Moore's Clinically Oriented Anatomy 7E PDF

Introduction to Clinically Oriented Anatomy APPROACHES TO STUDYING BLUE BOX: Joints. Joints of Newborn Cranium; ANATOMY / 2 Degenerative Joint Dise...

Introduction to Clinically Oriented Anatomy APPROACHES TO STUDYING BLUE BOX: Joints. Joints of Newborn Cranium; ANATOMY / 2 Degenerative Joint Disease; Arthroscopy / 28 Regional Anatomy / 2 MUSCLE TISSUE AND MUSCULAR SYSTEM / 29 Systemic Anatomy / 3 Types of Muscle (Muscle Tissue) / 29 Clinical Anatomy / 4 Skeletal Muscles / 29 ANATOMICOMEDICAL TERMINOLOGY / 4 TABLE I.1. Types of Muscle (MUSCLE Anatomical Position / 5 TISSUE) / 30 Anatomical Planes / 5 BLUE BOX: Skeletal Muscles. Muscle Terms of Relationship and Comparison / 6 Dysfunction and Paralysis; Absence of Muscle Tone; Muscle Soreness and “Pulled” Terms of Laterality / 7 Muscles; Growth and Regeneration of Terms of Movement / 7 Skeletal Muscle; Muscle Testing / 35 Cardiac Striated Muscle / 36 ANATOMICAL VARIATIONS / 12 Smooth Muscle / 36 INTEGUMENTARY SYSTEM / 12 BLUE BOX: Cardiac and Smooth Muscle. BLUE BOX: Integumentary System. Skin Hypertrophy of the Myocardium and Color Signs in Physical Diagnosis; Skin Myocardial Infarction; Hypertrophy and Incisions and Scarring; Stretch Marks in Skin; Hyperplasia of Smooth Muscle / 37 Skin Injuries and Wounds / 14 CARDIOVASCULAR SYSTEM / 37 FASCIAS, FASCIAL COMPARTMENTS, BURSAE, AND POTENTIAL SPACES / 16 Vascular Circuits / 37 BLUE BOX: Fascias. Fascial Planes and Blood Vessels / 37 Surgery / 19 BLUE BOX: Cardiovascular System. SKELETAL SYSTEM / 19 Arteriosclerosis: Ischemia and Infarction; Varicose Veins / 42 Cartilage and Bones / 19 LYMPHOID SYSTEM / 43 Bone Markings and Formations / 20 BLUE BOX: Lymphoid System. Spread BLUE BOX: Bones. Accessory of Cancer; Lymphangitis, Lymphadenitis, (Supernumerary) Bones; Heterotopic and Lymphedema / 45 Bones; Trauma to Bone and Bone Changes; NERVOUS SYSTEM / 46 Osteoporosis; Sternal Puncture; Bone Growth and Assessment of Bone Age; Central Nervous System / 47 Effects of Disease and Diet on Bone Growth; Displacement and Separation of Epiphyses; Peripheral Nervous System / 47 Avascular Necrosis / 23 BLUE BOX: Central and Peripheral Joints / 25 Nervous System. Damage to the CNS; Rhizotomy; Nerve Degeneration and Ischemia of Nerves / 53 1 Moore_Intro.indd 1 12/10/2012 6:28:18 PM  2 Introduction to Clinically Oriented Anatomy Somatic Nervous System / 57 Computed Tomography / 67 Autonomic Nervous System (Ans) / 57 Ultrasonography / 67 TABLE I.2. Functions of Autonomic Nervous Magnetic Resonance Imaging / 68 System (Ans) / 65 Nuclear Medicine Imaging / 70 MEDICAL IMAGING TECHNIQUES / 66 Conventional Radiography / 66 APPROACHES TO STUDYING outer covering and may be studied and examined in living individuals via surface anatomy. ANATOMY Surface anatomy is an essential part of the study of regional anatomy. It is specifically addressed in this book in Anatomy is the setting (structure) in which the events (func- “surface anatomy sections” (orange background) that provide tions) of life occur. This book deals mainly with functional knowledge of what lies under the skin and what structures human gross anatomy—the examination of structures of the are perceptible to touch (palpable) in the living body at rest human that can be seen without a microscope. The three and in action. We can learn much by observing the exter- main approaches to studying anatomy are regional, systemic, nal form and surface of the body and by observing or feel- and clinical (or applied), reflecting the body’s organization ing the superficial aspects of structures beneath its surface. and the priorities and purposes for studying it. The aim of this method is to visualize (recall distinct mental images of) structures that confer contour to the surface or are palpable beneath it and, in clinical practice, to distinguish Regional Anatomy any unusual or abnormal findings. In short, surface anatomy Regional anatomy (topographical anatomy) considers the requires a thorough understanding of the anatomy of the organization of the human body as major parts or segments structures beneath the surface. In people with stab wounds, (Fig. I.1): a main body, consisting of the head, neck, and trunk for example, a physician must be able to visualize the deep (subdivided into thorax, abdomen, back, and pelvis/perineum), structures that may be injured. Knowledge of surface anat- and paired upper limbs and lower limbs. All the major parts may omy can also decrease the need to memorize facts because be further subdivided into areas and regions. Regional anat- the body is always available to observe and palpate. omy is the method of studying the body’s structure by focusing Physical examination is the clinical application of sur- attention on a specific part (e.g., the head), area (the face), or face anatomy. Palpation is a clinical technique, used with region (the orbital or eye region); examining the arrangement observation and listening for examining the body. Pal- and relationships of the various systemic structures (muscles, pation of arterial pulses, for instance, is part of a physical nerves, arteries, etc.) within it; and then usually continuing to examination. Students of many of the health sciences will study adjacent regions in an ordered sequence. Outside of this learn to use instruments to facilitate examination of the body Introduction, the regional approach is followed in this book, (such as an ophthalmoscope for observation of features of with each chapter addressing the anatomy of a major part of the eyeballs) and to listen to functioning parts of the body the body. This is the approach usually followed in anatomy (a stethoscope to auscultate the heart and lungs). courses that have a laboratory component involving dissection. Regional study of deep structures and abnormalities in When studying anatomy by this approach, it is important to a living person is now also possible by means of radiographic routinely put the regional anatomy into the context of that of and sectional imaging and endoscopy. Radiographic and adjacent regions, parts, and of the body as a whole. sectional imaging (radiographic anatomy) provides useful Regional anatomy also recognizes the body’s organization information about normal structures in living individuals, dem- by layers: skin, subcutaneous tissue, and deep fascia cov- onstrating the effect of muscle tone, body fluids and pressures, ering the deeper structures of muscles, skeleton, and cavi- and gravity that cadaveric study does not. Diagnostic radiology ties, which contain viscera (internal organs). Many of these reveals the effects of trauma, pathology, and aging on normal deeper structures are partially evident beneath the body’s structures. In this book, most radiographic and many sectional Moore_Intro.indd 2 12/10/2012 6:28:25 PM  Introduction to Clinically Oriented Anatomy 3 Major parts of the body models. Prosections, carefully prepared dissections for the demonstration of anatomical structures, are also useful. Head Back Lower limb Neck Abdomen Upper limb However, learning is most efficient and retention is highest Thorax Pelvis/perineum when didactic study is combined with the experience of first- hand dissection—that is, learning by doing. During dissec- tion you observe, palpate, move, and sequentially reveal parts of the body. In 1770, Dr. William Hunter, a distinguished Scottish anatomist and obstetrician, stated: “Dissection alone teaches us where we may cut or inspect the living body with freedom and dispatch.” Systemic Anatomy Systemic anatomy is the study of the body’s organ systems that work together to carry out complex functions. The basic systems and the field of study or treatment of each (in paren- 1 theses) are: 2 The integumentary system (dermatology) consists of the 3 skin (L. integumentum, a covering) and its appendages— hairs, nails, and sweat glands, for example—and the sub- 4 5 cutaneous tissue just beneath it. The skin, an extensive sensory organ, forms the body’s outer, protective covering 6 and container. 7 The skeletal system (osteology) consists of bones and cartilage; it provides our basic shape and support for the 8 9 10 body and is what the muscular system acts on to produce 10 movement. It also protects vital organs such as the heart, Anterior view Posterior view lungs, and pelvic organs. The articular system (arthrology) consists of joints and Regions of lower limb their associated ligaments, connecting the bony parts of 1 = Gluteal region 6 = Anterior leg region the skeletal system and providing the sites at which move- 2 = Anterior thigh region 7 = Posterior leg region ments occur. 3 = Posterior thigh region 8 = Anterior talocrural (ankle) region 4 = Anterior knee region 9 = Posterior talocrural region The muscular system (myology) consists of skeletal mus- 5 = Posterior knee region 10 = Foot region cles that act (contract) to move or position parts of the body (e.g., the bones that articulate at joints), or smooth FIGURE I.1. Major parts of the body and regions of the lower limb. and cardiac muscle that propels, expels, or controls the Anatomy is described relative to the anatomical position illustrated here. flow of fluids and contained substance. The nervous system (neurology) consists of the central nervous system (brain and spinal cord) and the peripheral images are integrated into the chapters where appropriate. nervous system (nerves and ganglia, together with their The medical imaging sections at the end of each chapter pro- motor and sensory endings). The nervous system con- vide an introduction to the techniques of radiographic and sec- trols and coordinates the functions of the organ systems, tional imaging and include series of sectional images that apply enabling the body’s responses to and activities within its to the chapter. Endoscopic techniques (using a insertable flex- environment. The sense organs, including the olfactory ible fiber optic device to examine internal structures, such as organ (sense of smell), eye or visual system (ophthal- the interior of the stomach) also demonstrate living anatomy. mology), ear (sense of hearing and balance—otology), and The detailed and thorough learning of the three-dimensional gustatory organ (sense of taste), are often considered with anatomy of deep structures and their relationships is best the nervous system in systemic anatomy. accomplished initially by dissection. In clinical practice, sur- The circulatory system (angiology) consists of the face anatomy, radiographic and sectional images, endoscopy, cardiovascular and lymphatic systems, which function in and your experience from studying anatomy will combine to parallel to transport the body’s fluids. provide you with knowledge of your patient’s anatomy. The cardiovascular system (cardiology) consists of the The computer is a useful adjunct in teaching regional anat- heart and blood vessels that propel and conduct blood omy because it facilitates learning by allowing interactivity through the body, delivering oxygen, nutrients, and hor- and manipulation of two- and three-dimensional graphic mones to cells and removing their waste products. Moore_Intro.indd 3 12/10/2012 6:28:25 PM  4 Introduction to Clinically Oriented Anatomy The lymphatic system is a network of lymphatic vessels Clinical Anatomy that withdraws excess tissue fluid (lymph) from the body’s interstitial (intercellular) fluid compartment, filters it Clinical anatomy (applied anatomy) emphasizes aspects of through lymph nodes, and returns it to the bloodstream. bodily structure and function important in the practice of The alimentary or digestive system (gastroenterology) medicine, dentistry, and the allied health sciences. It incor- consists of the digestive tract from the mouth to the anus, porates the regional and systemic approaches to studying with all its associated organs and glands that function in anatomy and stresses clinical application. ingestion, mastication (chewing), deglutition (swallow- Clinical anatomy often involves inverting or reversing the ing), digestion, and absorption of food and the elimination thought process typically followed when studying regional of the solid waste (feces) remaining after the nutrients or systemic anatomy. For example, instead of thinking, “The have been absorbed. action of this muscle is to... ,” clinical anatomy asks, “How The respiratory system (pulmonology) consists of the air would the absence of this muscle’s activity be manifest?” passages and lungs that supply oxygen to the blood for cel- Instead of noting, “The... nerve provides innervation to this lular respiration and eliminate carbon dioxide from it. The area of skin,” clinical anatomy asks, “Numbness in this area diaphragm and larynx control the flow of air through the indicates a lesion of which nerve?” system, which may also produce tone in the larynx that is Clinical anatomy is exciting to learn because of its role in further modified by the tongue, teeth, and lips into speech. solving clinical problems. The clinical correlation boxes (pop- The urinary system (urology) consists of the kidneys, ularly called “blue boxes,” appearing on a blue background) ureters, urinary bladder, and urethra, which filter blood throughout this book describe practical applications of anat- and subsequently produce, transport, store, and intermit- omy. “Case studies,” such as those on the Clinically Oriented tently excrete urine (liquid waste). Anatomy website (http://thePoint.lww.com/COA7e), are The genital (reproductive) system (gynecology for integral parts of the clinical approach to studying anatomy. females; andrology for males) consists of the gonads (ova- ries and testes) that produce oocytes (eggs) and sperms, the ducts that transport them, and the genitalia that enable their union. After conception, the female repro- The Bottom Line ductive tract nourishes and delivers the fetus. The endocrine system (endocrinology) consists of STUDYING ANATOMY specialized structures that secrete hormones, including Anatomy is the study of the structure of the human body. discrete ductless endocrine glands (such as the thyroid ♦ Regional anatomy considers the body as organized into gland), isolated and clustered cells of the gut and blood segments or parts. ♦ Systemic anatomy sees the body as vessel walls, and specialized nerve endings. Hormones organized into organ systems. ♦ Surface anatomy provides are organic molecules that are carried by the circulatory information about structures that may be observed or system to distant effector cells in all parts of the body. palpated beneath the skin. ♦ Radiographic, sectional, and The influence of the endocrine system is thus as broadly endoscopic anatomy allows appreciation of structures in distributed as that of the nervous system. Hormones influ- living people, as they are affected by muscle tone, body flu- ence metabolism and other processes, such as the men- ids and pressures, and gravity. ♦ Clinical anatomy empha- strual cycle, pregnancy, and parturition (childbirth). sizes application of anatomical knowledge to the practice None of the systems functions in isolation. The passive skel- of medicine. etal and articular systems and the active muscular system col- lectively constitute a supersystem, the locomotor system or apparatus (orthopedics), because they must work together to produce locomotion of the body. Although the structures ANATOMICOMEDICAL directly responsible for locomotion are the muscles, bones, joints, and ligaments of the limbs, other systems are indi- TERMINOLOGY rectly involved as well. The brain and nerves of the nervous system stimulate them to act; the arteries and veins of the cir- Anatomical terminology introduces and makes up a large culatory system supply oxygen and nutrients to and remove part of medical terminology. To be understood, you must waste from these structures; and the sensory organs (espe- express yourself clearly, using the proper terms in the cor- cially vision and equilibrium) play important roles in direct- rect way. Although you are familiar with common, colloquial ing their activities in a gravitational environment. terms for parts and regions of the body, you must learn the In this Introduction, an overview of several systems sig- international anatomical terminology (e.g., axillary fossa nificant to all parts and regions of the body will be provided instead of armpit and clavicle instead of collarbone) that before Chapters 1 through 8 cover regional anatomy in detail. enables precise communication among healthcare profes- Chapter 9 also presents systemic anatomy in reviewing the sionals and scientists worldwide. Health professionals must cranial nerves. also know the common and colloquial terms people are likely Moore_Intro.indd 4 12/10/2012 6:28:25 PM  Introduction to Clinically Oriented Anatomy 5 to use when they describe their complaints. Furthermore, and if you learn their meanings and think about them as you you must be able to use terms people will understand when read and dissect, it will be easier to remember their names. explaining their medical problems to them. Abbreviations. Abbreviations of terms are used for brev- The terminology in this book conforms to the new Interna- ity in medical histories and in this and other books, such as in tional Anatomical Terminology. Terminologia Anatomica (TA) tables of muscles, arteries, and nerves. Clinical abbreviations and Terminologia Embryologica (TE) list terms both in Latin are used in discussions and descriptions of signs and symptoms. and as English equivalents (e.g., the common shoulder muscle Learning to use these abbreviations also speeds note taking. is musculus deltoideus in Latin and deltoid in English). Most Common anatomical and clinical abbreviations are provided terms in this book are English equivalents. Official terms are in this text when the corresponding term is introduced—for available at www.unifr.ch/ifaa. Unfortunately, the terminology example, temporomandibular joint (TMJ). The Clinically Ori- commonly used in the clinical arena may differ from the offi- ented Anatomy website (http://thePoint.lww.com/COA7e) cial terminology. Because this discrepancy may be a source provides a list of commonly used anatomical abbreviations. of confusion, this text clarifies commonly confused terms by More extensive lists of common medical abbreviations may placing the unofficial designations in parentheses when the be found in the appendices of comprehensive medical dictio- terms are first used—for example, pharyngotympanic tube naries (e.g., Stedman’s Medical Dictionary, 28th ed.). (auditory tube, eustachian tube) and internal thoracic artery (internal mammary artery). Eponyms, terms incorporating the Anatomical Position names of people, are not used in the new terminology because they give no clue about the type or location of the structures All anatomical descriptions are expressed in relation to one involved. Further, many eponyms are historically inaccurate in consistent position, ensuring that descriptions are not ambig- terms of identifying the original person to describe a structure uous (Figs. I.1 and I.2). One must visualize this position in or assign its function, and do not conform to an international the mind when describing patients (or cadavers), whether standard. Notwithstanding, commonly used eponyms appear they are lying on their sides, supine (recumbent, lying on the in parentheses throughout the book when these terms are first back, face upward), or prone (lying on the abdomen, face used—such as sternal angle (angle of Louis)—since you will downward). The anatomical position refers to the body surely encounter them in your clinical years. Note that epony- position as if the person were standing upright with the: mous terms do not help to locate the structure in the body. head, gaze (eyes), and toes directed anteriorly (forward), The Clinically Oriented Anatomy website (http://thePoint. arms adjacent to the sides with the palms facing anteri- lww.com/COA7e) provides a list of eponymous terms. orly, and Structure of terms. Anatomy is a descriptive science and lower limbs close together with the feet parallel. requires names for the many structures and processes of the body. Because most terms are derived from Latin and Greek, This position is adopted globally for anatomicomedical medical language may seem difficult at first; however, as you descriptions. By using this position and appropriate terminol- learn the origin of terms, the words make sense. For example, ogy, you can relate any part of the body precisely to any other the term gaster is Latin for stomach or belly. Consequently, part. It should also be kept in mind, however, that gravity the esophagogastric junction is the site where the esophagus causes a downward shift of internal organs (viscera) when the connects with the stomach, gastric acid is the digestive juice upright position is assumed. Since people are typically exam- secreted by the stomach, and a digastric muscle is a muscle ined in the supine position, it is often necessary to describe divided into two bellies. the position of the affected organs when supine, making spe- Many terms provide information about a structure’s cific note of this exception to the anatomical position. shape, size, location, or function or about the resemblance of one structure to another. For example, some muscles have Anatomical Planes descriptive names to indicate their main characteristics. Anatomical descriptions are based on four imaginary planes The deltoid muscle, which covers the point of the shoulder, (median, sagittal, frontal, and transverse) that intersect the is triangular, like the symbol for delta, the fourth letter of body in the anatomical position (Fig. I.2): the Greek alphabet. The suffix -oid means “like”; therefore, deltoid means like delta. Biceps means two-headed and tri- The median plane (median sagittal plane), the vertical ceps means three-headed. Some muscles are named accord- plane passing longitudinally through the body, divides the ing to their shape—the piriformis muscle, for example, is body into right and left halves. The plane defines the mid- pear shaped (L. pirum, pear + L. forma, shape or form). line of the head, neck, and trunk where it intersects the Other muscles are named according to their location. The surface of the body. Midline is often erroneously used as temporal muscle is in the temporal region (temple) of the a synonym for the median plane. cranium (skull). In some cases, actions are used to describe Sagittal planes are vertical planes passing through the muscles—for example, the levator scapulae elevates the scap- body parallel to the median plane. Parasagittal is com- ula (L. shoulder blade). Anatomical terminology applies logical monly used but is unnecessary because any plane paral- reasons for the names of muscles and other parts of the body, lel to and on either side of the median plane is sagittal Moore_Intro.indd 5 12/10/2012 6:28:26 PM  6 Introduction to Clinically Oriented Anatomy Median plane Frontal (coronal) plane Sagittal plane Transverse (axial) plane Median plane of hand Frontal (coronal) Median plane of plane of feet foot (A) (B) (C) FIGURE I.2. Anatomical planes. The main planes of the body are illustrated. by definition. However, a plane parallel and near to the the long axis of the foot runs horizontally, a transverse sec- median plane may be referred to as a paramedian plane. tion of the foot lies in the frontal plane (Fig. I.2C). Frontal (coronal) planes are vertical planes passing Oblique sections are slices of the body or any of its parts through the body at right angles to the median plane, divid- that are not cut along the previously listed anatomical ing the body into anterior (front) and posterior (back) parts. planes. In practice, many radiographic images and ana- Transverse planes are horizontal planes passing through tomical sections do not lie precisely in sagittal, frontal, or the body at right angles to the median and frontal planes, transverse planes; often they are slightly oblique. dividing the body into superior (upper) and inferior Anatomists create sections of the body and its parts anatomi- (lower) parts. Radiologists refer to transverse planes as cally, and clinicians create them by planar imaging technolo- transaxial, which is commonly shortened to axial planes. gies, such as computerized tomography (CT), to describe Since the number of sagittal, frontal, and transverse planes and display internal structures. is unlimited, a reference point (usually a visible or palpable landmark or vertebral level) is necessary to identify the loca- tion or level of the plane, such as a “transverse plane through Terms of Relationship the umbilicus” (Fig. I.2C). Sections of the head, neck, and and Comparison trunk in precise frontal and transverse planes are symmet- Various adjectives, arranged as pairs of opposites, describe rical, passing through both the right and left members of the relationship of parts of the body or compare the position paired structures, allowing some comparison. of two structures relative to each other (Fig. I.4). Some of The main use of anatomical planes is to describe sections these terms are specific for comparisons made in the ana- (Fig. I.3): tomical position, or with reference to the anatomical planes: Longitudinal sections run lengthwise or parallel to the Superior refers to a structure that is nearer the vertex, long axis of the body or of any of its parts, and the term the topmost point of the cranium (Mediev. L., skull). Cranial applies regardless of the position of the body. Although relates to the cranium and is a useful directional term, mean- median, sagittal, and frontal planes are the standard (most ing toward the head or cranium. Inferior refers to a struc- commonly used) longitudinal sections, there is a 180° ture that is situated nearer the sole of the foot. Caudal range of possible longitudinal sections. (L. cauda, tail) is a useful directional term that means toward Transverse sections, or cross sections, are slices of the feet or tail region, represented in humans by the coccyx the body or its parts that are cut at right angles to the (tail bone), the small bone at the inferior (caudal) end of the longitudinal axis of the body or of any of its parts. Because vertebral column. Moore_Intro.indd 6 12/10/2012 6:28:26 PM  Introduction to Clinically Oriented Anatomy 7 Longitudinal Transverse section Oblique section section (A) (B) (C) FIGURE I.3. Sections of the limbs. Sections may be obtained by anatomical sectioning or medical imaging techniques. Posterior (dorsal) denotes the back surface of the body Superficial, intermediate, and deep describe the posi- or nearer to the back. Anterior (ventral) denotes the front tion of structures relative to the surface of the body or the surface of the body. Rostral is often used instead of anterior relationship of one structure to another underlying or overly- when describing parts of the brain; it means toward the ros- ing structure. trum (L. for beak); however, in humans it denotes nearer the External means outside of or farther from the center of anterior part of the head (e.g., the frontal lobe of the brain is an organ or cavity, while internal means inside or closer to rostral to the cerebellum). the center, independent of direction. Medial is used to indicate that a structure is nearer to the Proximal and distal are used when contrasting positions median plane of the body. For example, the 5th digit of the hand nearer to or farther from the attachment of a limb or the (little finger) is medial to the other digits. Conversely, lateral central aspect of a linear structure, respectively. stipulates that a structure is farther away from the median plane. The 1st digit of the hand (thumb) is lateral to the other digits. Terms of Laterality Dorsum usually refers to the superior aspect of any Paired structures having right and left members (e.g., the part that protrudes anteriorly from the body, such as the kidneys) are bilateral, whereas those occurring on one side dorsum of the tongue, nose, penis, or foot. It is also used only (e.g., the spleen) are unilateral. Designating whether to describe the posterior surface of the hand, opposite the you are referring specifically to the right or left member of palm. Because the term dorsum may refer to both superior bilateral structures can be critical, and is a good habit to begin and posterior surfaces in humans, the term is easier to under- at the outset of one’s training to become a health professional. stand if one thinks of a quadripedal plantigrade animal that Something occurring on the same side of the body as another walks on its palms and soles, such as a bear. The sole is the structure is ipsilateral; the right thumb and right great (big) inferior aspect or bottom of the foot, opposite the dorsum, toe are ipsilateral, for example. Contralateral means occur- much of which is in contact with the ground when standing ring on the opposite side of the body relative to another struc- barefoot. The surface of the hands, the feet, and the digits of ture; the right hand is contralateral to the left hand. both corresponding to the dorsum is the dorsal surface, the surface of the hand and fingers corresponding to the palm is the palmar surface, and the surface of the foot and toes Terms of Movement corresponding to the sole is the plantar surface. Various terms describe movements of the limbs and other Combined terms describe intermediate positional arrange- parts of the body (Fig. I.5). Most movements are defined ments: inferomedial means nearer to the feet and median in relationship to the anatomical position, with movements plane—for example, the anterior parts of the ribs run infero- occurring within, and around axes aligned with, specific ana- medially; superolateral means nearer to the head and far- tomical planes. While most movements occur at joints where ther from the median plane. two or more bones or cartilages articulate with one another, Other terms of relationship and comparisons are inde- several non-skeletal structures exhibit movement (e.g., tongue, pendent of the anatomical position or the anatomical planes, lips, eyelids). Terms of movement may also be considered in relating primarily to the body’s surface or its central core: pairs of oppositing movements: Moore_Intro.indd 7 12/10/2012 6:28:28 PM  8 Introduction to Clinically Oriented Anatomy * Superficial Superior (cranial) Palmar vs. Dorsal Nearer to surface Nearer to head Anterior hand (palm) The muscles of the arm The heart is superior Posterior hand (dorsum) are superficial to its to the stomach. bone (humerus). Dorsal Palmar surface surface * Intermediate Dorsum Palm Between a superficial and a deep structure The biceps muscle is intermediate between the skin and the humerus. Plantar vs. Dorsal Inferior foot surface (sole) * Deep Superior foot surface (dorsum) Farther from surface The humerus is deep Dorsal Plantar to the arm muscles. surface surface Median plane Dorsum Sole Coronal plane Medial Nearer to median plane The 5th digit (little finger) is on the medial * Proximal side of the hand. Nearer to trunk or point of origin (e.g., of a limb) Lateral The elbow is proximal to Farther from median the wrist, and the prox- plane imal part of an artery is its beginning. The 1st digit (thumb) is on the lateral side of the hand. * Distal Farther from trunk or point of origin (e.g., of a limb) The wrist is distal to the elbow, and the distal Posterior (dorsal) part of the upper limb is the hand. Nearer to back The heel is posterior to the toes. Anterior (ventral) Nearer to front The toes are anterior to the ankle. Key Terms applied to the entire body Terms specific for hands and feet Inferior (caudal) Terms independent of anatomical position Nearer to feet * The stomach is inferior to the heart. FIGURE I.4. Terms of relationship and comparison. These terms describe the position of one structure relative to another. Moore_Intro.indd 8 12/10/2012 6:28:29 PM  Extension Flexion Extension Flexion Flexion Extension Flexion Extension Extension Flexion (A) Flexion and extension of upper limb at Flexion and extension of forearm at Flexion and extension of vertebral shoulder joint and lower limb at hip joint elbow joint and of leg at knee joint column at intervertebral joints Extension ion Flexion Supination Pronation Flexion n Extension Opposition Reposition (B) Flexion and extension Flexion and extension (C) Opposition and reposition of thumb (D) Pronation and supination of hand at wrist joint of digits (fingers) at and little finger at carpometacarpal of forearm at radio-lnar metacarpophalangeal and joint of thumb combined with flexion at joints interphalangeal joints metacarpophalangeal joints Adduction Abduction Extension Flexion Abduction Adduction Lateral Medial abduction abduction (F) The thumb is rotated 90° relative to other structures. Abduction and (E) Abduction and adduction Abduction of 3rd digit at adduction at metacarpophalangeal joint occurs in a sagittal plane; of 2nd, 4th, and 5th metacarpophalangeal flexion and extension at metacarpophalangeal and interphalangeal digits at metacarpo- joint joints occurs in frontal planes, opposite to these movements at all phalangeal joints other joints. FIGURE I.5. Terms of movement. These terms describe movements of the limbs and other parts of the body; most movements take place at joints, where two or more bones or cartilages articulate with one another. Moore_Intro.indd 9 12/10/2012 6:28:31 PM  10 Introduction to Clinically Oriented Anatomy Lateral (external) Dorsiflexion rotation Medial Abduction (internal) rotation Plantarflexion Dorsiflexion and plantarflexion of foot at ankle joint Adduction Lateral rotation Medial rotation Eversion Inversion Abduction Adduction Circumduction (G) Abduction and adduction of right limbs and (H) Circumduction (circular movement) of (I) Inversion and eversion of foot at rotation of left limbs at glenohumeral and hip lower limb at hip joint subtalar and transverse tarsal joints joints, respectively Lateral bending Rotation of head and neck Rotation of upper trunk, neck, and head Elevation Depression (K) Elevation and depression of shoulders (J) Lateral bending (lateral flexion) of trunk and rotation of upper trunk, neck, and head Retraction Retrusion Protrusion Protraction (L) Protrusion and retrusion of jaw at temporomandibular joints (M) Protraction and retraction of scapula on thoracic wall FIGURE I.5. (Continued) Moore_Intro.indd 10 12/10/2012 6:28:33 PM  Introduction to Clinically Oriented Anatomy 11 Flexion and extension movements generally occur in sag- and across the anterior aspect of the ulna (the other long bone ittal planes around a transverse axis (Fig. I.5A & B). Flex- of the forearm) while the proximal end of the radius rotates in ion indicates bending or decreasing the angle between the place (Fig. I.5D). Pronation rotates the radius medially so that bones or parts of the body. For most joints (e.g., elbow), flex- the palm of the hand faces posteriorly and its dorsum faces ante- ion involves movement in an anterior direction. Extension riorly. When the elbow joint is flexed, pronation moves the hand indicates straightening or increasing the angle between the so that the palm faces inferiorly (e.g., placing the palms flat on a bones or parts of the body. Extension usually occurs in a pos- table). Supination is the opposite rotational movement, rotat- terior direction. The knee joint, rotated 180° to other joints, is ing the radius laterally and uncrossing it from the ulna, return- exceptional in that flexion of the knee involves posterior move- ing the pronated forearm to the anatomical position. When the ment and extension involves anterior movement. Dorsiflex- elbow joint is flexed, supination moves the hand so that the palm ion describes flexion at the ankle joint, as occurs when walking faces superiorly. (Memory device: You can hold soup in the palm uphill or lifting the front of the foot and toes off the ground of your hand when the flexed forearm is supinated but are prone (Fig. I.5I). Plantarflexion bends the foot and toes toward the [likely] to spill it if the forearm is then pronated!) ground, as when standing on your toes. Extension of a limb or Eversion moves the sole of the foot away from the median part beyond the normal limit—hyperextension (overexten- plane, turning the sole laterally (Fig. I.5I). When the foot is sion)—can cause injury, such as “whiplash” (i.e., hyperexten- fully everted it is also dorsiflexed. Inversion moves the sole sion of the neck during a rear-end automobile collision). of the foot toward the median plane (facing the sole medi- Abduction and adduction movements generally occur in a ally). When the foot is fully inverted it is also plantarflexed. frontal plane around an anteroposterior axis (Fig. I.5E & G). Pronation of the foot actually refers to a combination of ever- Except for the digits, abduction means moving away from sion and abduction that results in lowering of the medial the median plane (e.g., when moving an upper limb laterally margin of the foot (the feet of an individual with flat feet away from the side of the body) and adduction means mov- are pronated), and supination of the foot generally implies ing toward it. In abduction of the digits (fingers or toes), the movements resulting in raising the medial margin of the foot, term means spreading them apart—moving the other fingers a combination of inversion and adduction. away from the neutrally positioned 3rd (middle) finger or Opposition is the movement by which the pad of the 1st moving the other toes away from the neutrally positioned 2nd digit (thumb) is brought to another digit pad (Fig. I.5C). This toe. The 3rd finger and 2nd toe medially or laterally abduct movement is used to pinch, button a shirt, and lift a teacup by away from the neutral position. Adduction of the digits is the handle. Reposition describes the movement of the 1st digit the opposite—bringing the spread fingers or toes together, from the position of opposition back to its anatomical position. toward the neutrally positioned 3rd finger or 2nd toe. Right Protrusion is a movement anteriorly (forward) as in and left lateral flexion (lateral bending) are special forms of protruding the mandible (chin), lips, or tongue (Fig. I.5L). abduction for only the neck and trunk (Fig. I.5J). The face Retrusion is a movement posteriorly (backward), as in and upper trunk are directed anteriorly as the head and/or retruding the mandible, lips, or tongue. The similar terms shoulders tilt to the right or left side, causing the midline of protraction and retraction are used most commonly for the body itself to become bent sideways. This is a compound anterolateral and posteromedial movements of the scapula movement occurring between many adjacent vertebrae. on the thoracic wall, causing the shoulder region to move As you can see by noticing the way the thumbnail faces anteriorly and posteriorly (Fig. I.5M). (laterally instead of posteriorly in the anatomical posi- Elevation raises or moves a part superiorly, as in elevat- tion), the thumb is rotated 90° relative to the other digits ing the shoulders when shrugging, the upper eyelid when (Fig. I.5F). Therefore, the thumb flexes and extends in the opening the eye, or the tongue when pushing it up against frontal plane and abducts and adducts in the sagittal plane. the palate (roof of mouth) (Fig. I.5K). Depression lowers or Circumduction is a circular movement that involves moves a part inferiorly, as in depressing the shoulders when sequential flexion, abduction, extension, and adduction (or standing at ease, the upper eyelid when closing the eye, or in the opposite order) in such a way that the distal end of the pulling the tongue away from the palate. part moves in a circle (Fig. I.5H). Circumduction can occur at any joint at which all the above-mentioned movements are possible (e.g., the shoulder and hip joints). Rotation involves turning or revolving a part of the body The Bottom Line around its longitudinal axis, such as turning one’s head to ANATOMICOMEDICAL TERMINOLOGY face sideways (Fig. I.5G). Medial rotation (internal rotation) brings the anterior surface of a limb closer to the median Anatomical terms are descriptive terms standardized in an plane, whereas lateral rotation (external rotation) takes the international reference guide, Terminologia Anatomica (TA). anterior surface away from the median plane. These terms, in English or Latin, are used worldwide. ♦ Pronation and supination are the rotational movements of Colloquial terminology is used by—and to communicate the forearm and hand that swing the distal end of the radius (the with—lay people. ♦ Eponyms are often used in clinical lateral long bone of the forearm) medially and laterally around Moore_Intro.indd 11 12/10/2012 6:28:36 PM  12 Introduction to Clinically Oriented Anatomy The Bottom Line settings but are not recommended because they do not provide anatomical context and are not standardized. ♦ ANATOMICAL VARIATIONS Anatomical directional terms are based on the body in the anatomical position. ♦ Four anatomical planes divide the Anatomical variations are common and students should body, and sections divide the planes into visually useful expect to encounter them during dissection. It is impor- and descriptive parts. ♦ Other anatomical terms describe tant to know how such variations may influence physical relationships of parts of the body, compare the positions examinations, diagnosis, and treatment. of structures, and describe laterality and movement. INTEGUMENTARY SYSTEM ANATOMICAL VARIATIONS Because the skin (L. integumentum, a covering) is readily Anatomy books describe (initially, at least) the structure of accessible and is one of the best indicators of general health, the body as it is usually observed in people—that is, the most careful observation of it is important in physical examina- common pattern. However, occasionally a particular struc- tions. It is considered in the differential diagnosis of almost ture demonstrates so much variation within the normal range every disease. The skin provides: that the most common pattern is found less than half the Protection of the body from environmental effects, such as time! Beginning students are frequently frustrated because abrasions, fluid loss, harmful substances, ultraviolet radia- the bodies they are examining or dissecting do not conform tion, and invading microorganisms. to the atlas or text they are using (Bergman et al., 1988). Containment for the body’s structures (e.g., tissues Often students ignore the variations or inadvertently dam- and organs) and vital substances (especially extracel- age them by attempting to produce conformity. Therefore, lular fluids), preventing dehydration, which may be you should expect anatomical variations when you dissect or severe when extensive skin injuries (e.g., burns) are inspect prosected specimens. experienced. In a random group of people, individuals differ from each Heat regulation through the evaporation of sweat and/or other in physical appearance. The bones of the skeleton vary the dilation or constriction of superficial blood vessels. not only in their basic shape but also in lesser details of sur- Sensation (e.g., pain) by way of superficial nerves and face structure. A wide variation is found in the size, shape, their sensory endings. and form of the attachments of muscles. Similarly, consid- Synthesis and storage of vitamin D. erable variation exists in the patterns of branching of veins, arteries, and nerves. Veins vary the most and nerves the least. The skin, the body’s largest organ, consists of the epidermis, Individual variation must be considered in physical examina- a superficial cellular layer, and the dermis, a deep connective tion, diagnosis, and treatment. tissue layer (Fig. I.6). Most descriptions in this text assume a normal range of The epidermis is a keratinized epithelium—that is, it variation. However, the frequency of variation often dif- has a tough, horny superficial layer that provides a protec- fers among human groups, and variations collected in one tive outer surface overlying its regenerative and pigmented population may not apply to members of another population. deep or basal layer. The epidermis has no blood vessels or Some variations, such as those occurring in the origin and lymphatics. The avascular epidermis is nourished by the course of the cystic artery to the gallbladder, are clinically underlying vascularized dermis. The dermis is supplied by important (see Chapter 2), and any surgeon operating with- arteries that enter its deep surface to form a cutaneous plexus out knowledge of them is certain to have problems. Clinically of anastomosing arteries. The skin is also supplied with affer- significant variations are described in clinical cor- ent nerve endings that are sensitive to touch, irritation (pain), relation (blue) boxes identified with an Anatomical and temperature. Most nerve terminals are in the dermis, Variation icon (at left). but a few penetrate the epidermis. Apart from racial and sexual differences, humans exhibit The dermis is a dense layer of interlacing collagen and considerable genetic variation, such as polydactyly (extra digits). elastic fibers. These fibers provide skin tone and account for Approximately 3% of newborns show one or more significant the strength and toughness of skin. The dermis of animals is birth defects (Moore et al, 2012). Other defects (e.g., atresia removed and tanned to produce leather. Although the bun- or blockage of the intestine) are not detected until symptoms dles of collagen fibers in the dermis run in all directions to occur. Discovering variations and congenital anomalies in produce a tough felt-like tissue, in any specific location most cadavers is actually one of the many benefits of firsthand dissec- fibers run in the same direction. The predominant pattern tion, because it enables students to develop an awareness of the of collagen fibers determines the characteristic tension and occurrence of variations and a sense of their frequency. wrinkle lines in the skin. Moore_Intro.indd 12 12/10/2012 6:28:37 PM  Introduction to Clinically Oriented Anatomy 13 Vascular and lymphatic Hair Basal (regenerating) capillary beds in layer of epidermis superficial dermis Epidermis Afferent nerve endings Small arteriole feeding vascular capillary bed Collagen and elastic Dermis fibers Arrector muscle of hair Sebaceous gland Hair follicle Fat Cutaneous nerve Subcutaneous tissue (superficial fascia) Lymphatic vessel Superficial blood vessels Deep fascia Skeletal muscle Skin ligament (L. retinaculum cutis) Sweat gland FIGURE I.6. Skin and some of its specialized structures. The tension lines (also called cleavage lines or Langer Located between the overlying skin (dermis) and underly- lines) tend to spiral longitudinally in the limbs and run trans- ing deep fascia, the subcutaneous tissue (superficial fascia) versely in the neck and trunk (Fig. I.7). Tension lines at the is composed mostly of loose connective tissue and stored fat elbows, knees, ankles, and wrists are parallel to the transverse and contains sweat glands, superficial blood vessels, lymphatic creases that appear when the limbs are flexed. The elastic vessels, and cutaneous nerves (Fig. I.6). The neurovascular fibers of the dermis deteriorate with age and are not replaced; structures course in the subcutaneous tissue, distributing only consequently, in older people, the skin wrinkles and sags as it their terminal branches to the skin. loses its elasticity. The subcutaneous tissue provides for most of the body’s The skin also contains many specialized structures (Fig. I.6). fat storage, so its thickness varies greatly, depending on the The deep layer of the dermis contains hair follicles, with person’s nutritional state. In addition, the distribution of sub- associated smooth arrector muscles and sebaceous glands. cutaneous tissue varies considerably in different sites in the Contraction of the arrector muscles of hairs (L. musculi same individual. Compare, for example, the relative abun- arrector pili) erects the hairs, causing goose bumps. Hair fol- dance of subcutaneous tissue evident by the thickness of the licles are generally slanted to one side, and several sebaceous fold of skin that can be pinched at the waist or thighs with the glands lie on the side the hair is directed toward (“points to”) anteromedial part of the leg (the shin, the anterior border of as it emerges from the skin. Thus, contraction of the arrec- the tibia) or the back of the hand, the latter two being nearly tor muscles causes the hairs to stand up straighter, thereby devoid of subcutaneous tissue. Also consider the distribution compressing the sebaceous glands and helping them secrete of subcutaneous tissue and fat between the sexes: In mature their oily product onto the skin surface. The evaporation of females, it tends to accumulate in the breasts and thighs, the watery secretion (sweat) of the sweat glands from the whereas in males, subcutaneous fat accumulates in the lower skin provides a thermoregulatory mechanism for heat loss abdominal wall. (cooling). Also involved in the loss or retention of body heat Subcutaneous tissue participates in thermoregulation, are the small arteries (arterioles) within the dermis. They functioning as insulation, retaining heat in the body’s core. It dilate to fill superficial capillary beds to radiate heat (skin also provides padding that protects the skin from compres- appears red) or constrict to minimize surface heat loss (skin, sion by bony prominences, such as those in the buttocks. especially of the lips and fingertips, appears blue). Other skin Skin ligaments (L. retinacula cutis), numerous small structures or derivatives include the nails (fingernails, toe- fibrous bands, extend through the subcutaneous tissue and nails), the mammary glands, and the enamel of teeth. attach the deep surface of the dermis to the underlying Moore_Intro.indd 13 12/10/2012 6:28:37 PM  14 Introduction to Clinically Oriented Anatomy An incision made across the cleavage lines is more likely to gape, increasing healing time, and result in increased scar tissue. An incision made parallel to the cleavage lines results in less gaping, faster healing, and less scar tissue. FIGURE I.7. Tension lines in the skin. The dashed lines indicate the pre- dominant direction of the collagen fibers in the dermis. Anterior view Posterior view deep fascia (Fig. I.6). The length and density of these such as in the palms and soles (Fig. I.8C). In dissection, ligaments determines the mobility of the skin over deep removal of skin where the skin ligaments are short and structures. Where skin ligaments are longer and sparse, abundant requires use of a sharp scalpel. The skin liga- the skin is more mobile, such as on the back of the hand ments are long but particularly well developed in the (Fig. I.8A & B). Where ligaments are short and abundant, breasts, where they form weight-bearing suspensory liga- the skin is firmly attached to the underlying deep fascia, ments (see Chapter 1). INTEGUMENTARY SYSTEM the skin can appear bluish (cyanotic). This occurs because the oxygen-carrying hemoglobin of blood is bright red Skin Color Signs in Physical Diagnosis when carrying oxygen (as it does in arteries and usually does in capillaries), and appears deep, purplish blue when Blood flow through the superficial capillary beds depleted of oxygen, as it does in veins. Cyanosis is espe- of the dermis affects the color of skin and can pro- cially evident where skin is thin, such as the lips, eyelids, vide important clues for diagnosing certain clinical and deep to the transparent nails. Skin injury, exposure to conditions. When the blood is not carrying enough oxygen excess heat, infection, inflammation, or allergic reactions from the lungs, such as in a person who has stopped breath- may cause the superficial capillary beds to become ing or in a person having a defective circulation that is engorged, making the skin look abnormally red, a sign sending an inadequate amount of blood through the lungs, Moore_Intro.indd 14 12/10/2012 6:28:38 PM  Introduction to Clinically Oriented Anatomy 15 called erythema. In certain liver disorders, a yellow pigment Skin Injuries and Wounds called bilirubin builds up in the blood, giving a yellow appearance to the whites of the eyes and skin, a condition Lacerations. Accidental cuts and skin tears are called jaundice. Skin color changes are most readily superficial or deep. Superficial lacerations violate observed in people with light-colored skin and may be the epidermis and perhaps the superficial layer of difficult to discern in people with dark skin. the dermis; they bleed but do not interrupt the continuity of the dermis. Deep lacerations penetrate the deep layer of the dermis, extending into the subcutaneous tissue or Skin Incisions and Scarring beyond; they gape and require approximation of the cut The skin is always under tension. In general, lacera- edges of the dermis (by suturing, or stitches) to minimize tions or incisions that parallel the tension lines usu- scarring. ally heal well with little scarring because there is Burns are caused by thermal trauma, ultraviolet or ion- minimal disruption of fibers. The uninterrupted fibers tend izing radiation, or chemical agents. Burns are classified, to retain the cut edges in place. However, a laceration or inci- in increasing order of severity, based on the depth of skin sion across the tension lines disrupts more collagen fibers. injury (Fig. BI.2): The disrupted lines of force cause the wound to gape and it 1st-degree (superficial) burn (e.g., sunburn): damage is may heal with excessive (keloid) scarring. When other con- limited to the epidermis; symptoms are erythema (hot red siderations, such as adequate exposure and access or avoid- skin), pain, and edema (swelling); desquamation (peeling) ance of nerves, are not of greater importance, surgeons of the superficial layer usually occurs several days later, attempting to minimize scarring for cosmetic reasons may but the layer is quickly replaced from the basal layer of use surgical incisions that parallel the tension lines. the epidermis without significant scarring. Stretch Marks in Skin The collagen and elastic fibers in the dermis form a tough, flexible meshwork of tissue. Because the skin can distend considerably, a relatively small incision Inflamed can be made during surgery compared with the much larger incision required to attempt the same procedure in an embalmed cadaver, which no longer exhibits elasticity. The skin can stretch and grow to accommodate gradual increases in size. However, marked and relatively fast size increases, such as the abdominal enlargement and weight gain accompanying pregnancy, can stretch the skin too much, damaging the colla- 1st-degree gen fibers in the dermis (Fig. BI.1). Bands of thin wrinkled (superficial) skin, initially red but later becoming purple, and white stretch burn - early stage; may marks (L. striae gravidarum) appear on the abdomen, but- "peel" at tocks, thighs, and breasts during pregnancy. Stretch marks later stage (L. striae cutis distensae) also form in obese individuals and in Superficial certain diseases (e.g., hypercortisolism or Cushing syndrome); they occur along with distension and loosening of the deep 2nd-degree fascia due to protein breakdown leading to reduced cohesion Deep (partial-thickness) between the collagen fibers. Stretch marks generally fade after burn pregnancy and weight loss, but they never disappear completely. 3rd-degree (full thickness) burn Umbilicus Stretch mark 2nd-degree (partial-thickness) burn FIGURE BI.1. FIGURE BI.2. Moore_Intro.indd 15 12/10/2012 6:28:40 PM  16 Introduction to Clinically Oriented Anatomy 2nd-degree (partial-thickness) burn: epidermis and super- area affected by a burn in an adult can be estimated by apply- ficial dermis are damaged with blistering (superficial 2nd ing the “Rule of Nines” in which the body is divided into degree) or loss (deep 2nd degree); nerve endings are dam- areas that are approximately 9% or multiples of 9% of the aged, making this variety the most painful; except for their total body surface (Fig. BI.3). most superficial parts, the sweat glands and hair follicles are not damaged and can provide the source of replace- ment cells for the basal layer of the epidermis along with Anterior and cells from the edges of the wound; healing will occur posterior head slowly (3 weeks to several months), leaving scarring and Anterior head and neck some contracture, but it is usually complete. and neck 9% 3rd-degree (full-thickness) burn: the entire thickness of the 4.5% Anterior and posterior arms, skin is damaged and perhaps underlying muscle. There is Anterior shoulders, forearms, and for marked edema and the burned area is numb since sensory arms, forearms, hands ha endings are destroyed. A minor degree of healing may occur and hands 18% 18 9% Anterior An Anterior and at the edges, but the open, ulcerated portions require skin trunk po posterior trunk grafting: dead material (eschar) is removed and replaced 4.5% 18% 4.5% 36 36% (grafted) over the burned area with skin harvested (taken) Pe Perineum from a non-burned location (autograft) or using skin from 1% human cadavers or pigs, or cultured or artificial skin. 9% 9% The extent of a burn (percent of total body surface affected) is generally more significant than the degree (severity in terms Anterior thighs, Anterior and legs, and feet posterior thighs, of depth) in estimating the effect on the well-being of the 18% legs, and feet victim. According to the American Burn Association’s clas- 36% sification of burn