Bone Structure and Physiology Practice Flashcards

A collection of vocabulary terms based on the lecture transcript regarding bone anatomy, cellular composition, and surface markings.

Epiphysis

The ends of bones at the joints, made of spongy bone.

Diaphysis

The bone shaft, made of compact bone.

Epiphyseal Plate

A layer of cartilage that allows bones to increase in length until the end of adolescence (approximately $18$ in females and $21$ in males).

Epiphyseal Line

A bony structure that remains after the epiphyseal plate fades and epiphyseal cartilage stops dividing.

Medullary Cavity

The cavity of the bone shaft that contains yellow marrow in adults and red marrow in infants.

Yellow Marrow

A substance consisting mostly of fat found in the medullary cavity of adults.

Red Marrow

The site of blood cell formation found in infants and within the trabeculae of spongy bone in adults.

Periosteum

Dense irregular connective tissue surrounding the diaphysis where tendons are cemented into lamellae by osteoblasts.

Endosteum

A thin membrane lining the medullary cavity which contains concentrated osteoclasts.

Articular Cartilage

Cartilage that covers the surface of both epiphyses to reduce friction between joint surfaces.

Osteogenic (Osteoprogenitor) Cells

Stem cells created in the embryo and found in the lining of adult bones; they are the only bone cells that divide.

Osteoblasts

Immature bone cells that "build" new bone by secreting osteoid, the organic bone matrix.

Osteocytes

Mature bone cells that maintain the bone matrix; they are surrounded by bone and located in lacunae.

Osteoclasts

Large multinucleate cells formed by fused white blood cells that use powerful lysosomal enzymes and acids to break down bone.

Osteoid

The organic component of the bone matrix secreted by osteoblasts.

Bone Spur

A painful outgrowth of bone that can occur when osteoblasts are imbalanced or too active.

Osteon

A unit of bone arranged in concentric rings, also known as the Haversian system.

Central (Haversian) Canal

The opening in the center of an osteon that carries blood vessels and nerves.

Perforating Canal

A canal running perpendicular to the central canal that carries blood vessels and nerves to reach deeper osteons.

Lacunae

Small cavities within the bone matrix that contain osteocytes.

Lamellae

Concentric rings found around the central canal which serve as the sites of lacunae.

Canaliculi

Tiny canals radiating from the central canal to the lacunae that form a transport system.

Trabeculae

The structural lattice found in spongy bone; this structure is not found in compact bone.

Parathyroid Hormone

A hormone from the parathyroid gland that stimulates osteoclasts and osteoblasts to increase calcium ion absorption from the small intestine into the blood.

Calcitonin

A hormone from the thyroid gland that inhibits osteoclasts.

Fissure

A narrow slit between bones for the passage of blood vessels or nerves.

Foramen

A hole through bone for the passage of blood vessels, nerves, or ligaments.

Fossa

A shallow depression on the surface of a bone.

Meatus

A tube-like opening, also known as a canal.

Facet

A smooth, flat, and slightly concave articular surface.

Condyle

A rounded projection with a smooth articular surface.

Head

A rounded articular process usually supported on a neck.

Crest

A prominent ridge or elongated process of a bone.

Epicondyle

A typically roughened projection located on a condyle.

Line

A long, narrow ridge or border that is less prominent than a crest.

Tuberosity

A variably sized projection with a rough, bumpy surface.

Process

A sharp, slender projection from a bone.