osteoblasts

bone building cells

osteocytes

mature bone cells

osteoclasts

bone destroying cells

compact bone

hard, dense bone tissue that has little space in between components

lamellae

concentric rings made up of hollow tubes of bone matrix

central haversian canal

opening of the center of an osteon, carries blood vessels and nerves

volkmanns canals

channels lying at right angles to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian canal

lacunae

small cavities in bone that contain osteocytes

Haversian system (Osteon)

structural unit of compact bone

Spongy bone

Layer of bone tissue having many small spaces and found just inside the layer of compact bone, spaces filled with Red Bone Marrow

Endochondral ossification

process in which bone forms by replacing hyaline cartilage

Intramembranous ossification

bone develops from a fibrous membrane; example is the skull

Wolff's Law

A bone grows or remodels in response to forces or demands placed upon it

Long bones

longer than they are wide

Short bones

equal in length and width; carpal and tarsal bones

Flat bones

These bones are thin, flat, and curved. They form the ribs, breastbone, and skull.

Irregular bones

bones that are complex in shape; vertebrae, facial bones

Sesamoid bones

small bones situated within tendons; patella

Diaphysis

shaft of a long bone

Epiphysis

Broadened End of a long bone

Metaphysis

growth zone between the epiphysis and the diaphysis during development of a long bone

Periosteum

A dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles.

Endosteum

membranous lining of the hollow cavity of the bone

Medullary cavity

cavity within the shaft of the long bones filled with bone marrow

Sinus

Cavity within a bone, filled with air and lined with mucous membrane

Tubercle

Small rounded projection or process

Meatus

Tubelike passageway within a bone

Tuberosity

Large rounded projection; may be roughened

Condyle

A smooth, rounded articular process creates smooth arc of motion

Process

any bony prominence

Trochanter

Very large, blunt, irregularly shaped process found on the proximal femur

Fossa

Relatively deep pit or depression

Foramen

Round or oval opening through a bone

Axial skeleton

Portion of the skeletal system that consists of the skull, rib cage, and vertebral column

Appendicular skeleton

Bones of the limbs and limb girdles that are attached to the axial skeleton

Coronal suture

the suture between the parietal and frontal bones of the skull

Sagittal suture

between the two parietal bones

Lambdoidal suture

suture that separates parietal bones from occipital bone

Squamosal suture

between parietal bone and temporal bone on side of the skull, bordered in back by occipital bone

Fontanels

Gaps between a baby's skull that slowly close up during the first 18 months of life

Anterior fontanel

Anterior side of the skull Where the sagittal suture and coronal suture meet

Posterior fontanel

back soft spot on fetal skull between parietal and occipital bone

anterolateral fontanel (sphenoidal)

soft spot between the parietal, frontal, temporal, and sphenoid bones

posterolateral fontanel (mastoid)

soft spot between the occipital, parietal, and temporal bones

Synarthrotic joints (fibrous)

immovable joints held together by connective tissue

Amphiarthrotic joints (cartilaginous)

slightly movable joints held together by cartilage

Diarthrotic joints (synovial)

freely movable joints held together by a synovial capsule containing synovial fluid

Gliding joint

allows one bone to slide over another; found in wrist and ankles

Hinge joint

Joint between bones (as at the elbow or knee) that permits motion in only one plane

Pivot joint

Allows for rotation around the length of a bone, and only allows for rotation.

Saddle joint

type of joint found at the base of each thumb; allows grasping and rotation

Ball and socket joint

rounded head articulates with depression; shoulder and hip

Tendons

Connect muscle to bone

Ligaments

Connect bone to bone

Menisci

Pads of cartilage that lie between the articular surfaces of the bones

Bursa

fluid-filled sac that allows for easy movement of one part of a joint over another

Fracture

broken bone

Sprain

injury to a ligament

Herniated disc

protrusion of a fragmented intervertebral disc in the intervertebral foramen with potential compression of a nerve

Spina Bifida

a congenital defect that occurs during early pregnancy when the spinal canal fails to close completely around the spinal cord to protect it

Kyphosis

excessive outward curvature of the spine, causing hunching of the back.

Lordosis

abnormal anterior curvature of the lumbar spine (sway-back condition)

Scoliosis

abnormal lateral curvature of the spine

Osteoarthritis

inflammation of the bone and joint

Osteoporosis

A condition in which the body's bones become weak and break easily.

Rheumatoid arthritis

a chronic autoimmune disorder in which the joints and some organs of other body systems are attacked