This document discusses anatomical terminology and how structures are named in clinical anatomy. It provides the following key points:
1. Terminology follows the International Anatomical Terminology and provides Latin and English equivalents. Commonly used clinical terms may differ and are clarified.
2. Structure names often describe shape, location, function or resemblance. Names are derived from Latin and Greek roots to convey meaningful information about structures.
3. Standard anatomical position, planes, sections and relative position terms are defined to ensure unambiguous descriptions of anatomy.
This document discusses anatomical terminology and how structures are named in clinical anatomy. It provides the following key points:
1. Terminology follows the International Anatomical Terminology and provides Latin and English equivalents. Commonly used clinical terms may differ and are clarified.
2. Structure names often describe shape, location, function or resemblance. Names are derived from Latin and Greek roots to convey meaningful information about structures.
3. Standard anatomical position, planes, sections and relative position terms are defined to ensure unambiguous descriptions of anatomy.
This document discusses anatomical terminology and how structures are named in clinical anatomy. It provides the following key points:
1. Terminology follows the International Anatomical Terminology and provides Latin and English equivalents. Commonly used clinical terms may differ and are clarified.
2. Structure names often describe shape, location, function or resemblance. Names are derived from Latin and Greek roots to convey meaningful information about structures.
3. Standard anatomical position, planes, sections and relative position terms are defined to ensure unambiguous descriptions of anatomy.
This document discusses anatomical terminology and how structures are named in clinical anatomy. It provides the following key points:
1. Terminology follows the International Anatomical Terminology and provides Latin and English equivalents. Commonly used clinical terms may differ and are clarified.
2. Structure names often describe shape, location, function or resemblance. Names are derived from Latin and Greek roots to convey meaningful information about structures.
3. Standard anatomical position, planes, sections and relative position terms are defined to ensure unambiguous descriptions of anatomy.
The text introduces anatomical terminology and describes the structure and meaning behind many anatomical terms.
The text describes different types of anatomical movements including flexion, extension, abduction, adduction, circumduction, rotation, pronation, supination, eversion, inversion, opposition, and reposition.
The deltoid muscle is triangular in shape, like the Greek letter delta, and the piriformis muscle is pear-shaped. The temporal muscle is named for its location in the temporal region.
Introduction to Clinically Oriented Anatomy 5
to use when they describe their complaints. Furthermore,
you must be able to use terms people will understand when explaining their medical problems to them. The terminology in this book conforms to the new Interna- tional Anatomical Terminology. Terminologia Anatomica (TA) and Terminologia Embryologica (TE) list terms both in Latin and as English equivalents (e.g., the common shoulder muscle is musculus deltoideus in Latin and deltoid in English). Most terms in this book are English equivalents. Ofcial terms are available at www.unifr.ch/ifaa. Unfortunately, the terminology commonly used in the clinical arena may differ from the of- cial terminology. Because this discrepancy may be a source of confusion, this text claries commonly confused terms by placing the un ofcial designations in parentheses when the terms are rst usedfor example, pharyngotympanic tube (auditory tube, eustachian tube) and internal thoracic artery (internal mammary artery). Eponyms, terms incorporating the names of people, are not used in the new terminology because they give no clue about the type or location of the structures involved. Further, many eponyms are historically inaccurate in terms of identifying the original person to describe a structure or assign its function, and do not conform to an international standard. Not with standing, commonly used eponyms appear in parentheses throughout the book when these terms are rst usedsuch as sternal angle (angle of Louis)since you will surely encoun ter them in your clinical years. Note that epony- mous terms do not help to locate the structure in the body. The Clinically Oriented Anatomy website (http://thePoint. lww.com/COA7e) provides a list of eponymous terms. Structure of terms. Anatomy is a descriptive science and requires names for the many structures and processes of the body. Because most terms are derived from Latin and Greek, medical language may seem difcult at rst; however, as you learn the origin of terms, the words make sense. For example, the term gaster is Latin for stomach or belly. Consequently, the esophagogastric junction is the site where the esophagus connects with the stomach, gastric acid is the digestive juice secreted by the stomach, and a digastric muscle is a muscle divided into two bellies. Many terms provide information about a structures shape, size, location, or function or about the resemblance of one structure to another. For example, some muscles have descriptive names to indicate their main characteristics. The deltoid muscle, which covers the point of the shoulder, is triangular, like the symbol for delta, the fourth letter of the Greek alphabet. The sufx -oid means like; therefore, deltoid means like delta. Biceps means two-headed and tri- ceps means three-headed. Some muscles are named accord- ing to their shapethe piriformis muscle, for example, is pear shaped (L. pirum, pear + L. forma, shape or form). Other muscles are named according to their location. The temporal muscle is in the temporal region (temple) of the cranium (skull). In some cases, actions are used to describe musclesfor example, the levator scapulae elevates the scap- ula (L. shoulder blade). Anatomical terminology applies logical reasons for the names of muscles and other parts of the body, and if you learn their meanings and think about them as you read and dissect, it will be easier to remember their names. Abbreviations. Abbreviations of terms are used for brev- ity in medical histories and in this and other books, such as in tables of muscles, arteries, and nerves. Clinical abbreviations are used in discussions and descriptions of signs and symptoms. Learning to use these abbreviations also speeds note taking. Common anatomical and clinical abbreviations are provided in this text when the corresponding term is introducedfor example, temporomandibular joint (TMJ). The Clinically Ori- ented Anatomy website (http://thePoint.lww.com/COA7e) provides a list of commonly used anatomical abbreviations. More extensive lists of common medical abbreviations may be found in the appendices of comprehensive medical dictio- naries (e.g., Stedmans Medical Dictionary, 28th ed.). Anatomical Position All anatomical descriptions are expressed in relation to one consistent position, ensuring that descriptions are not ambig- uous (Figs. I.1 and I.2). One must visualize this position in the mind when describing patients (or cadavers), whether they are lying on their sides, supine (recumbent, lying on the back, face upward), or prone (lying on the abdomen, face downward). The anatomical position refers to the body position as if the person were standing upright with the: head, gaze (eyes), and toes directed anteriorly (forward), arms adjacent to the sides with the palms facing anteri- orly, and lower limbs close together with the feet parallel. This position is adopted globally for anatomicomedical descriptions. By using this position and appropriate terminol- ogy, you can relate any part of the body precisely to any other part. It should also be kept in mind, however, that gravity causes a downward shift of internal organs (viscera) when the upright position is assumed. Since people are typically exam- ined in the supine position, it is often necessary to describe the position of the affected organs when supine, making spe- cic note of this exception to the anatomical position. Anatomical Planes Anatomical descriptions are based on four imaginary planes (median, sagittal, frontal, and transverse) that intersect the body in the anatomical position (Fig. I.2): The median plane (median sagittal plane), the vertical plane passing longitudinally through the body, divides the body into right and left halves. The plane denes the mid- line of the head, neck, and trunk where it intersects the surface of the body. Midline is often erroneously used as a synonym for the median plane. Sagittal planes are vertical planes passing through the body parallel to the median plane. Parasagittal is com- monly used but is unnecessary because any plane paral- lel to and on either side of the median plane is sagittal Moore_Intro.indd 5 12/10/2012 6:28:26 PM Introduction to Clinically Oriented Anatomy 6 by denition. However, a plane parallel and near to the median plane may be referred to as a paramedian plane. Frontal (coronal) planes are vertical planes passing through the body at right angles to the median plane, divid- ing the body into anterior (front) and posterior (back) parts. Transverse planes are horizontal planes passing through the body at right angles to the median and frontal planes, dividing the body into superior (upper) and inferior (lower) parts. Radiologists refer to transverse planes as transaxial, which is commonly shortened to axial planes. Since the number of sagittal, frontal, and transverse planes 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 the umbilicus (Fig. I.2C). Sections of the head, neck, and trunk in precise frontal and transverse planes are symmet- rical, passing through both the right and left members of paired structures, allowing some comparison. The main use of anatomical planes is to describe sections (Fig. I.3): Longitudinal sections run lengthwise or parallel to the long axis of the body or of any of its parts, and the term applies regardless of the position of the body. Although median, sagittal, and frontal planes are the standard (most commonly used) longitudinal sections, there is a 180 range of possible longitudinal sections. Transverse sections, or cross sections, are slices of the body or its parts that are cut at right angles to the longitudinal axis of the body or of any of its parts. Because the long axis of the foot runs horizontally, a transverse sec- tion of the foot lies in the frontal plane (Fig. I.2C). Oblique sections are slices of the body or any of its parts that are not cut along the previously listed anatomical planes. In practice, many radiographic images and ana- tomical sections do not lie precisely in sagittal, frontal, or transverse planes; often they are slightly oblique. Anatomists create sections of the body and its parts anatomi- cally, and clinicians create them by planar imaging technolo- gies, such as computerized tomography (CT), to describe and display internal structures. Terms of Relationship and Comparison Various adjectives, arranged as pairs of opposites, describe the relationship of parts of the body or compare the position of two structures relative to each other (Fig. I.4). Some of these terms are specic for comparisons made in the ana- tomical position, or with reference to the anatomical planes: Superior refers to a structure that is nearer the vertex, the topmost point of the cranium (Mediev. L., skull). Cranial relates to the cranium and is a useful directional term, mean- ing toward the head or cranium. Inferior refers to a struc- ture that is situated nearer the sole of the foot. Caudal (L. cauda, tail) is a useful directional term that means toward the feet or tail region, represented in humans by the coccyx (tail bone), the small bone at the inferior (caudal) end of the vertebral column. Median plane Frontal (coronal) plane Transverse (axial) plane Frontal (coronal) plane of feet Median plane of hand Median plane of foot (A) (B) (C) Sagittal plane FIGURE I.2. Anatomical planes. The main planes of the body are illustrated. Moore_Intro.indd 6 12/10/2012 6:28:26 PM Introduction to Clinically Oriented Anatomy 7 Posterior (dorsal) denotes the back surface of the body or nearer to the back. Anterior (ventral) denotes the front surface of the body. Rostral is often used instead of anterior when describing parts of the brain; it means toward the ros- trum (L. for beak); however, in humans it denotes nearer the anterior part of the head (e.g., the frontal lobe of the brain is rostral to the cerebellum). Medial is used to indicate that a structure is nearer to the median plane of the body. For example, the 5th digit of the hand (little nger) is medial to the other digits. Conversely, lateral stipulates that a structure is farther away from the median plane. The 1st digit of the hand (thumb) is lateral to the other digits. Dorsum usually refers to the superior aspect of any part that protrudes anteriorly from the body, such as the dorsum of the tongue, nose, penis, or foot. It is also used to describe the posterior surface of the hand, opposite the palm. Because the term dorsum may refer to both superior and posterior surfaces in humans, the term is easier to under- stand if one thinks of a quadripedal plantigrade animal that walks on its palms and soles, such as a bear. The sole is the inferior aspect or bottom of the foot, opposite the dorsum, much of which is in contact with the ground when standing barefoot. The surface of the hands, the feet, and the digits of both corresponding to the dorsum is the dorsal surface, the surface of the hand and ngers corresponding to the palm is the palmar surface, and the surface of the foot and toes corresponding to the sole is the plantar surface. Combined terms describe intermediate positional arrange- ments: inferomedial means nearer to the feet and median planefor example, the anterior parts of the ribs run infero- medially; superolateral means nearer to the head and far- ther from the median plane. Other terms of relationship and comparisons are inde- pendent of the anatomical position or the anatomical planes, relating primarily to the bodys surface or its central core: Supercial, intermediate, and deep describe the posi- tion of structures relative to the surface of the body or the relationship of one structure to another underlying or overly- ing structure. External means outside of or farther from the center of an organ or cavity, while internal means inside or closer to the center, independent of direction. Proximal and distal are used when contrasting positions nearer to or farther from the attachment of a limb or the central aspect of a linear structure, respectively. Terms of Laterality Paired structures having right and left members (e.g., the kidneys) are bilateral, whereas those occurring on one side only (e.g., the spleen) are unilateral. Designating whether you are referring specically to the right or left member of bilateral structures can be critical, and is a good habit to begin at the outset of ones training to become a health professional. Something occurring on the same side of the body as another structure is ipsilateral; the right thumb and right great (big) toe are ipsilateral, for example. Contralateral means occur- ring on the opposite side of the body relative to another struc- ture; the right hand is contralateral to the left hand. Terms of Movement Various terms describe movements of the limbs and other parts of the body (Fig. I.5). Most movements are dened in relationship to the anatomical position, with movements occur ring within, and around axes aligned with, specic ana- tomical planes. While most movements occur at joints where two or more bones or cartilages articulate with one another, several non-skeletal structures exhibit movement (e.g., tongue, lips, eyelids). Terms of movement may also be considered in pairs of oppositing movements: FIGURE I.3. Sections of the limbs. Sections may be obtained by anatomical sectioning or medical imaging techniques. Longitudinal section Transverse section Oblique section (A) (B) (C) Moore_Intro.indd 7 12/10/2012 6:28:28 PM Introduction to Clinically Oriented Anatomy 8 Dorsal surface Palmar surface Plantar surface Median plane Coronal plane * * * * * Dorsum Palm Sole Dorsum Dorsal surface Nearer to head The heart is superior to the stomach. Superior (cranial) Nearer to surface The muscles of the arm are superficial to its bone (humerus). Superficial Between a superficial and a deep structure The biceps muscle is intermediate between the skin and the humerus. Intermediate Farther from surface The humerus is deep to the arm muscles. Deep Nearer to median plane The 5th digit (little finger) is on the medial side of the hand. Medial Farther from median plane The 1st digit (thumb) is on the lateral side of the hand. Lateral Nearer to trunk or point of origin (e.g., of a limb) The elbow is proximal to the wrist, and the prox- imal part of an artery is its beginning. Proximal Farther from trunk or point of origin (e.g., of a limb) The wrist is distal to the elbow, and the distal part of the upper limb is the hand. Distal Nearer to back The heel is posterior to the toes. Posterior (dorsal) Anterior hand (palm) Posterior hand (dorsum) Palmar vs. Dorsal Inferior foot surface (sole) Superior foot surface (dorsum) Plantar vs. Dorsal Nearer to feet The stomach is inferior to the heart. Inferior (caudal) Nearer to front The toes are anterior to the ankle. Anterior (ventral) Terms applied to the entire body Terms specific for hands and feet *
Terms independent of anatomical position Key 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 Flexion and extension of upper limb at shoulder joint and lower limb at hip joint Flexion and extension of digits (fingers) at metacarpophalangeal and interphalangeal joints Flexion and extension of hand at wrist joint Extension Flexion Extension Flexion Extension Flexion Flexion Extension ion n Flexion Extension Flexion and extension of forearm at elbow joint and of leg at knee joint Flexion and extension of vertebral column at intervertebral joints Flexion Flexion Extension Extension Opposition Reposition Opposition and reposition of thumb and little finger at carpometacarpal joint of thumb combined with flexion at metacarpophalangeal joints Pronation and supination of forearm at radio-lnar joints Abduction Abduction of 3rd digit at metacarpophalangeal joint Adduction Extension Flexion Lateral abduction Medial abduction Adduction Abduction Abduction and adduction of 2nd, 4th, and 5th digits at metacarpo- phalangeal joints (A) (B) (E) The thumb is rotated 90 relative to other structures. Abduction and adduction at metacarpophalangeal joint occurs in a sagittal plane; flexion and extension at metacarpophalangeal and interphalangeal joints occurs in frontal planes, opposite to these movements at all other joints. (F) (C) (D) Pronation Supination 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 Introduction to Clinically Oriented Anatomy 10 FIGURE I.5. (Continued) Abduction Abduction Adduction Lateral rotation Medial rotation Lateral (external) rotation Medial (internal) rotation Adduction Circumduction Elevation Retrusion Protrusion Depression Eversion Inversion Abduction and adduction of right limbs and rotation of left limbs at glenohumeral and hip joints, respectively Inversion and eversion of foot at subtalar and transverse tarsal joints Protrusion and retrusion of jaw at temporomandibular joints Elevation and depression of shoulders Circumduction (circular movement) of lower limb at hip joint Dorsiflexion Dorsiflexion and plantarflexion of foot at ankle joint Plantarflexion Lateral bending Rotation of head and neck Rotation of upper trunk, neck, and head Lateral bending (lateral flexion) of trunk and rotation of upper trunk, neck, and head Protraction and retraction of scapula on thoracic wall Protraction Retraction (G) (J) (L) (M) (K) (H) (I) 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- ittal planes around a transverse axis (Fig. I.5A & B). Flex- ion indicates bending or decreasing the angle between the bones or parts of the body. For most joints (e.g., elbow), ex- ion involves movement in an anterior direction. Extension indicates straightening or increasing the angle between the bones or parts of the body. Extension usually occurs in a pos- terior direction. The knee joint, rotated 180 to other joints, is exceptional in that exion of the knee involves posterior move- ment and extension involves anterior movement. Dorsiex- ion describes exion at the ankle joint, as occurs when walking uphill or lifting the front of the foot and toes off the ground (Fig. I.5I). Plantarexion bends the foot and toes toward the ground, as when standing on your toes. Extension of a limb or part beyond the normal limithyperextension (overexten- sion)can cause injury, such as whiplash (i.e., hyperexten- sion of the neck during a rear-end automobile collision). Abduction and adduction movements generally occur in a frontal plane around an anteroposterior axis (Fig. I.5E & G). Except for the digits, abduction means moving away from the median plane (e.g., when moving an upper limb laterally away from the side of the body) and adduction means mov- ing toward it. In abduction of the digits (ngers or toes), the term means spreading them apartmoving the other ngers away from the neutrally positioned 3rd (middle) nger or moving the other toes away from the neutrally positioned 2nd toe. The 3rd nger and 2nd toe medially or laterally abduct away from the neutral position. Adduction of the digits is the oppositebringing the spread ngers or toes together, toward the neutrally positioned 3rd nger or 2nd toe. Right and left lateral exion (lateral bending) are special forms of abduction for only the neck and trunk (Fig. I.5J). The face and upper trunk are directed anteriorly as the head and/or shoulders tilt to the right or left side, causing the midline of the body itself to become bent sideways. This is a compound movement occurring between many adjacent vertebrae. As you can see by noticing the way the thumbnail faces (laterally instead of posteriorly in the anatomical posi- tion), the thumb is rotated 90 relative to the other digits (Fig. I.5F). Therefore, the thumb exes and extends in the frontal plane and abducts and adducts in the sagittal plane. Circumduction is a circular movement that involves sequential exion, abduction, extension, and adduction (or in the opposite order) in such a way that the distal end of the 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 around its longitudinal axis, such as turning ones head to face sideways (Fig. I.5G). Medial rotation (internal rotation) brings the anterior surface of a limb closer to the median plane, whereas lateral rotation (external rotation) takes the anterior surface away from the median plane. Pronation and supination are the rotational movements of the forearm and hand that swing the distal end of the radius (the lateral long bone of the forearm) medially and laterally around and across the anterior aspect of the ulna (the other long bone of the forearm) while the proximal end of the radius rotates in place (Fig. I.5D). Pronation rotates the radius medially so that the palm of the hand faces posteriorly and its dorsum faces ante- riorly. When the elbow joint is exed, pronation moves the hand so that the palm faces inferiorly (e.g., placing the palms at on a table). Supination is the opposite rotational movement, rotat- ing the radius laterally and uncrossing it from the ulna, return- ing the pronated forearm to the anatomical position. When the elbow joint is exed, supination moves the hand so that the palm faces superiorly. (Memory device: You can hold soup in the palm of your hand when the exed forearm is supinated but are prone [likely] to spill it if the forearm is then pronated!) Eversion moves the sole of the foot away from the median plane, turning the sole laterally (Fig. I.5I). When the foot is fully everted it is also dorsiexed. Inversion moves the sole of the foot toward the median plane (facing the sole medi- ally). When the foot is fully inverted it is also plantarexed. Pronation of the foot actually refers to a combination of ever- sion and abduction that results in lowering of the medial margin of the foot (the feet of an individual with at feet are pronated), and supination of the foot generally implies movements resulting in raising the medial margin of the foot, a combination of inversion and adduction. Opposition is the movement by which the pad of the 1st digit (thumb) is brought to another digit pad (Fig. I.5C). This movement is used to pinch, button a shirt, and lift a teacup by the handle. Reposition describes the movement of the 1st digit from the position of opposition back to its anatomical position. Protrusion is a movement anteriorly (forward) as in protruding the mandible (chin), lips, or tongue (Fig. I.5L). Retrusion is a movement posteriorly (backward), as in retruding the mandible, lips, or tongue. The similar terms protraction and retraction are used most commonly for anterolateral and posteromedial movements of the scapula on the thoracic wall, causing the shoulder region to move anteriorly and posteriorly (Fig. I.5M). Elevation raises or moves a part superiorly, as in elevat- ing the shoulders when shrugging, the upper eyelid when opening the eye, or the tongue when pushing it up against the palate (roof of mouth) (Fig. I.5K). Depression lowers or moves a part inferiorly, as in depressing the shoulders when standing at ease, the upper eyelid when closing the eye, or pulling the tongue away from the palate. ANATOMICOMEDICAL TERMINOLOGY Anatomical terms are descriptive terms standardized in an international reference guide, Terminologia Anatomica (TA). These terms, in English or Latin, are used worldwide. Colloquial terminology is used byand to communicate withlay people. Eponyms are often used in clinical The Bottom Line Moore_Intro.indd 11 12/10/2012 6:28:36 PM