Kaan Yücel M.D., Ph.D. 13. 15.September. 2011 Thursday

20. September. 2011 Tuesday

Terminology in anatomyGeneral information on the systems

Terminology in anatomyIt is important for medical personnel to have a sound knowledge and understanding of the basic anatomic terms. With the aid of a medical dictionary, you will find that understanding anatomic terminology greatly assists you in the learning process.

The accurate use of anatomic terms by medical personnel enables them to communicate with their colleagues both nationally and internationally. Without anatomic terms, one cannot accurately discuss or record the abnormal functions of joints, the actions of muscles, the alteration of position of organs, or the exact location of swellings or tumors.

The accurate use of anatomic terms by medical personnel enables them to communicate with their colleagues both nationally and internationally. Without anatomic terms, one cannot accurately discuss or record the abnormal functions of joints, the actions of muscles, the alteration of position of organs, or the exact location of swellings or tumors.

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 by—and to communicate with—lay people. Eponyms are often used in clinical settings but are not recommended because they do not provide anatomical context and are not standardized.

Many anatomical terms have both Latin and Greek equivalents, although some of these are used in English only as roots. Thus the tongue is lingua (L.) and glossa (Gk), and these are the basis of such terms as lingual artery and glossopharyngeal nerve.

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. Anatomical directional terms are based on the body in the anatomical position. Four anatomical planes divide the body, and sections divide the planes into visually useful and descriptive parts.

Terms Related to PositionAll descriptions of the human body are based on th eanatomic position. The various parts of the body are then described in relation to certain imaginary planes.

Median Sagittal PlaneThis is a vertical plane passing through the center of the body, dividing it into equal right and left halves. .

Coronal PlanesImaginary vertical planes at right angles to the median plane.

Horizontal, or Transverse,or Axial PlanesAt right angles to both the median and the coronal planes.

Anatomical terms are specific for comparisons made in the anatomical 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, meaning toward the head or cranium. Inferior refers to a structure 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.

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 rostrum (L. for beak);

To describe the relationship of two structures, one is said to be anterior or posterior to the other insofar as it is closer to the anterior or posterior body surface.

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 finger) is medial to the other digits.

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

.

Combined terms describe intermediate positional arrangements: inferomedial means nearer to the feet and median plane—for example, the anterior parts of the ribs run inferomedially; superolateral means nearer to the head and farther from the median plane.

Other terms of relationship and comparisons are independent of the anatomical position or the anatomical planes, relating primarily to the body's surface or its central core:Superficial, intermediate, and deep (Lat. Profundus, profunda) describe the position of structures relative to the surface of the body or the relationship of one structure to another underlying or overlying 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 (origin in general), respectively. For example, the arm is proximal to the forearm and the hand is distal to the forearm.

Terms of LateralityPaired 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. Something occurring on the same side of the body as another structure is ipsilateral. Contralateral means occurring on the opposite side of the body relative to another structure.

Terms of Movement

Various terms describe movements of the limbs and other parts of the body.

Most movements are defined in relationship to the anatomical position, with movements occurring within, and around axes aligned with, specific anatomical 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:Flexion and extension movements generally occur in sagittal planes around a transverse axis.

Flexion indicates bending or decreasing the angle between the bones or parts of the body. For most joints (e.g., elbow), flexion involves movement in an anterior direction, but it is occasionally posterior, as in the case of the knee joint. Lateral flexion is a movement of the trunk in the coronal plane.

Extension indicates straightening or increasing the angle between the bones or parts of the body. Extension usually occurs in a posterior direction.

The knee joint, rotated 180° to other joints, is exceptional in that flexion of the knee involves posterior movement and extension involves anterior movement.

Dorsiflexion describes flexion at the ankle joint, as occurs when walking uphill or lifting the front of the foot and toes off the ground. Plantarflexion bends the foot and toes toward the ground, as when standing on your toes.

Abduction and adduction movements generally occur in a frontal plane around an anteroposterior axis.

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 moving toward it.

Circumduction is a circular movement that involves sequential flexion, abduction, extension, and adduction in such a way that the distal end of the part moves in a circle. 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 one's head to face sideways. 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 rotates the radius medially so that the palm of the hand faces posteriorly and its dorsum faces anteriorly. When the elbow joint is flexed, pronation moves the hand so that the palm faces inferiorly (e.g., placing the palms flat on a table). Supination is the opposite rotational movement, rotating the radius laterally and uncrossing it from the ulna, returning the pronated forearm to the anatomical position. When the elbow joint is flexed, supination moves the hand so that the palm faces superiorly.

Eversion moves the sole of the foot away from the median plane, turning the sole laterally. Inversion moves the sole of the foot toward the median plane (facing the sole medially).

Opposition is the movement by which the pad of the 1st digit (thumb) is brought to another digit pad. 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.l

Protrusion is a movement anteriorly (forward) as in protruding the mandible (chin), lips, or tongue.Retrusion is a movement posteriorly (backward), as in retruding the mandible, lips, or tongue.

Elevation raises or moves a part superiorly, as in elevating the shoulders when shrugging. Depression lowers or moves a part inferiorly, as in depressing the shoulders when standing at ease.

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.

General considerations on the systems

Integumentary System

The skin (L. integumentum, a covering) is the body's largest organ, consists of the epidermis, a superficial cellular layer, and the dermis, a deep connective tissue layer.

Skeletal System

The skeleton is composed of cartilages and bones. The skeletal system may be divided into two functional parts:Axial skeleton Bones of the head Bones of the neckBones of the trunkAppendicular skeleton Bones of the limbs

JointsJoints (articulations) are unions or junctions between two or more bones or rigid parts of the skeleton. Joints exhibit a variety of forms and functions. Some joints have no movement, such as the epiphysial plates between the epiphysis and diaphysis of a growing long bone; others allow only slight movement, such as teeth within their sockets; and some are freely movable, such as the glenohumeral (shoulder) joint.

Classification of JointsThree classes of joints are described based on the manner or type of material by which the articulating bones are united.

Synovial joints: The bones are united by a joint (articular) capsule (composed of an outer fibrous layer lined by a serous synovial membrane) spanning and enclosing an articular cavity. The joint cavity of a synovial joint, like the knee, is a potential space that contains a small amount of lubricating synovial fluid, secreted by the synovial membrane. Inside the capsule, articular cartilage covers the articulating surfaces of the bones; all other internal surfaces are covered by synovial membrane.

Fibrous joints: The bones are united by fibrous tissue. The amount of movement occurring at a fibrous joint depends in most cases on the length of the fibers uniting the articulating bones. The sutures of the cranium are examples of fibrous joints. These bones are close together, either interlocking along a wavy line or overlapping. A syndesmosis type of fibrous joint unites the bones with a sheet of fibrous tissue, either a ligament or a fibrous membrane. Consequently, this type of joint is partially movable. The interosseous membrane in the forearm is a sheet of fibrous tissue that joins the radius and ulna in a syndesmosis. A dentoalveolar syndesmosis (gomphosis or socket) is a fibrous joint in which a peglike process fits into a socket articulation between the root of the tooth and the alveolar process of the jaw. Mobility of this joint (a loose tooth) indicates a pathological state affecting the supporting tissues of the tooth.

Cartilaginous joints: The bones are united by hyaline cartilage or fibrocartilage. In primary cartilaginous joints, or synchondroses, the bones are united by hyaline cartilage, which permits slight bending during early life. Primary cartilaginous joints are usually temporary unions, such as those present during the development of a long bone, where the bony epiphysis and the shaft are joined by an epiphysial plate. Primary cartilaginous joints permit growth in the length of a bone. When full growth is achieved, the epiphysial plate converts to bone and the epiphyses fuse with the diaphysis. Secondary cartilaginous joints, or symphyses, are strong, slightly movable joints united by fibrocartilage. The fibrocartilaginous intervertebral discs between the vertebrae consist of binding connective tissue that joins the vertebrae together.

Synovial joints, the most common type of joint, provide free movement between the bones they join; they are joints of locomotion, typical of nearly all limb joints. Synovial joints are usually reinforced by accessory ligaments that are either separate (extrinsic) or are a thickening of a portion of the joint capsule (intrinsic). Some synovial joints have other distinguishing features, such as a fibrocartilaginous articular disc or meniscus, which are present when the articulating surfaces of the bones are incongruous.

The six major types of synovial joints are classified according to the shape of the articulating surfaces and/or the type of movement they permit:1. Plane joints permit gliding or sliding movements in the plane of the articular surfaces. An example is the acromioclavicular joint between the acromion of the scapula and the clavicle.2. Hinge joints permit flexion and extension only, movements that occur in one plane (sagittal) around a single axis that runs transversely; thus hinge joints are uniaxial joints. The elbow joint is a hinge joint.3. Saddle joints permit abduction and adduction as well as flexion and extension, movements occurring around two axes at right angles to each other; thus saddle joints are biaxial joints that allow movement in two planes, sagittal and frontal. The carpometacarpal joint at the base of the 1st digit (thumb) is a saddle joint4. Condyloid joints permit flexion and extension as well as abduction and adduction; thus condyloid joints are also biaxial. The metacarpophalangeal joints (knuckle joints) are condyloid joints.5. Ball and socket joints allow movement in multiple axes and planes: flexion and extension, abduction and adduction, medial and lateral rotation, and circumduction; thus ball and socket joints are multi-axial joints. The hip joint is a ball and socket joint.6. Pivot joints permit rotation around a central axis; thus they are uniaxial. The median atlantoaxial joint is a pivot joint in which the atlas (C1 vertebra) rotates around a finger-like process, the dens of the axis (C2 vertebra), during rotation of the head.

The six major types of synovial joints are classified according to the shape of the articulating surfaces and/or the type of movement they permit:1. Plane joints permit gliding or sliding movements in the plane of the articular surfaces. An example is the acromioclavicular joint between the acromion of the scapula and the clavicle.

2. Hinge joints permit flexion and extension only, movements that occur in one plane (sagittal) around a single axis that runs transversely; thus hinge joints are uniaxial joints. The elbow joint is a hinge joint.

3. Saddle joints permit abduction and adduction as well as flexion and extension, movements occurring around two axes at right angles to each other; thus saddle joints are biaxial joints that allow movement in two planes, sagittal and frontal. The carpometacarpal joint at the base of the 1st digit (thumb) is a saddle joint.

4. Condyloid joints permit flexion and extension as well as abduction and adduction; thus condyloid joints are also biaxial. The metacarpophalangeal joints (knuckle joints) are condyloid joints.

5. Ball and socket joints allow movement in multiple axes and planes: flexion and extension, abduction and adduction, medial and lateral rotation, and circumduction; thus ball and socket joints are multi-axial joints. The hip joint is a ball and socket joint.

6. Pivot joints permit rotation around a central axis; thus they are uniaxial. The median atlantoaxial joint is a pivot joint in which the atlas (C1 vertebra) rotates around a finger-like process, the dens of the axis (C2 vertebra), during rotation of the head.

Joint vasculature and innvervationJoints receive blood from articular arteries that arise from the vessels around the joint. The arteries often anastomose (communicate) to form networks (periarticular arterial anastomoses) to ensure a blood supply to and across the joint in the various positions assumed by the joint. Articular veins are communicating veins that accompany arteries (L. venae comitantes) and, like the arteries, are located in the joint capsule, mostly in the synovial membrane.Joints have a rich nerve supply provided by articular nerves with sensory nerve endings in the joint capsule.

Muscular SystemThe muscular system consists of all the muscles of the body.

Voluntary skeletal muscles constitute the great majority of the named muscles. All skeletal muscles are composed of one specific type of muscle tissue. However, other types of muscle tissue constitute a few named muscles (e.g., the ciliary and detrusor muscles, and the arrector muscles of hairs) and form important components of the organs of other systems, including the cardiovascular, alimentary, genitourinary, integumentary, and visual systems.

Cardiovascular System

The heart consists of two muscular pumps that dividing the circulation into two components: the pulmonary and systemic circulations or circuits.

The right ventricle propels low-oxygen blood returning from the systemic circulation into the lungs. Carbon dioxide is exchanged for oxygen in the capillaries of the lungs, and then the oxygen-rich blood is returned to the heart's left atrium. This circuit, from the right ventricle through the lungs to the left atrium, is the pulmonary circulation.

The left ventricle propels the oxygen-rich blood returned to the heart from the pulmonary circulation, exchanging oxygen and nutrients for carbon dioxide in the remainder of the body's capillaries. Low-oxygen blood returns to the heart's right atrium. This circuit, from left ventricle to right atrium, is the systemic circulation.

Blood VesselsThere are three types of blood vessels: arteries, veins, and capillaries.Blood under high pressure leaves the heart and is distributed to the body by a branching system of arteries.The largest veins return low-oxygen blood to the heart.

Lymphoid System• Constitutes an “overflow” system that provides for the drainage of

surplus tissue fluid and leaked plasma proteins to the bloodstream, as well as for the removal of debris from cellular decomposition and infection.

• Lymph nodes, small masses of lymphatic tissue located along the course of lymphatic vessels through which lymph is filtered on its way to the venous system.

Respiratory SystemThe respiratory apparatus consists of the nose, nasopharynx, paranasal sinuses, larynx, trachea, bronchi, lungs, and pleuræ. 

Nose• Consists of the external nose and the nasal cavity, both of which are

divided by a septum into right and left halves. • Opens into the nasopharynx. • An amazing humidifier and warmer of air.

The paranasal sinuses are cavities found in the interior of the maxilla, frontal, sphenoid, and ethmoid bones. They are filled with air; they communicate with the nasal cavity through relatively small apertures. Infection of the paranasal sinuses is a common complication of nasal infections.We still are unsure as to all the functions of these air-filled spaces. Multiple theories of function exist.

NasopharnyxIt is located posterior to the nose and superior to the soft palate. Being one of the three parts of the pharyx, a structure belonging to the digestive system, nasopharnyx has a respiratory function. It is the posterior extension of the nasal cavities. The nose opens into the nasopharynx .

LarynxOrgan of voice voice box

• Located between the trachea and the root of the tongue, at the upper and forepart of the neck, where it presents a considerable projection in the middle line.

• Placed at the upper part of the air passage• Although most commonly known for its role as the phonating

mechanism for voice production, its most vital function is to guard the air passages, especially during swallowing when it serves as the “sphincter” or “valve” of the lower respiratory tract, thus maintaining a patent airway.

• Composed of nine cartilages connected by membranes and ligaments and containing the vocal folds.

Trachea• Extending from the larynx into the thorax, terminates inferiorly as

it divides into right and left main bronchi. • Transports air to and from the lungs.• A fibrocartilaginous tube, supported by incomplete cartilaginous

tracheal cartilages (rings), that occupies a median position in the neck.

• The tracheal cartilages keep the trachea patent.

PleuraEach pulmonary cavity (right and left) is lined by a pleural membrane (pleura) that also reflects onto and covers the external surface of the lungs occupying the cavities. Each lung is invested by and enclosed in a serous pleural sac.

Lungs• Vital organs of respiration. • Main function is to oxygenate the blood • Although cadaveric lungs may be shrunken, firm or hard, and

discolored, healthy lungs in living people are normally light, soft, and spongy, and fully occupy the pulmonary cavities.

Tracheobronchial Tree Beginning at the larynx, the walls of the airway are supported by horseshoe- or C-shaped rings of hyaline cartilage. The trachea constitutes the trunk of the tree. It bifurcates into main bronchi (right and left main bronchi), one to each lung. Within the lungs, the bronchi branch in a constant fashion to form the branches of the tracheobronchial tree.

Digestive System

Food passes from the mouth and pharynx through the esophagus to the stomach, where it mixes with gastric secretions. Digestion mostly occurs in the stomach and duodenum.The stomach is continuous with the duodenum, which receives the openings of the ducts from the pancreas and liver, the major glands of the digestive tract.

Peristalsis, a series of ring-like contraction waves, begins around the middle of the stomach and moves slowly toward the pylorus. It is responsible for mixing the masticated (chewed) food mass with gastric juices and for emptying the contents of the stomach into the duodenum.

Absorption of chemical compounds occurs principally in the small intestine, a coiled 5- to 6-m-long tube (shorter in life, when tonus is present, than in the cadaver) consisting of the duodenum, jejunum, and ileum.

The large intestine consists of:Cecum -receives the terminal part of the ileumAppendixColon (ascending, transverse, descending, and sigmoid)RectumAnal canal

Most reabsorption of water occurs in the ascending colon.Feces form in the descending and sigmoid colon and accumulate in the rectum before defecation.

The esophagus, stomach, and intestine constitute the digestive or gastrointestinal tract and are derived from the primordial foregut, midgut, and hindgut.

Peritoneum and Periotenal CavityThe peritoneum is a continuous, serous membrane which lines the abdominopelvic cavity and invests the viscera. The peritoneal cavity is within the abdominal cavity and continues inferiorly into the pelvic cavity.

Oral region includes: Oral cavityTeethGingivaeTonguePalateRegion of the palatine tonsils

• The oral cavity is where food is ingested and prepared for digestion in the stomach and small intestine.

• Food is chewed by the teeth, and saliva from the salivary glands facilitates the formation of a manageable food bolus (L. lump).

Pharynx: The pharynx is the superior expanded part of the alimentary system posterior to the nasal and oral cavities, extending inferiorly past the larynx.

Esophagus: The esophagus is a muscular tube that conveys food from the pharynx to the stomach.

Stomach: The stomach is the expanded part of the digestive tract between the esophagus and small intestine. It is specialized for the accumulation of ingested food, which it chemically and mechanically prepares for digestion and passage into the duodenum. The stomach acts as a food blender and reservoir; its chief function is enzymatic digestion.

Small Intestine: The small intestine, consisting of the duodenum, jejunum, and ileum, is the primary site for absorption of nutrients from ingested materials.

The duodenum (L. breadth of 12 fingers), the first and shortest part of the small intestine, is also the widest and most fixed part. The second part of the small intestine is the jejunum, whereas third part is, the ileum. Together, the jejunum and ileum are 6-7 m long.

Large Intestine: 

The large intestine consists of the cecum; appendix; ascending, transverse, descending, and sigmoid colon; rectum; and anal canal.

The large intestine is where water is absorbed from the indigestible residues of the liquid chyme, converting it into semi-solid stool or feces that is stored temporarily and allowed to accumulate until defecation occurs.

Excretory System

Kidneys: The ovoid kidneys remove excess water, salts, and wastes of protein metabolism from the blood while returning nutrients and chemicals to the blood. The kidneys produce urine that is conveyed by the ureters to the urinary bladder in the pelvis. The superomedial aspect of each kidney normally contacts a suprarenal gland. A weak fascial septum separates the glands from the kidneys so that they are not actually attached to each other. The suprarenal glands function as part of the endocrine system, completely separate in function from the kidneys.

Ureters: The ureters are muscular ducts with narrow lumina that carry urine from the kidneys to the urinary bladder. Each suprarenal gland has two parts: the suprarenal cortex and suprarenal medulla; these parts have different embryological origins and different functions.

Urinary bladder: The urinary bladder, a hollow viscus with strong muscular walls, is characterized by its distensibility. The urinary bladder is a temporary reservoir for urine and varies in size, shape, position, and relationships according to its content and the state of neighboring viscera.

Urethra: The male urethra is a muscular tube that conveys urine from the internal urethral orifice of the urinary bladder to the external urethral orifice, located at the tip of the glans penis in males. The urethra also provides an exit for semen (sperms and glandular secretions). The female urethra passes anteroinferiorly from the internal urethral orifice of the urinary bladder.

Endocrine System

The endocrine system is made up of glands that produce and secrete hormones. These hormones regulate the body's growth, metabolism (the physical and chemical processes of the body), and sexual development and function. The hormones are released into the bloodstream and may affect one or several organs throughout the body. Hormones are chemical messengers created by the body. They transfer information from one set of cells to another to coordinate the functions of different parts of the body.

The major glands of the endocrine system are the hypothalamus, pituitary, thyroid, parathyroids, suprarenal glands, pineal body, and the reproductive organs (ovaries and testes). The pancreas is also a part of this system; it has a role in hormone production as well as in digestion.

Reproductive System

The male internal genital organs include the testes, epididymides (singular = epididymis), ductus deferentes (singular = ductus deferens), seminal glands, ejaculatory ducts, prostate, and bulbourethral glands which are located in penis.

The female internal genital organs include the ovaries, uterine tubes, uterus, and vagina.