Chapter 6: Skeletal System Study Guide

Cartilage

Flexible, avascular connective tissue with types including hyaline, elastic, and fibrocartilage, primarily composed of chondrocytes.

Bone

Dense, mineralized connective tissue that is vascular and innervated, containing a matrix rich in calcium and phosphate, with two types:compact and spongy bone.

Spongy Bone

Porous, lightweight bone found at the ends of long bones and in the core of bones, containing trabeculae and red marrow.

Compact Bone

Dense bone forming the outer layer, providing strength and containing osteons for nutrient and waste transport.

Hyaline Cartilage

Most common type of cartilage, providing support with some flexibility, found in the nose, trachea, and ends of long bones.

Elastic Cartilage

Contains more elastin fibers, found in the external ear and epiglottis, and is highly flexible.

Fibrocartilage

Contains thick collagen fibers, found in intervertebral discs and pubic symphysis, known for its durability and ability to absorb compressive forces.

Interstitial Growth

Growth from within cartilage where chondrocytes divide and secrete new matrix.

Appositional Growth

Growth at the surface of cartilage where new chondroblasts differentiate and secrete matrix on the outer edge.

Chondroblast

Immature cartilage cell that produces cartilage matrix.

Chondrocyte

Mature cartilage cell located in lacunae, maintaining the cartilage matrix.

Osteogenic Cells

Stem cells that differentiate into osteoblasts.

Osteoblast

Bone-forming cell that secretes bone matrix.

Osteocyte

Mature bone cell that maintains the bone matrix, located in lacunae.

Osteoclast

Bone-resorbing cell that breaks down bone tissue during growth, healing, and remodeling.

Skeletal System

Provides structural support, protects vital organs, allows movement, stores minerals, and houses bone marrow for blood cell production.

Cartilage Functions

Provides flexibility and support, reduces friction between bones, and absorbs shock.

Bone Functions

Provides structural support, protection, mineral storage, blood cell production, and facilitates movement.

Osteons

Cylindrical structures in compact bone for nutrient and waste transport.

Trabeculae

Honeycomb structure in spongy bone supporting red marrow.

Periosteum

Outer fibrous layer covering the bone, providing nutrients and containing osteogenic cells.

Articular Cartilage

Hyaline cartilage covering joint surfaces, reducing friction and absorbing shock.

Endosteum

Thin membrane lining the medullary cavity, involved in bone growth, repair, and remodeling.

Epiphysis

Expanded ends of a long bone containing spongy bone and red marrow.

Diaphysis

Long, cylindrical part of the bone, primarily composed of compact bone.

Epiphyseal Plate

Growth plate in children that ossifies to become the epiphyseal line in adults.

Medullary Cavity

Central cavity in the diaphysis containing yellow marrow for fat storage.

Red Marrow

Located in spongy bone, site of hematopoiesis (blood cell formation).

Yellow Marrow

Found in the medullary cavity, stores fat.

Organic Components of Bone

Collagen fibers providing tensile strength and proteoglycans aiding in resisting compressive forces.

Inorganic Components of Bone

Hydroxyapatite crystals (calcium phosphate) providing hardness and resistance to compression.

Resting Zone

Small, inactive cartilage cells in the epiphyseal plate.

Proliferation Zone

Chondrocytes undergo rapid mitosis, increasing bone length.

Hypertrophic Zone

Chondrocytes enlarge and lacunae begin to erode.

Calcification Zone

Cartilage matrix calcifies, leading to chondrocyte death.

Ossification Zone

New bone forms as osteoblasts deposit bone matrix on calcified cartilage spicules.

Bone Markings

Projections and depressions on bones that serve various functions.

Process

Prominent projection on a bone (e.g., mastoid process).

Tuberosity

Large, rounded projection on a bone (e.g., tibial tuberosity).

Spine

Sharp, slender projection on a bone (e.g., ischial spine).

Fossa

Shallow depression on a bone (e.g., iliac fossa).

Foramen

Round or oval opening in a bone (e.g., foramen magnum).

Sulcus/Groove

Furrow on a bone (e.g., intertubercular groove).

Endochondral Ossification

Process