Anatomy Long Bone unit 12th grade

Comminuted

Bone breaks into three or more fragments, particularly common in older people whose poems are brittle

Impacted

Broken bone ends are forced into each other commonly occurs when someone attempts to break a fall with out stretched arms

Hematopoiesis

Blood cell formation happens in the bones

Osteon (Haversian system)

A unit of bone containing central canal and matrix rings, structural and functional unit of compact bone

Canaliculi

Tiny cells radiate from the central canal to lacunae, form a transport system, connecting all bone cells to a nutrient supply

Osteoclast

In the endosteum, remove bone from the inner surface of the diaphysis, bone destroying cells, release calcium ions into the blood

Periosteum

Outside covering of the diaphysis, fibrous, connective tissue membrane, perforating (sharpey’s) fibers secure periosteum to underlying bone

Depressed

Broken bone portion is pressed inward typical of skull fracture

Spongy bone

Small needle like pieces of bones, many open spaces

Osteoblast

Bone forming cells, they are in the periosteum and add bone matrix to the diaphysis

Medullary cavity

Cavity inside the shaft contains yellow marrow, mostly fat in adults, contains red marrow for blood cell formation until age 6 or 7

Axial

Forms a longitudinal axis of the body, divided into three parts: the skull, vertebral column, and bony thorax

Endosteum

Lines the inner surface of the shaft made of connective tissue

lamellae

Concentric circles of lacunae, situated around the central Haversian canal

Appendicular

Composed of 126 bones: limbs(appendages) , pectoral girdle and pelvic girdle

Diaphysis

Covered by the periosteum, makes up most of bones length, composed of compact bone

Osteocytes

Mature bone cell situated and bone matrix, Lacunae: which are cavities of the bone matrix house this

Spiral

ragged break occurs when excessive to existing forces are applied to bone common in sports fracture

Articular cartilage

Part of a synovial joint, covers the external surface of the epiphyses, made of hyaline cartilage, decreases friction at joint surfaces

Lacunae

Cavities in bone matrix that house Osteocytes

Greenstick

Bone breaks incompletely, much in the way a green twig breaks, common in children, whose bones are more flexible than those of adults

Epiphysis

Composed mostly of spongy bone, enclosed by a thin layer of compact bone, the end of bones