BIO50 Unit 4: Body Tissues and Membranes

Vocabulary practice flashcards covering cell differentiation, the four primary body tissues (epithelial, connective, muscle, nervous), and body membranes from Unit 4.

Differentiation

The process beginning soon after conception in which unspecialized cells develop into specialized cell types adapted for specific functions.

Epithelial Tissue

A primary tissue group that covers body surfaces, lines cavities, and forms glandular tissue, functioning in protection, absorption, filtration, and secretion.

Apical Surface

The exposed, unattached free surface or edge present on all epithelial tissues.

Basement Membrane

A structureless material that bounds and anchors the lower (basal) surface of an epithelial tissue layer to underlying connective tissue.

Avascular

Lacking a direct blood supply, a defining characteristic of epithelial tissues.

Simple Epithelium

An epithelium composed of only a single layer of cells, typically specialized for absorption, secretion, or filtration.

Stratified Epithelium

An epithelium composed of more than one cell layer, serving primarily as a protective barrier.

Simple Squamous Epithelium

A single layer of flattened cells forming thin membranes that line body cavities, lungs, and capillaries.

Simple Cuboidal Epithelium

A single layer of cube-shaped cells common in glands, forming the walls of kidney tubules and covering the ovaries.

Simple Columnar Epithelium

A single layer of tall, column-like cells lining the digestive tract, often containing mucus-producing goblet cells and cilia.

Goblet Cells

Specialized mucus-secreting cells commonly found within simple columnar epithelium.

Pseudostratified Simple Epithelium

A single layer of cells, commonly possessing cilia, lining respiratory passages and parts of the male reproductive system.

Stratified Squamous Epithelium

A multi-layered tissue with flattened cells at the free surface, providing protective coverage in areas subject to friction, such as the skin, mouth, and esophagus.

Stratified Cuboidal Epithelium

A rare epithelial tissue typically composed of two layers of cuboidal cells that lines the ducts of sweat glands.

Stratified Columnar Epithelium

A rare epithelium with columnar surface cells and variably sized underlying cells that lines the ducts of salivary glands.

Transitional Epithelium

A modified stratified epithelium whose cell shapes alter based on stretching, found lining the organs of the urinary system.

Gland

One or more epithelial cells specialized to synthesize and secrete a particular product.

Endocrine Gland

A ductless gland that secretes regulatory products, such as hormones, directly into the internal environment of the body.

Exocrine Gland

A gland that empties its secretions through ducts onto body surfaces or into cavities, such as sweat and oil glands.

Connective Tissue

The most abundant and widely distributed tissue group in the body, functioning to bind tissues together, support structures, and provide protection.

Extracellular Matrix

The non-living material surrounding living cells in connective tissues, allowing tissue to bear weight and endure stretching or abrasion.

Osseous Tissue

Bone connective tissue composed of osteocytes residing in lacunae within a hard matrix of calcium salts, functioning to support and protect the body.

Lacunae

Small cavities or chambers within the extracellular matrix that house osteocytes in bone or chondrocytes in cartilage.

Hyaline Cartilage

The most common cartilage type, composed of chondrocytes and collagen fibers embedded in a rubbery matrix, found in the voice box and attaching ribs to the breastbone.

Elastic Cartilage

A supportive cartilage made of chondrocytes, elastic fibers, and collagen fibers in a solid matrix, providing flexibility to structures such as the external ear.

Fibrocartilage

A highly compressible cartilage containing chondrocytes and collagen fibers that forms cushion-like discs between vertebrae.

Dense Connective Tissue

A fibrous connective tissue containing fibroblasts and a dense matrix of collagen fibers, composing tendons and ligaments.

Tendons

Dense fibrous connective tissue cords that attach skeletal muscles to bones.

Ligaments

Dense fibrous connective tissue bands that connect bone to bone at joints.

Areolar Connective Tissue

The most widely distributed connective tissue; a soft, pliable packaging tissue composed of fibroblasts and a loose fiber network that holds internal organs in place.

Adipose Tissue

A connective tissue commonly known as fat, composed of adipocytes containing large oil deposits with little to no matrix, specialized for insulation, protection, and energy storage.

Reticular Connective Tissue

A network of reticular fibers and reticular cells that forms the internal supportive stroma for white blood cells in lymphoid organs such as lymph nodes, the spleen, and bone marrow.

Blood

A fluid connective tissue consisting of blood cells suspended in non-living blood plasma, with visible protein fibers appearing only during the clotting process.

Muscle Tissue

A specialized contractile tissue group whose functions are to produce movement, maintain posture, and produce heat.

Skeletal Muscle

Voluntarily controlled muscle tissue attached to connective tissue, characterized by elongated, striated cells containing multiple nuclei.

Cardiac Muscle

Involuntarily controlled striated muscle tissue found exclusively in the heart wall, possessing uninucleate cells joined at intercalated discs.

Intercalated Discs

Striated cardiac muscle cells that allow free ion flow and rapid conduction of electrical impulses causing coordinated heart contractions.

Smooth Muscle

Involuntary, non-striated muscle composed of spindle-shaped cells with a single nucleus, located in the walls of hollow organs including the stomach, uterus, and blood vessels.

Nervous Tissue

Tissue composed of neurons and supporting cells specialized to receive stimuli and conduct electrical impulses throughout the body.

Cutaneous Membrane

The dry epithelial membrane covering the exterior body surface (the skin), consisting of stratified squamous epithelium resting on dense connective tissue.

Mucous Membrane

A moist epithelial membrane lining body cavities opening to the exterior (respiratory, digestive, urinary, and reproductive), resting on a connective tissue layer called the lamina propria.

Lamina Propria

The connective tissue membrane upon which epithelial cells rest in a mucous membrane.

Serous Membrane

A double-layered membrane consisting of simple squamous epithelium resting on areolar connective tissue that lines closed ventral body cavities and secretes lubricating fluid.

Peritoneum

The specific serous membrane lining the abdominal cavity (parietal layer) and covering its internal organs (visceral layer).

Pleura

The serous membrane enclosing the lungs, consisting of an outer parietal layer and an inner visceral layer.

Pericardium

The serous membrane surrounding the heart, formed by an outer parietal pericardium and an inner visceral pericardium.

Synovial Membrane

A connective tissue membrane containing no epithelial cells that lines the fibrous capsules surrounding joints and secretes lubricating synovial fluid.