Bone Anatomy, Growth, Remodeling, and Fractures Vocabulary

Flashcards covering key vocabulary terms, processes, fracture classifications, and clinical conditions discussed in the lecture notes.

Hypertrophy

The enlargement of cells in size, such as chondrocytes maturing and enlarging in zone three of bone growth or cardiac hypertrophy in an enlarged heart.

Calcification

The process in zone four of bone growth where the cartilage matrix hardens into rock-like tissue and the cartilage cells die off.

Epiphyseal line

The inactive structure formed around age 25 when the epiphyseal plate stops growing in length.

Appositional growth

Growth in bone width or thickness that occurs in response to increased stress from muscle use or weight.

Lamellae

Rings or layers of compact bone secreted around the outside of the bone by osteoblast cells.

Bone remodeling

A lifelong process involving bone resorption (removing old bone) and ossification (depositing new bone) that continues until death.

Bone resorption

The breakdown and removal of old or damaged bone tissue performed by osteoclasts using digestive enzymes.

Osteoclasts

A cell population in the body stimulated by parathyroid hormone (PTH) that breaks down and removes old or dead bone matrix.

Osteoid

The uncalcified, immature, wet-concrete-like initial bone matrix laid down by osteoblasts.

Osteoblasts

Bone-building cells regulated by calcitonin that fill in cracks and build new bone matrix by secreting osteoid.

Parathyroid hormone (PTH)

A hormone secreted by the parathyroid glands under the thyroid that activates osteoclasts to stimulate bone resorption.

Calcitonin

A hormone produced by the thyroid gland that controls and stimulates osteoblasts to rebuild bone.

Osteoporosis

A condition meaning porous bone where bone mass is lost faster than it is created, leading to low bone density and weakened bones.

Hematoma

A localized collection of clotting blood outside blood vessels that forms around a bone fracture in the first stage of bone repair.

Soft callus

A fibrocartilaginous repair tissue made of hyaline cartilage that forms around a broken bone during stage two of fracture repair.

Comminuted fracture

A bone fracture where the bone shatters into three or more pieces, particularly common in elderly people.

Compression fracture

A fracture caused by a crushing event where the bone gets compressed, typically seen in the lumbar spine.

Spiral fracture

A ragged bone break resulting from excessive twisting forces, commonly seen in sports injuries.

Depression fracture

A fracture pattern where broken bone tissue is pressed inward, typical of flat bone injuries such as those to the skull.

Greenstick fracture

An incomplete fracture where only one side of the shaft breaks and the other bends, common in children.

Osteosarcoma

A type of bone cancer, exemplified by the U-2 OS cell line originally taken from a 15-year-old girl's tibial tumor in 1964.

Osteogenesis imperfecta

A hereditary collagen disorder where an altered gene prevents tough collagen formation, causing bones to bend and break easily.

Axial skeleton

The skeletal division that consists of the skull, vertebral column, and rib cage.

Appendicular skeleton

The skeletal division comprising the limbs and the girdles (pelvis, shoulder blade, and clavicle) that attach limbs to the axial skeleton.

Cranium

The upper, rounded part of the skull that encloses the brain in the cranial cavity and provides muscle attachment sites.

Sutures

Unique, immovable joints that are found exclusively between bones of the skull.

Coronal suture

The skull suture that divides the frontal bone in front from the parietal bones in back.

Occipital condyles

Rounded bony structures located on the bottom of the occipital bone that articulate with the C1 vertebra (atlas) to form the head and neck joint.