Bone Tissue, Skeletal System, and Joints

Vocabulary practice flashcards covering bone tissue physiology, skeletal system anatomy, fractures, and joint classifications and pathologies.

Hematopoiesis

Blood cell formation that occurs in red bone marrow.

Yellow Bone Marrow

Bone marrow responsible for triglyceride storage for long-term energy.

Osteocalcin

A hormone produced by bone tissue that is involved in glucose homeostasis.

Diaphysis

The tube-shaped shaft of a long bone, composed of compact bone.

Medullary Cavity

The open space inside the diaphysis filled with yellow marrow.

Epiphysis

The wide end of a long bone filled with spongy bone containing red marrow.

Endosteum

A delicate, vascularized membranous connective tissue lining the medullary cavity where bone growth, repair, and remodeling occur.

Periosteum

A fibrous, protective membrane containing blood vessels, nerves, and lymphatic vessels that covers the outer surface of bone except at joint articulations.

Articular Cartilage

A thin layer of cartilage covering the epiphysis at joints that reduces friction and acts as a shock absorber.

Compact Bone

Dense bone tissue that provides support and protection and withstands compressive forces.

Osteon

The structural unit of compact bone characterized by a tree-ring pattern.

Haversian Canal

The central canal of an osteon containing blood vessels and nerves.

Osteocytes

Mature bone cells located in lacunae that maintain the mineral concentration of the bone matrix through enzyme secretion.

Canaliculi

Small channels that allow osteocytes to communicate and share substances like nutrients and waste.

Spongy Bone

Bone tissue with open spaces that supports shifts in weight distribution and contains red marrow between trabeculae.

Trabeculae

A lattice-like network of matrix spikes in spongy bone that makes bones lighter for easier muscle movement.

Collagen Fibers (Bone)

The organic component of bone tissue that gives bone shape and tensile strength, forming sacrificial bonds that break to prevent whole-bone fracture.

Hydroxyapatite

The inorganic component of bone tissue that gives bones their strength and hardness.

Intramembranous Ossification

Bone formation that begins with connective tissue without requiring a cartilage model; directly forms flat skull bones and most of the clavicle.

Endochondral Ossification

Bone formation that begins with a hyaline cartilage model where bone replaces cartilage; forms long bones and most of the skeleton.

Epiphyseal Plate

A cartilage layer that allows long bones to grow longer by producing new cartilage that is gradually replaced with bone.

Appositional Growth

The process increasing bone width wherein osteoblasts deposit new bone beneath the periosteum while osteoclasts resorb old bone along the medullary cavity.

Osteoblasts

Bone cells that lay down new bone tissue to replace bone that was broken down or resorbed.

Osteoclasts

Bone cells that break down old or damaged bone using acids and enzymes.

Growth Hormone (Skeletal Function)

A hormone that stimulates bone growth, increases long bone length, enhances mineralization, and improves bone density.

Testosterone (Skeletal Function)

A hormone that promotes osteoblastic activity, bone matrix production, adolescent growth spurts, and conversion of the epiphyseal plate to an epiphyseal line.

Parathyroid Hormone

A hormone that stimulates osteoclast proliferation and bone resorption, promotes calcium reabsorption in kidney tubules, and indirectly increases calcium absorption by the small intestine.

Calcitonin

A hormone that inhibits osteoclast activity and stimulates calcium uptake by bones.

Transverse Fracture

A fracture that occurs straight across the long axis of the bone.

Oblique Fracture

A fracture that occurs at an angle that is not 90 degrees.

Spiral Fracture

A common sports fracture where bone segments are pulled apart as a result of a twisting motion.

Comminuted Fracture

A fracture common in the elderly where several breaks result in many small pieces between two large segments.

Impacted / Compression Fracture

A fracture common in porous or osteoporotic bone where one bone fragment is driven into another, usually resulting from compression.

Depressed Fracture

A typical skull fracture in which the broken portion of bone is pressed inward.

Epiphyseal Fracture

A fracture occurring where cartilage cells are dying, causing the epiphysis to separate from the diaphysis along the epiphyseal plate.

Greenstick Fracture

A partial fracture common in children in which only one side of the bone is broken.

Open (Compound) Fracture

A fracture where at least one end of the broken bone tears through the skin, carrying a high risk of infection.

Closed (Simple) Fracture

A fracture in which the overlying skin remains intact.

Hematoma Formation

The first step of fracture repair where blood collects around the broken bone to form a clot.

Fibrocartilaginous Callus

A soft tissue mass formed during fracture repair that connects the broken ends of the bone.

Bony Callus

A rigid repair tissue composed of spongy bone that replaces the fibrocartilaginous callus.

Osteoporosis

A condition characterized by excessive bone loss resulting in decreased bone density ('thin bones'), porous structure, and enlarged spaces between trabeculae.

Osteopenia

A state of early or mild bone loss marked by lower than normal bone density, but not as severe or porous as osteoporosis.

Rickets

A skeletal disorder characterized by soft, weak, poorly mineralized bones that look bent or bowed.

Axial Skeleton

The skeletal division consisting of the head bones, cranial bones, facial bones, vertebral column, and thoracic cage; protects internal organs and provides attachment for head, neck, and back muscles.

Appendicular Skeleton

The skeletal division comprising upper and lower limb bones and their attachment girdles; enables movement, lifting, running, and grasping.

Hyaline Cartilage

Cartilage found in joints, attached to ribs, and in the respiratory tract (nose and trachea).

Elastic Cartilage

Flexible cartilage found in the external ear and epiglottis.

Fibrocartilage

Strong cartilage located between vertebrae (intervertebral discs) and between the halves of the pelvis (pubic symphysis).

Cranial Bones

The group of skull bones consisting of 2 parietal bones, 2 temporal bones, 1 frontal bone, 1 occipital bone, 1 sphenoid bone, and 1 ethmoid bone.

Facial Bones

The group of skull bones consisting of 2 maxillae, 2 zygomatic, 2 nasal, 2 lacrimal, 2 palatine, 2 nasal conchae, 1 mandible, and 1 vomer.

Thoracic Cage

The skeletal enclosure formed by 12 pairs of ribs with their costal cartilages, the sternum, and thoracic vertebrae.

True Ribs

Ribs that attach directly to the sternum through their costal cartilage.

False Ribs

Ribs that attach indirectly to the sternum by connecting to the cartilage of true ribs.

Floating Ribs

Ribs that do not attach to the sternum at all.

Cervical Vertebrae

The 7 neck vertebrae; C1-C2 feature a dens, C3-C7 possess a bifid spinous process with two branches, and all feature transverse and vertebral foramina.

Thoracic Vertebrae

The 12 chest vertebrae characterized by superior and inferior costal facets for rib attachment and sharply angled long spinous processes.

Lumbar Vertebrae

The 5 lower back vertebrae featuring a large vertebral body, a smaller vertebral foramen, and a short spinous process.

Scoliosis

An abnormal lateral, S-shaped curvature of the spine.

Kyphosis

An exaggerated thoracic spinal curvature presenting as a humpback or hunchback.

Lordosis

An exaggerated lumbar curvature pushing the lower spine forward with a protruding belly, often associated with pregnancy or obesity.

Pectoral Girdle

The skeletal support consisting of the clavicle (an S-shaped bone) and the scapula (shoulder blade).

Pelvic Girdle

A pair of hip bones each formed from three fused bones: the ilium, ischium, and pubis.

Acetabulum

The socket of the hip bone where the head of the femur attaches.

Obturator Foramen

The large opening found in each hip bone.

Joint (Articulation)

Any location in the skeletal system where two or more bones meet.

Fibrous Joints

Joints where adjacent bones are directly connected by collagen fibers without an intervening joint cavity.

Sutures

Narrow fibrous joints found between most bones of the skull.

Gomphoses

Narrow fibrous joints anchoring the roots of teeth into their jaw sockets.

Syndesmoses

Fibrous joints where separated bones are joined by a ligament or an interosseous membrane.

Synchondroses

Cartilaginous joints united by hyaline cartilage, such as the first sternocostal joint.

Symphyses

Cartilaginous joints united by fibrocartilage, such as the pubic symphysis and intervertebral discs.

Synovial Joints

Freely movable joints featuring a joint cavity filled with synovial fluid and enclosed within an articular capsule.

Synovial Fluid

Fluid inside a joint cavity that reduces friction and provides nutrients to chondrocytes.

Bursae

Fluid-filled sacs in synovial joints that function to reduce friction or pressure.

Plane Joint

A synovial joint type producing gliding movements, exemplified by the wrist.

Hinge Joint

A synovial joint producing flexion and extension movements, exemplified by the elbow.

Pivot Joint

A synovial joint producing rotational movement, exemplified by the articulation between the atlas and axis.

Condyloid Joint

A synovial joint that permits angular movement, exemplified by the knuckles.

Saddle Joint

A synovial joint permitting angular movement, exemplified by the joint at the base of the thumb.

Ball and Socket Joint

A multi-axial synovial joint permitting angular and rotational movement, exemplified by the hip and shoulder.

Bursitis

An inflammation and swelling of a bursa near a synovial joint, typically caused by friction or injury.

Tendonitis

An inflammation and swelling of a tendon or its sheath, typically resulting from overuse or injury.

Sprain

A joint injury that occurs when ligaments are stretched or torn.

Dislocation

A joint condition occurring when articulating bones are forced out of their normal alignment.

Osteoarthritis

The most common form of arthritis; an irreversible wear-and-tear condition where joint cartilage breaks down over time.

Rheumatoid Arthritis

An autoimmune disorder in which the immune system attacks joint tissue, treated with immunosuppressants, anti-inflammatory drugs, and pain relievers.

Gouty Arthritis

An inflammatory joint condition caused by uric acid crystal buildup in the joints, treated with anti-inflammatory drugs, pain medications, and increased water intake.