publisher. This book is an authorized and revised translation of the German edition published and copyrighted 2005 by Georg Thieme Verlag, Stuttgart, Germany. Title of the German edition: Schuenke et al.: Allgemeine Anatomie und Bewegungssystem: Prometheus Lernatlas der Anatomie. Illustrators Markus Voll, Fiirstenfeldbnuck, GeiTilany; Karl Wesker, Berlin, Germany (homepage: www.karlwesker.de) Translator TerryTelger, Fort Worth, Texas, USA
Important note: Medicine is an ever-changing science undergoing
continual development. Research and clinical experience are continually expanding our knowledge, in particular our knowledge of proper treatment and drug therapy. Insofar as this book mentions any dosage or application, readers may rest assured that the authors, editors, and publishers have made every effort to ensure that such references are in accordance with the state of knowledge at the time of production of the book.
Nevertheless, this does not involve, imply, or express any guarantee or responsibility on the part of the publishers in respect to any dosage instructions and forms of applications stated in the book. Every user Is requestl!d to eumlne carefully the manufacturers' leaflets accompanying each drug and to check, if necessary in consultation with a physician or specialist, whether the dosage schedules mentioned therein or the contraindications stated by the manufacturers differ from the statements made in the present book. Such examination is particularly important with drugs that are either rarely used or have been newly released on the market. Every dosage smedule or every form of application used is entirely at the user's own risk and responsibility. The authors and publishers request every user to report to the publishers any discrepancies or Inaccuracies noticed. If errors In this work are found after publication, errata will be posted at www.thleme.com on the product description page.
e corrected reprint 2010 Georg Thieme Verlag Riidigerstra8e 14 D-70469 Stuttgart Germany http:l/www. thieme.de Thieme New York. 333 Seventh Avenue, New York, NY 10001 USA http:ffwww.thieme.com
Typesetting byweyhing digital, Ostfildem-Kemnat Printed in China by Everbest Printing Ltd, Hong Kong
Plus Version- indudes online access to WinkingSkull.com PWS
Softcover ISBN 978-1-60406-286-1 Hardcover ISBN 978-1-60406-292-2
Some of the product names, patents, and registered designs referred to in this book are in fact registered trademarks or proprietary names even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain. This book, induding all parts thereof, is legally protected by copyright. Any use, exploitation, or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to prosecution. This applies In particular to photostat reproduction, copying, mimeographing, preparation of microfilms, and electronic data processing and storage.
Foreword
Preface
Our errthusiasm fur the THIEME Atlas of Anatomy began when each of us, Independently, saw preliminary material from this Atlas. Both of us were Immediately captivated by the new approach, the conceptual organization, and by the stunning quality and detail of the Images of the Atlas. We were delighted when the editors at Thieme offered us the opportunity to cooperate with them In making this outstanding resource available to our students and colleagues In North America.
As it started planning this Atlas, the publisher sought out the opinions and needs of students and lecturers In both the United States and Europe. The goal was to find out what the "Ideal" atlas of anatomy should be-Ideal for students wanting to learn from the atlas, master the extensive amourrts of Information while on a busy class schedule, and, In the process, acquire sound, up-to-date knowledge. The result of this work Is this Atlas. The THIEME Atlas of Anatomy, unlike most other atlases, Is a comprehensive educational tool that combines Illustrations with explanatory text and summarizing tables, introducing clinical applications throughout, and presenting anatomica I concepts in a step-by-step sequence that allows for the integration of both systemby-system and topographical views.
As consulting editors we were asked to review, fur accuracy, the English edition of the THIEME Atlas of Anatomy. Our work involved a conversion of nomenclature to terms in common usage and some organizational changes to reflect pedagogical approaches in anatomy programs in North America. This task was eased greatly by the clear organization of the original text. In all of this, we have tried diligently to remain faithful to the irrtentions and insights of the original authors. We would like to thank the team at Thieme Medical Publishers who worked with us. Heartfelt thanks go first to Cathrin E. Schulz, M.D.• Senior Editor, fur her assistance and constant encouragemerrt and availability. We would also like to extend our thanks to Stefanie Langner, Production Manager, and Annie Hollins, Assistant Editor, fur checking and correcting our work and preparing this volume with care and speed. Lawrence M. Ross, Edward D. Lamperti
Since the THIEME Atlas of Anatomy is based on a fresh approach to the underlying subject matter itself, it was necessary to create for it an entirely new set of illustrationr-a task that took eight years. Our goal was to provide illustrations that would compellingly demonstrate anatomical relations and concepts, revealing the underlying simplicity of the logic and order of human anatomy without sacrificing detail or aesthetics. With the THIEME Atlas of Anatomy, it was our intention to create an atlas that would guide students in their initial study of anatomy, stimulate their errthusiasm for this intriguing and vitally important subject. and provide a reliable reference for experienced students and professionals alike.
"Ifyou want ID attain the possible, you must attempt the impossible" (Rablndranath Tagore). Michael Schiinke, Erik Schulte, Udo Schumacher, Markus Vall, and Karl Wesker
Acknowledgments
First we wish tD thank our families. This atlas is dedicab!d to them. We also thank Prof. Reinhard Gossrau, M.D., for his critical comments and suggestions. We are grab!ful tD several colleagues who rendered valuable help In proofreading: Mrs. Gabriele Schunke, Jakob Fay, M.D., Ms. Claudia Ducker, Ms. Slmln Rassoull, Ms. Heinke Teichmann, and Ms. Sylvia Zllles. We are also grateful to Dr. julia jOrns-Kuhnke for helping with the figure labels. We extend spedal thanks to Stephanie Gay and Bert Sender, who composed the layouts. Their ability to arrange the text and illustrations on facing pages for maximum clarity has contributed greatly to the quality of the Atlas. We particularly acknowledge the efforts of those who handled this project on the publishing side: JGrgen Luthje, M.D.• Ph.D., executive editor at Thieme Medical Publishers, has "made the impossible possible.• He not only reconciled the wishes of the authors and artists with the demands of reality but also managed to keep a team of frve people working together for years on a project whose goal was known to us from the beginning but whose full dimensions we came to appreciate only over time. He is deserving of our most sincere and heartfelt thanks. Sabine Bartl, developmental editor, became a touchstone for the authors in the best sense of the word. She was able to deb!rmine whether a beginning student, and thus one who is not (yet) a professional, could clearly appreciate the logic of the presentation. The authors are Indebted tD her.
We are grateful toAntje Buhl, who was there from the beginning as proj-
ect assistant. working "behind the scenes• on numerous tasks such as repeated proofreading and helping to arrange the figure labels. We owe a great dept of thanks to Martin Spencker, Managing Director
of Educational Publications at Thieme, especially tD his ability tD make quick and unconventional decisions when dealing with problems and uncertainties. His openness to all the concerns of the authors and artists established conditions for a cooperative partnership. Without exception, our collaboration with the entire staff at Thieme Medical Publishers was consistently pleasant and cordial. Unfortunately we do not have room to list everyone who helped in the publication of this atlas, and we must limit our acknowledgments to a few colleagues who made a particularly notable contribution: Rainer Zepf and Martin Waletzko for support in all technical matters; Susanne TochterrnannWenzel and Manfred Lehnert, representing all those who were involved in the production of the book; Almut Leopold for the Index; Marie-Luise Kurschner and her team for creating the cover design; to Birgit Carlsen and Anne Dobler, representing all those who handled marketing, sales, and promotion. The Authors
Table of Contents
General Anatomy
Human Phylogeny and Ontogeny
5
The Musc:les
5.1 5.2
The Skeletal Muscles ................................. 40 The Tendons and Mechanisms That Assist Muscle Function .......................... 42
1.8 1.9
Human Phylogeny .................................... 2 Human Ontogeny: Overview, Fertilization, and Earliest Developmental Stages .............................. 4 Gastrulation, Neurulation, and Somite Formation ••••••• 6 Development of the Fetal Membranes and Placenta ..... 8 Development of the Pharyngeal (Branchial) Arches in Humans ......................................... 10 Early Embryonic Circulation and the Development of Major Blood Vessels .. • . .. . • . • .. • . • .. • . • . • .. • . • .. • . 12 Bone Development and Remodeling •.•.••.•.•.••.•.••. 14 Ossification of the Umbs ............................. 16 DevelopmentandPositionofthelimbs ................ 18
2
Overview of the Human Body
2.1
The Human Body (Proportions, Surface Areas, and Body Weights)•.••.•.••. 20 The Structural Design of the Human Body •.•.•.••.•.••. 22
1.1 1.2
1.3 1.4 1.5
1.6 1.7
2.2
3
Surface Anatomy of the Body, Landmarks and Reference Lines
3.1
Terms of Location and Direction, Cardinal Planes andAxes ........................................... 24 Body Surface Anatomy ................. . ... . ......... 26 Body Surface Contours and Palpable Bony Prominences • • 28 Landmarks and Reference Lines on the Human Body • ••• • 30 Body Regions (Regional Anatomy) •• • •• ••• •• •• •• • •• •• • • 32
3.2 3.3 3.4 3.5
4
The Bones and Joints
4.1
The Bony Skeleton and the Structure of Tubular Bones . •. . 34 Continuous and Discontinuous joints: Synarthroses and Diarthroses . . . . .. . . . .. . . . .. .. . . . .. . . 36 Basic Principles of joint Mechanics .• . . . .• . . . . .. •. . .. •. . 38
4.2
4 .3
6
The Vessels
6.1
Overview of the Human Cardiovascular System ••.•.••.•. 44 The Structure of Arteries and Veins .................... 46 The Terminal Vascular Bed ............................ 48
6.2 6.3
7
The Lymphatic System and Glands
7.1 7.2
The Human Lymphatic System ........................ 50 Exocrine and Endocrine Glands ........................ 52
8
General Neuroanatomy
Development of the Central Nervous System (CNS) .••.•. 54 Neural Crest Derivatives and the Development of the Peripheral Nervous System (PNS) •.•.•..•.•.••.•. 56 8.3 Topography and Structure of the Nervous System ........ 58 8.4 Cells of the Nervous System .... . .... . ................ 60 8.5 Structure of a Spinal Cord Segment .................... 62 8.6 Sensory Innervation: An Overview ..................................... 64 8.7 Dermatomes and Cutaneous Nerve Territories •.•. •• .•. 66 8.8 Motor Innervation .. . . . .... . . . .. . . . .. . . . .. . . . . .. . . . . 68 8.9 Differences between the Central and Peripheral Nervous Systems .. . . . .. . . . . .. . . . .. . . . . 70 8 .10 The Autonomic Nervous System ...... . .... .. ........ . 72
8.1 8.2
IX
Table ofContents
Trunk Wall
Bones, Ugament:s, and Joints
3.4
The Chest Wall Muscles and Endothoraclc Fascia •••••••• 144
3.5
Thoracoabdominal junction:
1.1
TheSkeletonoftheTrunk .•..........•.....•....•.... 76
1 .2
The Bony Spinal Column ..•....•.....•.....•....•.... 78
1.3
Development of the Spinal Column .....•.....•......... 80
3.6
The Lateral and Anterior Abdominal Wall Muscles ••••••• 148
1.4
The Structure of a Vertebra •.......... •.....•....•.... 82
3.7
Structure of the Abdominal Wall
1.5
The Cervical Spine ..•.....•....•................•.... 84
1 .6
The Thoradc Spine .•.....•....•...........•....•.... 86
1 .7
The Lumbar Spine ..•.....•....•................•.... 88
1 .8
The Sacrum and Coccyx •.••.•.••.•.•.••.•.••.•.••.•.• 90
1 .9
The Intervertebral Disk: Structure and Function .•.••.•.• 92
The Diaphragm .................................... 146
and Rectus Sheath .................................. 150 3.8
Overview of the Perineal Region and Superficial Fasciae............................. 152 3.9
1.10 The Ligaments of the Spinal Column: 1.11 1 .1 2 1 .13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1 .21
Overview and Thoracolumbar Region .•.••.•.••.•.••.•.• 94 Overview of the Ligaments of the Cervical Spine .•.••.•.• 96 The Ligaments of the Upper Cervical Spine (Atlanto·ocdpital and Atlantoaxial joints) •.•.••.•.••.•.• 98 The Intervertebral Facet joints, Motion Segments, and RangeofMotion inDifferent Spinal Regions .•.••.•. 100 The UncovertebraiJoints of the Cervical Spine ••.•.••.•. 102 Degenerative Changes in the Lumbar Spine •.••.•.••.•. 104 TheThoradcSkeleton .•.••.•.••.•.•.••.•.••.•.••.•. 106 The Sternum and Ribs .•.••.•.••.•.•.••.•.••.•.••.•. 108 The Costovertebral Joints and Thoracic Movements • . . • . 110 TheBonyPelvis •.•.••.•.••.•.••.•.•..•.•.••.•.••.•.• 112 The Pelvic Ligaments and Pelvic Measurements • . • . • • . • . 114 The Sacroiliac Joint . • • . • . • • . • . • • . • . • . . • . • . • • . • . • • . • . 116
2
Musculature: Functional Groups
2.1
The Muscles of the Trunk Wall, Their Origin The Intrinsic Back Muscles:
Female versus Male •.••.•.•.••.•.••.•.••.•.•.••.•. 154 3.11 3.12
2.4
4.1
The Arteries ....................................... 162
4.2
The Veins ......................................... 164 The Lymphatic Vessels and Lymph Nodes •.•.••.•.••.•. 166 The Nerves ........................................ 168
4.3 4.4
5
Neurovascular Systems: Topographical Anatomy
5.1
AnteriorTrunkWall: Surface Anatomy and Superficial Nerves and Vessels •.... 170
5.2 5.3
The Short Nuchal and Craniovertebral Joint Muscles
5.5
Anterior and Posterior Muscles .. . . . .• . . . . .. . . . .. • . . 128 The Functions of the Abdominal Wall Muscles • . . .. • . . 130
2.8
2.9
The Muscles of the Thoracic Cage
Nerves and Vessels . .. . . . . .. ... .. . . . .. . . . .... . . . .. 178 5.6
Nerves, Blood Vessels, and Lymphatics
5.7
The Inguinal Canal . .. . • . . . .. • . . .. . . . .. . • . .. . . •.... 182
in the Female Breast . . . •.... . • . .. . • . .. . . . .... •.... 180 5.8
Anterior Abdominal Wall: Anatomy and Weak Spots • . . .. 184
5.9
Inguinal and Femoral Hernias .. . • . .. . • . .... . . . .. • . . .. 186
and Transversus thoracis) • . . . .• . . . . .• . . . . .• . . . .• . . . 132
5.10 Rare External Hernias .. ... . . .. . . . .. . . . .... . . . .. . . . .. 188
The Diaphragm .. . . . ...• . . . .• . . . .. • . . .. . • . . . .. . . . 134 (Pelvic Diaphragm, Urogenital Diaphragm, Sphincter
5.11
3
Musculature: Topographical Anatomy
3.1
The Back Muscles and Thoracolumbar Fascia . . • . .. . • . .. 138
3.2
The Intrinsic Back Muscles: Lateral and Medial Tracts • . .. . • . .... . .... . . . .. . • . .. 140 Short Nuchal Muscles .. . • . ...• . .... •.... . •........ 142
Diagnosis and Treatment of Hernias .. . • . .. . . •.... •.... 190
5.12 Development ofthe External Genitalia • . .. . . •.... • .... 192 5.13 Male External Genitalia: Testicular Descent and the Spermatic Cord . •.... •.... 194
and Erectile Muscles) . . ...• . ...• . .... . . . .. . . . .. . • . . . 136
X
AnteriorTrunkWall:
(lntercostales, Subcostales, Scaleni,
2.10 The Muscles of the Pelvic Floor
3.3
Anterior View . . .• . . . .• . . . .. • . . .... . . . .• . . . .. • . . .. 176 Overview and Location of Clinically Important
The Muscles of the Abdominal Wall:
2.6
Posterior Trunk Wall: Posterior View . .. . . . . .. . . .... . .... . . . .. . . . . .. . . .. 174
5.4
2.7
Posterior Trunk Wall: Surface Anatomy and Superficial Nerves and Vessels •.... 172
Medial Tract ••.•.••.•.••.•.••.•.•. • •.•.•..•.•. • •. 122
Lateral and Oblique Muscles • • •• • • • •• • • • • •• • ••• •• • • 126
The Levator ani .................................. 158 Their Relation to Organs and Vessels in Males and Females ••.•.•.••.•.••.•.••.•.•.••.•. 160
Neurovascular Systems: Forms and Relations
and the Prevertebral Muscle • • •• • • • • •• • • • • •• • • • •• • • 124 2.S
The Pelvic Floor Muscles:
4
Lateral Tract • •.•. • •.•.••.•.••.•.•..•.•.••.•.••.•. 120 2.3
Structure of the Pelvic Floor and Pelvic Spaces:
3.10 The Muscles of the Female Pelvic Floor and Wall. .•.••.•. 156
and Function . • •.•. • •.•. •• .•. •• .•.•..•.•. • •.•. •• .•. 118 2.2
The Pelvic Aoor Muscles:
5.14
The Testis and Epididymis ... •.... . . . .. . • . .... •.... 196
5.15
The Fasciae and Erectile Tissues of the Penis ..... .. ... 198
5.16
NervesandVesselsofthePenis •....•..... •.... •.... 200
5.17 Female External Genitalia: 5.18
Overview and Episiotomy . . . . .. . . . .. . . . . .. . . . .. . . . . 202 Neurovascular Structures, Erectile Tissues, Erectile Muscles, and Vestibule • • • • •• • • • • •• • • • • •• • • • 204
Tobie of Contents
Upper Limb
3
Musc:ulature: Topographical Anatomy
The Upper Limb as a Whole .•..........•......•....•. Integration ofthe Shoulder Girdle irrto the Skeleton of the Trunk .........•....•..........•...........•. The Bones of the Shoulder Girdle ..•....•......•....•. The Bones of the Upper Limb: The Humerus ......•....•..........•...........•. Torsion of the Humerus ...•..........•.....•....•.
208
3.1
210 212
3.2 3.3
214 216
3.4 3.5
The Posterior Muscles of the Shoulder Girdle and Shoulder joint .................................. 284 The Posterior Muscles of the Shoulder joint and Arm •... 286 The Anterior Muscles of the Shoulder Girdle and Shoulder joint .................................. 288 The Anterior Muscles of the Shoulder joint and Arm .•... 290 The Anterior Muscles of the Forearm .................. 292
1.6 The Radius and Ulna .............................. 1.7 The Articular Surfaces of the Radius and Ulna •.••.•.•• 1.8 The Hand ....................................... 1.9 The Carpal Bones ................................. 1.10 Thejoirrts of the Shoulder: Overview, Clavicular joints ......................... 1.11 Ugaments of the Clavicular and Scapulothoracic joints ............................ 1.12 The Capsule and Ligaments of the Glenohumeral joint ............................... 1.13 The Subacromial Space ........................... 1.14 The Subacromial Bursa and Subdeltoid Bursa •.•.••.•.•• 1.15 Movements of the Shoulder Girdle and Shoulder joint ... 1.16 The Elbow Joint as a Whole ...................................... 1.17 Capsule and ligaments ........................... 1.18 The Forearm: Proximal and Distal Radioulnar Joirrts •.•.••.•.•.••.•.•• 1.19 Movements of the Elbow and Radioulnar joints ......... 1.20 The Ligaments of the Hand .......................... 1.21 The Carpal Tunnel .................................. 1.22 The Ligaments of the Fingers ........... . ... . ........ 1.23 The Carpometacarpal Joint of the Thumb • •.•.•. • •.•. • • 1.24 Movements of the Hand and Anger joints • •.•.•. • •.•. • •
218 220 222 224
3.6 3.7 3.8 3.9 3.10
Bones, Ligaments, and joints 1.1 1.2 1.3 1.4 1.5
2
Musculature: Functional Croups
2.1 2.2
Functional Muscle Groups . .. . . . . .. . . .... . . . . .. . . . .. . The Muscles of the Shoulder Girdle: Trapezius, Sternocleidomastoid, and Omohyoid . . .. •. Serratus anterior, Subdavius, Pectoralis minor, Levator scapulae, and Rhomboid major and minor . . .. The Rotator Cuff .. .. ........ . ...... .. ........ .... The Deltoid .... . . . .. . . . .. ... .. ... . . .. . . . .. ... .. .. Latissimus dorsi and Teres major ... . . . .. . . . .. ... .. .. Pectoralis major and Coracobrachialis . .• . . . .. • . . .. •. The Muscles of the Arm: Biceps brachii and Bradhialis . . .. ... .. ... . .... . . .. .. Triceps brachii and Anconeus . .. ... .. ... . . .. . . . .. .. The Muscles of the Forearm: The Superficial and Deep Flexors ... .. ... .. . . .. . . . .. The Radialis Musdes ...... .. ... ... .... . .... .. ... .. The Superficial and Deep Extensors . .. . • . .. . . •.... •. The Intrinsic Muscles of the Hand: The Thenar and Hypothenar Muscles .. •. . .. . . •.. . . •. Lumbricals and Interossei (Metacarpal Muscles} •.... . .
2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14
226 228 230 232 234 236 238 240 242 244 246 248 250 252 254
The Posterior Muscles of the Forearm .••.•.•.••.•.••.• 294 Cross Sections of the Arm and Forearm ••.•.•.••.•.••.• 296 The Tendon Sheaths of the Hand ..................... 298 The Dorsal Digital Expansion ......................... 300 The Intrinsic Muscles of the Hand: Superficial Layer ................................. 302 3.11 Middle layer ..................................... 304 3.12 Deep layer ...................................... 306
4 4.1 4.2 4.3 4.4
The Arteries ....................................... 308 The Veins ......................................... 310 The lymphatic Vessels and lymph Nodes .•.•.••.•.••.• 312 The Brachial Plexus: Structure ....................................... 314 Supraclavicular Part ............................... 316 4.5 Infraclavicular Part-Overview and Short Branches ••.• 318 4.6 Infraclavicular Part-The Musrulocutaneous Nerve 4.7 and Axillary Nerve ................................ 320 4.8 lnfraclavirular Part-The Radial Nerve .••.•.••.•.••.• 322 4.9 lnfraclavirular Part-The Ulnar Nerve •. • •.•. • •.•. •• .• 324 4.10 lnfraclavlrularPart-TheMedlan Nerve .............. 326
5
Neurovasc:ular Systems: Topographical Anatomy
5.1
Surface Anatomy and Superficial Nerves and Vessels: Anterior View . . . .. . . . .... . . . .. . . . . .. . . . .. . . . .. . . . 328 Posterior View . . .. . . . . .. . . . . .. . . . .. . . . .... . . .. . . . 330 The Shoulder Region: Anterior View . . . .• . . . . .. . . . .• . . . 332 The Axilla: Anterior Wall . . . .. . . . . .. . . . .... . . .... . .... . . .. . . . 334 Posterior Wall . . . .. . . . . .. . . . . .. . . . .. . . . .... . . .. . . . 336 The Anterior Bradhial Region . . ...... . . .. . . . .. . . . .. . . . 338 The Shoulder Region: Posterior and Superior Views ..• . . 340 The Posterior Brachial Region . .... . . . .. . . . .. . . . . .. . . . 342 The Elbow (Cubital Region) ... ...... . . .. . . . .. . . . .. . . . 344 The Anterior Forearm Region . . ...... . . .. . . . .. . . . .. . . . 346 The Posterior Forearm Region and the Dorsum of the Hand . . ...... . . .. . . . .. . . . .. . . . 348 The Palm of the Hand: Epifascial Nerves and Vessels .. . ..... .. ... .. . . . .. . . . 350 Vascular Supply ........................ .. .... .. .. 352 The Carpal Tunnel ... . ... .. . . .... . .. . ..... .. . . . .. . . . 354 The Ulnar Tunnel and Anterior Carpal Region .. .. ....... 356
256 258 260 262 264 266 268 270 272 274 276 278 280 282
Neurovasmlar Systems: Forms and Relations
5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12 5.13 5.14 5.15
XI
Table ofContents
Lower Limb
Bones, Ugament:s, and Joints 1.1
The Lower Limb: General Aspects .•....•.....•....•... 360
1.2
The Anatomical and Mechanical Axes of the Lower Limb . 362
1.3
TheBonesofthePelvlcGirdle .........•.....•....•... 364
1.4
The Femur: Importance of the Femoral Neck Angle ..... 366
1.5
The Femoral Head and Deformities of the
1.6
The Patella ...•....•.....•....•...........•....•... 370
Femoral Neck .•....•.....•....•.....•.....•....•... 368 1.7
The Tibia and Fibula ••.•.••.•.•..•.•.••.•.••.•.••.•. 372
1.8
The Bones of the Foot from the Dorsal and Plantar Views •.••.•.••.•.•..•.•.••.•.••.•.••.•. 374
1.9
The Posterior Compartment (Superficial Flexor Group) .....•....•..........•.... 434 The Posterior Compartment 2.9 (Deep Flexor Group) ...•.....•....•..........•.... 436 2.10 The Intrinsic Musdes of the Foot: Dorsum and Medial and Lateral Sole of the Foot .•.... 438 2.11 The Intrinsic Musdes of the foot: Central Sole....•.... 440 2.8
3
Musculature: Topographical Anatomy
3.1
The Muscles of the Thigh
The Bones of the Foot from the Lateral
Hip and Gluteal Region from the Medial and Anterior Views .•.••.•.••.•.•..•.•.••.•. 442
and Medial Views; Accessory Tarsal Bones .•.••.•.••.•. 376 1.10 The Hip joint: Articulating Bones ..•.•.••.•.••.•.••.•. 378 1.11
The ligaments of the Hip joint: Stabilization of the Femoral Head •.•.••.•.••.•.••.•. 380
1.12
3.2
Origins and Insertions .••.•.••.•.••.•.•..•.•.••.•. 444 3.3 3.4
1.14 The Movements and Biomechanics of the Hip joint .•..•. 386 1.15 TheDevelopmentoftheHip]oint .•.•.••.•.••.•.••.•. 388
Hip and Gluteal Region from the Lateral and Posterior Views .•.••.•.••.•.••.•.•..•.•.••.•. 446
Nutrition of the Femoral Head •.••.•.••.•.•.••.•.••. 382
1.13 Cross·SectionaiAnatomyofthe Hip joint •.•.••.•.••.•. 384
Hip and Gluteal Region from the Anterior View;
Hip and Gluteal Region from the Posterior View; Origins and Insertions .••.•.••.•.••.•.•..•.•.••.•. 448
3.5
1.16 TheKneejoint: Articulating Bones ••.•.••.•.•..•.•.••.•.••.•.••.•. 390
The Muscles of the Leg from the Lateral and Anterior Views; Origins and Insertions •.•.•.••.•.••.•.••.•.•.••.•. 450
1.17
The ligaments of the Knee joint An Overview ••.•.••. 392
3.6
from the Posterior View; Origins and Insertions •.••.•. 452
1.18
The Cruciform and Collateral Ligaments .•.•.••.•.••. 394
3.7 3.8
The Tendon Sheaths and Retinacula of the Foot •.•.••.•. 454 The Intrinsic Foot Muscles from the Plantar View;
3.9
The Intrinsic Foot Muscles from the Plantar View .•.••.•. 458
1.19
The Menisci ••.•.••.•.••.•.•..•.•.••.•.•..•.•.••. 396
1.20
The Movements ofthe Knee joint •.•.••.•.•.••.•.••. 398
1.21
Capsule and joint Cavity ••.•.•..•.•.••.•.•.••.•.••. 400
1.22 The joints of the Foot Overview of the Articulating Bones and joints .•.•..•. 402 1.23
Articular Surfaces •• .•.• • .•.•.. • .•. •• .•. • . • •.•. • •. 404
1.24
The Talocrural and Subtalar joints •.•. • •.•.•. • •.•. • •. 406
the Plantar Aponeurosis ••.•.•.••.•.••.•.••.•.•.••.•. 456 3.10
Origins and Insertions •.••.•.••.•.••.•.•..•.•.••.•. 460
3.11
Cross-Sectional Anatomy ofthe Thigh, Leg, and Foot •.•. 462
4
Neurovascular Systems: Forms and Relations
1.26 The Movements of the Foot •.•.•..•.•. • •.•.••.•.••.•. 410
4.1
The Arteries • •.•.••.•.••.•.•. • •.•.••.•.••.•.•..•.•. 464
1.27 Overview of the PlantarVaultandtheTransverseArch .•. 412
4.2
The Veins •. • •.•.••.•.••.•.•. • •.•.••.•.••.•.•..•.•. 466
1.28 The Longitudinal Arch of the Foot •• • • • • •• • • • • •• • • • •• • • 414
4.3
The Lymphatic Vessels and Lymph Nodes • • • •• • • • •• • • • • 468
1 .29 The Sesamoid Bones and Deformities of the Toes • • • •• • • 416
4.4
The Structure of the Lumbosacral Plexus • • • •• • • •• • • • • • 470
1.30 Human Gait .. • . . .. • . . . . .• . . . .• . . . . .• . . . . .• . . . .• . . . 418
4.5
The Nerves of the Lumbar Plexus:
1.25 The Ligaments of the Foot ••.•.•..•.•. • •.•.••.•.••.•. 408
The Iliohypogastric, Ilioinguinal, Genitufemoral,
2
Musculature: Functional Groups
2.1
The Muscles of the Lower Limb: Classification .• . . . .. . . . 420
2.2
The Hip and Gluteal Muscles:
and Lateral Femoral Cutaneous Nerves .... . . . .. • . . .. 472 4.6 4.7
The Superior Gluteal, Inferior Gluteal,
The Inner Hip Muscles ...• . .... • . . .. • . . . . .• . . . .. . . . 422 2.3
The Outer Hip Muscles . .• . . . .. . . . .. • . . . .. . • . . .. • . . 424
2.4
The Adductor Group . . . .• . . . .. . . . .. • . . . .. . • . . .. • . . 426
2.5
The Anterior Thigh Muscles: The Extensor Group . . .. . • . .... . . . .. • . . .. . • . . .. • . . . 428
2.6 2.7
The Aexor Group . . • . .. . • . .... . . . .. • . . .. . . . .. . . •.. 430 The Leg Muscles: The Anterior and Lateral Compartments (Extensor and Fibularis Group) . . .... •.... . • . . •. • . .. 432
XII
The Obturator and Femoral Nerves .• . . . .. . . . . .• . . . . 474 The Nerves of the Sacral Plexus: and Posterior Femoral Cutaneous Nenll!s .. . . . .. • . . . . 476
4.8
The Sciatic Nerve (Overview and Sensory Distribution) • . . . .. . . . .. • . . .. 478
4 .9
The Sciatic Nerve (Course and Motor Distribution) . . .. 480
4.10
The Pudendal and Coccygeal Nerves • . . . .. . . . .. • . . .. 482
Tobie of Contents
5
Neurovascular Systems: TopographiC411 Anatomy
5.1
Surface Anatomy and Superficial Nerves and Vessels: Anterior View ......•....•..........•...........•. 484
5.2 5.3
Posterior View •....•.....•....•...........•....•. 486 The Anterior Femoral Region Including the Femoral Triangle ..•....•..........•...... • ....•. 488
5.4
Arterial Supply to the Thigh .•..........•......•....•. 490
5.5
The Gluteal Region: OVerview of Its Vessels and Nerves ....•......•....•. 492
5.6
The Sciatic Foramen and Sciatic Nerve ..•..... • ....•. 494
5.7
The lschioanal Fossa ..•....•..........•...........•. 496
5.8
The Pudendal Canal and Perineal Region (Urogenital and Anal Region) ..........•......•....•. 498
5.9
The Posterior Thigh Region and Popliteal Region .•....•. 500
5.10 The Posterior Leg Region and the Tarsal Tunnel ..•....•. 502 5.11
The Sole of the Foot ..•....•..........•...........•. 504
5.12 The Anterior Leg Region and Dorsum of the Foot: Cutaneous Innervation •••••••••••••••••••••••••••••• 506 5.13 TheArterlesoftheDorsumoftheFoot •••••••••••••••• 508
Appendix
References ... .. .. ... .. ... .. ... .. ... .. .. ... .. ... .. .. ... 513 Index . .. . . . .. . . . . . .. . . . .. . . . .. . . . . .. . . . . .. . . . . .. . . . . .. 515
XIII
General Anatomy Hum C Formatron of tfle br.~rtdllal or phuyngeal an:hes In il ftve..weet-
old humanembryo view. The br~nchi~l or pharynge~l;arches of tfle vertebrate embryo have a ml!fX/mmc arrar~gement (similar to tfle somltes. lhe primitive segments of the embryo tile mesoderm); this means that they are organized into a series of segments tflat haw the s.ame basic struc· ture.Amongthelrotherfunctlons,theyprovldethe rJWmaterlalforlhe spedes-spedflc development ofthevlsaeral skeleton (ITiiDdlla and mandible. middle ear. hyoid bone,laryruc), the as:sodiltl!d facial muscles, and the pharyngeal gut (seep. 11}. ~ft lateral
2
General AncJtomy - - 7. Human Phylogeny ond Ontogeny
Branchial arches, branchial clefts
Intestinal vein
NotDChord
Oral callltywlth buccalcilli
An ray
Neural tube Myomere (musculature)
Neural tube
Aortic root
Foregut
Branchial lleSSel Gonads Hindgut
Atrlopore
Hepatic cecum
Branchial artertes
Hypobranchial
Branchial artery
greave
Spinal card In neural canal Neural arch Artery
Sex organ
Liver
Vein Hemal arch
Notochord
H Characteristic features of vertebrilltes
• Nervi! cells, sensory organs, and oral apparatus con--/--
Glossopharyngeal nerve(aanial nerve IX)
pharyngeal arch with pharyngeal arch nerve (h)ooid arch)
~nd
D
Third pharyngeal arch with pharyngeal arch nerve
D
Fourth and sixth pharyngeal arches with pharyngeal arch nerve (flfth rudimentary only)
I
•
Mandibular nerve (from trigeminal nerve)
Arst pharyngeal arch with pharyngeal arch nerve (mandibular arch)
)
M~~l's
"" Temporollsmi.ISd~ ~rtllage
Sphenomandibular ligament
/-- ::.-::.~
~
_ _ Ocdpllillls mi.ISde Mosseter mi.ISde ""\-h.fl----- Digastric muscle. posterior belly
Mall.,..
~~t
~=id
\ l . l 9 - - - - Pharyngeal muscles
b l.oryngeal nerve (from vagus nerve)
Digastric muscle, Stylopharyngeus antertor belly mi.ISde
Greater comu
d
of h)ooid bone
lesser cornu of h)oold bone
Cricoid cartilage
Thyroid cartilage
MIIICIIIm.re
Nerw.s
E The system of phar;mgeal or branchial arches (after Sadler and Drews) a Anlage of the embryonic pharyngeal arches with the associated pharyngeal arch nerves.
b Definitive arrangement of the future cranial nerves V, VII, IX, and X. c Muscular derivatives of the pharyngeal arches. d Skeletal derivatives of the pharyngeal arches.
F Derivatives of the phai1'Jigeal (branchial) arches In humans
Muscle First (mandibular arch)
Cranial nerve V (mandibular nerve from the trigeminal)
Masticatory muscles
Second (h}'Oid arch)
Cranial nerve VII (fadal nerve)
Mimetic facial muscles Stylohyoid muscle Digastric muscle (posterior belly)
Slilpes Styloid process of the temporal bone Lesser cornu of hyoid bone Upper part of hyoid body
Third
Cranial nerve IX (gl0550pharyngeal nerve)
Stylopharyngeus muscle
Gremr cornu of h}'Oid bone ~r part of hyoid body
Fourltland sixth
Cranial nerve X (superior and recurrent laryngeal nerve)
Pharyngeal and laryngeal muscles
Laryngeal skeleton (thyroid cartilage, cricoid cartilage, arytenoid cartilage, corniculate and cuneiform cartilages)
- Temporalls -Masseter - Lateral pterygoid -Medial pterygoid Mylohyoid Digastric (anterior belly) Tensor tympani Tensor veli palatini
Malleus and incus Portions of the mandible Meckel's cartilage Sphenomandibular ligament Anterior ligament of malleus
11
Genenll Anatomy - - 1. Human Phylogeny and Ontogeny
1.6
Early Embryonic Circulation and the Development of Major Blood Vessels Aortic ardu!!s
Anb!rior cardinal Vl!in
lnb!mal carotid artery
----!'-----~~~~
Chorionic pial!! of the plaCl!llbl
Ventr.JI aortic root
Vascular pleJws lntheyolksoc
A Cra.llatory sysb!m of a 3· to 4-week-old human embryo (after Drews) Lateral view. The cardiovascular system of a 3- to 4-week-old human embryo consists of a well-functioning two-chambered heart and three distinct circulatory systems:
1. An lntnembryonk systemic drc:ulatlon (ventral and dorsal aorta. branchial arch and aortic arches. anterior and posterior cardinal veins) 2. An extraembryonic vitelline circulation (omphalomesenteric arterIes and veins) 3. A placental drculatlon (umbilical arteries and veins) The vascular pathways still show a largely symmetrical arrangement at this stage.
Dorsal aorta
Aortic arches
First
Second Third Fourth Fifth
Sixth
Ventral aorta
Internal carotid artery Rightsubclavian artery
External carotid artery Right common carotid artely Aortic
Right subclavian artery Brathlo-
arch
arteriosum
trunk b
B Development of the arteries derived from the aortic arch (after Lippert and Pabst) a Initial stage (4-week-old embryo, ventral view). An artery develops in each of the pharyngeal arches. proceeding in the craniocaudal direction. These arteries arise from the paired ventral aortic roots. course through the mesenchyme of the pharyngeal arches. and open into an initially paired dorsal aorta. These vessels give rise to segmental trunk arteries. The six aortic arches are not all present at any one time, however. For example, while the fourth arch is forming, the first two arches are already beginning to regress. The development proceeds In such a waythatthe original symmetry Is lost in favor of a preponderance on the left side. b Stnudu1'1!5 that fe91'1!55 or penlst: The first, second. and fifth aortic arches on both sides regress with continued development. The third
12
External carotid artely Common carotid artery Left subclavlan artery Ugamentum
Ductus ilrter10SU5
cephalic
a
Internal carotid artery
c
Descending aorta
aortic arch gives rise to a common carotid artery on each side and the proximal portion of the internal carotid artery. The left fourth aortic arch later becomes the definitive aortic arch, while the artery on the right side becomes the brachiocephalic trunk and the right suj). clavian artery. The left subclavian artery is derived from the seventh segmental artery. The trunk of the pulmonary arteries and the ductus arteriosus are derived from the sixth aortic arch. c V.rfants In the adult: Besides the typical case pictured here (77%). there are numerous variants of the brachiocephalic trunk that occur with different frequencies. In the second most common pattern (13 %). the left common carotid artery also arises from the brachiacephalic trunk. A right~ided aortic arch and a duplicated aortic arch each occur with a frequency of about 0.1 %.
General AncJtomy - - 7. Human Phylogeny ond Ontogeny
Anterior cardinal vein
Anastomosis of the cranial cardinal vein Oeft brachioceph;JIIcveln)
Cardinal venous: trunk
Superior vena""'" Coronary sinw
Hep;~tic segment of the future
(rightcommonardinal vein) Supracardinal vein
Azygos vein
lnferlor venil cava
-
Subcardinal veins
E---::=:---
-...._ _ Hemiazygosvein
Renal segment of thelnferlorvena c.wa Left gonadal vein
inferior vena cava
1--- f - - Leftgonadal
Posterior\ cardinal vein J
Hepatic segment of the inferior vena CiiVil
Renal segment ofthe future
Rl!nalvelns --+--"fl
cardinal venous trunk Kidney Anterior Supracardlnal Posterior cardinal vein vein cardinal vein
vein
Left common llioc""ln
Sacrocardlnal vein
b
C Development of the cndlnal venous system from weeks 5-7 to bird! (after Sadler)
a At 5-7 weeks (ventral view), b at term (ventral view), c lateral view at 5-7 weeks.
Up until the fourth week of development, three paired venous trunks reb.Jrn the blood to the heart: the vitelline, umbilical, and cardinal veins. The cardinal venous system at this stage consists of the anterior, posterior, and common cardinal veins. The following additional cardinal venous systems are formed between weeks 5 and 7: • Supr.cardlnal veins: These vessels replace the posterior cardinal
veins and receive blood from the intercostal veins (future azygos system: azygos and hemiazygos veins). • Subcardlnal valns: These vessels develop to drain the kidneys-the right subcardinal vein becoming the middle part of the inferior vena
C.rdlna~ /l~ \.__)G" ~ ~~':.us
venoustnmk
'
~
Cutedge ofthe,olk sac
wnosus
Characteristic transverse anastomoses are formed bebveen the individual cardinal venous systems. These connections transfer blood from the right to the left side, channeling it to the irrllow tract of the heart. The transverse anastomosis between the anterior cardinal veins, for example, forms the future left brachiocephalic vein. The fub.Jre superior vena cava develops from the right anterior and common cardinal veins, while the left common cardinal vein contributes to the venous drainage ofthe heart (coronary sinus).
Sinus
Left
venosus
hepatic vein
Inferior ""n• cava
Hep;~tic
Right vitelline vein
slnusolds
Obliterated umbilical
~nos
..,;n
Guttubo
Portal vein oflivl!r
Liver
Anastomotic notwori
If~f--~tt----tt...'¥--11'1'_..,'--
Functional n!modeUng In response to gruter stresses
=:sm:lar
(e.g~ lncreaslr~g body weight)
•
bon~
a
~p11ary
Os1l!o-
loop
~ltlll'aU
Osteobtms
~n bone'l'Ath
Llllllller(mltuN) bone
d!OI\I~osteotYW
D DIM!Iopment of;m osteon (ilfter Hees)
E
The process offunctlonal remodeling (see upper left pi!ge) begins with the lr111a1lon of blood wssels and acccmpi!~ng osteodasts ("bone-eat~r~g ctlfs•) Into ...-en bone. Tiley bUITOYt through the_.. b~ne lilae a drill, cutting a 1/iscul;uized channel (l'\!$0rpticm anal ~r cavity) wflich is equallr1 diameter to the future osteon.
a J.Qngltudlnal section through a resorption anal. b '"'"section at the level of the l'\!$0rption unal.
'!Wei of boiMI diMIIopm~nt {ost.I!Ogenests)
Note: Most borii!S ire formed by flld1recros1Jeo.
genesis (the l1!w exaptioM include the clavi· de and art.1ln bones of lfle alllirla). But portions of these bones still develop from the direct transformation of mesenchyme, I.e., by di~ osteogenesis.
c Transformation zone: osteoprogenltor cells (a ldnd of precursor for bone·fonnlng cells) are transformed Into osteoblasts. d Osteogenic mne (osteoblasts product bony lamellae).
• Newlyformedosteon.
BontmlrTOW
-~~
spaces
I
(uOOJidfled bone mltllx)
I )
/ ( I
IC
the~spaoes)
,-
r
\'
(ails linlr~g die m1m1W~>
............ Ostii!Odastlna
~~ HCIW'IIfplaaln;~ j
; ~
Enclo.sb!um (cells lnlng
""""'7 Endosteum
Ill
I 1 1
•
umellae
Osteoid
Osteoc:ytes
F c:rowth artd l"'!mCCdd!Rrtg processes wttfltn tfle ancelous porUon of a larnelllir bone a Three-dlmenslonal represent.ttlon of cancellous bone tissue. b Detail from a: remodeling of a anCt!llaLJS trabecula.
15
Genenll Anatomy - - 1. Human Phylogeny and Ontogeny
1.8
Ossification of the Limbs reAl Mondls V..Ors manilas 2 4 6 8 10 2 4 6 8 10 12 2 3 4 56 7 8 910 111 1314 1516 171 192( 212J 2312425
Body
Sapulo
CcrOCDid proass lnframromld
=
{Acromion Epiphyses
I•
1•1. 111
Ill
lnferlor:;:'
Body
a.vtde
Praxlrnal { Head iphysls Gn>Jtertubermity op Lessertuberoslty
I• • ~
--------- ----Shott
Distal r•pitEilum Trochlea epiphysis tmnl opicood)llo Medial opimndyte
I• ;
Proxlmoleplphysl Dls131 epiphysis
r"'T"T"
Shalt
~
Ulno
Proximoloplphysi Dls131 epiphysis
C.rpol bonn
Glpit112
Hamm Triquetrum LunatE Tropezlum Trope,gid Scaphoid
a
1::
·:• ~
Shaft: First S
•
-lla
nblo
Shaft Prax. eplph)'sls Tibial wbo.:f----=~--=!-- llbs
tnralmalleoh.a
r~ ---1.----'--~-- MeM<JI'IO· ~':; phllinlll!llllo'nb
M;Jnubrium Sterno· ltiL'ml diMcullr.)olnt
A Surfaocuontours 1ncl p1lp1ble ~ promlnenCitS ottfle flee
anclne.Jrotld-m;us:eller!c region
Subrnandbular !Jtange Subment • Pl'edomlnanllyfut-twltcllllbers (type 2 fibers. apprc~~~lmately 30 ms) • Brfef periods~ lntense;~ctMty
• l'allgue siCMiy • Large mator units • Rich In II'I)"'globln • Abundant mitochondria • Energy derflled from Glddat11111 (aerobic) metaboliSm • Utile g¥togen (MS~egaiiW)
• filllgue more rapidly
• Rellllhely highly wsa.olarfmd • Prone to shortenii'Q Oncrased restilg tonus) and req~ rttular stmchlng
• Mud! smaller capillary supply • Prone to atrophy and require regular strengthening
Intercostal muscles. INStlcatory musdes. tr.llpezlus (descending part), hamstrings. diopso~s. adductors. reClus femoris. soleus. Intrinsic back musdll!l (mainly ltle a!Nlal and lumbar part)
Bleeps bracl\11, vastus latera lis .1nd medllllls. tlbllllls anterior, serratus anll!rior. gluteus mlllimus. gastrocn•
• SmallmotDrunlb
• • • •
Scant II'I)"'globln Few mitochondria Energy derflled mainly from
lymphatic vessel Skin Subcut:aneoust:l5sue Fascia
MuKie
Bone
a
vascular sheath
Proximal valve Laxrollector segment (filling phase)
Phases af lymphatic
Arll!ryand b
iiCCOmpanying vein
D Organization and strudure of the different lymphatic regions (after Kubik) a Lymphatics In the skin and muscles. b Detail from a, showing the structure and function of a collector segment. Both the superficial and deep lymphatics originate with the extremely thin-walled lymphatic c.aplllalies, which are approximately 50 11m In diameter. Their endothelium Is bounded by an Incomplete basal lamIna, and they are attached by collagenous "anchoring filaments" to elastic fibers and collagen fibers In their surroundings. The network of lymphatic capillaries opens Into larger pnecollecton approximately
Cortex
dr.olnap
1OOJlm In diameter. Unlike the lymphatic capillaries, these vessels contain valve cusps and their wallis reinforced by a layer of connective tl~ sue. They open Into collectors, which also contain valves and have a transverse diameter of 150-600 11m. Like the larger lymphatic vessels and the lymphatic trunks, the collectors have a venous-type wall structure dMded Indistinctly Into an Intima (endothelium and basement membrane), a smooth-muscle media, and a Hbrous adventitia. Lymph transport Is effected by series of rhythmic contractile waves (10-12/mln) that are generated In the smooth-muscle, valveless collector segments. The direction of lymph flow Is controlled by closing the distal valves and opening the proximal valves of the precollectors and collectors.
TrabeaJia Paracortex
Serondary follicle Capsule
Eff...,nt
Gaplllary loops around a(serondary) lymph folhde
Medullary sinus Vein
vessel
Arll!ry Hilum
Postraplllaryvenule A1'11!11ole Intermediate sinus
Afferent
......r.
sinus
a
Arrangement of musdefibers
Marginal sinus
E Structure of a lymph node a Lymph circulation, b blood supply to the lymph node. Lymph nodes are small filtering stations located in the course of lymphatic vessels and are components ofthe specific immune response (they contain T- and 8-lymphocytes). Regional lymph nodes are distinguished from the collecting lymph nodes that receive lymph from multiple regional nodes. The lymph enters the lymph node through multiple afferent vessels. As the fluid passes along the various lymph sinuses to the efferent vessels, It comes Into contact with the lymph node tissue over a broad surface area. From outside to Inside, a lymph node con-
Seoondary follicle
b
Gapsule
Marginal sinus
sists of the cortex, paracortex. and medulla. The numerous secondary follicles in the cortl!x fonm the 8-lymphocyte region, and the lymphocyte-rich areas between and below the secondary follicles are the T-lymphocyte regions (parocortv:). Lymphocytes leave the bloodstream in the high-endothelial postc.apillary venules of the T-lymphocyte region; then, after differentiating, they leave the lymph node with the draining lymph via efferent lymph vessels, which often become the afferent vessel of another lymph node of a lymph node group.
51
Generol Anatomy - - 7. The tymphtJtlc System and Glands
7.2
Exocrine and Endocrine Glands
A Development and classification of glands Glands are epithelial aggregations of highly specialized single cells (goblet cells, multicellular intraepithelial glands) or oflarger cell groups that have migrated to deeper levels. Their function is to synthesize and release secretions. Glands fall into two main categories:
• Exoalne glands (e.g., salivary glands, sweat glands): These glands release their secretion emmallytothe skin or mucosa, either directly or through excretory ducts. • Endocrine glands: Their secretions (in this case hormonal messen· gers) are released Internally, i.e., into the bloodstream, lymphatics, or intercellular spaces. Endocrine glands do not have excretory ducts (see F for mechanisms af hormone release). Once released into the bloodstream, the honmones are distributed throughout the body and are transported to their target cells, where they bind to specific receptors and eXl!rt their effect
Multicellular lntr.leplthellal gland Goblet cells
Endocrine gland without a fulllde
Exocrine gland
Afferent blood,.,ssel
Elu:ll!tory duct
Endocrine gland wtthafolllde
Epithelial cells
Afferent blood vessel
Foilide
Pinched-offsecll!tlon
(!j:J
ccl
~ Bulging membronebound secretion
cJ
Membrane-bound secre!Dry"""lcle
Tronsfom1atlon of the glandular cellln!Dthe seaetion
r:r-1 ~•---
Ml • • cQ \~-
.
Golgi apparatus
r)
t
Secll!toryvesicle
a
~
..
•
B Medlanlsms by which exocrine glands release their secretions (light-microscopic scale) • Emcytosls: In this mechanism, the secretion is released without an enclosing membrane (merocrine or e
56
Gangloblasts S)mpa1hetlc p>91cn anlaoe '~'r-:.-...~.=-'-----t:--4--+-
Melanoblasts
Adl'l!nllanll!lf
Genenil Anatomy - - 8. General NeuroanciiDmy
D D11- ofna~1111 Cftlt delfnltw1 (teleded eumplel)
'*-
......CNit
..
•
C N. . .l ClWit d•m.tlwlln th• '-d and narwglan Besides the equlwlents oftfle structures named In 1 (such~ melanocyta), otherstnlctu~s in tfle heild and neck ~gion that originate frGm the cranial nam1l aert Include saletil, artllaglnous, and desmal musdH.
era nlal neur.lll crest derhi.Jtlloti In tfle adult slalleton: facia I bones, hyoid bone, portions of the thyroid artllllge. b Mort of the faclal.sldn Is derfVed frGm the neural crest. a
P~vlsceral
~
gongla
(mallgnantchldhood tumar)
~-~
Hlrschsprung . . _ (agan9lonkallon)
Glial mls (sm-.. .....
~
md~mls)
(lleddlnghaustn dlstlst)
MeLanocytes
Malignant mellncma,alblnlsm
Adre111l medulla
Pheothromocytoma (.clren~lgl•nd l!.lmor)
Endoclfne cells of the lung and
Clrdnolds (malrg111nt l!.lmors with 111docl1not actMty)
heart
Par.folllculumlls (C czlls) of the thyroid gLand
~>..!---
DDtulroat (Jplnol)gargllan
Spwllrg lfrlnnt
-··of
the do!YI roat In tile donal roat (splnall!l'•!l.,"
~~---- Spwllllg~
-••ofthe wntnl IOCit
..
Medullary thyroid cardnoma
E Dtwlapment of 11Nfiph1111lnerw Afferent (blue) and ~nt (red) UDns sprout ~ 1\"om the neuron somata during e _.,;, .•..£ ,;,
proms
l'lferlarartlcular ptDCKS
Spinous
lnferiarc:omll
__;~[~•--"'lr-"'""'r-- S~rlararllcullr
~
fllc:1ot
p-
a Sealnd thoradcvertebra
Inferior artlculllrfllc:lot
b Slxththoraclc'Witebra
lnlerlor wrll!bnl nob:h c;
A 111Dr.ldc: spine, left l;l1;e1111l vtew The thor~dc wrtebral bodies gr.-a dually bealme tiller ~nd bro.ilder from superior to inferior, the lower vertebral bodies i!ISsuming a lr.!nsve<W cw.rl shape like that of the lumbar vertebrae. The vembr.-al foramen Is roughlydrcular .-arid Is smaller than In thecervlCOII<md lumbarwnebr.-ae. The l!rldplates ;are rounded and trtangular. The spiDOUS processes are long arid <Jngled sharply infl!riorly, cre~~ting an over~pping <Jrr.~ngemertt that lnterllnb the thoradc:Yeftebrae. The f.lcets of the tn(fltor articular processes ire directed interforly, while the f.-acets ofUle superior articular proceS$eS face postl!rlor so ti\at they can articulate with the Inferior facets tofonm the zygapos~hy:H;ll orf<Jcetjoints (p.100).AnotherspeciCIIII
llody
\ !o\lporlar
costal fact( !o\lportar
wrttlnl nold!
b Sixth thoracic vertebra
b Sixth thoracic vertebra
lmnor.UW•r --;f7::\i:::~.AJ. PIUCIOII
c
Twelfththoradc~ril
c
Twelfththoradc~ril
c TllaiWCkvertebree, supet1Drvtew The limln.e ilnd pedlclesm;lle up the ~rill uch.
87
Tnrnk wan
1.7
--
J. Bona, Ugoments, ond}olnts
The Lumbar Spine
Fhth.mbarwrtlebrli(Ll)
nf~or -,l_~~~~~~~~~
Yeflebr.JI lntl!f· { Wl'tebral for;~ men
notd't
Superior ~,..=:!!!:;:!!1~'7 Vffimnl notd't
• Second lumbar vertebra
lnfufar artla.farfaat
'hl'tebral body
Flftilklmbn-wrtSir.t{l.S)
Inferior
Inferior
artk:UiarprocHs
artk:Uiarfam
A wmbauptM,II!ft llf:lnt vtew The bodies of the lumb;rrvertebrae are large and have a transverse 0'1'afpltil membr.~ne
99
Tnrnk
wan --
J. Bones, Ugoments, ond}olnts
The Intervertebral Facet joints, Motion Segments, and Range of Motion in Different Spinal Regions
1.13
•
SUperior
costal facet
Longltl.ldlnal
fa reeL
lnftrlar mstal facet
4~--lnfel1arartlalar proa!.SS
--1---;
.'/Aflll!·~r-- TanSICntlill forQe St
~~~:...._ Ncnnalfo~Sn
....._...,.....=:...--=:--:;--- lnfel1ar articular proeMS ~....,_--':1_.---
SUJlj!ffar articular proeMS
+-+- LIQ;Imentum flr;um
b
Meni!Olld syn~Malfalds
lnlhe)ottt
Sjllnalnerws
upsu~
d
A Tile lnterwrb!bral f.lcetjatnts {zyg;~pophyse;ll Joints) The diagrams show the posltfofl of the artlaJiar surfaces of the lntl!rvertebral fiC!I!t joir~ts in dilli:!rent regicms d the spinal column. g_, from the left posterosuperior view: a cuvfc;rl splr~e. b thorCipiUijalnt ltrl joint= AllaniDildaljolnt
•To each side
F Musurwment ofthe l'llnge oflhDI"'clc11'111 lumlllrtplnll flexion by the nwthod ofSchllber 1nd Ott 1n the metnocl of Schober and ott, the patient stands erect..tllle the ex· amlner rna rb the S1 5plnous proces! and a semnd point 10 an higher. When the patient bends as far forward as possible, the distance between the two skin markings will lnanse to approxlmmly 15 (1 0 + 5) em (range of maCion of the lumbar spine). The thoradc range of motion Is determined by measuring 30 an down fio'om the spinous proass vi the C7 vertebra (ve.Ubra pramillft'ls) and marking that point on the skin. When the patient balds forward, the dlsbnce between the muldngs may Increase by up to llcm. An alternatiW melttod Is m measure the smallestflnger-tD.floor dlstana (FFD) wltt1 the knees extended.
101
Dunk wan
1.14
- - '. 801H!:f, Uganretra, and}olnrs
The Uncovertebral Joints of the Cervical Spine
v.rulnl body
Antlorior tubordo
nt2r-
Und'latJ.o
- I nI
processes
disk
.....:~=----=~- OuiB' ......
donuus
flbi'IIRIS
It
A Tbe u.-rtebnljolnb t1 a ~1'19 ..tult Cavlal spine ohn 18-yelr-old man, antalor'llew. a The upper endplitl!s ofthe C3 through C7 vertebral bodies have later.d projKtions (undN~ prvcesses) that dMop during childhood. Starting at 1bout 10 ye1rs of age. the undllite proc::esses gridually
came IntO mntlct with the oblique, crescent-shaped nvrgln on the und~urface of lhe next higher vembral body. This results In the formltlon of literal clefts (unl:l)llertebral d~ orjoints, see b) In the outer portions of thto interverta111l disks.
b C4 thi'GII!Ih C7 n rtebrne. The bodies of the C4-C6 nrtebrae han been sectioned In the ooron~l pllne to demonstritl! more de.irly the unmwrtebral joints or clefts. ~ dtfts ~~bounded lmrally by a mnn~tlssuutructu~.aldnd ofjolntc.apsule,whkh causestltem to resemble true Joint sp-. These defts 01 ftssures In the lnterwrtl!lnl disk -re first deMribed by the 1natomist Hubert wn Luschki in 1158, who called them ·~m~u~ MnllonhtDses. "He Interpreted them il5 primary mechanisms designed tD enhance the ftl!ldblllty of the aMcal spine and mnfer il functlontl adv.nt:age (dfi'Mngs based on specimens from lhe Anatomical Collection It ICiel University).
Dens
I
TDpagn~phlc reladanshlp of
the •phil nen~e and ver1lebrll ararytD the und!Ytl! proc:eg
Alln(Cll
C1 splnol
""""'
- 4 L - - Axls(C2)
a Fourth a rvl'-'11 vertebra ...tth
spinal cord. spinal roots. spinal nerves, and vertebroil arteries, superior view,
b Cervlc.a) spine with both vertl!br~l al'tll!rles and the emerg lng spinal nerws, anterior view.
Ventral raot Spl~lnenoe
Undn1ta I
102
proeos&
It
Verttlnl body (0)
NoU the murse of the vertebril artery through 1he transverse furamiN and the tDUI"R of the spin~l nave it the level of the Intervertebral fllramlna. Glwn their close proldmlty, both tltu rteryand nerw IN)' be cornpnessed by osteophyte (bony ~rowth~) aused by uncovembrlllllrthrosls (see D).
Tnmkwall - - 1. BotJes.UgamenB.amljolnts
l.lrb!!'ll Dens
itlll1toalcllljalnt
TranswM foramen
C Degenet'ilttve cN"'JJ!S b the c:ervful
tpbe (urlaM!ftl!bralartflrosfs) Coronal $«tion tftrough tfte cervical spine or a 35-ye;~r-old man, anterior view. Nat!! !he course or the vertebral arteries on botft sides or lfle vertebral bodies. The development of the unawertdlralj11lnts at appi'Oldmately 10 years of age Initiates a process of cleft fonnatlon In lfle Intervertebral disb. This proa!SS spreads tDward the unter of the disk wttft aging, eventually resulting In the fonnatlon of complere transverse deft:s that subdMde the lntl!rvertebral disks Into two ~bs of roughly equal tftidcness. The result is a progressive degenerative process marked by flattening of the disks and consequent lnsta· blllty of the motion segments (dl'a'Mng based on specimens ~ the Anatomical Collection at klel Unlwnlty).
Verttbral body
'-:A~---
lnll!MrtSiral
rw~Ina us
• D AdvaiiCIId uncovert.bl'ill ~11hl'lllll ofdJ• c.rwkoll spine • Fourth aMc:al venebra, SIJperforvfew. b Fourth and ftfth cel'llfcal vertebrae, lateral view (dr.a'WI'ngs based Ol'l specimecu from the An;atomiclal Collection Jt Kiel University). The unarvertl!bral joints undergo degenerative changes comp.arable tD tftose seen In other jolnu, Including the fonnation of omophytes (called spondylophytes when they occur an vertebral bodies). Theie sllles of new bane fonnatlon servem distribute the Imposed forces aver a larger area, lflereby reducing tfte pn!SSure an the joint. Wrth progres·
PI'OCI!SS
sive destabil~tion of tfte corTesponding motion segment. the facet joints undergo osteoarthritic changes leading to osteophyte formation. Osteophyte$ of the uncovertebral joints have major clinical Importance because of their relation tD lhe Intervertebral foramen and vertebral artery (uncovertebral arthrwis). They cawe a gradu;al!y progressive nar· rowing of the Intervertebral foramen, with Increasing compression of the spinal nerve ;md often of the vertebral artery as well (see C). Meanwhile the spinal canal Itself may become srgnlftcantly nai'I'!IIN!!d (spiN I stc!no$is) by the same proce.$5.
103
Tnrnk
wan --
1.15
Po:st81ar longitudinal
J. Bones, Ugoments, ond}olnts
Degenerative Changes in the Lumbar Spine
-----;;.:;.-,~
llglment
"'"""- ' - - - - - Spl'!OUI
proass Caudl
equlna
-----\''---~
- + -:--- lnb!r.spfnous llglment
A Mk!AgltQisedlanthroughthel-rputofthespliiiiGIIumn Left lmr;rl view. Not!!: The a udal end of Ule spinal cord, the conus medullarts, terml· nates at the lew! of the firstot second lumbar w.ttebra. The spinal cord ;rnd spinal anal ;rre appi'Olllmately the same length until the 12th week of prenml development. so tflat e;rch p;rlr of spinal nuves emerges through tfle rntervertebrill foramen at the level ofUie ne!'YI!S. Wltfl furthet" g!VNth, howevet', tfle W!rtl!llral column lengthens more rapidly than tfle spinal cord, resulting In ;rn lncrea5lng cephiilad dlsplacemmt ofUie COni medullilr1s. At blrtfl tile COni medullar1s ha5 alre;rdy re;rched the leW!I of tfle tfllrd lumbar vertebra, and It continues Its gr;rdual upw.~rd shift until ;rbout the 1Oth year of life. ll«ause of tflese diip;arm growth rates, tfle spln;rl roots run obliquely downward from tfldr segmmt of ortgln In tfle cord to re;rch Ulelr corresponding lntervertellral fDr;rmen. The spinal roots that descend from the lower end of the cord are colle«ively termed the atUdcr equlno (•horw's tall"). Because the manbr;rnes tflat mdoseUie spinal cord (tfle meninges) extend Into the sacral canal, a needle can be ufely Introduced Into tfle subilrilchnold space below tfle COl'! us medullaris to sample cen!brospinil fluid without Injuring tfle c:wd (hlmbor puncrure). This site Is also used for lumbar $INn aIanesthesia to block both tfle ilffa'ent nerve roots (for analgesia) and the efl'et"ent nerve roots (for muscular p;rralysls) that supply tfle pelvic region and lgwer limbs.
f.ltlnthe epldlnl space 13
Hemtrn!d
dlslc L4
Cluda
equln.a'l'l CSF-fllled dur.als;ac
B Posterfor clsk heml~ttan In tfle lumiNrsplne Mlds;agltbl T2-welghU!d magnetic resonance Image of the lumb.ilr spine, left lmralview. The im;~ge show$ a corupicuous hem~te m~rTWJits.
Ill Alds of liMier rib m<M!meflts.
c Direction at rib rnaYBT~ents (see c for the mstovertl!broiil joints}.
The ues of rib mavementnre dire~ p~rallel to the necks of the ribs. The ilCI!5 for the upper ribs are closer tD the coronal p~ne (01), while those for the IDMr lfbs are closer Ill the Soilgltbl pbne
Ventralr.~musoftheC1nen~e
The Ttvnk Woll - - 2. MUJCUiature: Functional Gn:Hips
s~
klferior nudlalllne
nuch1llne
R.ettus t.JPiti5 postl!rla rminor
C 111e short nuchal ;md cnniOIII'I!ftebJ';II Obllquus capitis superior M~..-s
• lhanswr~e
Ma!told
proczssd;!tias
proc
Joint musdts: recti upltis postl!rfor and
obllqull capltlt Posterior view, b latel'ill view. In a strict sense. the short nudlal muscles conslst only of the muscles Innervated by the dorsal ramus of the first spinal nerve (suboa:ipi· tal nerve). They Include representatives of the late!"al tnct (obllquus capitis Inferior) and the medial tr.ict{obllquus capltls superior .ind rectus capitis posb!rior major and minor). The an· terior groop of short nuchal muscles (recti C-~-+o/l,fl..,t;H--
hmnolt.
--,~r.l-fi.J..J---- ltenolfadlo,
pas11!rlor lllotr
~~~~--- Santul
posli!riOt Walar
lhor.aaoumbor } floscll
B Thoraoolumberfatd• a Tr;msverse section through the neck K the lew! of the C6 vertebra,
su pelfor view. b Tr01nsverse section through the post2rior trunk wall at the lew! of the l3 vertebra (cauda eq ulna removed), superior vtew. The thorico Iumbil r fudi forms the li!Rral portion of in osseoflbrous Qnal thit ~osa all of the ltttrinsic bockmu.sdes. Besides the thaniCO' lumbarf.sc:la, this una I b also formed bythewrtebral arches and the
spinous and costaI processes of the assocfmd W!Ubrae. The thoramlumbar fascli CUnJists of i1 superfldilla nd I deep ~r, especially In the lumbar region; both layers unite K the lmral m~rgln of the Intrinsic bade: muscles. At the back of the ned
(c) betM.len the ell est wall and diaphragm Is a potemlal space that enlarges on lnsplr.ll:lon QO!Nerlng of the diaphragm) to 01ccommodate the expanding lung. The plana! space i5 the potential space located between the parfet;llf costal pleura and the visceral pleura, which dl· rectly ln-ts the lung tissue.
145
1M T1Vnlc wall - - 3. ll.fusallature: TopogtGphloal Anatomy
3.5
Thoracoabdominal junction: The Diaphragm
CCistllpaltd - --f-;-f, daphn~gm
A The dl•phngm,superklntew The diaphragm consists of three
parts: costal, lumbar, ;mel rternal. the mlllde that separates the thoracic and abdominal cavities, the diaphragm hiS characteristic apertures for the piSsage of the As
e.sophi\lgus, infi:!rigr Vl!na av;~, and aCII1a (see Cb and Dd}.
wnbiri);Jrt ofdiphr.~gm,
Intrinsic
backmusclu
left crus
5tl!mocostll triangle (loi!Te)'s deft)
Lumbirpalt ofdlaph~. right crus
Sternum Stlernil~d dl1ph~
Rectus
ibdomhis
Cost.1l part of
Med1n
tdrwmflex lllacarte'Y SUpllt1!ctalcnurnllex I lac .artery
~..,..._
__............_
~llllll'ttfy
8 Artertesofthe tnmk wall Antenor view. The ;mtenor portions of the r1bs haYe beer1 removed Ofl
the left side.
Tnrnk wall - - 4.. Neui'OIIVSGIIGr Systems: Fomu ami Rt!lattons
vettmral artl!ry
DeepuN'cal artery
Supl!f!arlnt«·
Verut!n~lartery
cmt.11.-tery
Comman CMOUdartery
CD!toci!Mc.al tt\lnk
Bradlloa!)hallc tt\lrk
A«tkaV>
lnt!mal tharaoc army Post!flcr
lntl!rmstal artl!rleS
Dcrs.1l r;mus
Antl!rfar lntl!rmstal artl!rleS
l------"'>- l'a'41Sb!mi11 lymph node
"Wmnhed"
C AI'Ns d111tned bydluuperfidal frmpN1kveuel,ofthe i!ntlriortnlnk'Wllll Anterior llfew. lymphiltfc p.;l1hwiy3 ;md reglorlill lymph nodes of the ;mterlortrunk wall (~m:IWS lnd!ute !he direction of lymph flow). b Superficial network d lymphatic vessels in the f'!lht anterior trunk wall.
01
t:ymph from tile slcin of tile trunk wall is collected mainly by tile ~xil· lary and superflclallngulnallymph nodes, following the genml pilttan
of lll!nous dr;~iflilge in the anterior trunk wall. The "w..te----=!!!--- Anal deft
b
D Sul'filat anatomy ofthe pol'ltt!rfortrunk wall a Male, b female. In both 5eXe$ a Sjlinol {um:ttN runs vertically in the pomrior midline of the trunk below the C7 spinous process. It Is formed by the fbc.ttlon of the SIJbcut
nen~e
Clltlneaur. branclles
lnfe!or
wmbu plexus
Ilioinguinal nerw L-.u,,. .z/.___ lntl!rlobular
abdcmnalfasda
a~nnedii.Oetlr.su~
~
I.Gbulu
f~=: Ac_,l
c
180
Tennlnal duct
Tem~lnal duct labuiN !.flit(TDW)
B Tile ~n~mmllfY ridges The rudiments of tt!e m
Sl.tld;Mcular
~ lntan~lthonlck:
arteyandw'n
1
-
ln1e'alst.li Mti'+'K, } - medial mammary
brand!K
'-!..__ _ _ _ Mllmrnarybranclles D Blood Rlpply to the breut The breast de!'IVes ItS blood supply ftom perforating br;mches af the
internal thoracic artery (• medial mammary branches from the sea~nd through fourth lnta't:o.Jtal spaces), branches of the lmral thor01· de artery (lilter.ll mam!Tiilry branches), ;md direct branches from the second through fifth Intercostal ~rterfes (!Tiilm!Tiilry branches}. The b~ art is drained by the internal and lateral thoracic veins.
E Nerve supply to ttu~ brent
The sensory Innervation ofthe breast has a segmental ~rr;mgement and is supplied by branches of the second through sixth intercostal nerves (later.al and medial mammarybr01nches). Branches ofthearvical plexus (supradallfcular ne!Vel) also supply the upper portion ofthe breast.
G Dldl1'buUon of mellgnenttumors byqUidr~~ntTn the flmillllu-.;~rt The numbers Indicate the .il'llel'3ge pen:entage location of malignant breast tumors.
F Lymphltkdnrlnl;eofthebn:.t The lymphatic vessels of the breast c.;rn be dMded Into a superficial, subcutaneous. ;md deep systl!m. The deep system begins with lym· phatic capillaries at the acinar IJ!Vel (see Cb and c:} ;and is particularly lmportilnt as a route for tumor metastasis. The main regional filtering stations .are the axJII.ary and parasternal lymph nodes, the appi'QlCTITiil· tely 30-60 axillary lymph nodes receiving most of the lymphatic drai· nage. They are the first nodes to be affected by met
Yagillil
• Very rare form of hermaphroditism (approximately 70S of cases have a fl!male karyotype: 46,XX). The gonads contain both testicular and ovarian tissue (ottnstis), but with a preponderanCI! of ovarian tissue. Hence the external genitalia tend to have a fl!male appearanCI! with a markedly enlai!Jed clitoris. A uterus Is frequently present. Most hermaphrodites are raised as girls.
• Etiology and pathog-lls The male phenotype results from fetal androgen exposure: 1. Congenil:ill enzyme defect 2. Diaplacental •ndrogen exposure • Example: congenlt.r adrenogenbl syndrome (1: 5000 live births):
- 46,XX chromosome complement - Fem.le Internal genital org;mswlth m•scullnlzed extmKII genitlliil (enlarged clitoris, partial fusion of the labi• mijor;,, sm~ ll urogenital sinus. see D) - CoiJ>f!: adrenocortic.l hyperpl.asi• with impaired steroid synthesis based on a genetic enzyme defect (most mmmonly a 21-hydroxylase defidency). The low hormone lew! Icauses increased ACTH secretion, leading to the overproduction of androgens. - Trea!ml!!lt: hydrocortisone therapy for life, which may be combined with a mineralocorticoid.
'lntersexu• llty refers to • condition malted by contr•dlctlonsln the development of general extern;~ I sexchar;,ctenstlcs, the gonads, and the chromosom;,l sex. "N~med ~fterHermophroditos. theandrogynoussonofHermes~ndAphroditefrom Greek mythology.
193
Ttunk waR - - S. Neui'OWJ'CIIIor Sysmns: TopographlcaiAncrtomy
5.13
Male External Genitalia: Testicular Descent and the Spennatic Cord l'roc:l!ssus
wgt.ars
Urm!f
~
_ ___,__.........,
A~~~~~--u~
BulbcHnlllnll ---?5~~L.-:1' gand
Perilebub
Peris IHJ~~-\1-\\-1--'H--
Ductus deferens Ciubemac&lum
Cilbemlallum
Spnphysls
A OftMI!woftflemillesenltllollilnS The lntl!mal and external mal~ genlt.illla ire dlstfngulshed by their OJ1. gins: The intemal n!productivl! organs originate from the two urogenlteB)
:.....:~,.--
Hf!lldM..u.!K
..
B111nch af deep
TunlculblllJIIIII
Bloodermfng
ttuuugh holldne
po~ftbon)
a111el1a Dlmddeep ponllultay
Dorsal penle .....,. (atrellnt iUNI!c ftbon)
F owm.w fAth•ll'llleiUIRiretThe se~WII refti!USin males are evoked by 11 nri~ of stimuli (e.g., uctil~ visual, olfad:Dry, uoustic, and psychogenic}. SOmatic and auiDnl)o mlc nerve pathw.lys transmit the stlmul us to U!e erection ilnd ejiiKllla· tlon centers In U!e thol'iiCOiumbar ;~nd suril splnil cord. from which It Is rel.tyed to higher c:enters (e.g., the hypothalamus and Umble systEm). For example, lrrelile cutoneous 5timuli to the genitlllla are transmitted to the Siltral cord by af'l'mnt !iOI7IQflc fibers (do11PillD
PI!Mc splondlnlc nerws (efferent
£mlaorywtns
Clm.unfleltwn
-T~~tit.~ . -. .~~~- CGmpre:ned d111lrlng vein
c
G MIKNnllm vf p111lle -dian (after Lehnert) • Penis In C'OSS section, showing the blood vessels Involved In erection (enlarged VIews In blind c). b Co~J~us ~rnowm in U!e ftiKOd state. c CooJ!us ~rnowm In U!e erect state.
Penile erection Is based essentially on mOJdmum fll90~ and pressure elevitlon In the Civltles (cavernous Spices) of the corpora ciYI!rnosa mmblned with a cans01dton of wnous outflcw. This medlinlsm raile$ the intrauvemous blood prmure to approximately 10 times the normal systolic blood pressure (approximately 1200mmHg In young men). Mlcroscopltilly, the erectile tissue of the pen Is consists of an arborized trabecular meshwork of connective-tissue lind smoothmuscle cells that is mnnected to the tunic:il albuginea. Among the tri· beculile ue lnteranastomoslng cavities that are lined with end.othellum. Branches of the deep penile ilrtery, tilled the hellclne ilr11!rles, open Into these caY~tles. In the fliiiCdd s.tm, the 1\ehdne artllfes are more or less ocduded by •tnttmal pads." When iln erection occurs, die lfferent iii'Urles dilate ilnd the hellclne iii'Urles open under the Influence of dluutonomlc nervous system. The result Is that w1th eadl pulse WolVe, blood is forc;ed into the c.avemous Spices, increasing U!e volume of the erectile tissue, and rihlng the lntracmtlry pressure. The tunica albu· glnea. whldl has a limited apndition is media I; one option Is the use ofvasoconstr1ctun (etrlefrlne or norepinephrine). Surgical treatment Involves ll'lillifng "pundl ;anastomoses" to promote the outflow of blood.
201
Tronk WfiH - - 5. NevrowJJ~CUIGr Systmls: Topogn~phkaiAnafomy
5.17
Female External Genitalia: Overview and Episiotomy
Mens pubis Prepuce
---:::~iiilli!~~;-.,--:-.;._---1-\ 6(j~-"!l!
of dltoris
~"g of --3==o,.--~
llard>olln
~-----;;-- Po
glindJ l'lrtleal raphe
labial (l)lllmlsiiJre
--=----
cartilage. the glenoid labrum (see c). \lAliie ttlis size dlscrep;mcy of the articulating surfaces serves to lr1Creise the r.rnge of shoulder motion, It compromises Ute st.ablllty of the Joint. Slna the jolflt c.1psule .and ligaments are weak. tfle rotator cuff b!ndans are the primary stabilill!rs of the glenohumeral joint (seep. 264). Dlsloc.rtfons of the shoulder joint are notoriously common. Approxlmmly 45 Xof all dlslacatforu lrwollle the shoulder )oint. In typical cases tfle tlead of the humerus dislocates anteriorly or anb!roinll!riorly in response to fordble external rot3tlon of the raised amn. WherNS considerable triluma Is generally needed to c.1use the lnlt:lal dislocation, certain movements of Ute shoulder (e.g .• excessiVe inn rotation during siHP) may be wff!Cient to redisiOC.il!t the humeral head .,_, the glenoid cavity (recun-ent shoulder dlsloc.rtfon).
Almnlod!MC\IIIr Coi1Kll:ld!MC\IIIr ligllmlnt ligament
Sapulllr notxh
SUperior IT.Inswrse scapular ligament
lnlltl"-----'---'-"1• tubtrculor syn~Mal
slleath
Jo'htapsult.
joint
glenolu.meral fgaments
eapule
B Clplu~,ISIIIIMnts.a'ldJolntc:nttyoftflertghtlhouldef a Anterior view. b Pomrlorvlew.
c jolntcavltyfromthe antErtor'lltew. The capsule of the shoulder joint Is broad and Is very thlr1 posteriorly, where It Is not refnforced by ligaments. But It Is strengthened interforly by three ligamentous strudlJres (the supenor, medial. and lnfertor gl~ nohumeral ligi!ments) and superiorly by the COI H151d of ractus. lunula
Anular
Praxtnal radioulnar
Coronald
Anular
lig;!ment
jelnt
praass
lig;!ment
D Course of thnrdill' l;ament In the right pi'Gldrnal r.tdlou!Nr )ornt • VIew of the pi'OlClrnal artlaJiar surfaces of the r.adl~ and ulna after
remOIIill of the humerus. b Silme view as in • with the l'i'dius also removed. The anular ligament Is of key lmport.ilnce In stabilizing Ute proximal radioulnar joinL It nms from the anterior to the posterior border of the
radial notdl of the ulna (-cartilage
