Anatomy Lec 3: Osteology 1

Functions of bone

-physical (levers, protection, support)

-metabolic (mineral metabolism, sites of hematopoiesis, fat storage)

Long Bones

Found in limbs and act as levers. Elongated in one dimension. Example humerus

What does a lever system include?

fulcrum, load, and effort

Short Bone

Are equidimensional and found in all limbs. Used for complex movement. Examples include carpal and tarsal bones

Flat Bones

Reduced in size in one dimension, sites of hematopoiesis. Examples include scapula, ribs, some bones of the skull

Flat bones: pneumatic bones

Have air filled spaces. In mammals these are paranasal sinues

Irregular Bones

Irregular shape. Examples include vertebrate, some skull bones, and pelvis bones

Sesamoid bones

Seed shape found embedded in tendons. Function as bearing surfaces to protect tendons from friction

appendicular skeleton

bones of the limbs

axial skeleton

bones of the skull, vertebral column, ribs, and sternum

Heterotopic Skelton

bones in unusual but normal location such as os penis in dogs

compact bone

dense or cortical bone usually in the middle of long bones

spongey bone

trabecular or cancellous bone, found in extremities of long bones, forms internal substance of short and irregular bones, and is interposed between 2 compact layers of flat bones

Cartilaginous (endochondral) bone

Bone progressively replaces a previously formed, continuous growing cartilage model

dermal (intermembranous) bone

bone forms directly within a sheet of connective tissue includes bones of the face and dorsum of the skull

endochondral ossification - bone growth

Bone starts out as a hyaline cartilage model and starts to develop primary and secondary ossification enters. Cartilage/epiphyseal/growth plates remain between the two centers until bones are mature. Grows bone in length.

Intramembranous ossification -bone growth

Responsible for bone growth width wise. No cartilage model. Bone forms directly within sheet of connective tissue.

diaphysis

shaft and primary center of ossification

epiphysis

end and secondary center of ossification

physis (epiphyseal plate)

plate of growing cartilage in immature bone m

metaphysis

rapidly growing flared segment of bone located on diaphyseal side of epiphyseal plate

apophysis

certain large, bony projections which develop centers of ossification

periosteum

connective tissue surrounding the diaphysis

medullary cavity

hollow space within diaphysis e

endosteum

thin membrane lining medullary cavity

Nutrient artery

largest single source of blood supply to bone and passes through nutrient foramen in middle of diaphysis