Bones and Skeletal Tissue Vocabulary

Vocabulary practice flashcards covering Chapter 6: Bones and Skeletal Tissue, including key structures, cell types, classification, growth pathways, and homeostatic hormones.

Osseous Tissue

A hard, dense connective tissue that forms most of the adult skeleton.

Orthopedist

A physician who specializes in diagnosing and treating disorders and injuries related to the musculoskeletal system.

Hematopoiesis

The process of blood cell formation, producing red cells, white cells, and platelets within red bone marrow cavities.

Axial Skeleton

The skeleton division located along the long axis of the body, including the skull, vertebral column, and rib cage.

Appendicular Skeleton

The skeleton division comprising the upper and lower limbs and the shoulder and pelvic girdles that attach them to the axial skeleton.

Long Bone

A bone that is cylindrical in shape and longer than it is wide, functioning primarily as a lever.

Short Bone

A cube-like bone roughly equal in length, width, and thickness, providing stability and support with limited motion.

Flat Bone

A thin, often curved bone that serves as an attachment point for muscles and protects internal organs.

Irregular Bone

A bone with a complex or non-standard shape that does not fit into other classifications, functioning to protect internal organs.

Sesamoid Bone

A small, round bone formed inside tendons that protects tendons from compressive forces.

Diaphysis

The tubular shaft running between the ends of a long bone, composed of hard compact bone.

Epiphysis

The wider region at each end of a long bone, filled with spongy bone and red marrow.

Medullary Cavity

The hollow region in the diaphysis filled with yellow bone marrow in adults.

Periosteum

A fibrous membrane covering the outer surface of bone, containing blood vessels, nerves, and lymphatic vessels, and serving as the attachment site for tendons and ligaments.

Endosteum

The delicate membranous lining of the medullary cavity where bone growth, repair, and remodeling occur.

Osteogenic Cells

The only mitotic bone stem cells, found in the deep layers of the periosteum and marrow, which differentiate into osteoblasts.

Osteoblasts

Bone-building cells responsible for synthesizing and secreting new bone matrix.

Osteocytes

Mature bone cells located within spaces called lacunae that maintain the bone matrix.

Osteoclasts

Large, multinucleated cells originating from white blood cells that break down bone tissue for calcium and mineral reabsorption.

Osteoporosis

A skeletal disorder characterized by low bone mass and increased fracture risk, occurring when bone resorption by osteoclasts exceeds bone deposition by osteoblasts.

Osteon (Haversian System)

The structural unit of compact bone consisting of concentric layers of matrix called lamellae surrounding a central canal.

Trabeculae

A lattice-like network of matrix spikes in spongy bone that forms along lines of stress to provide strength.

Nutrient Foramen

Small openings in the diaphysis through which arteries, veins, and nerves enter the bone.

Intramembranous Ossification

The process of bone development directly from fibrous membranes, forming the flat bones of the face, most cranial bones, and clavicles.

Endochondral Ossification

The process of bone development in which hyaline cartilage is replaced by bone tissue, forming long bones and bones at the base of the skull.

Appositional Growth

An increase in bone diameter or thickness that can continue even after longitudinal bone growth ceases.

Epiphyseal Plate

A layer of hyaline cartilage in growing long bones where cartilage growth on one side is balanced by bone replacement on the other.

Fracture Repair Stages

The four-phase healing process of a broken bone consisting of hematoma formation, cartilaginous callus formation, bony callus formation, and bone remodeling.

Rickets

A disorder in children caused by a lack of vitamin D, leading to soft and weakened bones.

Osteomalacia

A condition in adults caused by vitamin D deficiency that leads to softening of the bones.

Scurvy

A condition caused by vitamin C deficiency, impairing collagen synthesis by osteoblasts and causing unhealed wounds and lost teeth.

Calcitonin

A hormone released by C cells in the thyroid gland when blood $Ca^{2+}$ levels are high, which inhibits osteoclasts to slow bone resorption.

Parathyroid Hormone (PTH)

A hormone secreted by parathyroid cells when blood $Ca^{2+}$ levels are low, stimulating osteoclasts and triggering calcium reabsorption by the kidneys.