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Test #3
Chapter 6
Term | Definition |
---|---|
Medullary Cavity | The space within a bone that contains the marrow. |
Trabecula | A connective tissue partition that subdivides an organ. |
Articular cartilage | The cartilage pad that covers the surface of a bone inside a joint cavity. |
Fossa | A shallow depression or furrow in the surface of a bone. |
Epiphysis | The head of a long bone. |
Metaphysis | The region of a long bone between the epiphysis and diaphysis, corresponding to the epiphyseal cartilage of a developing bone. |
Parathyroid glands | Four small glands embedded in the posterior surface of the thyroid, secrete parathyroid hormone. |
Meatus | An opening or entrance into a passageway. |
Endochondral Ossification | The replacement of a cartilaginous model by bone; the characteristic mode of formation for skeletal elements other than the bones of the cranium, the clavicles, and the sesamoid bones. |
Tuberculum | A small, localized elevation on a bony surface. |
Osteoblast | A cell that produces the fibers and matrix of bone. |
Sulcus | A groove or furrow. |
Intramembranous ossification | The formation of bone within a connective tissue without the prior development of a cartilaginous model. |
Sutural Bones | Irregular bones that form in fibrous tissue between the flat bones of the developing cranium, also called Wormian bones. |
Compact bone | Dense bone that contains parallel osteons. |
Calcitonin | The hormone secreted by C cells of the thyroid when calcium ion concentrations are abnormally high; restores homeostasis by increasing the rate of bone deposition and the rate of calcium lost by the kidneys. |
Sesamoid bone | A bone that forms within a tendon. |
Appositional growth | The enlargement of a cartilage or bone by the addition of cartilage or bony matrix at its surface. |
Osteolysis | The breakdown of the mineral matrix of bone. |
Trochanter | Large process near the head of the femur. |
Sinus | A chamber or hollow in a tissue; a large, dilated vein. |
Thyroid gland | A endocrine gland whose lobes are lateral to the thyroid cartilage of the larynx. |
Parathyroid hormone (PTH) | A hormone secreted by the parathyroid glands when plasma calcium levels fall below the normal range; causes increased osteoclast activity, increased intestinal calcium uptake, and decreased calcium ion loss at the kidneys. |
Osteoclast | A cell that dissolves the fibers and matrix of bone. |
Diaphysis | The shaft of a long bone. |
Condyle | A rounded articular projection on the surface of a bone. |
Osteocyte | A bone cell responsible for the maintenance and turnover of the mineral content of the surrounding bone. |
Endosteum | An incomplete cellular lining on the inner (medullary) surfaces of bone. |
Foramen/foramina | An opening or passage through a bone. |
Epiphyseal cartilage | The cartilaginous region between the epiphysis and diaphysis of a growing bone. |
Trochlea | A pulley; the spool shaped-shaped medial portion of the condyle of the humerus. |
Central Canal | Longitudinal canal in the center of an osteon that contains blood vessels and nerves, a passageway along the longitudinal axis of the spinal cord that contains cerebrospinal fluid. |
Periosteum | The layer that surrounds a bone, consisting of an outer fibrous region and inner cellular region. |
Fissure | An elongated groove or opening. |
Lacuna | A small pit or cavity. |
Fracture | A break or crack in a bone. |
Canaliculi | Microscopic passageways between cells; bile canaliculi carry bile to bile ducts in the liver; In bone, canaliculi permit the diffusion of nutrients and wastes to and from osteocytes. |
Ossification | The formation of bone; osteogenesis. |
Lamellae | Concentric layers; The concentric layers of bone within an osteon. |
Tuberosity | A large, roughened elevation on a bony surface. |
Axial skeleton | The axial skeleton consists of the bones of the skull, thorax, and vertebral column; forms the longitudinal axis of the body. |
Appendicular skeleton | The appendicular skeleton includes the bones of the limbs and the pectoral and pelvic girdles that attach the limbs to the axial skeleton. |
Flat bones | Flat bones have thin, roughly parallel surfaces. They form the roof of the skull, the sternum, the ribs, and the scapulae. They provide protection for underlying soft tissues and offer extensive surface area for the attachment of skeletal muscles. |
Long bones | Long and slender bones, located in the arm, forearm, thigh, leg, palms, soles, fingers, and toes. |
Irregular bones | Complex shaped bone, have short, flat, notched or ridged surfaces. Spinal vertebrae, the bones of the pelvis, and several skull bones are irregular bones. |
Short bones | Small and boxy bones. Bones of the wrist (carpals) and in the ankles (tarsals) are examples. |
Surface features | Bone markings |
Process | Any projection or bump. |
Head | An expanded proximal end of a bone that forms part of a joint. |
Neck | A narrow connection between the head of a bone and the diaphysis. |
Facet | Small, flat articular surface. |
Crest | Prominent ridge. |
Line | Low ridge, more delicate than a crest. |
Spine | A pointed or narrow process. |
Ramus | An extension of a bone that makes an angle with the rest of the structure. |
Spongy bone | Also called trabecular bone. Consists of an open network of struts and plates. |
Red bone marrow | Highly vascular, involved in production of blood cells. |
Yellow bone marrow | Adipose tissue, important in storage of energy reserves. |
Nutrient Foramen | A tunnel that penetrates the diaphysis and provides access for the nutrient artery/vein. |
Osteon | The basic functional unit of mature compact bone or Haversian system. |
Perforating Canals | Canals that extend perpendicular to the surface of compact bone. |
Epiphyseal Line | Former location of epiphyseal cartilage, remains after epiphyseal growth has ended. |
Dermal bones | Membrane bones |
Ossification center | Location in a tissue where ossification begins. |
Spicules | Small struts where developing bone grow outward from ossification center. |
Pituitary growth failure | Inadequate production of growth hormone leads to reduced epiphyseal cartilage and abnormally short bones. |
Achondroplasia | Results from abnormal epiphyseal activity. The epiphyseal cartilages of the long bones grow unusually slowly and are replaced by bone early in life. |
Marfan syndrome | This condition has characteristic variations in body proportions. |
Gigantism | Results from an overproduction of growth hormone before puberty. |
Fibro dysplasia Ossificans Progressiva (FOP) | A rare single gene mutation disorder that involves the deposition of bone around skeletal muscles. |
Heterotopic or ectopic bones | Bones that develop in unusual places |
Acromegaly | When growth hormone levels rise after the epiphyseal cartilages close. The skeleton does not grow longer, but the bones get thicker, especially in the face, jaw and hands. |
Calcium | Most abundant mineral in the human body. |
Fracture | A break or crack in a bone. |
Fracture hematoma | Large blood clot. |
Internal callus | Forms as a network of spongy bone and unites the inner edges. |
External callus | Formed from cartilage and bone; stabilizes the outer edges. |
Closed (simple) fractures | Completely internal; can only be seen on x-rays because they do not penetrate skin. |
Open (compound) fractures | Project through the skin |
Transverse fractures | Break a bone across its long axis |
Spiral fractures | Produced by twisting stresses that spread along the length of a bone. |
Displaced fractures | Produce new and abnormal bone alignments. |
Nondisplaced fractures | Retain the normal alignment of the bones or fragments. |
Compression fractures | Occur in vertebrae subjected to extreme stresses. |
Greenstick fractures | Occurs mainly in children. Happens when only one side of the shaft is broken and the other is bent. |
Comminuted fractures | Shatter the affected area into a multitude of bony fragments. |
Epiphyseal fractures | Tend to occur where the bone matrix is undergoing calcification and chondrocytes are dying. |
Colles fractures | A break in the distal portion of the radius. |