CH6 - BONE PT 1 - bone tissue & structure

Vocabulary flashcards covering bone structure, cell types, bone tissue, and bone types as discussed in the video notes.

Movement

The skeletal system enables body movement when muscles contract and pull on bones via joints and tendons.

Protection

Bones encase and protect vital organs (brain, heart, lungs, pelvic organs) in bony cages.

Support

The skeleton provides a structural framework that supports the body and maintains posture.

Hematopoiesis

Blood cell production, mainly in red bone marrow, producing red blood cells, white blood cells, and platelets.

Red bone marrow

Marrow located in the ends of long bones and in flat bones where hematopoiesis occurs.

Yellow bone marrow

Marrow located in the medullary cavity of long bones that stores fat.

Osteoprogenitor cells

Bone stem cells from mesenchyme that can divide and differentiate into osteoblasts.

Osteoblasts

Bone-forming cells that secrete osteoid; they become osteocytes and do not divide.

Osteocytes

Mature bone cells housed in lacunae; maintain bone and communicate via canaliculi.

Osteoclasts

Large cells that resorb and digest bone, helping bone remodeling.

Mesenchyme

Embryonic connective tissue from which osteoprogenitor cells originate.

Osteoid

Unmineralized bone matrix secreted by osteoblasts; later becomes mineralized.

Calcium phosphate

Mineral salts in bone that harden the matrix (hardness of bone).

Compact bone

Dense bone with organized osteons (Haversian systems) for strong support.

Osteon (Haversian system)

Structural unit of compact bone: concentric lamellae around a central Haversian canal.

Haversian canal

Central vertical canal within an osteon that contains blood vessels and nerves.

Volkmann canals

Perforating canals that run horizontally, linking Haversian canals and supplying blood.

Lamellae

Concentric rings of bone matrix around a central canal in an osteon.

Lacunae

Small spaces containing osteocytes within bone tissue.

Canaliculi

Tiny channels connecting lacunae to each other and to the central canal.

Periosteum

Outer fibrous membrane covering bone; two layers (outer fibrous, inner cellular) with Sharpey’s fibers anchoring to bone.

Endosteum

Inner lining of the medullary cavity; contains osteoblasts and osteoclasts for remodeling.

Sharpey’s fibers

Collagen fibers that anchor the periosteum to the underlying bone.

Articular cartilage

Hyaline cartilage covering the ends of long bones to reduce friction in joints.

Hyaline cartilageage

Type of cartilage that forms articular surfaces in joints.

Epiphysis

Ends of a long bone; proximal and distal epiphyses; contain red marrow and are capped by articular cartilage.

Diaphysis

Shaft of a long bone; hollow center (medullary cavity) surrounded by compact bone.

Medullary cavity

Hollow center of the diaphysis; contains yellow marrow and is lined by endosteum.

Diploe

Layer of spongy bone between two compact bone layers in flat bones (e.g., skull).

Trabeculae

Mesh-like lattice of spongy bone; contains red marrow and lacks a central canal.

Spongy bone

Cancellous bone with trabeculae; lighter than compact bone and contains red marrow; no osteons.

Diploe

Layer of spongy bone in flat bones between two compact bone layers.

Wormian bone

Accessory bone that can form within a skull suture.

Sesamoid bone

Bone embedded within a tendon; example is the patella, which changes tendon leverage.