Level 1: Chapter 7 – The Skeletal System: Bones and Joints

A comprehensive set of vocabulary flashcards covering major terms, structures, functions, and disorders related to bones and joints from Chapter 7.

Skeleton

The entire framework of bones, joints, and supporting connective tissues of the body.

Axial skeleton

The 80 bones of the head and trunk (skull, vertebral column, ribs, sternum).

Appendicular skeleton

The 126 bones of the upper and lower extremities, including shoulder and pelvic girdles.

Bone marrow

Soft connective tissue in bone cavities; red marrow makes blood cells, yellow marrow stores fat.

Osteocyte

A mature bone cell that maintains the bone matrix.

Osteoblast

A bone-forming cell that deposits new bone tissue.

Osteoclast

A bone-resorbing cell that breaks down bone matrix during remodeling.

Resorption

The process of breaking down and removing bone tissue, mainly by osteoclasts.

Osseous tissue

Hardened connective tissue of bone, rich in collagen fibers and calcium salts.

Periosteum

Fibrous membrane covering a bone’s surface; contains blood vessels and osteoblasts.

Endosteum

Thin membrane lining the medullary cavity inside a bone.

Diaphysis

The shaft of a long bone, surrounding the medullary cavity.

Epiphysis

The expanded end of a long bone; often covered by articular cartilage.

Osteon (Haversian system)

The structural cylinder unit of compact bone containing lamellae and a central canal.

Ossification

The process of bone formation.

Parathyroid hormone (PTH)

Hormone that raises blood calcium by stimulating bone resorption.

Bone marking

Surface feature of a bone that forms joints, serves as muscle attachment, or allows passage of vessels and nerves.

Foramen

A rounded opening in a bone for vessels or nerves (e.g., vertebral foramen).

Condyle

A rounded articular projection that helps form a joint (e.g., femoral condyle).

Fossa

A shallow depression in a bone (e.g., olecranon fossa).

Crest

A prominent narrow ridge of bone (e.g., iliac crest).

Process

Any bony prominence (e.g., mastoid process, coracoid process).

Spine (bone)

A sharp, slender projection (e.g., scapular spine).

Head (bone)

Rounded articular end of a bone set off by a neck (e.g., femoral head).

Sinus

A cavity within a bone, filled with air and lined with mucous membrane (e.g., frontal sinus).

Meatus

A canal-like passageway in a bone (e.g., external auditory meatus).

Synarthrosis

An immovable joint held together by fibrous tissue (e.g., skull suture).

Amphiarthrosis

A slightly movable joint with cartilage or fibrous tissue between bones (e.g., pubic symphysis).

Diarthrosis (synovial joint)

A freely movable joint with a fluid-filled cavity (e.g., shoulder, elbow).

Synovial fluid

Viscous lubricant within a synovial joint cavity that reduces friction.

Ligament

Band of dense connective tissue that stabilizes and reinforces joints by connecting bone to bone.

Articular cartilage

Hyaline cartilage covering bone ends in synovial joints, protecting surfaces.

Circumduction

Circular movement of a limb combining flexion, extension, abduction, and adduction.

Bone growth (long bone)

Lengthening at epiphyseal plates and thickening by appositional growth beneath periosteum.

Osteopenia

Mild to moderate reduction in bone density.

Osteoporosis

Severe loss of bone density, increasing fracture risk, common in postmenopausal women.

Osteosarcoma

A malignant bone tumor arising from osteoblasts.

Chondrosarcoma

Cancer of cartilage cells within bone or soft tissue.

Osteomyelitis

Infection and inflammation of bone, usually caused by pyogenic bacteria.

Kyphosis

Exaggerated thoracic spinal curvature (“hunchback”).

Lordosis

Exaggerated lumbar spinal curvature (“swayback”).

Scoliosis

Lateral curvature of the vertebral column.

Sprain

Tear or rupture of a ligament due to excessive joint movement.

Herniated disk

Protrusion of nucleus pulposus through intervertebral fibrocartilage, compressing nerves.

Osteoarthritis (degenerative joint disease)

Joint disorder from wear and tear causing cartilage breakdown and pain.

Rheumatoid arthritis

Autoimmune inflammation of synovial joints that destroys articular cartilage.

Gout

Arthritis caused by deposition of uric acid crystals in joints.

Soft callus

Fibrocartilaginous tissue that bridges a bone fracture during early healing.

Hard (bony) callus

Spongy bone that replaces soft callus during fracture repair.

Red bone marrow

Hematopoietic tissue that produces red and white blood cells and platelets.

Yellow bone marrow

Fat-rich marrow found mainly in the medullary cavities of adult long bones.

Fontanel

Soft membranous gap between incompletely ossified skull bones of an infant.

Bursa

Small fluid-filled sac reducing friction between tendons, ligaments, and bones.

Arthroscope

A fiber-optic instrument inserted into a joint cavity for visual examination or surgery.

Arthroplasty

Surgical replacement or reconstruction of a joint (e.g., total hip replacement).

Extremity

A limb of the body; upper extremity (arm) or lower extremity (leg).