BIO 201 Lecture 5 - Intro to Skeletal System

Comprehensive vocabulary flashcards generated from BIO 201 Lecture 5 notes covering bone tissue properties, classification, anatomical structures, markings, cellular components, and growth processes.

Bone

Hard, dense connective tissue that forms most of the adult skeleton and support structure of the body.

Cartilage

Semi-rigid connective tissue that provides smooth surfaces for bone articulation and movement.

Yellow Marrow

Bone marrow that contains adipose tissue storing triglycerides as a source of energy.

Red Marrow

Bone marrow that is the site of hematopoiesis, where all blood cells and platelets are produced.

Long Bones

Bones that are longer than they are wide (length > diameter), consisting of a shaft and variable number of endings (e.g., femur, tibia, fibula, humerus, ulna, radius).

Short Bones

Bones that are approximately cube-shaped, where length is similar to width, depth, or diameter (e.g., scaphoid, lunate, hamate, cuboid, first cuneiform, second cuneiform).

Flat Bones

Bones with a thin shape that provide mechanical protection to underlying soft tissues and offer surfaces for muscle attachments (e.g., cranial bones, sternum, ribs, scapulae).

Irregular Bones

Bones with complicated shapes that cannot be classified as long, short, or flat (e.g., atlas and axis bones C1, C2, hyoid bone, sphenoid bone, zygomatic bones).

Sesamoid Bones

Bones that develop in some tendons in locations where there is considerable friction, tension, and physical stress (e.g., patella).

Diaphysis

The tubular shaft that runs between the proximal and distal ends of a long bone, composed of hard compact bone.

Medullary Cavity

The hollow area inside the diaphysis filled with yellow marrow.

Endosteum

The membrane lining the medullary cavity where bone growth, repair, and remodeling occur.

Epiphysis

The wider section at each end of a long bone filled with spongy bone and red marrow, covered with articular cartilage.

Metaphysis

The region of a long bone containing the epiphyseal plate (cartilage growth plate), which turns into an epiphyseal line when bone growth stops.

Periosteum

A fibrous membrane covering the outer surface of bone except over articular cartilage, containing blood vessels, nerves, lymphatic vessels, and serving as an attachment site for tendons.

Body (Bone Marking)

The main part of a bone, such as the diaphysis of long bones.

Canal (Bone Marking)

A passage through bone

Condyle

A rounded surface on a bone

Crest

A ridge on a bone

Foramen

A hole through bone

Head (Bone Marking)

A prominent rounded surface on a bone

Sinus

An air-filled cavity within a bone

Trochanter

A bony protrusion near the hip joint found exclusively on the femur.

Tubercle

A small, rounded process on a bone

Tuberosity

A rough surface on a bone

Osteogenic Cells

Undifferentiated bone cells that are the only bone cells that divide; they develop into osteoblasts.

Osteoblasts

Bone-building cells found in the growing portions of bone, periosteum, and endosteum that secrete a collagen matrix and calcium salts.

Osteocytes

The most common type of bone cell, formed when osteoblasts become trapped in calcified matrix inside a lacuna; they maintain matrix mineral concentration and communicate via canaliculi.

Osteoclasts

Cells that break down old bone tissue, working alongside osteoblasts to constantly reshape bone.

Compact Bone

Dense, strong bone tissue that forms the diaphysis of long bones and outer layers of most bones; composed of osteons.

Osteon

The basic cylindrical structural unit of compact bone, consisting of a central canal, lamellae, lacunae, and canaliculi.

Central Canal (Haversian Canal)

A central passage in an osteon containing blood vessels and nerves, surrounded by concentric layers of lamellae.

Lamellae

Rings of strong mineral salts surrounding the central canal that give hardness to compact bone.

Lacunae

Small spaces located between the lamellae that contain osteocytes.

Canaliculi

Channels linking lacunae together that serve as routes for nutrients and waste products.

Perforating Canal

A canal through which blood vessels and nerves branch off at right angles from the central canal.

Spongy Bone

Bone tissue containing open spaces and a lattice-like matrix called trabeculae; fills the epiphyses of long bones and inner layers of most bones.

Trabeculae

The lattice-like matrix in spongy bone that forms along lines of stress to provide strength and house red bone marrow.

Histology of Compact Bone Microstructure

Microscopic view displaying a Haversian canal at the center, surrounding lacunae spaces, and radiating canaliculi channels.

Appositional Growth

The process by which bones increase in diameter or width.

Bone Modeling

The process during growth where osteoclasts resorb old bone lining the medullary cavity while osteoblasts produce new bone tissue beneath the periosteum.

Bone Remodeling

The ongoing process in adult bone where old or damaged bone is reabsorbed and replaced with new bone by osteoblasts on the same surface.

Osteoporosis Trabecular Changes

Pathological state where trabeculations in spongy bone become thinner and more fragile compared to normal spongy bone structure.