Introduction To Anatomy PDF

 INTRODUCTION TO ANATOMY   BY   Dr EDU OTONG What is anatomy? Anatomy includes those structures that can be seen grossly (without the aid of magnification) and microscopically (with the aid of magnification). Typically, when used...

 INTRODUCTION TO ANATOMY   BY   Dr EDU OTONG What is anatomy? Anatomy includes those structures that can be seen grossly (without the aid of magnification) and microscopically (with the aid of magnification). Typically, when used by itself, the term anatomy tends to mean gross; that is, the study of structures that can be seen without using a microscopic. Microscopic anatomy, also called histology, is the study of cells and tissues using a microscope.  Anatomy forms the basis for the practice of medicine. Anatomy leads the physician toward an understanding of a patient' s disease, whether he or she is carrying out a physical examination or using the most advanced imaging techniques. Anatomy is also important for dentists , physical therapists, and all others involved in any aspect of patient treatment that begins with an analysis of clinical signs. The ability to interpret a clinical observation correctly is  The three main approaches to studying anatomy are: Systemic, Regional, Clinical (or applied).  Systemic anatomy is an approach to anatomic study organized by organ systems, such as the respiratory, digestive, or reproductive systems, which relates structure to function. Regional anatomy is an approach to anatomic study based on regions and deals with structural relationships among the parts of the body, such as the thorax and abdomen, emphasizing the relationships among various systemic structures such as muscles, nerves, and blood vessels. Clinical anatomy emphasizes the practical application of anatomical knowledge to the solution of clinical problems and has real pertinence to the practice of medicine. ANATOMICAL PARTS BASED ON REGIONS Head Neck Thorax Back Abdomen Pelvis/perineu m Lower limb Upper limb Studying anatomy……. Anatomical position Movements and planes of the body Anatomical terms Bones and Joints Anatomical position 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 anteriorly, lower limbs close together with the feet parallel. Anatomical position 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 anteriorly,  lower limbs close together Anatomical planes Major planes passing through the body in the anatomical position are: Sagittal planes also are oriented vertically but are at right angles to the coronal planes and divide the body into right and left parts. Coronal planes are oriented vertically and divide the body into anterior and posterior parts. NB: The plane that passes through the center of the body dividing it into equal right and left halves is termed the median sagittal plane.  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. NOTE Oblique sections are slices of the body or any of its parts that are not cut along the previously listed anatomical planes. ANATOMICAL PLANES Sagittal planes Coronal planes Transverse sections Sections of the limbs Oblique sections Sagittal planes Transverse sections Anatomical terms Terms to describe location Anterior (ventral) and posterior (dorsal) , Medial and lateral, Superior and inferior Proximal and distal, Cranial and caudal, Superficial and deep Terms of Movement  Flexion and extension movements  Abduction and adduction movements  Rotation (medial and lateral)  Circumduction  Pronation and supination  Eversion and Inversion  Dorsiflexion and Plantarflexion  Pronation and supination  Opposition and Reposition  Protraction and Retraction  Elevation and Depression SKELETA L SYSTEM  The skeletal system consists of  cartilage and  bone  It can be divided into two subgroups,  the axial skeleton and  the appendicular skeleton CARTILAGE  Cartilage is an avascular form o f connective tissue consisting of extracellular fibers embedded in a matrix that contains cells localized in small cavities.  The amount and kind of extracellular fibers in the matrix varies depending on the type of cartilage.  The functions of cartilage are to:  support soft tissues,  provide a smooth, gliding surface for bone articulations at joints, and  enable the development and growth of long bones. Types of cartilage There are three types of cartilage: Hyaline-most common; matrix contains a moderate amount of collagen fibers (e.g. , articular surfaces of bones); Elastic-matrix contains collagen fibers along with a large number of elastic fibers (e.g. , external ear) ; Fibrocartilage-matrix contains a limited number of cells and ground substance amidst a substantial amount of BONES Are calcified connective tissue consisting of cells (osteocytes) embedded in a matrix of ground substance and collagen fibers. Have a superficial thin layer of compact bone around a central mass of spongy bone, and contain internal soft tissue, the marrow, where blood cells are formed. Serve as a reservoir for calcium and phosphorus and act as biomechanical levers on which muscles act to produce the movements permitted by joints.  Are classified, according to shape, into;  long,  short,  flat,  irregular, and  sesamoid bones and,  According to their developmental history, into;  endochondral and  membranous bones.  Long Bones Include the humerus, radius, ulna, femur, tibia, fibula, metacarpals, and phalanges. Develop by replacement of hyaline cartilage plate (endochondral ossification). Have a shaft (diaphysis) and two ends (epiphyses). The metaphysis is a part of the diaphysis adjacent to the epiphyses.  1. Diaphysis Forms the shaft (central region) and is composed of a thick tube of compact bone that encloses the marrow cavity. 2. Metaphysis Is a part of the diaphysis, the growth zone between the diaphysis and epiphysis during bone development. 3. Epiphyses Are expanded articular ends, separated from the shaft by the epiphyseal plate during bone growth and composed of a spongy bone surrounded by a thin layer of compact bone.  B. Short Bones Include the carpal and tarsal bones and are approximately cuboid shaped. Are composed of spongy bone and marrow surrounded by a thin outer layer of compact bone. C. Flat Bones Include the ribs, sternum, scapulae, and bones in the vault of the skull. Consist of two layers of compact bone enclosing spongy bone and marrow space. Have articular surfaces that are covered with fibrocartilage and grow by the replacement of connective  D. Irregular Bones Include bones of mixed shapes such as bones of the skull, vertebrae, and coxa. Contain mostly spongy bone enveloped by a thin outer layer of compact bone. E. Sesamoid Bones Develop in certain tendons and reduce friction on the tendon, thus protecting it from excessive wear. Are commonly found where tendons cross the ends of long bones in the limbs, as in the wrist and the knee (i.e., patella). CLINICAL CORRELATION Osteoblast synthesizes new bone and osteoclast functions in the resorption (break down bone matrix and release calcium and minerals) and remodeling of bone. Parathyroid hormone causes mobilization of calcium by promoting bone resorption, whereas calcitonin suppresses mobilization of calcium from bone. Osteoid is the organic matrix of bone prior to calcification  Osteomalacia is a gradual softening of the bone due to failure of the bone to calcify because of lack of vitamin D or renal tubular dysfunction. Osteopenia is a decreased calcification of bone or a reduced bone mass due to an inadequate osteoid synthesis. Osteoporosis is an age related disorder characterized by decreased bone mass and increased susceptibility to fractures of the hip, vertebra, and wrist.  It occurs when bone resorption outpaces bone formation, since bone constantly undergoes cycles of resorption and formation (remodeling) to maintain the concentration of calcium and phosphate in the extracellular fluid. Signs of osteoporosis are vertebral compression, loss of body height, development of kyphosis, and hip fracture. Osteopetrosis is an abnormally dense bone, obliterating the marrow cavity, due to defective resorption of immature bone. JOINTS Are places of union between two or more bones. Are innervated as follows: The nerve supplying a joint also supplies the muscles that move the joint and the skin covering the insertion of such muscles (Hilton’s law). Are classified on the basis of their structural features into:  fibrous,  cartilaginous, and  synovial types.  A. Fibrous Joints (Synarthroses) Are joined by fibrous tissue, have no joint cavities, and permit little movement. 1. Sutures Are connected by fibrous connective tissue and found between the flat bones of the skull. 2. Syndesmoses Are connected by fibrous connective tissue. Occur as the inferior tibiofibular and tympanostapedial syndesmoses.  B. Cartilaginous Joints Are united by cartilage and have no joint cavity. 1. Primary Cartilaginous Joints (Synchondroses) Are united by hyaline cartilage and permit no movement but growth in the length. Include epiphyseal cartilage plates (the union between the epiphysis and the diaphysis of a growing bone) and sphenooccipital and manubriosternal synchondroses. 2. Secondary Cartilaginous Joints (Symphyses) Are joined by fibrocartilage and are slightly movable joints. Include the pubic symphysis and the intervertebral disks.  C. Synovial (Diarthrodial) Joints Permit a great degree of free movement and are classified according to the shape of the articulation and/or the type of movement. Are characterized by four features: joint cavity, articular (hyaline) cartilage, synovial membrane (which produces synovial fluid), and articular capsule. 1. Plane (Gliding) Joints Are united by two flat articular surfaces and allow a simple gliding or sliding of one bone over the other. Occur in the proximal tibiofibular, intertarsal, intercarpal, intermetacarpal, carpometacarpal, sternoclavicular, and acromioclavicular joints.  2. Hinge (Ginglymus) Joints Resemble door hinges and allow only flexion and extension. Occur in the elbow, ankle, and interphalangeal joints. 3. Pivot (Trochoid) Joints Are formed by a central bony pivot turning within a bony ring and allow only rotation (movement around a single longitudinal axis). Occur in the superior and inferior radioulnar joints and in the atlantoaxial joint.  4. Condylar (Ellipsoidal) Joints Have two convex condyles articulating with two concave condyles. Allow flexion and extension and occur in the wrist (radiocarpal), metacarpophalangeal, knee (tibiofemoral), and atlantooccipital joints. 5. Saddle (Sellar) Joints Resemble a saddle on a horse’s back and allow flexion and extension, abduction and adduction, and circumduction but no axial rotation. Occur in the carpometacarpal joint of the thumb and between the femur and patella.  6. Ball-and-Socket (Spheroidal or Cotyloid) Joints Are formed by the reception of a globular (ball-like) head into a cup-shaped cavity and allow movement in many directions. Allow flexion and extension, abduction and adduction, medial and lateral rotations, and circumduction and occur in the shoulder and hip joints. CLINICAL CORRELATION Osteoarthritis is a noninflammatory degenerative joint disease characterized by degeneration of the articular cartilage and osseous outgrowth at the margins. It results from wear and tear of the joints; commonly affects the hands, fingers, hips, knees, feet, and spine; and is accompanied by pain and stiffness.  Rheumatoid arthritis is an inflammatory disease primarily of the joints. It is an autoimmune disease in which the immune system attacks the synovial membranes and articular structures, leading to deformities and disability. There is no cure for rheumatoid arthritis, and its most common symptoms are joint swelling, stiffness, and pain. Gout is a painful form of arthritis and is caused by too much uric acid in the blood. Uric acid crystals are deposited in and around the joints, causing an inflammation and pain, heat, redness, stiffness, tenderness, and swelling of the joint tissues