Tissues, Connective Tissue, Membranes, and Integumentary System - Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering tissue types, connective tissue components, membranes, and the integumentary system, including skin layers, accessory organs, and related substances.

Epithelial tissue

Tissue that lines surfaces, cavities, and glands; functions include protection, absorption, secretion, and filtration.

Epithelial surfaces

The exterior body surfaces and the linings of internal cavities formed by epithelial tissue.

Epithelial junctions

Connections between epithelial cells (tight junctions, desmosomes, gap junctions) that regulate permeability and adhesion.

Squamous epithelium (general)

Flat, scale-like cells; includes simple squamous (single layer) and stratified squamous (many layers) for diffusion or protection.

Simple squamous

One layer of flat cells; rapid diffusion/filtration; lines blood vessels and air sacs.

Stratified squamous

Multiple layers of cells; provides strong protection against abrasion; skin, mouth, esophagus.

Cuboidal epithelium (general)

Cube-shaped cells; secretion and absorption; forms glands and kidney tubules.

Simple cuboidal

One layer of cube-shaped cells; lines kidney tubules and some glands.

Stratified cuboidal

Multiple layers of cuboidal cells; protective lining of ducts and glands.

Columnar epithelium (general)

Tall, column-shaped cells; absorption and secretion; often with goblet cells.

Simple columnar

One layer of tall cells; lines stomach/intestines; may have microvilli for absorption.

Pseudostratified columnar epithelium

Looks layered but is a single layer; often ciliated in the respiratory tract.

Transitional epithelium

Stratified, stretchable epithelium; lines urinary tract and distends with filling.

Glandular epithelium

Epithelial tissue that forms glands and secretes substances; can be merocrine, apocrine, or holocrine.

Merocrine (eccrine) glands

Secretions released by exocytosis; most sweat glands; watery secretions.

Apocrine glands

Secretions released with part of the cell cytoplasm; found in armpits and groin.

Holocrine glands

Secretions produced when whole cells rupture; example: sebaceous glands.

Connective tissue

Tissue with cells, fibers, and a ground substance; supports, binds, protects, and transports.

Loose connective tissue

Areolar tissue; loose arrangement of fibers and cells; cushions and wraps organs.

Areolar tissue

Loose connective tissue with a gel-like ground substance and a mix of fibers; binds skin to underlying tissues.

Adipose tissue

Loose connective tissue that stores fat in adipocytes; insulates, cushions, and provides energy storage.

Reticular tissue

Loose connective tissue with reticular fibers forming a supportive stroma for lymphoid organs.

Dense connective tissue

Tightly packed collagen and/or elastic fibers; provides strength; forms tendons and ligaments.

Dense regular connective tissue

Fibers arranged parallel; strong in one direction; makes tendons and ligaments.

Dense irregular connective tissue

Dense fibers arranged irregularly; withstands tension in multiple directions; dermis.

Elastic connective tissue

Dense tissue rich in elastic fibers; Allows recoil after stretching; walls of large arteries, etc.

Cartilage

Flexible connective tissue with chondrocytes in lacunae within a gel-like matrix.

Hyaline cartilage

Most common cartilage with a glassy matrix; supports and cushions; ends of bones, trachea.

Elastic cartilage

Cartilage with abundant elastic fibers; maintains shape with flexibility (ear, epiglottis).

Fibrocartilage

Tough cartilage rich in collagen; shock absorption (intervertebral discs, pubic symphysis, menisci).

Bone (osseous tissue)

Mineralized connective tissue providing support and protection; compact and spongy forms.

Spongy bone

Trabecular (cancellous) bone with many spaces; houses marrow.

Compact bone

Dense bone with osteons; provides strength and houses blood supply.

Blood

Fluid connective tissue with plasma, red and white blood cells, and platelets; transports substances.

Red blood cells (erythrocytes)

Cells that transport oxygen via hemoglobin; lack organelles in mature forms.

White blood cells (leukocytes)

Immune cells that defend against infection; numerous types (neutrophils, lymphocytes, etc.).

Plasma

Fluid portion of blood containing water, proteins, electrolytes, and nutrients.

Collagen

Most abundant connective tissue protein; provides tensile strength.

Elastic fibers

Fibers made of elastin; allow tissues to stretch and recoil.

Reticular fibers

Thin collagen fibers forming a supportive network in organs like the spleen and lymph nodes.

Ground substance

Gellike matrix component of connective tissue between cells and fibers.

Matrix (extracellular matrix)

The structural framework of connective tissue, including fibers and ground substance.

Mucous membranes

Membranes lining passages open to the exterior; secrete mucus to protect and lubricate.

Serous membranes

Membranes lining closed body cavities and covering organs; secrete serous fluid to reduce friction.

Integumentary system

Skin and its accessory structures; protection, temperature regulation, sensation, vitamin D synthesis.

Epidermis

Outer layer of the skin composed of stratified squamous epithelium.

Dermis

Middle layer of skin; dense irregular connective tissue; houses vessels, nerves, glands, and hair follicles.

Hypodermis (subcutaneous layer)

Deepest skin layer; mainly adipose tissue; anchors skin to underlying tissue.

Stratum basale (germinativum)

Deepest epidermal layer; single row of dividing keratinocytes; melanocytes present.

Stratum spinosum

Layer above basale; several cell layers of keratinocytes with spiny appearance and Langerhans cells.

Stratum granulosum

Layer where keratinization begins; keratohyalin granules form keratin devices.

Stratum lucidum

Thin, clear layer present only in thick skin (palms, fingertips, soles).

Stratum corneum

Outermost layer of dead, keratinized cells providing barrier function.

Dermal papilla

Dermal projections into the epidermis that increase surface area for exchange.

Subpapillary plexus

Capillary network just beneath dermal papillae supplying the epidermis.

Papillary region

Superficial dermal layer containing dermal papillae and capillary loops.

Reticular region

Deeper dermal layer with dense irregular connective tissue; provides strength and elasticity.

Hair

Keratinized filament produced by hair follicles; provides protection and insulation.

Sebaceous glands

Glands producing sebum; holocrine secretion; lubricates skin/hair and has antimicrobial properties.

Apocrine sweat glands

Sweat glands in axillae and groin; secretions contain cytoplasm; odor develops with bacterial action.

Merocrine (eccrine) sweat glands

Most numerous sweat glands; secrete by exocytosis; regulate body temperature.

Lamellar corpuscle (Pacinian corpuscle)

Sensory receptor that detects deep pressure and vibration in deep dermis/hypodermis.

Tactile corpuscle (Meissner’s corpuscle)

Sensory receptor for light touch; located in dermal papillae of hairless skin.

Arrector pili muscles

Small smooth muscles that raise hairs (goosebumps) in response to cold or fear.

Merkel discs

Tactile receptors for sustained touch; located at the epidermal-dermal junction.

Nails

Keratinized plates protecting distal digits; produced by the nail matrix.

Sebum (function)

Oily secretion from sebaceous glands that lubricates skin/hair and has antimicrobial properties.

Sweat (function)

Secretions from sweat glands used for thermoregulation and modest excretion.

Melanin

Pigment produced by melanocytes; protects against UV radiation and determines skin color.

Keratin

Fibrous protein that hardens cells to form the protective outer layer of skin, hair, and nails.

Mucous membrane (location/function)

Lines cavities open to exterior; secretes mucus to protect and moisten surfaces.

Serous membrane (location/function)

Lines closed body cavities and covers organs; secretes serous fluid to reduce friction.