Fundamentals of Anatomy & Physiology - Chapter 4: The Tissue Level of Organization

A comprehensive set of vocabulary flashcards covering the four major tissue types, epithelial specializations, connective tissue components, muscle types, and nervous tissue structure based on Chapter 4 lecture notes.

Tissues

Collections of specialized cells and cell products that perform specific functions.

Histology

The study of tissues.

Epithelial tissue

Tissue that covers exposed surfaces, lines internal passageways, and forms glands.

Connective tissue

Tissue that fills internal spaces, supports other tissues, transports materials, and stores energy.

Muscle tissue

Tissue specialized for contraction, including skeletal muscle, heart muscle, and muscular walls of hollow organs.

Nervous tissue

Tissue that carries electrical signals from one part of the body to another.

Microvilli

Specializations on the apical surface of epithelial cells that increase absorption or secretion.

Cilia

Hair-like extensions on a ciliated epithelium that move fluids over the surface.

Cell adhesion molecules (CAMs)

Transmembrane proteins used for intercellular connections to support and communicate.

Gap junctions

Intercellular connections held together by interlocking transmembrane proteins called connexons that allow rapid communication and passage of small molecules.

Connexons

Interlocking transmembrane proteins that hold cells together at gap junctions.

Tight junctions

Connections between two plasma membranes that prevent the passage of water and solutes, keeping enzymes and acids in the lumen of the digestive tract.

Desmosomes

Intercellular connections where CAMs and proteoglycans link opposing plasma membranes; spot desmosomes tie cells together, while hemidesmosomes attach cells to the basement membrane.

Basal lamina

The layer of the basement membrane closest to the epithelium.

Reticular lamina

The deeper portion of the basement membrane that provides strength.

Mesothelium

The simple squamous epithelium that lines body cavities.

Endothelium

The simple squamous epithelium that forms the inner lining of the heart and blood vessels.

Keratin

A protein found in stratified squamous epithelia that adds strength and water resistance.

Transitional epithelia

Epithelia found in the urinary bladder that can tolerate repeated cycles of stretching without damage.

Goblet cells

Unicellular exocrine glands in the intestines that secrete mucin, which mixes with water to form mucus.

Merocrine secretion

A method of secretion where the product is released by secretory vesicles through exocytosis, such as in salivary glands.

Apocrine secretion

A method of secretion involving the loss of apical cytoplasm and other cytoplasmic components, such as in mammary glands.

Holocrine secretion

A method of secretion where the cell bursts to release cytoplasmic contents, killing the gland cell, such as in sebaceous glands.

Matrix

The extracellular components of connective tissue, consisting of extracellular protein fibers and ground substance, which determines specialized function.

Fibroblasts

The most abundant cell type in connective tissue proper that secretes proteins and hyaluronan (cellular cement).

Mesenchymal cells

Stem cells in connective tissue that respond to injury or infection by differentiating into fibroblasts, macrophages, or other cells.

Mast cells

Cells that stimulate inflammation after injury or infection by releasing histamine and heparin.

Collagen fibers

Long, straight, and unbranched fibers that are the most common in connective tissue proper; they are strong and resist force in one direction.

Reticular fibers

Interwoven fibers that form a network (stroma) to stabilize functional cells (parenchyma) and resist forces in many directions.

Elastic fibers

Fibers containing elastin that are branched and wavy, returning to their original length after stretching.

Mesenchyme

The first embryonic connective tissue to appear in an embryo.

Wharton's jelly

Another name for mucous connective tissue, a sample of which is taken from the umbilical cord of a fetus.

Tendons

Dense regular connective tissue structures that attach muscles to bones.

Ligaments

Dense regular connective tissue structures that connect one bone to another and stabilize organs.

Aponeuroses

Tendinous sheets that attach a broad, flat muscle to another structure.

Fasciae

Connective tissue layers and wrappings that support and surround organs.

Chondroitin sulfates

Polysaccharide derivatives found in the firm gel matrix of cartilage.

Chondrocytes

Cartilage cells located in chambers called lacunae.

Antiangiogenesis factor

A substance produced by chondrocytes that discourages the formation of blood vessels, making cartilage avascular.

Perichondrium

A membrane covering cartilage that contains an outer fibrous layer for support and an inner cellular layer for growth.

Osteocytes

Bone cells located in lacunae that are arranged around central canals within the matrix.

Canaliculi

Small channels through the bone matrix that allow for the exchange of materials between osteocytes and the blood.

Lamina propria

The layer of areolar tissue found in mucous membranes.

Intercalated discs

Specialized connections that interconnect cardiac muscle cells.

Neuroglia

Supporting cells of nervous tissue that maintain structure, repair framework, perform phagocytosis, and provide nutrients to neurons.

Dendrites

Short branches extending from the neuron cell body that receive incoming signals.

Axon

A long, thin extension of the neuron cell body that carries outgoing electrical signals to their destination.