Bones and Skeletal Tissues: Structure & Physiology

Vocabulary flashcards covering the anatomical structure, microscopic organization, cell biology, ossification processes, remodeling mechanisms, hormonal regulation, and clinical pathologies of bone tissue.

Long Bones

Bones that are distinctly longer than they are wide, such as the femur and humerus.

Short Bones

Approximately cube-shaped. Examples: carpals, tarsals

Flat Bones

Thin, flattened, and often curved. Examples: sternum, ribs, skull bones

Irregular Bones

Complex shapes that do not fit the other categories Examples: vertebrae, hip bones

Sesamoid Bones

Develop within tendons Example: patella (kneecap)

Compact Bone

Dense and solid-looking bone tissue. Forms the outer portion of most bones

Spongy Bone

Has an open, lattice-like structure, Spaces between the trabeculae may contain bone marrow

Trabeculae

thin, branching plates of bone tissue

Diaphysis

Shaft (long central portion) of the bone. Made mostly of compact bone, Surrounds the medullary cavity

Epiphyses

Enlarged ends of the bone Made mostly of spongy bone, with a thin outer layer of compact bone

Medullary Cavity

Hollow space inside the diaphysis. Contains mainly yellow bone marrow In adults

Articular Cartilage

smooth hyaline cartilage covering the ends of bones where they form a joint

Epiphyseal Line

A thin line in adult bone showing where the epiphyseal plate (growth plate) used to be

Periosteum

Membrane covering the external surface of bone, except where articular cartilage is present

Endosteum

Thin membrane lining the internal surfaces of bone.

Red Bone Marrow

Site of hematopoiesis (blood cell production). Produces red blood cells, white blood cells, and platelets. In adults, found mainly within spongy bone of certain bones

Yellow Bone Marrow

Contains mainly fat. Stores fat as an energy reserve. In adults, found mainly in the medullary cavity of long bones

Osteogenic Cells

Stem cells that can develop into osteoblasts

Osteoblasts

Form new bone by producing bone matrix

Osteocytes

Mature bone cells. Maintain bone matrix and detect stress on the bone

Osteoclasts

Resorb bone = break down and remove bone tissue

Osteon (Haversian System)

Basic structural unit of compact bone. Built around a central canal

Central Canal

Runs through the center of each osteon. Contains blood vessels and nerves

Concentric Lamellae

Together, they form rings of bone matrix around the central canal

Lacunae

Small spaces between the lamellae. Contain osteocytes

Canaliculi

Tiny channels connecting the lacunae. Allow osteocytes to receive nutrients and remove wastes

Ossification (Osteogenesis)

formation of bone tissue

Endochondral Ossification

Bone begins with a temporary hyaline cartilage model — a smooth cartilage version of the developing bone

Intramembranous Ossification

Bone forms directly within a fibrous connective

tissue membrane

Epiphyseal Plate

allows bones to grow in length during childhood and adolescence.

Appositional Growth

increase in the width (diameter) of a bone

Growth Hormone (GH)

Stimulates growth at the epiphyseal (growth) plates during childhood

Bone Remodeling

continuous replacement of old or damaged bone with new bone

Wolff's Law

Bone remodels in response to the stress placed on it.

Hematoma Formation

The first stage of fracture repair in which torn blood vessels bleed and form a localized clot at the site of injury.

Osteoporosis

bones lose mass and become weaker, increasing fracture risk.