STRUCTURE OF A LONG STRUCTURE OF A LONG BONEBONE

GROSS ANATOMYGROSS ANATOMY

DIAPHYSIS – shaftDIAPHYSIS – shaftMakes up most of bone’s Makes up most of bone’s

lengthlengthComposed of compact Composed of compact

bonebone

PeriosteumPeriosteumFibrous connective tissue Fibrous connective tissue

membranemembraneCovers and protects diaphysisCovers and protects diaphysis

Connected by Connected by Sharpey’s Sharpey’s FibersFibers

EPIPHYSESEPIPHYSESEnds of long boneEnds of long boneComposed of thin layer Composed of thin layer of compact bone of compact bone enclosing area of enclosing area of spongy bonespongy bone

ARTICULAR CARTILAGEARTICULAR CARTILAGE

Covers epiphysesCovers epiphysesGlassy, hyaline Glassy, hyaline Provides smooth, slippery Provides smooth, slippery

surface to decrease friction at surface to decrease friction at jointsjoints

Epiphyseal LineEpiphyseal LineAdult bones: thin line of bony tissue Adult bones: thin line of bony tissue

spanning the epiphysis spanning the epiphysis Remnant of Remnant of epiphyseal plateepiphyseal plate (plate (plate

of hyaline cartilage in young, growing of hyaline cartilage in young, growing bone)bone)

Cause lengthwise growth until end of Cause lengthwise growth until end of pubertypuberty

MEDULLARY CAVITYMEDULLARY CAVITY Yellow marrow – cavity of shaftYellow marrow – cavity of shaft In adults: storage for adipose tissueIn adults: storage for adipose tissue

In infants: area forms blood cells, red marrowIn infants: area forms blood cells, red marrow

(In adults: red marrow is confined to cavities of (In adults: red marrow is confined to cavities of spongy bone of flat bones, and epiphyses of spongy bone of flat bones, and epiphyses of some long bones: sternum, ribs, femur, cranium)some long bones: sternum, ribs, femur, cranium)