Exam #5 Study Focus: Bone Tissue and Joints (Chapters 6 and 9)

Comprehensive vocabulary flashcards covering the study guide for Exam #5 on Bone Tissue and Joints (Chapters 6 and 9), including bone anatomy, histology, ossification, fracture repair, hormonal regulation, and joint classifications.

Femur (Bone Shape Classification)

A representative example of a long bone.

Carpal (Bone Shape Classification)

A representative example of a short bone.

Skull Bone (Bone Shape Classification)

A representative example of a flat bone.

Vertebra (Bone Shape Classification)

A representative example of an irregular bone.

Diaphysis

The tubular shaft or central elongated portion of a long bone.

Epiphyses

The proximal and distal expanded ends of a long bone.

Articular Cartilage

A layer of hyaline cartilage covering the epiphyses at joint surfaces to reduce friction and absorb shock.

Periosteum

The dense, fibrous vascular membrane that covers the outer surface of a bone, except at articular cartilage surfaces.

Endosteum

The thin cellular vascular membrane lining the inner surfaces of bone tissue, including the medullary canal.

Medullary Canal

The central cavity within the diaphysis of a long bone that houses bone marrow.

Osteoprogenitor Cells

Mesenchymal stem cells located in the periosteum and endosteum that divide to produce osteoblasts.

Osteoblasts

Bone-forming cells that synthesize and secrete organic bone matrix components and initiate ossification.

Osteocytes

Mature bone cells that reside within lacunae and maintain the mineral and protein content of the surrounding matrix.

Osteoclasts

Large, multinucleated bone-resorbing cells derived from monocyte lineage that break down and dissolve bone matrix.

Inorganic Bone Matrix

The mineralized portion of bone matrix, mainly composed of calcium phosphate and hydroxyapatite crystals, that provides compressive strength and hardness.

Organic Bone Matrix

The unmineralized osteoid component consisting of collagen fibers and ground substance, providing tensile strength and flexibility.

Compact Bone

Dense, solid bone tissue organized into repeating cylindrical structural units called osteons (Haversian systems), located primarily on the outer shell of bones.

Spongy Bone

Porous, lightweight bone tissue composed of an open latticework of thin plates or struts called trabeculae, found in the interior of bones and epiphyses.

Endochondral Ossification

The developmental process of bone formation where a pre-existing hyaline cartilage model is replaced by bone tissue, forming most bones including the femur and long bones.

Intramembranous Ossification

The developmental process of bone formation directly within embryonic mesenchyme or fibrous connective tissue membranes, forming flat bones such as those of the skull.

Epiphyseal Cartilage (Epiphyseal Plate)

A plate of hyaline cartilage situated between the diaphysis and epiphysis that allows bone elongation; it ossifies into an epiphyseal line when longitudinal growth ceases in early adulthood (typically around ages 18 to 25).

Interstitial Bone Growth

Growth in bone length occurring within the epiphyseal plate via chondrocyte division and subsequent ossification.

Appositional Bone Growth

Growth in bone width or diameter through the deposition of new bone matrix beneath the periosteum while osteoclasts resorb bone along the endosteal surface.

Bone Remodeling

The continuous coupled physiological process involving bone deposition (ossification) by osteoblasts and bone resorption by osteoclasts to maintain mineral homeostasis and repair microdamage.

Achondroplastic Dwarfism

A skeletal growth disorder caused by defective endochondral ossification and failure of cartilage proliferation in the epiphyseal plates of long bones, producing disproportionate dwarfism with short limbs.

Gigantism

A skeletal disorder characterized by excessive bone elongation resulting from hypersecretion of growth hormone (GH) prior to the closure of the epiphyseal plates.

Parathyroid Hormone (PTH)

A hormone secreted by the parathyroid glands that acts to raise blood calcium levels by stimulating osteoclast activity, promoting renal calcium reabsorption, and increasing intestinal calcium uptake.

Calcitonin

A hormone produced by the thyroid gland (parafollicular C cells) that acts to lower blood calcium levels by inhibiting osteoclast activity and promoting renal excretion of calcium.

Open Fracture

A fracture where the broken ends of the bone break through the skin, increasing infection risk (also termed a compound fracture).

Closed Fracture

A fracture in which the broken bone does not pierce or rupture the surrounding skin (also termed a simple fracture).

Comminuted Fracture

A bone fracture in which the bone is splintered, crushed, or broken into three or more small fragments.

Greenstick Fracture

An incomplete fracture in which one side of the bone shaft is broken and the other side is bent, occurring commonly in children.

Spiral Fracture

A helical bone fracture that wraps around the shaft, produced by excessive torsional or twisting forces.

Fracture Repair (Sequence)

The orderly four-stage healing process: 1) Hematoma formation, 2) Soft callus (fibrocartilaginous) formation, 3) Hard callus (bony) formation, and 4) Bone remodeling.

Joints (Articulations)

Sites where two or more bones meet, functioning to facilitate movement, bear body weight, and provide skeletal stability.

Bony Joint (Synostosis)

An immovable joint formed when the fibrous or cartilaginous space between two adjacent bones completely ossifies into a single bone.

Fibrous Joints

Joints connected by dense fibrous connective tissue lacking a joint cavity; categorized into three types: sutures, syndesmoses, and gomphoses.

Cartilaginous Joints

Joints held together by hyaline or fibrocartilage lacking a joint cavity; categorized into two types: synchondroses (hyaline cartilage) and symphyses (fibrocartilage).

Synovial Joint

A freely movable joint characterized by a fluid-filled joint cavity enclosed by a fibrous capsule and lined with a synovial membrane.

Joint Capsule

A double-layered connective tissue envelope surrounding a synovial cavity, comprising an outer fibrous capsule and an inner synovial membrane.

Synovial Membrane

The delicate inner vascular layer of a synovial joint capsule that secretes viscous synovial fluid to lubricate and nourish articular cartilage.

Bursa

A fibrous sac lined with synovial membrane and filled with synovial fluid, situated between bones and soft tissues to reduce friction during movement.

Shoulder vs. Hip Joint (Morphological Differences)

Two ball-and-socket synovial joints: the hip possesses a deep socket (acetabulum) and powerful ligaments prioritizing stability and load-bearing, whereas the shoulder has a shallow socket (glenoid cavity) and looser ligaments prioritizing maximum range of motion.

Knee Joint

The largest and most structurally complex joint in the human body, classified as a modified hinge synovial joint containing menisci, cruciate ligaments, and extensive bursae.

Dislocation (Luxation)

The complete abnormal displacement or separation of the articular ends of bones forming a joint, causing loss of articular contact.