Connective Tissue, Cartilage, Bone, and Adipose Biology

Comprehensive vocabulary flashcards covering the histology, cellular components, extracellular matrix, and pathology of connective tissue, cartilage, bone, and adipose tissue.

Hyaline cartilage

A type of cartilage that provides smooth, low-friction joint surfaces and general cushioning, and serves as the mold for endochondral ossification.

Fibrocartilage

The cartilage type that is best at compression resistance.

Extracellular matrix (ECM)

The non-cellular component of connective tissue composed of ground substance and fibers.

Connective tissue (CT)

A tissue primarily composed of cells and extracellular matrix (ECM), with secondary functions in storage and tissue repair.

Fibroblasts

The principal cells of connective tissue that produce fibers and regulate the extracellular matrix (ECM) through matrix metalloproteinases (MMPs) and TIMPs.

Matrix metalloproteinases (MMPs)

Enzymes synthesized by fibroblasts that break down extracellular matrix (ECM) proteins.

TIMPs

Proteins produced by fibroblasts that inhibit matrix metalloproteinases (MMPs).

Collagen fibers

Glycoproteins assembled from procollagen units whose synthesis is promoted by vitamin C; includes Type 1 (most common), Type 2 (hyaline cartilage), and Type 3 (reticular).

Reticular fibers

Connective tissue fibers arranged in a narrow mesh-like configuration that act solely as a structural framework or support.

Proteoglycan

A molecular complex composed of a core protein bound to glycosaminoglycans (GAGs).

Hyaluronic acid

A long, rigid glycosaminoglycan (GAG) that is not bound by proteoglycans.

Mesenchymal cells

Precursor cells capable of differentiating into various connective tissue cell types.

Elastic tissue

A connective tissue containing elastic fibers found in organs such as the aorta and lungs.

Epidermis

The most superficial layer of the skin, which lacks connective tissue entirely.

Papillary dermis

The superficial layer of the dermis composed primarily of loose connective tissue.

Reticular dermis

The deeper layer of the dermis composed primarily of dense irregular connective tissue.

Hypodermis

The deepest skin layer whose thickness varies depending on the presence or absence of adipose tissue.

Cytokines

Signaling proteins that promote vascularization upon injury.

Articular cartilage

The cartilage lining joint surfaces that is aneural.

Chondrocytes

Cartilage cells that reside within localized spaces called lacunae.

Lacunae

Nest-like compartments where chondrocytes are localized within cartilage.

Synovial joint capsule

A joint enclosure consisting of two layers: an outer fibrous layer and an inner synovial lining containing secretory cells.

Synovial fluid

A viscous fluid found in joints composed of plasma, hyaluronic acid, and glycosaminoglycans (GAGs).

Haversian canals

Channels in bone necessary to facilitate blood diffusion, which is restricted by the bone's high mineral density.

Periosteum

A highly vascular and highly innervated outer bone structure that is anchored to bone by Sharpey's fibers.

Sharpey's fibers

Fibers that physically anchor the periosteum to bone.

Osteoclasts

Multinucleated bone cells responsible for bone resorption.

Osteoblasts

Bone-forming cells that secrete matrix; during fracture healing, periosteal cells divide and convert into these cells.

Osteocytes

Mature osteoblasts responsible for maintaining the bone matrix.

Hydroxyapatite

A mineralized calcium and phosphate compound in the bone matrix that provides hardness and stiffness.

Osteoprogenitors

Stem or precursor cells that give rise to bone cells.

Endochondral ossification

A bone formation process where bone forms from a pre-existing hyaline cartilage mold.

Intramembranous ossification

A bone formation process where bone develops directly from connective tissue without a cartilage mold, forming flat bones.

Osteoporosis

A bone disorder characterized by an overall loss of bone mass, representing an issue of quantity.

Osteomalacia ('malacia' meaning softening).

A bone disorder in which bone tissue is present but improperly mineralized, representing an issue of quality

Osteopetrosis

A bone pathology characterized by excess mineralization.

Flat bones

A type of bone formed via intramembranous ossification that continues to grow throughout life.

Osteophytes

Bony outgrowths, also referred to colloquially as phone bones.

Adipogenesis

The developmental process through which precursor cells differentiate into mature adipocytes.

Beige-ing

The phenomenon in which white adipose tissue (WAT) acquires characteristics of brown adipose tissue (BAT).

Brown adipose tissue (BAT)

A specialized form of adipose tissue normally found in infants.