A&P: Osseous Tissue and Skeletal System Introduction

Flashcards about Osseous Tissue and the Skeletal System

Mineralization/Calcification

Hardening of bone through mineral deposition.

Ligaments

Dense regular connective tissue; connects bone to bone.

Functions of the Skeletal System

Provides support, protection, leverage (movement), mineral/electrolyte/lipid storage, acid/base balance, and blood cell production.

Axial Skeleton

Skull (cranial and facial), vertebrae (cervical, thoracic, lumbar, sacral, coccygeal), sternum (manubrium, body, xiphoid process), and ribs (12 pairs).

Appendicular Skeleton

Pectoral girdle, pelvic girdle, upper and lower appendages.

Long Bones

Types of bones that are longer than they are wide.

Short Bones

Types of bones that are cube-shaped.

Flat Bones

Thin, flattened, and usually curved bones; examples include most skull bones, ribs, and sternum.

Sutural/Intrasutural/Wormian Bones

Small bones located within sutures of the skull.

Irregular Bones

Bones with complex shapes, such as vertebrae and some facial bones.

Sesamoid Bones

Small, round bones embedded in tendons; patella is an example.

Epiphysis

The end of a long bone, proximal or distal.

Metaphysis

Region between the diaphysis and epiphysis.

Diaphysis

Shaft of a long bone.

Articular Cartilage

Hyaline cartilage covering the epiphysis at a joint.

Spongy Bone

Cancellous bone; contains trabeculae.

Compact Bone

Dense outer layer of bone.

Medullary Cavity

Marrow cavity within the diaphysis.

Endosteum

Connective tissue membrane covering internal bone surfaces.

Periosteum

Connective tissue membrane covering the external surface of bone.

Nutrient Foramen

Small opening for nutrient artery and vein to enter bone.

Osteogenic Cells (Osteoprogenitor cells)

Stem cells that differentiate into osteoblasts.

Osteoblast

Bone-forming cells that secrete osteoid.

Osteoid

Un-mineralized bone matrix.

Osteocyte

Mature bone cells in lacunae.

Canaliculi

Small channels connecting lacunae.

Osteoclast

Bone-resorbing cells; macrophages.

Osteolysis

Resorption of bone.

Hydroxyapatite

Calcium phosphate salts (85%) and calcium carbonate (10%).

Osteon (Haversian system)

Structural unit of compact bone.

Central Canal (Haversian canal)

Channel in the center of an osteon containing blood vessels and nerves.

Perforating Canal (Volkmann’s canal)

Channels perpendicular to central canals, connecting blood and nerve supply of the periosteum to the central canals and medullary cavity.

Concentric Lamellae

Layers of bone matrix arranged concentrically around a central canal.

Interstitial Lamellae

Irregular lamellae filling the spaces between osteons.

Circumferential Lamellae

Lamellae that extend around the entire circumference of the diaphysis.

Spicules

Needle-like or spike-like pieces of bone in spongy bone.

Trabeculae

Supporting bundles of bony fibers in spongy bone.

Red Bone Marrow (Myeloid tissue)

Hematopoietic tissue that produces blood cells.

Yellow Bone Marrow

Bone marrow primarily composed of adipose tissue.

Ossification/Osteogenesis

Bone formation.

Intramembranous Ossification

Formation of bone directly from mesenchymal cells.

Mesenchymal cells

Develop into hyaline cartilage; ossification center.

Spicule Development

Trabeculae precursor.

Endochondral Ossification

Bone formation that begins with a cartilage model.

Vascularization

Perichondrium transitions to periosteum, forming a bony “collar;” primary ossification center.

Epiphyseal Closure

Estrogen

Zone of Stasis

Anchors to bone; reserve cartilage.

Zone of Hyperplasia (Proliferation)

Increase number of cells.

Zone of Hypertrophy

Increase in the size of cells.

Giantism

High GH before epiphyseal plates close.

Acromegaly

High GH after epiphyseal plates close.

Pituitary Growth Failure

Low GH before epiphyseal plates close

Fibrodysplasia Ossificans Progressiva (FOP)

Heterotopic (ectopic) bones.

Calcium

99% of body’s Ca2+ is in bone.

Hypocalcemia

Less than 8.5mg/dL blood calcium levels.

Parathyroid Hormone (PTH)

The parathyroid gland, osteoclasts, calcitriol

Hypercalcemia

Greater than 11mg/dL blood calcium levels.

Thyroid gland

Calcitonin

Bone Fractures

Stress fracture (trauma) Pathological fracture (disease)

Colles’ Fx

radius displaces anteriorly, typically outstretched hand during fall.

Smith Fx

Radius displaced posteriorly, hand flexed inward, land on back of wrist.

Osteoporosis

porous and brittle, Usually aging/hormonal, Osteopenia is early stage of osteoporosis with less bone degradation

Osteomalacia

bones soft, Usually vit D or Ca2+ deficiency