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Terminology

Basic terms for anatomical-osteological description.
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Anterior
A term indicating that a point or region lies nearer to the frontal surface of the body. The term VENTRAL is sometimes used synonymously.
Posterior
A term indicating that a point or region lies nearer the rear surface of the body. The term DORSAL is sometimes used synonymously.
Proximal
A term indicating a point or region which is nearest the point of central attachment. LONG BONES.
Distal
A term indicating a point or region which lies farthest from the point of central attachment. LONG BONES.
Superior
A point or region which lies above another point or region in the normal articulated position.
Inferior
A point or region which lies below another point or region in the normal articulated position.
Sagittal Plane
Any plane passing longitudinally through the body. Divides the body into two equal parts of right and left = mid-sagittal plane.
Coronal Plane
Bisects body from front and back.
Medial
Indicates a point or region lying nearest the mid-sagittal plane.
Lateral
Indicates a point or region lying farthest from the mid-sagittal plane.
Foramen
A hole or opening in bone for transmission of ligaments, blood vessels and nerves.
Fossa
A pit, depression or concavity in or on bone. Deeper and smaller.
Cavity
An open area within bone or formed by one or more bones. Shallow and wide.
Meatus
An elongated, tube-like passageway. Term CANAL sometimes synonymous.
Process
A general term describing any marked eminence on bone. (EX: scapula --> chromian process)
Tuberosity
A large process or eminence. Larger areas on bones where muscle attaches; rough. (EX: proximal humerus)
Tubercle
A small process or eminence.
Spinous
Sharp, slender process.
Condyle
A rounded process. Articulation points of joints. (EX: distal end or femur.)
Hematopoiesis
the formation of blood cells in the living body (especially in the bone marrow)
Types of bones
long, short, flat, irregular
Compact/ Cortical Bone
Dense, outer layer of bone; comprises 80% of the skeleton
Spongy/ Cancellous Bone
inner layer honeycombed with flat projections called trabeculae
Periosteum
thin membrane that covers a bone; richly supplied with nerve fibers, lymphatic vessels and blood vessels. These enter the bone of the shaft via a nutrient foramen. connected to the bone matrix via strong strands of collagen
Osteoblasts
bone forming cells; new bone that form and lay down in part of bone that needs it. Synthesize and secrete collagen fibers and other organic components of bone matrix.
Initiate calcification process.
Osteocytes
mature bone cells; osteoblasts that have become trapped by secretion of matrix; responsible for maintaining bone tissue
Osteoclasts
large cells that resorb or break down bone matrix, releasing calcium ions into the blood. Concentrated in the endosteum
Organic Bone Matrix
1/3 of bone by weight; several materials that are secreted by the osteoblasts. EX: collagen fibers for resilience and resistance.
Inorganic Bone Matrix
2/3 of bone by weight; 2 salts = 1)calcium phosphate 2)calcium hydroxide in interaction hydroxyapatite; smaller amounts of magnesium, fluoride, and sodium (These minerals give bone its characteristic hardness and the ability to resist compression)
Diaphysis
shaft of long bone; thick collar or compact bone surrounding a central marrow cavity
Epiphyses
expanded ends of long bones; thin layer of compact bone covering an interior of spongy bone
Articular Cartilage
thin hyaline cartilage layer that covers epiphyses of bones in synovial joints; cushions bone and decrease friction
Endosteum
thin layer, internal bone surfaces covered; covers trabeculae in marrow and lines the canals that pass through compact bone
Diploe
the internal layer of spongy bone in flat bones
Osteons
HAVERSIAN SYSTEM. Structural unit of compact bone consisting of a central canal, called the haversian canal, surrounded by a number of concentric rings of bony matrix called lamellae.
Interstitial Lamella
in between osteons and incomplete lamella
circumferential lamellae
extend around the circumference of the shaft. There are inner circumferential lamellae surrounding the endosteum and outer circumferential lamellae just inside the periosteum.