Ebook Textbook of anatomy (5/E): Part 1

(BQ) Part 1 book “Textbook of anatomy” has contents: Some essential terms, bones of upper extremity, pectoral region, axilla and breast, pectoral region, axilla and breast, cutaneous nerves and veins of the free upper limb, the forearm and hand, general features of joints and joints of the upper limb,… and other contents.

VOLUME ONE Textbook of ANATOMY Fifth Edition JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD New Delhi • Panama City • London Published by Jaypee Brothers Medical Publishers (P) Ltd Corporate Office 4838/24 Ansari Road, Daryaganj, New Delhi - 110002, India Phone: +91-11-43574357, Fax: +91-11-43574314 Website: www.jaypeebrothers.com Offices in India • Ahmedabad, e-mail: ahmedabad@jaypeebrothers.com • Bengaluru, e-mail: bangalore@jaypeebrothers.com • Chennai, e-mail: chennai@jaypeebrothers.com • Delhi, e-mail: jaypee@jaypeebrothers.com • Hyderabad, e-mail: hyderabad@jaypeebrothers.com • Kochi, e-mail: kochi@jaypeebrothers.com • Kolkata, e-mail: kolkata@jaypeebrothers.com • Lucknow, e-mail: lucknow@jaypeebrothers.com • Mumbai, e-mail: mumbai@jaypeebrothers.com • Nagpur, e-mail: nagpur@jaypeebrothers.com Overseas Offices • Central America Office, Panama City, Panama, Ph: 001-507-317-0160 e-mail: cservice@jphmedical.com, Website: www.jphmedical.com • Europe Office, UK, Ph: +44 (0) 2031708910, e-mail: info@jpmedpub.com Textbook of Anatomy (Vol 1) © 2011, Jaypee Brothers Medical Publishers All rights reserved No part of this publication should be reproduced, stored in a retrieval system, or transmitted in any form or by any means: electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the author and the publisher This book has been published in good faith that the material provided by author is original Every effort is made to ensure accuracy of material, but the publisher, printer and author will not be held responsible for any inadvertent error (s) In case of any dispute, all legal matters are to be settled under Delhi jurisdiction only First Edition: Second Edition: Third Edition: Fourth Edition: Fifth Edition: 1996 1999 2003 2007 2011 ISBN 978-93-5025-381-6 Typeset at JPBMP typesetting unit Printed in India Preface to the Fifth Edition Over the years, the considerations taken into account during preparation of the first edition of this book remain unchanged even as I begin to write this new edition of the “Textbook of Anatomy” In the present fifth edition, all chapters have been thoroughly updated and revised The general format of the book has been changed and now it holds a completely fresh and new look with the addition of clinical correlations on most of the anatomical structures at the end of each topic, instead of listing them in the form of a single chapter as done in the previous edition Clinical matter has been arranged in the form of separate light-green coloured boxes titled “Clinical Correlation” Almost every chapter is liberally illustrated with 4-coloured, easy-to-understand illustrations, which the students can easily draw during their examinations Most of the text on important topics has been tabulated in an easy-to -grasp and readily comprehensible format, which would make it pretty interesting for the undergraduate students to understand the concepts of anatomy This textbook is divided into well-elucidated three volumes, with volume one on upper and lower extremities, volume two on thorax, abdomen and pelvis, and volume three on head, neck and central nervous system The book is mainly meant for undergraduate students and may also be of help to students at the postgraduate level Through this book, I try to take the young reader through a journey of discovering human anatomy that is as interesting as it is informative It contains numerous high quality, hand-drawn simple illustrations, which would be self-explanatory for undergraduates as well as postgraduates and can be easily drawn at the time of examination The information given is graded into different levels for undergraduates and postgraduate level students with the information meant for students pursuing postgraduation and bright students being arranged in light-pink coloured boxes titled as “Want to Know More” This further helps simplify the text Printing technology continues to make rapid advances and taking advantage of these, this edition has been made much more attractive and beautiful A majority of illustrations have been improved and errors corrected Overall, the book has been presented with its original virtues of accuracy and clarity along with the new style and comprehensiveness Last but not least, I would like to express deep gratitude to Shri Jitendar P Vij, Chairman and Managing Director, Jaypee Brothers Medical Publishers for his constant encouragement and support in helping me write a new edition at 82 years of age INDERBIR SINGH Rohtak, 2011 Preface to the First Edition Textbooks of anatomy (like the subject itself) have the unenviable reputation of being dull and boring This book makes an attempt to (hopefully) change this image The emphasis throughout the book is on a picture memory rather than a verbal one; and on understanding of facts rather than their cramming The author tries to take his young reader (figuratively) by the hand; and lead him, or her, through a journey of discovery that is as interesting as it is informative It is with this objective that this book incorporates a colour atlas The atlas is realistic to the extent that normal contours and relationships are maintained in the illustrations; but it is schematic in that some structures present in the field of dissection are omitted, or are delineated more clearly than is possible to see in actual dissections In describing any part of the body, the region is first reviewed using the atlas figures as a guide This is followed by detailed consideration of individual structures For the medical student, the study of anatomy is not an end in itself It is a necessary beginning to the study of physiology, pathology, and the signs and symptoms of disease The subject acquires interest if the student is made aware of the clinical importance of what he studies in the anatomy classroom This is why there has always been emphasis on what has been called ‘applied anatomy’ However, many surgeons and physicians feel that much of what goes under the name of traditional applied anatomy is obsolete, and has to be unlearnt In this book, therefore, the emphasis is on providing students some examples of clinical correlations of anatomical structures Instead of spreading out this information in small bits throughout the book a separate chapter is devoted to clinical correlations at the end of each major part I shall be grateful to students and teachers who point out errors, typographical or factual, and shall welcome suggestions for improvement I am grateful to the many students and colleagues who have encouraged me in my book writing endeavours, and this book might never have been written but for their good wishes and encouragement INDERBIR SINGH Rohtak, January 1995 Contents of Volume One PART 1: UPPER EXTREMITY Some Essential Terms The Subject of Anatomy Main Subdivisions of the Human Body Some Commonly Used Descriptive Terms Structures Constituting the Human Body How Muscles are Named Some Features of Joints 3 3 Bones of Upper Extremity Skeleton of the Upper Limb The Skeleton of the Hand 13 13 34 44 44 44 45 48 49 53 53 54 56 64 Pectoral Region, Axilla and Breast The Pectoral Region Cutaneous Nerves of the Pectoral Region Muscles of the Pectoral Region The Axilla The Axillary Artery The Axillary Vein Lymph Nodes and Lymphatic Drainage Lymph Nodes of Upper Limb The Brachial Plexus and its Branches The Mammary Glands (Breasts) The Back and Scapular Region The Back Muscles of the Back Nerves of the Back The Scapular Region Nerves of Scapular Region Arteries of Scapular Region 68 68 69 69 73 79 80 84 84 86 88 91 94 96 97 Cutaneous Nerves and Veins of the Free Upper Limb Cutaneous Nerves of the Free Upper Limb Veins of the Upper Limb Anterior Compartment of the Arm The Brachial Artery Nerves of the Front of the Arm Cubital Fossa Posterior Compartment of the Arm The Forearm and Hand Front of Forearm and Hand Muscles of the Front of the Forearm 100 100 100 Important Fascia in the Wrist and Hand Muscles in the Palm Nerves of the Forearm and Hand Arteries of the Forearm Back of the Forearm and Hand Muscles of the Back of the Forearm Nerves and Arteries on the Back of the Forearm and Hand 104 106 109 118 128 128 133 General Features of Joints and Joints of the Upper Limb Classification of Joints Classification of Joints on the Basis of Structure Classification of Joints on the Basis of Movements Joints of the Upper Limb Joints Connecting the Scapula and Clavicle The Sternoclavicular Joint The Shoulder Joint The Elbow Joint The Radioulnar Joints The Wrist Joint Other Joints of the Upper Limb 135 135 135 139 141 141 141 143 149 151 153 154 Surface Marking and Radiological Anatomy of Upper Limb Surface Marking Radiological Anatomy 157 157 162 PART 2: LOWER EXTREMITY Bones of Lower Extremity The Hip Bone Pelvis as a Whole The Femur The Patella The Tibia The Fibula The Skeleton of the Foot 167 167 177 180 186 188 193 197 10 Cutaneous Nerves, Veins and Lymphatic Drainage: Front and Medial Side of Thigh Cutaneous Innervation of the Lower Limb Veins of the Lower Limb Lymph Nodes and Lymphatic Drainage of the Lower Limb General Review of the Front and Medial Side of Thigh Muscles of Front of Thigh Muscles of Medial Side of Thigh The Femoral Artery Femoral Vein Nerves on Front and Medial Side of Thigh 209 209 214 216 218 224 229 232 235 238 11 Gluteal Region, Back of Thigh and Popliteal Fossa Gluteal Region Muscles of the Gluteal Region 245 245 245 Arteries of Gluteal Region Muscles of the Back of the Thigh Popliteal Fossa Popliteal Vessels Nerves in the Gluteal Region and Back of Thigh Sacral Ventral Rami and Sacral Plexus The Sciatic Nerve The Tibial Nerve The Common Peroneal Nerve 248 250 253 254 256 256 258 259 260 12 Front and Lateral Side of Leg and the Dorsum of Foot Compartments of the Leg Muscles of Anterior Compartment of Leg Extensor and Peroneal Retinacula Muscles of Lateral Compartment of Leg Blood Vessels of the Region The Tibial Nerve (in Popliteal Fossa) The Common Peroneal Nerve The Deep Peroneal (Fibular) Nerve The Superficial Peroneal (Fibular) Nerve 263 263 263 265 268 270 273 274 274 276 13 278 279 286 288 294 297 298 300 Back of Leg and Sole Muscles of the Back of the Leg Arteries of the Back of the Leg Muscles and Related Structures in the Sole Arteries of the Sole The Tibial Nerve Medial Plantar Nerve The Lateral Plantar Nerve 14 Joints of the Lower Limb Joints and Ligaments of the Pelvis The Hip Joint The Knee Joint The Ankle Joint Intertarsal Joints Other Joints of the Lower Limb Arches of the Foot 303 303 304 306 313 315 316 316 15 Surface Marking and Radiological Anatomy of the Lower Limb Surface Marking Radiological Anatomy 319 319 323 Index Part Upper Extremity 456 Part ♦ Thorax Cardiac Branches and Cardiac Plexuses While descending through the neck each vagus nerve gives off one (or more) superior cervical cardiac branch and an inferior cervical cardiac branch a These branches descend into the thorax and take part in forming the cardiac plexuses described below b Additional cardiac branches arise from the nerve in the superior mediastinum and also from the recurrent laryngeal branches a The superficial cardiac plexus is located just below the arch of the aorta, close to the ligamentum arteriosum (22.21) b It is formed by the inferior cervical cardiac branch of the left vagus nerve and the superior cervical cardiac branch of the left sympathetic trunk The deep cardiac plexus is situated in front of the bifurcation of the trachea It receives several branches from the right and left vagus nerves as follows: a Right superior and inferior cervical cardiac branches b Left superior cervical cardiac branch c Branches from right and left vagi arising in the thorax d Branches from the right and left recurrent laryngeal nerves The plexus also receives numerous cardiac branches from the right and left sympathetic trunks Branches from the superficial and deep cardiac plexuses supply the heart Pulmonary Branches On reaching the root of the lung each vagus divides into a number of branches that form the posterior pulmonary plexus (right or left) Each plexus also receives several branches from the sympathetic trunk Some branches of the vagus reach the front of the root of the lung and forms a less prominent anterior pulmonary plexus Branches from these plexuses accompany the bronchi and supply the smooth muscle in their wall Oesophageal Branches Fibres of the right and left vagus nerves emerge from the posterior pulmonary plexuses and descend on the oesophagus forming an anterior and a posterior oesophageal plexus Although both plexuses receive fibres from the nerves of both sides, the anterior plexus is formed mainly by fibres from the left vagus and the posterior plexus mainly by fibres from the right vagus Branches from these plexuses supply the oesophagus and the posterior part of the pericardium Fibres emerging from the lower end of the anterior oesophageal plexus collect to form the anterior vagal trunk which is made up mainly of fibres from the left vagus Similarly fibres arising from the posterior oesophageal plexus (mainly right vagus) collect to form the posterior vagal trunk The anterior and posterior vagal trunks enter the abdomen through the oesophageal opening in the diaphragm Their distribution will be taken up in the section on the abdomen Basic Arrangement of Sympathetic pathways The ganglia related to the sympathetic nerves are located mainly in the sympathetic trunk (right or left) Each trunk is a long nerve cord placed on either side of the vertebral column and extending from the base of the skull above, to the coccyx below The sympathetic ganglia are seen as enlargements along the length of the trunk Chapter 22 ♦ The Oesophagus, The Thymus, Lymphatics and Nerves of the Thorax 22.20: Relationship of subclavian artery to the vagus nerve The phrenic nerve is also shown 457 22.21: Course of recurrent laryngeal nerves on the right and left sides Basically, there is one ganglion corresponding to each spinal nerve, but in many situations the ganglia of adjoining segments fuse so that they appear to be fewer in number than the spinal nerves The ventral primary ramus of each spinal nerve receives fibres from a sympathetic ganglion through a delicate communication called the grey ramus communicans In the case of spinal nerves T1 to L2 (or L3) there is, in addition to the grey ramus, a white ramus communicans through which fibres pass from the spinal nerve to the ganglion (22.22) The cell bodies of sympathetic preganglionic neurons are located in the intermediolateral grey column of the spinal cord in spinal segments T1 to L2 (or L3) (22.22) Their axons leave the spinal cord through the anterior nerve root to enter the corresponding spinal nerve After a very short course through the ventral primary rami these fibres pass into the white rami communicantes and reach the sympathetic ganglia These preganglionic fibres leaving the spinal cord through spinal nerves T1 to L2 (or L3) collectively form the thoracolumbar outflow (22.19) On reaching the sympathetic trunk, the preganglionic fibres may behave in one of the following ways (22.23) want to know more? a They may terminate in relationship to cells of the sympathetic ganglion concerned b They may travel up or down the sympathetic trunk to terminate in ganglia at higher or lower levels in the trunk c They may leave the sympathetic trunk through one of its branches to terminate in relation to neurons located in a peripheral autonomic plexus 458 Part ♦ Thorax 10 Sympathetic postganglionic neurons are located primarily in ganglia located on the sympathetic trunks (22.22 and 22.23) Some are located in peripheral autonomic plexuses Axons arising from them behave in one of the following ways (22.24): a The axons may pass through a grey ramus communicans to reach a spinal nerve They then pass through the spinal nerve and its branches to innervate sweat glands and arrectores pilorum muscles of the skin in the region to which the nerve is distributed b The axons may reach a cranial nerve through a communicating branch and may be distributed through it as in the case of a spinal nerve c The axons may pass into vascular branches which form plexuses over the vessels and their branches Some fibres from these plexuses may pass to other structures in the neighbourhood of the vessels Fibres meant for blood vessels may also reach them through spinal nerves or their branches d The axons of postganglionic neurons located in sympathetic ganglia may travel through visceral branches and through autonomic plexuses to reach some viscera (e.g., the heart) e The axons of postganglionic neurons located in peripheral autonomic plexuses innervate neighbouring viscera These fibres often travel along blood vessels Confirm the connections described above in 22.19 22.22: Grey and white rami connecting a spinal nerve to the sympathetic trunk, and the fibres passing through them Preganglionic fibres are shown in red line and postganglionic fibres in blue or green THE SYMPATHETIC TRUNK We have seen that the sympathetic trunk (right or left) is a long nerve cord extending from the base of the skull to the coccyx, and that it bears a number of ganglia along its length In the neck the trunk lies posterior to the carotid sheath, anterior to the transverse processes of the cervical vertebrae In the thorax the trunk descends in front of the heads of the ribs, and in the abdomen it is anterolateral to the lumbar vertebrae Lower down, the trunk descends anterior to the sacrum Passing medially as they descend the right and left sympathetic trunks join each other in front of the coccyx Chapter 22 ♦ The Oesophagus, The Thymus, Lymphatics and Nerves of the Thorax 22.23: Mode of termination of sympathetic preganglionic neurons 459 22.24: Course and termination of sympathetic postganglionic neurons We have also seen that basically the sympathetic trunk bears one ganglion for each spinal nerve, but the number is reduced by fusion of some of the ganglia a In the cervical region, there are usually three ganglia; superior, middle and inferior b The first thoracic ganglion is usually fused to the inferior cervical ganglion the two forming the cervicothoracic ganglion c There are usually eleven ganglia in the thorax, four in the lumbar region, and four or five in the sacral region d The lower fused ends of the right and left sympathetic trunks are thickened by the presence of a midline ganglion called the ganglion impar Details of the thoracic part of the sympathetic trunk are considered below Some cardiac branches arising from the cervical part of the sympathetic chain descend into the thorax They will also be considered here want to know more? Cardiac Branches of Cervical Part of Sympathetic Trunk We have seen that the cervical part of each sympathetic trunk bears three ganglia: superior, middle and inferior Each ganglion gives off a cardiac branch, so that there are a total of six cardiac branches (three right and three left) The left superior cervical cardiac branch descends into the thorax along the common carotid artery It runs across the lateral side of the arch of the aorta and ends in the superficial cardiac plexus All other cervical sympathetic cardiac branches (left middle and inferior; right superior, middle and inferior) end in the deep cardiac plexus 460 Part ♦ Thorax 22.25: Branches of the thoracic part of the sympathetic trunk Thoracic Part of Sympathetic Trunk The first thoracic ganglion is fused with the inferior cervical ganglion to form the cervicothoracic ganglion (22.25) There are usually eleven thoracic ganglia, there being one each for nerves T2 to T12 These ganglia give off medial and lateral branches a Lateral branches arising from each ganglion connect it to the corresponding spinal nerve by white and grey rami communicans as already described (22.22) b The medial branches arising from the ganglia supply viscera i Those arising from the upper thoracic ganglia are small They supply the thoracic aorta (T2 to T6); join the posterior pulmonary plexus (T2 to T6), or join the deep cardiac plexus (T2 to T5) ii Some of them supply the trachea and the oesophagus Chapter 22 ♦ The Oesophagus, The Thymus, Lymphatics and Nerves of the Thorax 461 The lower thoracic ganglia give origin to prominent medial branches called the greater, lesser and lowest splanchnic nerves (22.25) Their origin is highly variable want to know more? a The greater splanchnic nerve is usually formed by branches from ganglia T5 to T9 b The lesser splanchnic nerve by branches from ganglia T9 to T10 c The lowest splanchnic nerve from ganglion T11 All these nerves pass through the diaphragm and enter the abdomen a The greater splanchnic nerve ends mainly in the coeliac ganglion b The lesser splanchnic nerve ends in the aorticorenal ganglion c The lowest splanchnic nerve ends in the renal plexus Details of these will be studied in the abdomen Afferent fibres accompany almost all efferent sympathetic fibres These afferent fibres are peripheral processes of unipolar neurons located in dorsal nerve root ganglia of spinal nerves T1 to L2 or L3 For some details see Figure 22.26 In this chapter, we have so far concentrated our attention on the arrangement of sympathetic nerves, and of parasympathetic nerves as represented by the vagus nerves We will conclude by summarising the nerve supply of the heart and lungs and pleura The nerve supply of the trachea and that of the oesophagus is considered with these organs Nerve Supply of the Heart The heart is supplied by nerves passing through the superficial and deep cardiac plexuses The nerves contributing to these plexuses have been mentioned above Parasympathetic preganglionic neurons for the heart are located in the medulla oblongata of the brain (dorsal nucleus of the vagus) They reach the heart through cardiac branches of the vagus Parasympathetic postganglionic neurons are located within the superficial and deep cardiac plexuses and also in the walls of the atria Preganglionic sympathetic neurons are located in segments T1 to T5 of the cord On reaching, the sympathetic trunk their axons synapse with postganglionic neurons in the upper thoracic ganglia Some of them run upwards in the sympathetic trunk to end in cervical ganglia Postganglionic fibres leave these ganglia through their cardiac branches and join the vagal fibres in forming the cardiac plexuses Contraction of cardiac muscle is not dependent on nerve supply It can occur spontaneously The nerves supplying the heart, however, influence heart rate Sympathetic stimulation increases heart rate and parasympathetic stimulation slows it Sympathetic nerves supplying the coronary arteries cause vasodilatation increasing blood flow through them Afferent fibres from the heart travel through both sympathetic and parasympathetic pathways a Impulses of pain arising in the heart travel along sympathetic pathways b They are carried mainly by the cardiac branches of the middle and inferior cervical ganglia Some fibres also pass through cardiac branches of thoracic ganglia c These fibres pass through the sympathetic trunks and enter the spinal cord through spinal nerves T1 to T5 d The cell bodies of the neurons concerned are located in the dorsal nerve root ganglia on these nerves These pathways convey impulses of pain produced as a result of anoxia of heart muscle (angina) Afferent fibres running along the vagus are concerned with reflexes controlling the activity of the heart Nerve Supply of Lungs and Bronchi Parasympathetic preganglionic neurons that supply the bronchi are located in the dorsal nucleus of the vagus The fibres travel through the vagus and its branches, to reach the anterior and posterior pulmonary plexuses 462 Part ♦ Thorax Postganglionic neurons are located near the roots of the lungs their axons run along the bronchi and supply them The sympathetic preganglionic neurons concerned are located in spinal segments T2 to T5 Their axons terminate in the corresponding sympathetic ganglia Postganglionic fibres arising in these ganglia reach the bronchi through branches from the sympathetic trunks to the pulmonary plexuses Parasympathetic stimulation causes bronchoconstriction, while sympathetic stimulation causes bronchodilatation Parasympathetic stimulation also produces vasodilatation and has a secretomotor effect on mucous glands in the bronchi Sympathetic stimulation produces vasoconstriction Afferent fibres arise in alveoli and bronchial mucosa They are important in respiratory reflexes Nerve Supply of Pleura The parietal pleura receives its nerve supply through nerves supplying the thoracic wall, while the visceral pleura receives branches from nerves that supply the lungs Thus, the parietal pleura is supplied by branches from intercostal and phrenic nerves The visceral pleura is innervated by sympathetic and parasympathetic nerves that supply the lungs An important result of this difference in nerve supply is that the parietal pleura is much more sensitive to pain than the visceral pleura 22.26: Afferent autonomic pathway involving the sympathetic nerves 23 CHAPTER Surface Marking and Radiological Anatomy of the Thorax SURFACE MARKING The thorax is a region of considerable clinical importance Having a clear idea of the relationship of internal organs within it to the surface of the body is, therefore, very useful The most important organs within the thorax are the heart and lungs The surface projection of the pleura and lungs has already been described on pages 397 and 399 (19.24 and 19.25) The surface projection of the borders and valves of the heart has been described on page 418 (20.21) The projections of some other structures are described below Some Landmarks on the Thorax Before going on to understand the surface markings of structures in the thorax, it is necessary that the students have a clear idea of the formation of the thoracic cage The clavicle, the sternum, the costal cartilages and the ribs serve as important landmarks that help us to mark projections of individual structures on the surface of the body Beginners often have difficulty in correctly identifying individual costal cartilages and ribs The anterior part of the first rib is overlapped by the clavicle and because of this it cannot be felt Identify some landmarks on the front of the thorax as follows Begin by placing your fingers over the clavicle a Trace the clavicle to its expanded medial end that forms a marked projection b Now put one finger in the interval between the medial ends of the right and left clavicles and feel for the upper border of the manubrium sterni c Notice that this border is concave and lies at a distinctly lower level than the medial ends of the clavicles Pass one finger downwards over the manubrium sterni (in the midline) till you come to a ridge-like prominence a This prominence is the manubriosternal junction or sternal angle b At this level pass the fingers laterally and you will be able to feel the second costal cartilage (Remember that the second costal cartilage meets the sternum at the junction of the manubrium and the body of the sternum) Passing further laterally along the second costal cartilage you can feel the second rib a Other ribs and costal cartilages can be felt by counting downwards from the second b Trace each rib laterally up to the midaxillary line Remember that the lowest rib here is the tenth The ribs can be traced beyond the midaxillary line onto the back of the thorax The spines of thoracic vertebrae can be identified as follows: a Put your fingers on the back of the neck, in the midline, and feel for the ligamentum nuchae b When the fingers are run down the midline they reach the spine of the 7th cervical vertebra c Thoracic vertebral spines can be identified by counting downwards from here 464 Part ♦ Thorax Surface Marking of the Trachea Place a finger just above the upper border of the manubrium sterni and pass it upwards for about one inch a You will feel the firm prominence of the cricoid cartilage b Just below this level, you can feel the softer cartilages of the trachea  a To mark the trachea, draw two vertical lines parallel to each other, and about cm apart, starting just below the cricoid cartilage and ending at the level of the sternal angle b Near its lower end, the trachea inclines slightly to the right side c The trachea ends at this level by dividing into the right and left principal bronchi Surface Marking of Right Principal Bronchus The upper end of the right principal bronchus lies, more or less in the midline, at the level of the sternal angle Its lower end lies over the sternal end of the right third costal cartilage The bronchus is marked by drawing two lines cm apart, running downwards and to the right, joining these two levels The bronchus is about 2.5 cm long Surface Marking of Left Principal Bronchus Before trying to mark this bronchus remember that, as compared to the right bronchus, it is twice as long (5 cm), and is placed more transversely Like the right bronchus its upper end lies at the level of the sternal angle Its lower end lies over the left third costal cartilage, cm from the median plane The bronchus is marked by two lines, cm apart joining these two levels Surface Marking of Oesophagus The upper end of the oesophagus lies at the lower border of the cricoid cartilage that can be located as described for the trachea  a From here draw two lines, 2.5 cm apart, descending to the upper border of the manubrium sterni b Continue the two lines downwards till they reach the sternal angle a These lines should be drawn so that at the level of the cricoid cartilage and at the level of the sternal angle, the oesophagus is seen to be in the middle line b However, at the level of the thoracic inlet (i.e., the upper border of the manubrium sterni) the lines should deviate slightly to the left side a To mark the part of the oesophagus that lies in the posterior mediastinum continue the same lines downwards, but with a distinct inclination to the left side b The lines should end at the level of the left 7th costal cartilage c Here the centre of the oesophagus should be 2.5 cm to the left of the midline The lowest half inch of the oesophagus marked as described above outlines the abdominal part Internal Thoracic Artery The upper end of this artery lies in the neck, cm above the sternal end of the clavicle, 3.5 cm from the median plane The lower end of the artery lies in the sixth intercostal space 1.2 cm from the lateral border of the sternum The line joining these two points runs downwards behind the upper six costal cartilages and lies about 1.2 cm lateral to the sternum Pulmonary Trunk a N  ote that the pulmonary valve is about 2.5 cm broad It lies transversely, partly behind the left third costal cartilage and partly behind the sternum b This gives us the lower end (beginning) of the pulmonary trunk Chapter 23 ♦ Surface Marking and Radiological Anatomy of the Thorax 465 a From here draw two vertical parallel lines upwards to the level of the left second intercostal cartilage b This gives us the level at which the pulmonary trunk divides into the right and left pulmonary arteries Ascending Aorta The first point to remember is that this vessel lies entirely in the middle mediastinum a Its lower end corresponds to the position of the aortic valve b This valve is placed obliquely behind the left half of the body of the sternum at the level of the third intercostal space c It is about 2.5 cm broad Mark the valve as described above From the ends of the line representing the valve draw two parallel lines passing upwards and to the right to reach the sternal angle (right half) Arch of the Aorta The projection of the arch onto the anterior wall of the thorax is shown in 21.4 (page 421) Note the following points: The lower end of the arch of the aorta corresponds to the upper end of the ascending aorta described above In other words, the anterior end of the arch lies behind the right half of the sternal angle The posterior end of the arch also lies at the level of the sternal angle a It lies partly behind the left half of the sternal angle and partly behind the second left costal cartilage b Do not forget that the posterior end really lies against the posterior wall of the thorax, at the level of the lower border of the fourth thoracic vertebra The summit of the arch reaches up to the level of the middle of the manubrium sterni When viewed from the front the arch looks much smaller than it actually is because of foreshortening a To mark the convex upper border of the arch begin, the line at the right end of the sternal angle and carry it upwards and to the left with a curve that reaches the middle of the manubrium sterni b From there, continue the convexity downwards and to the left to end over the second left costal cartilage near the sternal margin c You can draw the lower border in the form of a sharply convex short line as shown in 21.4 Descending Thoracic Aorta a The upper end of the descending thoracic aorta corresponds to the lower end of the arch of the aorta b It lies at the level of the lower border of the fourth thoracic vertebra Its projection onto the anterior wall of the thorax lies over the left part of the sternal angle and the adjoining part of the second left costal cartilage In other words, the upper end of the descending aorta lies to the left of the midline a The lower end has to be marked at the level of the lower border of the twelfth vertebra This level lies over the anterior abdominal wall b To mark it you have to first mark the transpyloric plane (This is an imaginary transverse line drawn on the anterior abdominal wall midway between the upper end of the sternum and the upper border of the pubic symphysis It lies roughly at a hand’s breadth below the xiphoid process) Take a point 2.5 cm above this plane, in the midline Remember that the lower end of the thoracic aorta is about 2.5 cm broad and lies in the median plane The aorta can now be marked merely by drawing two parallel lines, 2.5 cm apart joining the upper and lower ends As the vessel descends it gradually passes from the left side to a median position Branches of Arch of Aorta These are the brachiocephalic artery, the left common carotid artery and the left subclavian artery They all arise from the summit of the arch of the aorta Therefore, to mark any of these arteries first mark the upper border of the arch of the aorta as described above 466 Part ♦ Thorax Brachiocephalic Artery Its lower end lies over the centre of the manubrium sterni Its upper end lies behind the right sternoclavicular joint Join these two levels by two parallel lines about one-fourth inch (8 mm) apart Left Common Carotid Artery in Thorax Its origin from the arch of the aorta lies just to the left of the centre of the manubrium (i.e., just to the left of the origin of the brachiocephalic artery) From here it passes upwards and to the left to reach the left sternoclavicular joint (At this level, the artery enters the neck) To mark the artery join the two levels by two parallel line about one-fourth inch (8 mm) apart The lines pass upwards and somewhat to the left Left Subclavian Artery in Thorax The origin of this artery from the arch of the aorta is to the left of that of the left common carotid i.e., it is near the left border of the manubrium sterni The artery is marked by two parallel, vertical, lines that extend to the left sternoclavicular joint The lines should be about one-fourth inch (8 mm) apart Superior Vena Cava This vessel lies partly in the superior mediastinum and partly in the middle mediastinum Its surface projection is, therefore, partly above the level of the sternal angle and partly below this level The surface projection of the superior vena cava is shown in 21.17 (page 437) Note that the vessel lies along the right side of the sternum The vena cava can be represented by two parallel and vertical lines cm apart a Its upper end (beginning) lies over the lower border of the first right costal cartilage b Its lower end (termination) is at the level of the upper border of the third right costal cartilage Right Brachiocephalic Vein The upper end of the vein lies behind the medial end of the clavicle The lower end (termination) of this vein corresponds to the upper end of the superior vena cava (and lies over the lower border of the first right costal cartilage) The lines representing the vein should be vertical and 1.5 cm apart Left Brachiocephalic Vein The upper end of the vein lies deep to the medial end of the left clavicle The lower end of this vein (termination) corresponds to the upper end of the superior vena cava (and lies over the lower border of the first right costal cartilage) The vein is represented by two lines 1.5 cm apart joining these two levels Note that the vein runs obliquely and crosses behind the left sternoclavicular joint and the manubrium sterni Chapter 23 ♦ Surface Marking and Radiological Anatomy of the Thorax 467 Radiological Anatomy of the thorax The radiological anatomy of the thorax is shown in 23.1 to 23.4 23.1: Plain radiograph of the chest Posteroanterior view, in a female adult Observe the following in 23.1: Skeletal elements: The posterior parts of the ribs form a series of shadows running laterally and downwards The anterior parts of ribs are seen (in the lateral part) as less prominent shadows curving downwards and medially (The costal cartilages not case any shadows) The vertebrae can be made out in the upper part of the radiograph Lower down, the vertebrae and the sternum cannot be made out as they are overlapped by the shadow of the heart, and of structures in the mediastinum The clavicle and scapula are seen, on each side, in the upper lateral part of the radiograph The heart casts a shadow as it is full of blood The right and left borders of the heart can be made out When traced upwards, the left border becomes continuous with a shadow convex to the left This shadow is produced by the arch of the aorta and is referred to as the aortic knuckle Just below the aortic knuckle, the border of the heart shadow represents the pulmonary trunk When this is enlarged it may be seen as a projection called the pulmonary conus The right border of the heart merges, above and below, with the corresponding vena cava The areas occupied by the lungs are seen as dark areas (as they are full of air) However, just lateral to the cardiac shadow irregular shadows are produced by structures in the hilum of each lung Finally, note the shadow cast by the diaphragm (and structures below it) Note the domes of the diaphragm The right dome is higher than the left 468 Part ♦ Thorax 23.2: Cross-section (axial section) of thorax obtained by CT scan The section is viewed from the foot end of the patient That is why the structures belonging to the left half of the thorax are seen in the right half of the picture The section passes through the upper part of the heart (mainly atria), just below the level of the bifurcation of the trachea The areas filled with air (lungs, lumen of bronchi) appear dark, while other structures appear light DA: descending thoracic aorta; OE: oesophagus; LB: left principal bronchus; RB: right principal bronchus; PV: pulmonary vessels Ramifications of pulmonary vessels are seen as radiating shadows within the lungs Chapter 23 ♦ Surface Marking and Radiological Anatomy of the Thorax 23.3: Radiograph taken immediately after the patient had swallowed a suspension of barium sulphate (which is opaque to X-rays) The oesophagus is clearly outlined Any defects in the lumen produced by disease can be made out An enlarged left atrium (abnormal) produces an indentation on the shadow of the oesophagus 469 470 Part ♦ Thorax 23.4: Bronchogram showing bronchi of the left lung (oblique view) A catheter was passed into the trachea, and then into the left principal bronchus, and a contrast medium was injected to outline the bronchi See 21.13 (page 429) (Coronary angiography) ... Other Joints of the Upper Limb 13 5 13 5 13 5 13 9 14 1 14 1 14 1 14 3 14 9 15 1 15 3 15 4 Surface Marking and Radiological Anatomy of Upper Limb Surface Marking Radiological Anatomy 15 7 15 7 16 2 PART 2: LOWER... Back of the Forearm and Hand Muscles of the Back of the Forearm Nerves and Arteries on the Back of the Forearm and Hand 10 4 10 6 10 9 11 8 12 8 12 8 13 3 General Features of Joints and Joints of the... EXTREMITY Bones of Lower Extremity The Hip Bone Pelvis as a Whole The Femur The Patella The Tibia The Fibula The Skeleton of the Foot 16 7 16 7 17 7 18 0 18 6 18 8 19 3 19 7 10 Cutaneous Nerves,