Chapter 7: Bones and Skeletal Tissue

A comprehensive vocabulary review of Chapter 7: Bones and Skeletal Tissue, covering bone anatomy, fracture classifications, cell types, ossification processes, and skeletal physiology.

Epiphysis (Figure 6.2, Label A)

The end section of a long bone, indicated by label A in Figure 6.2.

Epiphyseal Line Location (Figure 6.2, Label B)

The region between the epiphysis and diaphysis of a mature long bone, designated by label B in Figure 6.2.

Compact Bone (Figure 6.2, Label C)

The dense external layer of bone tissue located along the shaft, designated by label C in Figure 6.2.

Yellow Marrow Area (Figure 6.2, Label D)

The medullary cavity within the shaft where fat-storing yellow bone marrow is found, designated by label D in Figure 6.2.

Greenstick Fracture

An incomplete fracture or cracking of the bone without actual separation of the parts, commonly occurring in children.

Comminuted Fracture

A fracture pattern in which the bone shatters or fragments into many pieces.

Spiral Fracture

A common sports fracture resulting from a twisting force applied to the bone.

Hematopoiesis

The physiological process of blood cell formation occurring within the red marrow cavities of certain bones.

Red Bone Marrow

Tissue found in the cavities of certain bones that is actively responsible for hematopoiesis (blood cell production).

Periosteum

A protective tissue membrane enclosing bone that is richly supplied with blood vessels and nerves.

Osteon

The structural unit of compact bone that resembles the concentric growth rings of a tree trunk.

Central (Haversian) Canal

A longitudinal channel running through the core of each osteon that contains blood vessels and nerve fibers.

Lamellae

Concentric layers or rings of bone matrix surrounding the central canal within an osteon.

Osteocytes

Mature bone cells situated within lacunae that help maintain the bone matrix in compact bone.

Trabeculae

The delicate struts or honeycomb-like spicules of spongy bone that orient themselves toward lines of stress.

Spongy Bone

Bone tissue characterized by an open latticework of trabeculae rather than osteons.

Lines of Stress

Mechanical load vectors along which the trabeculae of spongy bone align to resist physical force.

Osteoblast

The bone cell responsible for secreting the organic matrix of bone during ossification.

Osteoclast

The multinucleated cell responsible for bone resorption (breaking down bone tissue).

Bone Resorption

The breakdown and destruction of bone matrix by osteoclasts to release minerals like calcium into the blood.

Diaphysis

The elongated central shaft of a long bone.

Epiphyseal Plate

A hyaline cartilage structure that allows the diaphysis of a long bone to increase in length during infancy and childhood.

Epiphyseal Line

The osseous remnant left behind in adult long bones after the epiphyseal plate finishes growing and closes.

Growth Hormone

The single most important hormonal stimulus for epiphyseal plate activity during infancy and childhood.

Parathyroid Hormone (PTH)

The hormone that increases osteoclast activity to release more calcium ions into the bloodstream.

Calcitonin

A thyroid-secreted hormone that is not the primary hormone involved in the control of bone remodeling.

Appositional Growth

The developmental process by which bones increase in thickness or diameter.

Interstitial Growth of the Epiphyseal Plates

The mechanism exclusively responsible for the lengthwise elongation of long bones during infancy and youth.

Intramembranous Ossification

The form of bone development wherein ossification centers form directly within fibrous connective tissue membranes.

Endochondral Ossification

The form of bone formation that utilizes a pre-existing hyaline cartilage model as a precursor.

Ossification (Osteogenesis)

The biological process of bone formation.

Canaliculi

Microscopic hairlike canals that most directly provide nutrients and remove wastes from osteocytes in compact bone.

Yellow Bone Marrow

Marrow tissue found within the medullary cavity that contains a large percentage of fat.

Osteoporosis

A condition involving decreased bone mass and bone fragility, frequently seen in older women due to estrogen deficiency after menopause.

Estrogen Deficiency

A hormonal deficit occurring after menopause that is implicated in the onset of osteoporosis in older women.

Cranial Bones

Bones of the head that develop intramembranously within fibrous membranes.

Cartilage Model

The initial tissue structure that forms the blueprint for endochondral ossification.

Support (Skeletal Function)

A major physiological function of the skeletal system providing structural framework for the body.

Mineral Storage (Skeletal Function)

A function of the skeleton acting as an internal reservoir for essential minerals such as calcium.

Shaft Fracture

A fracture occurring specifically along the diaphysis of a long bone.

Calcium Intake

An essential dietary requirement whose adequate intake is crucial in the prevention of osteoporosis.

Vitamin D Intake

A vital nutrient taken alongside calcium to support bone health and prevent osteoporosis.

Thin Epiphyseal Plate

An X-ray feature of a femur observed at an archeological site characteristic of an 18-year-old male finishing longitudinal growth.

Fibrous Connective Tissue Membrane

The embryonic precursor tissue within which ossification centers form during intramembranous ossification.

Bone Remodeling

The ongoing physiological turnover of bone tissue through balanced resorption and deposition, regulated primarily by parathyroid hormone.

Perforating (Volkmann's) Canals

Canals that lie at right angles to the long axis of the bone, distinct from the canaliculi that directly supply osteocytes.

Bone Collar

A structure formed around the cartilage model during endochondral ossification, rather than during intramembranous ossification.

Adolescent Bone Growth

The concept that bone growth does not entirely stop across all skeletal components by the end of adolescence.

Bone Classification Criteria

The anatomical taxonomy of bones based on shape and structure, rather than functional categories like weight bearing or protection.

Epiphyseal Plate Closure

The developmental event ending lengthwise bone elongation that does not stop all subsequent bone growth, such as appositional thickening.