Skeletal System Structure, Histology, and Bone Formation

Comprehensive vocabulary flashcards reviewing skeletal anatomy, functions, histology, growth factors, remodeling, and bone formation mechanisms.

Skeletal System

The body system consisting of the entire framework of bones and their cartilages, along with tendons and ligaments.

Support (Function of the Skeleton)

The structural role of the skeleton where it serves as a framework for the body by supporting soft tissues and providing attachment points for tendons.

Protection (Function of the Skeleton)

The function of the skeleton in shielding internal organs from injury, such as cranial bones protecting the brain.

Assistance in Movement

The skeletal function where skeletal muscles attach to bones and pull on them upon contraction to produce movement.

Mineral Homeostasis

The storage and controlled release of critical minerals (especially calcium and phosphorus) by bone tissue to maintain blood mineral balance and distribute them throughout the body.

Red Bone Marrow

A connective tissue found within certain bones that produces red blood cells, white blood cells, and platelets.

Hemopoiesis

The process of blood cell production that occurs within red bone marrow.

Yellow Bone Marrow

Bone marrow consisting mainly of adipose cells that store fats as a potential chemical energy reserve.

Diaphysis

The shaft or body of a long bone; its long, cylindrical main portion.

Epiphyses

The proximal and distal ends of a long bone.

Metaphyses

The regions in a long bone located between the diaphysis and the epiphyses.

Articular Cartilage

A thin layer of hyaline cartilage covering the portion of the epiphysis where a bone forms a joint (articulation) with another bone.

Periosteum

A tough connective tissue sheath and its associated blood supply that covers bone surfaces wherever they are not covered by articular cartilage.

Medullary Cavity

A hollow, cylindrical space within the diaphysis of a long bone that contains fatty yellow bone marrow and numerous blood vessels in adults.

Osteogenic Cells

Unspecialized bone stem cells derived from mesenchyme; they are the only bone cells capable of undergoing cell division.

Osteoblasts

Bone-building cells that synthesize and secrete collagen fibers and other organic components to form extracellular bone matrix, initiating calcification.

Osteocytes

Mature bone cells that represent the principal cells in bone tissue and maintain daily metabolism, including nutrient and waste exchange with blood.

Osteoclasts

Huge cells concentrated in the endosteum, formed from the fusion of as many as 50 monocytes, that release powerful lysosomal enzymes and acids to break down bone extracellular matrix.

Bone Resorption

The breakdown and destruction of the bone extracellular matrix by osteoclasts to release calcium into the bloodstream.

Bone Deposition

The ongoing process of building bone extracellular matrix carried out by osteoblasts.

Osteon

The basic, circular structural unit of compact bone tissue.

Compact Bone Tissue

The strongest form of bone tissue with few spaces, situated beneath the periosteum of all bones and composing the bulk of the diaphysis of long bones.

Spongy Bone Tissue

Bone tissue always located in the interior of a bone, shielded by compact bone, featuring spaces filled with red or yellow bone marrow.

Appositional Growth

The process by which bones throughout the body increase in thickness during infancy, childhood, and adolescence.

Interstitial Growth (of Bone)

Growth in length of long bones involving cartilage division on the epiphyseal side of the epiphyseal plate followed by replacement with bone via endochondral ossification.

Bone Remodeling

The continuous, ongoing replacement of old bone tissue with newly formed bone tissue.

Insulin-Like Growth Factors (IGFs)

Hormones produced by the liver and bone tissue during childhood that stimulate osteoblasts, promote cell division, and boost the synthesis of bone-building proteins.

Vitamin A (Role in Bone)

A vitamin that stimulates the cellular activity of osteoblasts during bone growth and remodeling.

Vitamin C (Role in Bone)

A vitamin required for the proper synthesis of collagen, the main protein of bone tissue.

Intramembranous Ossification

The simpler method of bone formation where bone develops directly; it forms the flat bones of the skull, most facial bones, mandible, medial part of the clavicle, and infant soft spots.

Endochondral Ossification

The process of bone formation wherein preexisting cartilage is replaced by bone tissue, best observed in the development of long bones.

Fracture

Any break in the continuity of a bone.