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Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy TERMINOLOGY IN ANATOMY GENERAL INFORMATION ON THE SYSTEMS 15. September.2011 Thursday 20. September. 2011 Tuesday 1. TERMINOLOGY IN ANATOMY It 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. 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 Position All descriptions of the human body are based on the assumption that the person is standing erect, with the upper limbs by the sides and the face and palms of the hands directed forward. This is the so-called anatomic position. The various parts of the body are then described in relation to certain imaginary planes. Median Sagittal Plane This is a vertical plane passing through the center of the body, dividing it into equal right and left halves. Planes situated to one or the other side of the median plane and parallel to it are termed paramedian. Coronal Planes These planes are imaginary vertical planes at right angles to the median plane. Horizontal, or Transverse,or Axial Planes These planes are at 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); however, in humans it denotes nearer the anterior part of the head (e.g., the frontal lobe of the http://www.facebook.com/yeditepeanatomy1 1 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy brain is rostral to the cerebellum). 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. http://en.wikipedia.org/wiki/Anatomical_terms_of_location 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. 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. 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. http://www.facebook.com/yeditepeanatomy1 2 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy http://www.imaios.com/Media/Images/e-anatomy/Anatomical-terms-of-location-position-motion/Standard-anatomical-positionAnatomical-terms-of-location-en 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. 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 occurring on the opposite side of the body relative to another structure; 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. 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. http://www.facebook.com/yeditepeanatomy1 3 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy http://learn-anatomy.blogspot.com/2009/06/terms-of-movement.html 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. Extension of a limb or part beyond the normal limit—hyperextension (overextension)—can cause injury, such as “whiplash” (i.e., hyperextension of the neck during a rear-end automobile collision). http://www.imaios.com/cn/Media/Images/e-anatomy/Anatomical-terms-of-location-position-motion/extension-flexiondorsiflexion-plantar 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. In abduction of the digits (fingers or toes), the term means spreading them apart—moving the other fingers away from the neutrally positioned 3rd (middle) finger or moving the other toes away from the neutrally positioned 2nd toe. The 3rd finger and 2nd toe medially or laterally abduct away from the neutral position. Adduction of the digits is the opposite—bringing the spread fingers or toes together, toward the neutrally positioned 3rd finger or 2nd toe. http://www.facebook.com/yeditepeanatomy1 4 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy http://www.imaios.com/Media/Images/e-anatomy/Anatomical-terms-of-location-position-motion/abduction-adduction Circumduction is a circular movement that involves sequential flexion, abduction, extension, and adduction (or in the opposite order) 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). http://www.imaios.com/Media/Images/e-anatomy/Anatomical-terms-of-location-position-motion/circumduction-illustrationdiagram-movements-anatomy 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. http://www.facebook.com/yeditepeanatomy1 5 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy http://www.imaios.com/Media/Images/e-anatomy/Anatomical-terms-of-location-position-motion/supination-pronation Eversion moves the sole of the foot away from the median plane, turning the sole laterally. When the foot is fully everted it is also dorsiflexed. Inversion moves the sole of the foot toward the median plane (facing the sole medially). When the foot is fully inverted it is also plantarflexed. http://www.imaios.com/Media/Images/e-anatomy/Anatomical-terms-of-location-position-motion/inversion-eversion 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. http://teleanatomy.com/introductiontoanatomy-TermsRelatedtoMovements.html 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. 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. Elevation raises or moves a part superiorly, as in elevating the shoulders when shrugging, the upper eyelid when opening the eye, or the tongue when pushing it up against the palate (roof of mouth). http://www.facebook.com/yeditepeanatomy1 6 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy 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. Positions of the body The supine position of the body is lying on the back. The prone position is lying face downward. Some basic rules in the Latin language Pronunciation Though largely unchanged in its grammar, today’s academic and medical Latin differs greatly from classical Latin in its pronunciation. It is accepted today, in English as well as Anglicized Latin, that c before e and i is pronounced like s (acetabulum), but c before a, o, and u is pronounced like k (calcaneus). g before e and i is pronounced like (English) j (pharyngeus) 1, but g before a, o, and u is pronounced like g in gap (laryngopharynx). Vowels Words encountered in anatomical Latin often have certain vowel endings. In particular Terminal –ae (palpebrae) may be pronounced (at the speaker’s choice and ideally consistently) EE, EYE, or AY. In particular, the EE is recommended by scientific Latin; the AY rarely and mainly by the British (though it has near exclusive hold of vertebrae); and the EYE by the authentic classical pronunciation. The last pronunciation is perhaps due to attraction to the ending –i, which, as discussed later, performs many of the same grammatical functions in different words· Terminal –i (rami) is usually pronounced EYE, but is occasionally (and authentically) pronounced. Adjectives Paired with nouns, adjectives form an important part of anatomical nomenclature. As in many European languages, nouns and their modifying adjectives must agree in· Number (singular/plural). Therefore, adjectives must be pluralized with their nouns An adjective may appear before, (typically) after, or disjoint from the noun it modifies, as in flexor digitorum profundus, the deep flexor of the digits. This variance in word order is permitted by the aforementioned grammatical agreement, which links the adjective profundus to the noun flexor that it modifies. Diminutives Diminutives are alterations to a word that produce a sense of smallness, such as –ito in Spanish and –ette in French. Many noun roots ending in a syllable containing –ul or –ol are actually diminutives of parent nouns. A surprising number of these turn up in anatomy and biology, though perhaps this is not surprising since biology is full of little things. For instance, fasciculus is a diminutive of fasces, bundle; reticulum of rete, net; tuberculum of tuber, swelling; other terms whose parents are more obscure include capsule (capsula) and patella. And few would ever guess that a muscle (musculus) really is a little mouse—yet the same comparison is made in Greek, German, and Arabic. Many diminutives can be restored to their parent forms by removal of the characteristic letters –ul or –ol. You are probably familiar with the parent forms of nucleolus, malleolus, cerebellum, lingula; what are they? Verbs Verbs may generate noun and adjective forms relevant to anatomy. Words ending in –ns are present active participles (–ing) of verbs. These are merely adjectives of the third-declension type (which we have covered briefly). Examples: ductus reuniens, the reuniting duct; ramus communicans, the communicating branch. Like many Latin words, these present active participles entered English, as well as the Romance languages, in their genitive stem form (–nt): therefore ductus deferens is often translated deferent duct and the abducens (leading-away) nerve as the abducent. Words ending in –atus are perfect passive participles (–ed) of certain verbs. Examples: fasciculus cuneatus, the wedged bundle; ligamentum cruciatum, the crossed ligament. Such words entered English in –ate, so the latter term is usually translated cruciate ligament. Plural Forming proper plurals of medical words is one of the more challenging aspects of medical terminology. http://www.facebook.com/yeditepeanatomy1 7 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy Greek and Latin each have differing rules to be applied when forming the plural form of the word root. Often such details can be found using a medical dictionary. Adding the suffixes “-i” or “a” -or “-ae at the end of the word are popular pluralization rules for some words in medical terminology to e.g., musculus (muscle); musculi (muscles), retinaculum; retinacula, bursa; bursae. Another popular pluralization suffix is “es” as in levatores. https://meded-portal.ucsd.edu/webportal/forum/fileattachments/anat-latin-3.pdf GENERAL INFORMATION ON THE SYSTEMS Regions and cavities in the body Diaphragm: divides body cavity into thoracic and abdominopelvic cavities. Mediastinum: contains all structures of the thoracic cavity except the lungs Ventral Body Cavity Membranes • Parietal serosa lines internal body walls • Visceral serosa covers the internal organs • Serous fluid separates the serosae Serous Membranes • Cover the organs of trunk cavities & line the cavity • Fist represents an organ • Inner balloon wall represents visceral serous membrane • Outer balloon wall represents parietal serous membrane • Cavity between two membranes filled with lubricating serous fluid that is produced by the membranes • Inflammation of the serous membranes Serous Membranes: Named for Their Specific Cavities and Organs Pericardium refers to heart. Pleura refers to lungs and thoracic cavity. Peritoneum refers to abdominopelvic cavity. Other Body Cavities Oral and digestive – mouth and cavities of the digestive organs Nasal –located within and posterior to the nose Orbital – house the eyes Middle ear – contain bones (ossicles) that transmit sound vibrations http://www.facebook.com/yeditepeanatomy1 8 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy Synovial – joint cavities Integumentary system Because the skin (L. integumentum, a covering) is readily accessible and is one of the best indicators of general health, careful observation of it is important in physical examinations. It is considered in the differential diagnosis of almost every disease. The skin, the body's largest organ, consists of the epidermis, a superficial cellular layer, and the dermis, a deep connective tissue layer. Skeletal System Os=Bone, osteologia is the discipline related to bones.. The skeleton is composed of cartilages and bones. The skeletal system may be divided into two functional parts: The axial skeleton consists of the bones of the head, neck, and trunk. The appendicular skeleton consists of the bones of the limbs, including those forming the pectoral (shoulder) and pelvic girdles. Joints Joints (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. Muscular System Mus-culus means muscle which is derived from the Latin word musculus (little mouse). The 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. There are three types of muscles: 1) Striated muscle (skeletal muscles)-voluntarily controlled, though exceptions exist 2) Non-striated muscle (smooth muscle) - involuntary 3) Cardiac muscle 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 Vessels There 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 final distributing vessels, arterioles, deliver oxygen-rich blood to capillaries. Capillaries form a capillary bed, where the interchange of oxygen, nutrients, waste products, and other substances with the extracellular fluid occurs. Blood from the capillary bed passes into venules, which resemble wide capillaries. Venules drain into small veins that open into larger veins. The largest veins return low-oxygen blood to the heart. Large elastic arteries (conducting arteries) have many elastic layers (sheets of elastic fibers) in their walls. These large arteries initially receive the cardiac output. Examples of large elastic arteries are the aorta, the arteries that originate from the arch of the aorta (brachiocephalic trunk, subclavian and carotid arteries), and the pulmonary trunk and arteries. http://www.facebook.com/yeditepeanatomy1 9 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy Medium muscular arteries (distributing arteries) have walls that consist chiefly of circularly disposed smooth muscle fibers. Their ability to decrease their diameter (vasoconstrict) regulates the flow of blood to different parts of the body as required by circumstance (e.g., activity, thermoregulation). Most of the named arteries, including those observed in the body wall and limbs during dissection such as the brachial or femoral arteries, are medium muscular arteries Small arteries and arterioles have relatively narrow lumina and thick muscular walls. The degree of filling of the capillary beds and level of arterial pressure within the vascular system are regulated mainly by the degree of tonus (firmness) in the smooth muscle of the arteriolar walls. If the tonus is above normal, hypertension (high blood pressure) results. Small arteries are usually not named or specifically identified during dissection, and arterioles can be observed only under magnification. Anastomoses (communications) between multiple branches of an artery provide numerous potential detours for blood flow in case the usual pathway is obstructed by compression due to the position of a joint, pathology, or surgical ligation. Veins are more abundant than arteries. Although their walls are thinner, their diameters are usually larger than those of the corresponding artery. Since the arteries and veins make up a circuit, it might be expected that half the blood volume would be in the arteries and half in the veins. Because of the veins' larger diameter and ability to expand, typically only 20% of the blood occupies arteries, whereas 80% is in the veins. Lymphoid System The lymphoid system thus constitutes a sort of “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. The important components of the lymphoid system are: Lymphatic plexuses, networks of lymphatic capillaries that originate blindly in the extracellular (intercellular) spaces of most tissues. Lymphatic vessels (lymphatics), a nearly bodywide network of thinwalled vessels that have abundant lymphatic valves. In living individuals, the vessels bulge where each of the closely spaced valves occur, giving lymphatics a beaded appearance. Lymphatic capillaries and vessels occur almost everywhere blood capillaries are found, except for example, teeth, bone, bone marrow, and the entire central nervous system. (Excess tissue fluid here drains into the cerebrospinal fluid.) Lymph (L. lympha, clear water), the tissue fluid that enters lymph capillaries and is conveyed by lymphatic vessels. 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. Lymphoid organs, parts of the body that produce lymphocytes, such as the thymus, red bone marrow, spleen, tonsils, and the solitary and aggregated lymphoid nodules in the walls of the alimentary tract and appendix. Nervous System The nervous system enables the body to react to continuous changes in its internal and external environments. It also controls and integrates the various activities of the body, such as circulation and respiration. Nervous system controls the systems in the body and regulates its functions according to the impulses received from the outer world (sensations). The nervous system controls and integrates the activities of the different parts of the body together with the endocrine system. For descriptive purposes, the nervous system is divided: Structurally into the central nervous system (CNS), consisting of the brain and spinal cord, and the peripheral nervous system (PNS), the remainder of the nervous system outside of the CNS. Functionally into the somatic nervous system (SNS) and the autonomic nervous system (ANS). Nervous tissue consists of two main cell types: neurons (nerve cells) and neuroglia (glial cells), which support the neurons. Neurons are the structural and functional units of the nervous system specialized for rapid communication. Neuroglia (glial cells or glia), approximately five times as abundant as neurons, are non-neuronal, nonexcitable cells that form a major component of nervous tissue, supporting, insulating, and nourishing the neurons. The principal roles of the CNS are to integrate and coordinate incoming and outgoing neural signals and to carry out higher mental functions, such as thinking and learning. The peripheral nervous system (PNS) http://www.facebook.com/yeditepeanatomy1 10 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy consists of nerve fibers and cell bodies outside the CNS that conduct impulses to or away from the CNS. The PNS is organized into nerves that connect the CNS with peripheral structures. The PNS is anatomically and operationally continuous with the CNS. Its afferent (sensory) fibers convey neural impulses to the CNS from the sense organs (e.g., the eyes) and from sensory receptors in various parts of the body (e.g., in the skin). Its efferent (motor) fibers convey neural impulses from the CNS to effector organs (muscles and glands). Nerves are either cranial nerves or spinal nerves, or derivatives of them. Cranial nerves exit the cranial cavity through foramina (openings) in the cranium (G. kranion, skull) and are identified by a descriptive name (e.g., “trochlear nerve”) or a Roman numeral (e.g., “CN IV”). Spinal (segmental) nerves exit the vertebral column (spine). Spinal nerves arise in bilateral pairs from a specific segment of the spinal cord. The 31 spinal cord segments and the 31 pairs of nerves arising from them are identified by a letter and number (e.g., “T4”) designating the region of the spinal cord and their superior-to-inferior order (C, cervical; T, thoracic; L, lumbar; S, sacral; Co, coccygeal). Cranial Nerves As they arise from the CNS, some cranial nerves convey only sensory fibers, some only motor fibers, and some carry a mixture of both types of fibers. Somatic and Visceral Fibres The types of fibers conveyed by cranial or spinal nerves are as follows: Somatic fibers General sensory fibers (general somatic afferent [GSA] fibers) transmit sensations from the body to the CNS; they may be exteroceptive sensations from the skin (pain, temperature, touch, and pressure) or pain and proprioceptive sensations from muscles, tendons, and joints. Somatic motor fibers (general somatic efferent [GSE] fibers) transmit impulses to skeletal (voluntary) muscles. Visceral fibers Visceral sensory fibers (general visceral afferent [GVA] fibers) transmit pain or subconscious visceral reflex sensations (information concerning distension, blood gas, and blood pressure levels, for example) from hollow organs and blood vessels to the CNS. Visceral motor fibers (general visceral efferent [GVE] fibers) transmit impulses to smooth (involuntary) muscle and glandular tissues. Two varieties of fibers, presynaptic and postsynaptic, work together to conduct impulses from the CNS to smooth muscle or glands. Somatic Nervous System The somatic nervous system (SNS), composed of somatic parts of the CNS and PNS, provides sensory and motor innervation to all parts of the body (G. soma), except the viscera in the body cavities, smooth muscle, and glands. The somatic sensory system transmits sensations of touch, pain, temperature, and position from sensory receptors. Most of these sensations reach conscious levels (i.e., we are aware of them). The somatic motor system innervates only skeletal muscle, stimulating voluntary and reflexive movement by causing the muscle to contract, as occurs in response to touching a hot iron. Autonomic Nervous System The autonomic nervous system (ANS), classically described as the visceral nervous system or visceral motor system, consists of motor fibers that stimulate smooth (involuntary) muscle, modified cardiac muscle (the intrinsic stimulating and conducting tissue of the heart), and glandular (secretory) cells. The efferent nerve fibers and ganglia of the ANS are organized into two systems or divisions: the sympathetic (thoracolumbar) division and the parasympathetic (craniosacral) division. Respiratory System The respiratory apparatus consists of the nose, nasopharynx, paranasal sinuses, larynx, trachea, bronchi, lungs, and pleuræ. Nose http://www.facebook.com/yeditepeanatomy1 11 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy The nose consists of the external nose and the nasal cavity, both of which are divided by a septum into right and left halves. The nose opens into the nasopharynx. The nose is an amazing humidifier and warmer of air. Even at seven liters/minute of airflow, the nose has not reached it's maximal ability to perform this function. Paranasal Sinuses The paranasal sinuses are cavities found in the interior of the maxilla, frontal, sphenoid, and ethmoid bones. They are filled with air and communicate with the nasal cavity through relatively small apertures. Infection of the paranasal sinuses is a common complication of nasal infections. The physiology and function of the sinuses has been the subject of much research. Unfortunately, we still are unsure as to all the functions of these air-filled spaces. Multiple theories of function exist. These include the functions of warming/humidification of air, assisting in regulation of intranasal pressure and serum gas pressures (and subsequently minute ventilation), contributing to immune defense, increasing mucosal surface area, lightening the skull, giving resonance to the voice, absorbing shock, and contributing to facial growth. Nasopharynx It is located posterior to the nose and superior to the soft palate. Being one of the three parts of the pharynx, a structure belonging to the digestive system, Nasopharynx has a respiratory function. It is the posterior extension of the nasal cavities. The nose opens into the nasopharynx. Larynx The larynx is located situated 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. The larynx or organ of voice is 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. The larynx is the complex organ of voice production (the “voice box”) composed of nine cartilages connected by membranes and ligaments and containing the vocal folds. Trachea The trachea, extending from the larynx into the thorax, terminates inferiorly as it divides into right and left main bronchi. It transports air to and from the lungs. The trachea is 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. Pleura Each 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. As the lung grows into the space, it picks up a layer of pleura (outside of balloon) and this is called the visceral pleura. The remainder of the pleura is called the parietal pleura. Pleura is a membrane that is single celled. Normally it produces a small amount of fluid that fills the gap between the parietal and visceral layers of pleura. The pleural cavity—the potential space between the layers of pleura—contains a capillary layer of serous pleural fluid, which lubricates the pleural surfaces and allows the layers of pleura to slide smoothly over each other during respiration. The surface tension of the pleural fluid provides the cohesion that keeps the lung surface in contact with the thoracic wall; consequently, the lung expands and fills with air when the thorax expands while still allowing sliding to occur, much like a film of water between two glass plates. The pleural cavity is a closed space (like the inside of a balloon) within which the lung has grown. Lungs (Pulmones) The lungs are the vital organs of respiration. Their 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. They are also elastic and recoil to approximately one third their size when the thoracic cavity is opened. 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 http://www.facebook.com/yeditepeanatomy1 12 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy 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 The apparatus for the digestion of the food consists of the digestive tube and of certain accessory organs. The Digestive Tube (alimentary canal) is a musculomembranous tube, about 9 metres long, extending from the mouth to the anus, and lined throughout its entire extent by mucous membrane. It has received different names in the various parts of its course: at its commencement is the mouth, where provision is made for the mechanical division of the food (mastication), and for its admixture with a fluid secreted by the salivary glands (insalivation); beyond this are the organs of deglutition, the pharynx and the esophagus, which convey the food into the stomach, in which it is stored for a time and in which also the first stages of the digestive process take place. 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. 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. The stomach is followed by the small intestine, which is divided for purposes of description into three parts, the duodenum, the jejunum, and ileum. In the small intestine the process of digestion is completed and the resulting products are absorbed into the blood and lacteal vessels. Finally the small intestine ends in the large intestine, which is made up of cecum, colon, rectum, and anal canal, the last terminating on the surface of the body at the anus. The accessory organs are the teeth, for purposes of mastication; the three pairs of salivary glands— the parotid, submaxillary, and sublingual—the secretion from which mixes with the food in the mouth and converts it into a bolus and acts chemically on one of its constituents; the liver and pancreas, two large glands in the abdomen, the secretions of which, in addition to that of numerous minute glands in the walls of the alimentary canal, assist in the process of digestion. 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. Peristalsis also occurs in the jejunum and ileum; however, it is not forceful unless an obstruction is present. The large intestine consists of the cecum (which receives the terminal part of the ileum), appendix, colon (ascending, transverse, descending, and sigmoid), rectum, and anal 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. Peritoneum and Periotenal Cavity The 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. The peritoneal cavity is a potential space of capillary thinness. It contains no organs but contains a thin film of peritoneal fluid, which is composed of water, electrolytes, and other substances derived from interstitial fluid in adjacent tissues. Peritoneal fluid lubricates the peritoneal surfaces, enabling the viscera to move over each other without friction, and allowing the movements of digestion. Oral region: The oral region includes the oral cavity, teeth, gingivae, tongue, palate, and the region 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. The general direction of the esophagus is vertical; but it presents two slight curves in its course. 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 http://www.facebook.com/yeditepeanatomy1 13 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy 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 (25 cm) part of the small intestine, is also the widest and most fixed part. The duodenum pursues a C-shaped course around the head of the pancreas. 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. 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. The endocrine system is regulated by feedback in much the same way that a thermostat regulates the temperature in a room. For the hormones that are regulated by the pituitary gland, a signal is sent from the hypothalamus to the pituitary gland in the form of a "releasing hormone," which stimulates the pituitary to secrete a "stimulating hormone" into the circulation. The stimulating hormone then signals the target gland to secrete its hormone. As the level of this hormone rises in the circulation, the hypothalamus and the pituitary gland shut down secretion of the releasing hormone and the stimulating hormone, which in turn slows the secretion by the target gland. This system results in stable blood concentrations of the hormones that are regulated by the pituitary gland. 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 testes and epididymides are considered internal genital organs on the basis of their developmental position and homology with the internal female ovaries. The ductus deferens (vas deferens) is the continuation of the duct of the epididymis. http://www.facebook.com/yeditepeanatomy1 14 Dr.Kaan Yücel http://yeditepeanatomy1.wordpress.com Yeditepe Anatomy Each seminal gland (vesicle) is an elongated structure (approximately 5 cm long but sometimes much shorter) that lies between the fundus of the bladder and the rectum. The seminal glands are obliquely placed superior to the prostate and do not store sperms, as the “vesicle” term implies. They secrete a thick alkaline fluid with fructose (an energy source for sperms) and a coagulating agent that mixes with the sperms as they pass into the ejaculatory ducts and urethra. The ejaculatory ducts are slender tubes that arise by the union of the ducts of the seminal glands with the ductus deferentes. The prostate is the largest accessory gland of the male reproductive system. The firm, walnutsize prostate surrounds the prostatic urethra. The two pea-size bulbourethral glands (Cowper glands) lie posterolateral to the intermediate part of the urethra. The female internal genital organs include the ovaries, uterine tubes, uterus, and vagina. The ovaries are almond-shaped and -sized female gonads in which the oocytes (female gametes or germ cells) develop. They are also endocrine glands that produce reproductive hormones. The uterine tubes (formerly called oviducts or fallopian tubes) conduct the oocyte, discharged monthly from an ovary during child-bearing years, from the periovarian peritoneal cavity to the uterine cavity. They also provide the usual site of fertilization. The uterus (womb) is a thick-walled, pear-shaped, hollow muscular organ. The embryo and fetus develop in the uterus. Its muscular walls adapt to the growth of the fetus and then provide the power for its expulsion during childbirth. The uterus is a very dynamic structure, the size and proportions of which change during the various changes of life. The vagina, a distensible musculomembranous tube, extends from the middle cervix of the uterus to the vaginal orifice, the opening at the inferior end of the vagina. http://www.facebook.com/yeditepeanatomy1 15