ADVO 3000: Unit 1 - The Skeletal System and Bone Tissue

Comprehensive vocabulary flashcards covering skeletal terminology, bone histology and cellular functions, ossification processes, and bone mineral and hormonal regulation from ADVO 3000 Unit 1.

Osseous tissue

Bone tissue.

Calcification

The development of bone; the process of bone formation.

Canaliculi

Small canals that form an extremely narrow tubular passage or channel radiating through the bone matrix.

Osteon

The basic structural and functional unit of compact bone, also known as the Haversian system.

Ossification (Osteogenesis)

The process of forming bone.

Diaphysis

The shaft or long portion of a bone.

Epiphysis

The extremities or ends portion of a bone.

Metaphysis

The region where the diaphysis joins the epiphysis; during childhood, it houses the epiphyseal plate and allows bone elongation by replacing cartilage with solid bone during endochondral ossification.

Articular cartilage

Cartilage that covers the surfaces of articulating bones at joint surfaces without binding the bones together.

Periosteum

A dense white fibrous covering of bone.

Medullary canal

The space within the diaphysis containing yellow marrow.

Endosteum

The layer of osteoblasts that lines the medullary canal.

Osteogenic cell

Undifferentiated stem cells found in the deep layer of the periosteum that divide and mature into osteoblasts to support bone growth and repair.

Osteoclast

Bone-removing cell located at sites of old, injured, or unneeded bone that breaks down bone through bone resorption.

Osteoblast

Bone-forming cell that builds bone, located in the growing portions of bone including the periosteum and endosteum.

Osteocyte

Bone cell that has cellular extensions (canaliculi) allowing it to affect the metabolism of the surrounding matrix and maintain its mineral concentration.

Bone matrix

The intracellular substance of bone consisting of collagen fibres, ground substance, and inorganic salts.

Spongy bone (Cancellous bone)

Lighter and less dense interior bone consisting of plates and bars (trabeculae) adjacent to small irregular cavities containing red bone marrow, receiving blood supply via canaliculi rather than Haversian canals.

Compact bone (Cortical bone)

The dense, hard outer layer of bone tissue composed of closely packed osteons that provides structural support and protection.

Haversian canal (Central canal)

A hollow channel running lengthwise parallel to the long axis of bone that contains blood vessels, nerves, and lymphatic vessels to supply nourishment and signals.

Volkmann's canal

Right-angle perforating canals that connect Haversian canals to each other and to blood vessels on the surface of the bone.

Lamellae

Concentric, onion-like layers of calcified matrix arranged around a Haversian canal.

Lacunae

Spaces located between the matrix rings (lamellae) where osteocytes reside.

Trabeculae

A lattice-like network of matrix spikes in spongy bone made of lacunae and osteocytes; forms along stress lines to provide strength and a large surface area for mineral exchange.

Red bone marrow

Tissue found in spongy bone where hematopoiesis takes place to produce red blood cells (RBC), white blood cells (WBC), and platelets.

Yellow bone marrow

Tissue located in the innermost central cavities of long bones that contains adipose tissue and stores triglycerides in adipocytes as an energy source.

Intramembranous ossification

The process where compact and spongy bone develops directly from mesenchymal connective tissue; occurs in the flat bones of the face, cranial bones, and clavicle, beginning in utero and continuing into adolescence.

Osteoid

Uncalcified, unmineralized bone matrix secreted by osteoblasts that calcifies within a few days as mineral salts deposit.

Endochondral ossification

The process of bone development occurring in the base of the skull and long bones, where mesenchymal cells differentiate into chondrocytes to form a cartilage model that is subsequently replaced by solid bone.

Primary ossification centre

The site deep in the periosteal collar where ossification begins during endochondral ossification.

Secondary ossification centre

The ossification centre that develops in the epiphyseal region of growing bone during endochondral ossification.

Calcitonin

A hormone produced by cells of the thyroid that stimulates calcium uptake by bones and transiently inactivates osteoclasts in adults to block bone breakdown.

Parathyroid hormone (PTH)

A hormone that stimulates osteoclast proliferation, bone resorption, renal calcium conservation, and calcitriol production to increase blood calcium levels.

Calcium

A vital dietary mineral that must be absorbed with the help of Vitamin D in the GI tract; combines with phosphate and carbonate to form hydroxyapatite crystals that give bone its hardness.

Phosphate

A mineral needed to create hydroxyapatite crystals and to control the life cycle of cells in the epiphyseal plate.

Osseous tissue

Bone tissue.

Calcification

Development of bone; the process of bone formation.

Canaliculi

Small, extremely narrow tubular passages or channels that radiate from Haversian canals to provide passageways through the hard bone matrix.

Osteon

The basic structural and functional unit of compact bone.

Ossification

The process of forming bone (also referred to as osteogenesis).

Diaphysis

The shaft or long portion of a bone.

Epiphysis

The extremities or ends of a bone.

Metaphysis

The region where the diaphysis joins the epiphysis; it houses the epiphyseal plate during childhood and allows bone elongation by replacing cartilage with solid bone during endochondral ossification.

Articular cartilage

Cartilage that covers the surfaces of articulating bones at joint surfaces without binding the bones together.

Periosteum

A dense white fibrous covering of bone.

Medullary canal

The space within the diaphysis that contains yellow marrow.

Endosteum

A layer of osteoblasts that lines the medullary canal.

Osteogenic cell

Undifferentiated stem cells found in the deep layer of the periosteum that divide and mature into osteoblasts to support bone growth and repair.

Osteoclast

Bone-removing cells located at sites of old, injured, or unneeded bone that break down bone tissue via resorption.

Osteoblast

Bone-forming cells located in growing portions of bone, including the periosteum and endosteum, that build bone matrix.

Osteocyte

Mature bone cells situated within lacunae that maintain the mineral concentration of the matrix and possess canaliculi extensions allowing them to affect the metabolism of surrounding matrix.

Bone matrix

The intracellular substance of bone consisting of collagen fibres, ground substance, and inorganic salts.

Compact bone (Cortical bone)

The dense, hard outer layer of bone tissue made of tightly packed osteons that provides structural support and protection.

Spongy bone (Cancellous bone)

Lighter, less dense inner bone tissue consisting of plates (trabeculae) and bars adjacent to small irregular cavities containing red bone marrow.

Haversian canal (Central canal)

A hollow osteonic channel running lengthwise in compact bone that contains blood vessels, lymphatic vessels, and nerve fibres to provide nourishment and signals.

Lamellae

Concentric, onion-like rings or layers of calcified matrix arranged around a Haversian canal.

Lacunae

Spaces located between the lamellae matrix rings in which osteocytes reside.

Volkmann's canal

Right-angle (perforating) canals that connect Haversian canals with blood vessels on the surface of the bone.

Trabeculae

A lattice-like network of matrix spikes made of lacunae and osteocytes that forms along stress lines in spongy bone to provide skeletal strength, integrity, and a large surface area for mineral exchange.

Red bone marrow

Bone marrow located in spongy bone where hematopoiesis occurs, producing red blood cells, white blood cells, and platelets.

Yellow bone marrow

Bone marrow located in the innermost central cavities of long bones that contains adipose tissue and stores triglycerides in adipocytes for energy.

Osteoid

Uncalcified, unmineralized bone matrix secreted by osteoblasts around capillaries that later calcifies into bone as mineral salts are deposited.

Intramembranous ossification

The process by which compact and spongy bone develops directly from mesenchymal connective tissue; occurs in the flat bones of the face, cranial bones, and clavicle.

Endochondral ossification

The process of bone formation at the base of the skull and in long bones, where mesenchymal cells differentiate into chondrocytes to create a cartilage model that is gradually replaced by bone.

Primary ossification centre

The region deep in the periosteal collar of a developing bone where endochondral ossification begins.

Secondary ossification centre

The region located in the epiphyseal ends of a bone where ossification develops after the primary centre.

Calcitonin

A hormone produced by thyroid cells that stimulates calcium uptake by bones and transiently inhibits bone breakdown in adults by inactivating osteoclasts.

Parathyroid hormone (PTH)

A hormone that stimulates osteoclast proliferation and bone resorption, increases renal calcium reabsorption, stimulates calcitriol production to enhance intestinal calcium absorption, and raises blood calcium levels.

Calcium

A dietary mineral requiring Vitamin D for gastrointestinal absorption that combines with phosphate and carbonate to form hydroxyapatite crystals, providing bone with hardness.

Phosphate

A mineral essential for creating hydroxyapatite crystals that also controls the life cycle of cells within the epiphyseal plate.