Bones and Skeletal Tissue

These flashcards cover key terms and concepts regarding the anatomy and functions of bones and skeletal tissue as discussed in the lecture.

Skeletal Cartilage

Cartilage that forms the initial skeleton in human embryos and is later replaced by bone, except in areas requiring flexibility.

Perichondrium

A dense connective tissue layer that surrounds cartilage, aiding in nutrient delivery and resisting outward expansion.

Hyaline Cartilage

The most abundant type of cartilage providing support and flexibility, found in joints, ribs, and respiratory structures.

Elastic Cartilage

A type of cartilage that contains elastic fibers, allowing it flexibility; found in the external ear and epiglottis.

Fibrocartilage

Cartilage containing thick collagen fibers, providing great tensile strength; found in menisci of the knee and intervertebral discs.

Appositional Growth

Cartilage growth where new matrix is added to the outside of existing cartilage, increasing its width.

Interstitial Growth

Cartilage growth involving the division of chondrocytes within lacunae, leading to expansion of the cartilage from within.

Axial Skeleton

The part of the skeleton that includes the skull, vertebral column, and rib cage; forms the long axis of the body.

Appendicular Skeleton

The skeletal components that include the bones of the limbs and girdles attaching them to the axial skeleton.

Osteogenic Cells

Stem cells in the periosteum and endosteum that differentiate into osteoblasts or bone-lining cells.

Osteoblasts

Bone-forming cells that secrete the bone matrix called osteoid and are actively mitotic.

Osteocytes

Mature bone cells residing in lacunae that maintain the bone matrix and regulate bone remodeling.

Osteoclasts

Multinucleate cells responsible for the resorption or breakdown of bone.

Compact Bone

Dense outer layer of bone that appears smooth and solid, containing structural units called osteons.

Spongy Bone

A type of bone made up of a network of trabeculae, containing bone marrow and lacking osteons.

Lamellae

Rings of bone matrix surrounding central canals in osteons, providing structural integrity.

Hydroxyapatites

Mineral salts in bone, primarily calcium phosphate, that contribute to the hardness and resistance to compression.

Bone Markings

Sites on bones for muscle, ligament, and tendon attachment, as well as regions involved in joint formation.

What are the main functions of the skeletal system?

Support, protection, movement, mineral and growth factor storage, blood cell formation (hematopoiesis), and triglyceride storage.

Diaphysis

The shaft of a long bone, primarily composed of compact bone, surrounding the medullary cavity.

Epiphysis

The ends of a long bone, consisting of compact bone externally and spongy bone internally, covered with articular cartilage.

Medullary Cavity

The hollow central cavity within the diaphysis of long bones, typically containing yellow bone marrow (fat) in adults.

Endosteum

A delicate connective tissue membrane covering internal bone surfaces, containing osteogenic cells that can differentiate into osteoblasts and osteoclasts.

Osteon (Haversian System)

The structural unit of compact bone, consisting of a central canal surrounded by concentric rings of lamellae and lacunae containing osteocytes.

Canaliculi

Hairlike canals that connect lacunae to each other and to the central canal, allowing osteocytes to communicate and receive nutrients.