Glands, Connective Tissue, and Cartilage - Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering gland types, connective tissue components, and cartilage biology from the lecture notes.

Holocrine glands

Glands that release their secretions by rupture of secretory cells; the product is released with cell debris as the cells die.

Apocrine glands

Glands that store and partially shed secretory products along with some cytoplasm, then heal and rebuild; examples include mammary glands.

Merocrine (eccrine) glands

Glands that continuously release product by exocytosis without losing cellular contents.

Endocrine glands

Ductless glands that secrete hormones directly into the bloodstream via exocytosis to coordinate internal body activities.

Exocytosis

Process by which secretory vesicles fuse with the plasma membrane to release their contents outside the cell.

Connective tissue

Tissue that is the most abundant and varied, derived from mesenchyme, with cells embedded in an extracellular matrix; provides protection, support, energy storage, insulation, and transport.

Matrix (extracellular matrix)

Nonliving background material of connective tissue composed of ground substance and fibers, produced by resident cells.

Ground substance

Amorphous, gel-like component of the matrix containing interstitial fluid, cell adhesion proteins, and proteoglycans; enables diffusion of nutrients.

Collagen fibers

Thick, strong fibers with high tensile strength; the most common protein in the body; provide structural support in connective tissues.

Elastic fibers

Thin, coiled fibers that provide elasticity and recoil after stretching; found in skin, blood vessels, and lungs.

Reticular fibers

Fine, branching fibers forming nets that support cells in soft tissues and organs.

Mesenchyme

Fetal stem cells that are the precursor to all connective tissues; not typically present in adults.

Mucus connective tissue

A loose, embryonic-like connective tissue seen in the umbilical cord; largely absent in adult tissues.

Areolar connective tissue

Loose connective tissue underlieing epithelia; highly distributed, nutrient-rich ground substance with scattered fibers; supports epithelium and stores fluids.

Adipose tissue

Loose connective tissue dominated by adipocytes; stores fat; highly vascular; little matrix; adipocytes do not divide once mature.

Brown adipose tissue

Fat that generates heat (thermogenesis) with many mitochondria; prominent in infants and diminishes with age in humans.

White adipose tissue

Fat tissue primarily for energy storage (lipid) in adults.

Reticular connective tissue

Loose connective tissue with a network of reticular fibers supporting lymphoid and other organs; stores and supports blood cells.

Dense connective tissue

Tissue with abundant fibers and little ground substance; subdivided into dense regular, dense irregular, and elastic types.

Dense regular connective tissue

Collagen fibers are aligned parallel to each other, providing tensile strength in one direction; includes tendons, ligaments, and aponeuroses.

Dense irregular connective tissue

Collagen fibers run in many directions to withstand forces from multiple directions; found in joint capsules and dermis.

Elastic connective tissue

Dense connective tissue with predominantly parallel elastic fibers, allowing greater stretch and recoil (e.g., some ligaments).

Dense irregular connective tissue (fibers in multiple directions)

Opposite of regular; fibers arranged in many directions to resist forces from all directions.

Blood (as connective tissue)

Fluid connective tissue with plasma as the matrix and cells including erythrocytes, leukocytes, and platelets; transports oxygen, nutrients, waste, and hormones; clotting involves fibrin.

Plasma

Liquid portion of blood; contains water, proteins, nutrients; the matrix in which blood cells suspend.

Fibrin

Fibrous protein threads formed during blood clotting that create a mesh to trap cells and form a clot.

Lymph

Fluid derived from blood that leaks into tissues and is collected by lymphatic vessels to be returned to the bloodstream; rich in lymphocytes.

Cartilage

A supportive, avascular, aneural connective tissue; chondrocytes reside in lacunae and are surrounded by a gel-like matrix.

Chondroblast

Cartilage-forming cell that produces cartilage matrix and divides until trapped in lacunae.

Chondrocyte

Mature cartilage cell housed in a lacuna; maintains cartilage matrix and often produces antiangiogenesis factors.

Lacuna

Small cavity within cartilage or bone matrix that houses an osteocyte or chondrocyte.

Perichondrium

Dense irregular connective tissue surrounding cartilage that supplies nutrients via diffusion and contains blood vessels.

Antiangiogenesis factor

Substance released by chondrocytes that inhibits blood vessel formation near cartilage.

Hyaline cartilage

Most common cartilage; provides support and flexibility with high collagen content; found in joints, nose, trachea, and fetal skeleton.

Elastic cartilage

Cartilage with a high content of elastic fibers; highly flexible; found in the ear and epiglottis.

Fibrocartilage

Tough cartilage with dense collagen fibers; resists compression; found in intervertebral discs, pubic symphysis, and menisci.

Interstitial growth (cartilage)

Growth inside the cartilage where chondroblasts divide within the cartilage matrix before being imprisoned in lacunae.

Appositional growth (cartilage)

Growth at the outer surface of cartilage from chondroblasts in the perichondrium, increasing thickness.

Osteoblast

Bone-forming cell that secretes the bone matrix and later becomes an osteocyte when embedded in bone.

Osteocyte

Mature bone cell housed in a lacuna; maintains bone matrix and communicates with other cells.

Osteoporosis

Condition characterized by decreased bone density and strength, increasing fracture risk due to imbalanced remodeling.