Anatomy and Physiology: Tissues and Integumentary System Vocabulary

Vocabulary flashcards covering epithelial, connective, muscular, and nervous tissues, cell junctions, exocrine gland types, and structures and physiology of the integumentary system.

Histology

The science that deals with the study of tissues.

Pathologist

A physician who examines tissues for changes that may indicate damage or disease.

Differentiation

The process through which dividing cells form distinct properties and specialized structures during development.

Ectoderm

The outer embryonic germ layer of cells formed during early development.

Mesoderm

The middle embryonic germ layer of cells formed during early development.

Endoderm

The inner embryonic germ layer of cells formed during early development.

Epithelial tissue

A primary tissue type that covers body surfaces, forms glands, and lines body cavities, hollow organs, and ducts.

Connective tissue

The most widespread and varied tissue type in the body that connects, supports, binds, or protects organs, stores energy reserves as fat, and provides immunity.

Muscular tissue

Tissue composed of contractile cells or fibers that generates the physical force needed to make body structures move.

Nervous tissue

Tissue with a high degree of excitability and conductivity that detects changes inside and outside the body and generates nerve impulses to maintain homeostasis.

Simple epithelium

Epithelium consisting of a single layer of cells whose primary function is to move materials.

Pseudostratified epithelium

Epithelium having a single layer of cells that appears stratified because the nuclei of the cells are positioned at different levels.

Stratified epithelium

Epithelium consisting of multiple layers of cells designed for protection against wear and tear.

Squamous cells

Thin, flat epithelial cells that facilitate diffusion and filtration.

Cuboidal cells

Cube-shaped epithelial cells that may possess microvilli at their apical surface for active transport, secretion, or absorption.

Columnar cells

Tall, narrow epithelial cells that may feature microvilli or cilia at their apical surface for secretion and absorption.

Transitional cells

Epithelial cells that change shape from cuboidal or columnar to low cuboidal or squamous when stretched, found in organs like the urinary bladder.

Goblet cell

A modified columnar cell containing secretory vesicles that produce and secrete large quantities of mucus.

Tight junctions

Cell junctions that fuse cells together tightly to prevent substances from passing or leaking between them.

Adherens junctions

Cell junctions containing a dense plaque of proteins linked to transmembrane glycoproteins (adhesion belts) that resist cell separation under stretching.

Desmosomes

Spot-like cell connections where protein plaques attach to intermediate filaments to bind adjacent cells firmly together.

Hemidesmosomes

Structures resembling half of a desmosome that anchor epithelial cells to the basement membrane rather than to adjacent cells.

Gap junctions

Cell junctions containing channels that allow ions and small molecules to pass between cells, permitting electrical impulses and chemical communication to spread rapidly.

Endocrine gland

A ductless gland that secretes its products (hormones) directly into the interstitial fluid and bloodstream.

Exocrine gland

A gland that secretes its products into ducts that open onto an epithelial surface or into a body cavity.

Merocrine gland

An exocrine gland that releases secretions through exocytosis without losing any portion of the cell body.

Apocrine gland

An exocrine gland in which secretory products collect near the duct lumen and a portion of the cell is pinched off to release the secretion.

Holocrine gland

An exocrine gland in which entire dead cells filled with secretory products are shed into the duct as the secretion.

Fibroblasts

Large, flat connective tissue cells that produce fibers and ground substance in the extracellular matrix.

Macrophages

Connective tissue cells derived from white blood cells that engulf and digest bacteria and cellular debris via phagocytosis.

Plasma cells

Small cells derived from B lymphocytes that secrete antibodies to attack and neutralize foreign antigens.

Mast cells

Connective tissue cells situated near blood vessels that produce histamine to dilate blood vessels during inflammatory reactions.

Adipocytes

Fat cells specialized for storing lipids, protecting internal organs, and serving as thermal insulation.

Suffix -blast

A suffix meaning germ, designating active connective tissue cells that produce the extracellular matrix.

Suffix -cyte

A suffix meaning cell, designating mature connective tissue cells responsible for maintaining the extracellular matrix.

Suffix -clast

A suffix meaning break, designating connective tissue cells that break down matrix for tissue remodeling.

Areolar connective tissue

Loose connective tissue consisting of a fine network of collagen and elastic fibers containing fibroblasts, macrophages, and lymphocytes.

Adipose tissue

Loose connective tissue composed predominantly of closely packed adipocytes with minimal extracellular matrix, functioning in energy storage and thermal insulation.

Reticular tissue

Connective tissue made of reticular fibers and cells that forms the supportive framework (stroma) of organs like the spleen, lymph nodes, and bone marrow.

Chondrocytes

Mature cartilage cells located in small matrix spaces called lacunae.

Hyaline cartilage

Semi-solid connective tissue containing chondrocytes and collagen fibers that covers long bone ends and forms structures in the ribs, nose, larynx, and trachea.

Fibrocartilage

Cartilage packed with thick collagen fiber bundles capable of withstanding heavy pressure, found in intervertebral disks and the pubic symphysis.

Elastic cartilage

Cartilage containing abundant coiled elastic fibers that allow it to bend and spring back to its original shape, found in the external ear and epiglottis.

Osseous tissue

Bone tissue characterized by a hard matrix arranged in lamellae, with osteocytes situated inside lacunae.

Skeletal muscle

Muscle tissue composed of long, cylindrical, striated cells containing multiple nuclei under voluntary control.

Cardiac muscle

Involuntary striated muscle tissue with branching cylindrical cells linked by intercalated discs that coordinate heart contractions.

Smooth muscle

Involuntary non-striated muscle tissue made of spindle-shaped cells with a single nucleus, located in walls of hollow internal organs.

Neurons

Nerve cells composed of a cell body, dendrites, and an axon that generate and transmit electrical impulses (action potentials).

Neuroglia

Non-conductive supporting cells of nervous tissue that protect, nourish, and insulate neurons.

Epidermis

The superficial, thinner layer of skin composed of keratinized stratified squamous epithelium.

Dermis

The deep, thick layer of skin composed of dense collagenous connective tissue that provides structural strength.

Subcutaneous tissue

The hypodermis layer deep to the dermis consisting of areolar and adipose tissue that attaches skin to underlying organs.

Keratinization

The process by which epidermal cells fill with the protein keratin and undergo structural changes as they move toward the skin surface.

Stratum basale

The deepest epidermal layer consisting of a single layer of cuboidal or columnar stem cells that undergo mitotic division approximately every 19 days.

Stratum spinosum

Epidermal layer consisting of 8 to 10 layers of polyhedral keratinocytes that provide mechanical strength and flexibility.

Stratum granulosum

Epidermal layer of 3 to 5 layers of flattened keratinocytes undergoing apoptosis, containing keratohyalin and lamellar granules.

Stratum lucidum

Epidermal layer composed of 4 to 6 layers of clear, dead keratinocytes, present only in thick skin like fingertips, palms, and soles.

Stratum corneum

The outermost epidermal layer made of 25 to 30 layers of dead, flattened, keratin-filled squamous cells.

Callus

A thickened area of stratum corneum formed in response to repeated friction or pressure.

Melanin

A pigment produced by melanocytes in the stratum basale that provides skin coloration and protects against ultraviolet radiation.

Carotene

A yellow-orange lipid-soluble pigment found in plant foods that accumulates in stratum corneum and subcutaneous fat.

Cyanosis

A bluish skin discoloration resulting from reduced oxygen content in blood hemoglobin.

Albinism

An inherited inability to produce melanin, leading to lack of pigment in skin, hair, and eyes.

Vitiligo

A skin condition characterized by irregular white patches due to partial or total loss of melanocytes.

Arrector pili

Smooth muscle bundles attached to hair follicles that contract under cold or fright, pulling hairs upright to create goosebumps.

Sebaceous glands

Exocrine glands in the dermis that secrete sebum into hair follicles or onto the skin surface.

Sebum

An oily secretion containing lipids and cell debris that lubricates hair, softens skin, and prevents water loss.

Eccrine glands

Abundant sweat glands that produce a clear, watery perspiration to cool the body through evaporation.

Apocrine glands

Sweat glands in the axillary and pubic regions that produce a viscous sweat in response to emotional stress or sexual stimulation.

Eponychium

The cuticle of the nail, formed by a narrow band of stratum corneum extending from the margin of the nail fold.

Lunula

The white, crescent-shaped area at the proximal end of the nail body overlaying the thickest part of the nail matrix.

Mucous membrane

An epithelial membrane lining cavities and tubes that open directly to the outside of the body.

Serous membrane

A membrane lining closed internal body cavities and covering internal organs, composed of simple squamous epithelium resting on areolar tissue.

Fibrosis

The repair process of damaged tissue through replacement with dense connective tissue, primarily collagen.

Granulation tissue

A delicate, vascular, newly formed connective tissue that develops inside a healing wound.