glands and specialized cells

Comprehensive practice flashcards defining key terminology, cellular features, junctions, tissues, glands, membranes, and tissue repair mechanisms covered in Chapter 4.

Endocrine Glands

Ductless glands that secrete hormones directly into the interstitial fluid, which then diffuse into the blood for systemic transport.

Exocrine Glands

Glands that release their secretory products through ducts onto the body's surface or into the cavity or lumen of a hollow organ.

Goblet Cell

A unicellular exocrine gland found in simple columnar and pseudostratified epithelia that secretes mucus.

Merocrine Secretion

A mode of exocrine secretion where products are packaged in secretory vesicles and released into ducts via exocytosis without injury to the cell.

Holocrine Secretion

A mode of exocrine secretion where secretory cells accumulate products within their cytosol and release them only when the entire cell ruptures and dies.

Apocrine Secretion

A mode of exocrine secretion in which the apical portion of the cytoplasm is pinched off with the product being released.

Fibroblasts

The most common resident cell type in connective tissue proper; mature cells with properties of immature cells that produce protein fibers, ground substance, and other components of the ECM.

Adipocytes

Resident fat cells whose cytoplasm is dominated by a single large lipid droplet, flattening and pushing the nucleus to the cell periphery.

Mast Cells

Large resident connective tissue cells containing cytosolic granules filled with inflammatory mediators such as histamine that trigger inflammation upon release.

Phagocytes

Immune cells—including resident or migrant macrophages and migrant neutrophils—that ingest foreign substances, microorganisms, and cellular debris.

Endomysium

A small amount of extracellular matrix surrounding each individual muscle cell that holds myocytes together.

Striations

Alternating light and dark bands observed in skeletal and cardiac muscle tissues produced by regular overlapping patterns of myofilaments.

Intercalated Discs

Specialized intercellular junctions in cardiac muscle tissue that link branching cells and contain desmosomes and gap junctions.

Neuron

An excitable cell type in nervous tissue that generates, conducts, and receives electrical signals (nerve impulses or action potentials).

Soma

The biosynthetic center or cell body of a neuron that houses the nucleus and most organelles.

Axon

A long neuronal process responsible for propagating nerve impulses away from the cell body toward a target cell.

Dendrites

Short, highly branched extensions of a neuron that receive impulses from other neurons and convey them toward the cell body.

Neuroglial Cells

Supportive cells of nervous tissue that provide protection, nourishment, and structure to neurons, and retain the capacity for cell division.