5.2 Connective Tissue: Cells

Vocabulary flashcards covering terms related to connective tissue types, cells, and features described in the notes.

Connective tissue proper

A broad category divided into loose connective tissue and dense connective tissue, based on relative amounts of cells, fibers, and ground substance.

Loose connective tissue

Tissue with relatively few cells and fibers, abundant viscous ground substance, and high vascularity; acts as packing material around structures.

Fibroblast

The principal cell type in many connective tissues that produces fibers and ground substance.

Ground substance

Noncellular component of the extracellular matrix; ranges from semi-solid to solid and fills the space between cells and fibers.

Areolar connective tissue

Loose connective tissue with scattered fibroblasts, abundant ground substance, and a loose arrangement of fibers; highly vascularized and binds skin to deeper tissues.

Adipose connective tissue (fat)

Loose connective tissue dominated by adipocytes; stores lipids and provides insulation and cushioning.

Adipocyte

Fat cell that stores lipid droplets and pushes the nucleus to the cell edge.

Brown adipose tissue

Type of adipose tissue that generates heat; common in newborns.

White adipose tissue

Type of adipose tissue that stores triglycerides and provides insulation and cushioning.

Reticular connective tissue

Connective tissue with reticular fibers forming a stroma that supports leukocytes in lymphoid organs and bone marrow.

Dense irregular connective tissue

Dense connective tissue with collagen fibers in multiple directions; provides strength in many directions; found in dermis, organ capsules, and sheaths.

Dense regular connective tissue

Dense connective tissue with collagen fibers packed parallel to each other; resists stress in a single direction; found in tendons and ligaments.

Elastic connective tissue

Dense connective tissue rich in elastic fibers allowing stretch and recoil; located in walls of large arteries, trachea, and vocal cords.

Cartilage

Firm, semisolid extracellular matrix containing collagen and/or elastic fibers; avascular; chondrocytes reside in lacunae.

Chondrocyte

Mature cartilage cell that lives within a lacuna in the cartilage matrix.

Lacuna

A small cavity within bone or cartilage that houses a cell (osteocyte or chondrocyte).

Avascular cartilage

Cartilage that lacks blood vessels; nutrients diffuse in from surrounding tissues.

Hyaline cartilage

Most common type of cartilage with a glassy matrix; chondrocytes sparsely distributed and collagen not easily seen; found in nose, trachea, bronchi, larynx, costal cartilage, growth plates, and fetal skeleton.

Fibrocartilage

Weight-bearing cartilage with coarse collagen fibers; little ground substance; resists compression; located in intervertebral discs, pubic symphysis, and knee menisci.

Elastic cartilage

Cartilage rich in elastic fibers; highly flexible; found in external ear and epiglottis.

Cartilage avascularity

Cartilage lacks blood vessels; chondrocytes exchange nutrients by diffusion from surrounding tissues.

Bone (osseous) tissue

Vascularized connective tissue with organic components (collagen and glycoproteins) and inorganic calcium phosphate; forms bones.

Osteocyte

Mature bone cell housed in a lacuna within the bone matrix.

Lacuna (bone)

Small space in bone matrix containing an osteocyte.

Osteon

Functional unit of compact bone, surrounding a central (Haversian) canal with blood vessels and nerves, with concentric lamellae.

Lamellae

Concentric rings of bone matrix around an osteon.

Central canal (Haversian canal)

Vertical channel in an osteon that contains blood vessels and nerves.

Compact bone

Dense, solid-appearing bone composed of osteons; highly organized with few vascular spaces.

Spongy bone (trabecular bone)

Lightweight, strong bone with a lattice of trabeculae that supports bone marrow.