General Osteology and Arthrology

Flashcards covering general osteology, bone classifications, internal/external bone anatomy, skeletal divisions, arthrology, and synovial joint types and movements.

Hydroxyapatite

The mineral form of calcium and phosphate stored within the bone matrix.

Hematopoiesis

The process of blood cell production occurring within the bone.

Long bone

A bone classification for bones that are longer than they are wide, such as the humerus, femur, radius, and ulna.

Short bone

Bones that are approximately as long as they are wide, such as the carpals and tarsals.

Flat bone

Bones that are thin, flat, and slightly curved, including cranial bones, the scapula, ribs, and the sternum.

Irregular bone

Bones that do not fit into other classification categories, such as the vertebrae, os coxae, and facial bones.

Diaphysis

The shaft of a long bone composed of compact bone surrounding the medullary cavity.

Epiphysis

The expanded ends of a long bone.

Medullary cavity

The central cavity within the diaphysis that contains yellow bone marrow in adults.

Compact bone

The dense outer layer of bone that is microscopically arranged into functional units called osteons.

Spongy bone

Bone tissue composed of a lattice-work called trabeculae, which houses red bone marrow.

Osteon

The microscopic structural unit of compact bone.

Trabeculae

The structural beams or plates that compose spongy bone.

Periosteum

A connective tissue membrane surrounding the outside of the bone consisting of an outer fibrous layer and an inner cellular layer of osteoblasts and osteoclasts.

Endosteum

The connective tissue lining the medullary cavity which contains both osteoblasts and osteoclasts.

Nutrient foramen

An opening in the bone through which the nutrient artery enters to supply the bone with blood.

Articular cartilage

Hyaline cartilage located on the ends of long bones to provide protection and reduce friction.

Epiphyseal plate

A layer of hyaline cartilage, also known as the growth plate, found in the metaphysis of growing bones.

Epiphyseal line

The remnant of the epiphyseal plate that forms after the plate has ossified in adults.

Axial skeleton

The skeletal division consisting of the skull, vertebral column, hyoid, and thoracic cage.

Appendicular skeleton

The skeletal division consisting of the pectoral girdle, upper extremity, pelvic girdle, and lower extremity.

Fibrous joints

Joints joined by fibrous connective tissue; most are functionally classified as synarthrotic.

Synarthrotic

A functional classification for joints that allow no movement.

Amphiarthrotic

A functional classification for joints that are slightly movable.

Diarthrotic

A functional classification for joints that are freely movable, typically applied to synovial joints.

Suture

A type of synarthrotic fibrous joint found between the bones of the skull.

Syndesmosis

An amphiarthrotic fibrous joint where bones are connected by ligaments, such as the interosseous membrane between the radius and ulna.

Gomphosis

A synarthrotic fibrous "peg-in-socket" joint found between the teeth and the alveolar processes of the face.

Cartilaginous joints

Joints where the bones are connected by cartilage.

Synchondrosis

A synarthrotic cartilaginous joint connected by hyaline cartilage, such as the first rib-sternum joint or the epiphyseal plate.

Symphysis

An amphiarthrotic cartilaginous joint connected by fibrocartilage, such as the pubic symphysis and intervertebral disks.

Synovial joints

Freely movable (diarthrotic) joints characterized by a joint cavity and synovial fluid.

Articular capsule

A structure in synovial joints consisting of an outer fibrous layer and an inner synovial membrane.

Synovial membrane

The inner layer of the articular capsule that releases lubricating synovial fluid.

Bursa

Fluid-filled sacs that cushion tendons as they cross over bony or ligamentous surfaces.

Tendon sheath

A tubular bursa sac that surrounds a tendon along its length.

Articular disks or menisci

Plates of fibrocartilage found in some synovial joints to reduce friction and absorb shock.

Flexion

A synovial joint movement that decreases the angle between two bones.

Extension

A synovial joint movement that increases the angle between two bones.

Hyperextension

Increasing the angle of a joint beyond $180^\circ$.

Abduction

Movement of an appendage away from the midline of the body.

Adduction

Movement of an appendage toward the midline of the body.

Rotation

Pivoting of a bone around its own central axis.

Pronation

Rotation of the forearm so that the palms face posteriorly.

Supination

Rotation of the forearm so that the palms face anteriorly.

Eversion

Turning the sole of the foot outward to face away from the midline.

Inversion

Turning the sole of the foot inward toward the midline.

Plantar flexion

Movement of the foot that points the toes downward, as if standing on "tippie" toes.

Dorsiflexion

Movement of the foot that points the toes upward toward the ceiling.

Protraction

Anterior movement of a body part in the transverse plane.

Retraction

Posterior movement of a body part in the transverse plane.

Elevation

Lifting a body part superiorly.

Depression

Moving a body part inferiorly.

Circumduction

Moving an appendage so that it inscribes the shape of a cone.

Opposition

The specific movement of touching the thumb to the tips of the fingers.

Planar joint

A type of synovial joint with flat articular surfaces where bones glide past one another, such as intercarpal joints.

Hinge joint

A uniaxial synovial joint where the convex end of one bone fits into the concave end of another, allowing movement like a door hinge.

Pivot joint

A uniaxial synovial joint where a rounded bone surface fits into a ring, allowing rotation around a central axis.

Condylar joint

A biaxial synovial joint where an oval, convex surface articulates with a concave surface, allowing circumduction.

Saddle joint

A biaxial synovial joint with convex and concave surfaces resembling a saddle, such as the carpometacarpal joint of the thumb.

Ball-and-socket joint

A multiaxial synovial joint where a spherical head fits into a cuplike socket, such as the hip and shoulder joints.