Anatomy: Bone Classifications + Features

Long bones

• diameter is smaller than length

• have a diaphysis, two metaphysis, two epiphyses, and a medullary cavity

• found in limbs

Flat bones

• have parallel surfaces of compact bone with inner diploe

• strong but light

• protect underlying soft tissue and have extensive surface for muscle attachment

Short bones

• boxlike with compact bones surrounding spongy bone

• found in wrist and ankle

Wormian Bones

• small, flat, oddly shaped bones found between the flat bones of the skull along the sutures

• develop from separate ossification centers

Pneumatized Bones

• bones that are hollow or contain numerous air pockets

Sesamoid Bone

• usually small, round, and flat

• develop inside tendons and are most often at joints of knee, hands, and feet

Irregular Bones

• have complex shapes with varied structures

• found in vertebrae

Process

any projection or bump

Ramus

An extension that forms an angle with the rest of the structure

Sinus/antrum

a chamber within a bone, normally filled with air

Canal/Meatus

A passageway for blood vessels and/or nerves

Fissure

A deep furrow, cleft or slit

Foramen

A rounded passageway for blood vessels and/or nerves

Sulcus

A narrow roove

Fossa

A shallow depression

Trochanter

A large, rough projection

Crest

A prominent ridge

Spine

A pointed process

Line

A low ridge

Tubercle

A small, rounded projection

Tuberosity

A rough projection

Head

the expanded articular end of an epiphysis, often separated from the shaft by a narrower neck

Neck

A narrower connection between the epiphysis and diaphysis

Facet

A small, flat articular surface

Condyle

A smooth, rounded articular process

Trochlea

A smooth, grooved articular process shaped like a pulley