Chapter 6: The Skeletal System - Bone Tissue

Flashcards for reviewing the skeletal system and bone tissue.

Diaphysis

The shaft of a long bone.

Epiphysis

One end of a long bone.

Metaphyses

Areas between the epiphysis and diaphysis, including the epiphyseal plate in growing bones.

Articular Cartilage

Covers joint surfaces and acts as a friction reducer and shock absorber.

Medullary Cavity

Marrow cavity within a long bone.

Endosteum

Lining of the marrow cavity.

Periosteum

Tough membrane covering the bone, but not the cartilage.

Fibrous Layer (Periosteum)

Dense irregular connective tissue layer of periosteum.

Osteogenic Layer (Periosteum)

Layer of periosteum containing bone cells and blood vessels for nourishment and repair.

Bone Tissue Matrix

Composed of 25% water, 25% collagen fibers, and 50% crystallized mineral salts.

Calcification/Mineralization

The process where inorganic salts are deposited in a framework of collagen fibers.

Osteoprogenitor Cells

Bone stem cells that can divide and become osteoblasts, found in the inner layer of periosteum and endosteum.

Osteoblasts

Cells that form bone matrix and collagen fibers, eventually turning into osteocytes.

Osteocytes

Mature bone cells that no longer secrete matrix.

Osteoclasts

Huge cells from fused monocytes that function in bone resorption.

Compact Bone

Dense, hard layer of bone that makes up the shaft of long bones and the external layer of all bones.

Spongy Bone

Bone that does not contain osteons, consists of trabeculae surrounding red marrow filled spaces, and is light to support/protect red bone marrow.

Trabeculae

Found in ends of long bones and inside flat bones, such as hipbones, sternum, skull sides, and ribs.

Osteogenesis/Ossification

The process of bone formation.

Intramembranous Ossification

Formation of bone directly from or within fibrous connective tissue membranes.

Endochondral Ossification

Formation of bone from hyaline cartilage models.

Appositional Growth

Growth of bone in thickness or diameter.

Closed Fracture

A fracture with no break in the skin.

Open Fracture

A fracture where the skin is broken.

Comminuted Fracture

A fracture where the broken ends of bones are fragmented.

Pott's Fracture

A distal fibular fracture.

Colles's Fracture

A distal radial fracture.

Stress Fracture

Microscopic fissures in bone from repeated strenuous activities.

Parathyroid Hormone (PTH)

Hormone secreted when Ca+2 levels fall.

Calcitonin

Hormone secreted when Ca+2 blood levels get too high.

Demineralization

Loss of bone minerals.

Osteoporosis

Decreased bone mass resulting in porous bones.

Rickets

A condition where calcium salts are not deposited properly, leading to soft bones in growing children.

Osteomalacia

A condition where new adult bone produced during remodeling fails to ossify.