Tissue Types and Integumentary System — Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering tissue types (epithelium, connective tissue, cartilage, bone, muscle, nervous tissue), membranes, skin layers, and key cells/structures from Pages 1–3 of the notes.

Epithelial tissue (epithelium)

Tissue that lines surfaces and cavities; classified by number of cell layers (simple vs. stratified) and by cell shape (squamous, cuboidal, columnar).

Simple epithelium

Epithelium with a single cell layer; often involved in diffusion, absorption, and filtration.

Stratified epithelium

Epithelium with two or more cell layers; primarily protective.

Squamous epithelium

Flat, scale-like epithelial cells.

Cuboidal epithelium

Cube-shaped epithelial cells; often lining glands and ducts.

Columnar epithelium

Tall, column-like epithelial cells; often involved in absorption and secretion.

Connective tissue

Tissue with a matrix of ground substance and fibers; supports, binds, and protects the body.

Areolar (loose) connective tissue

Loose connective tissue with few fibers; provides support, holds water, defends against infection, and stores nutrients.

Adipose tissue

Fat tissue composed of adipocytes; stores energy, cushions, insulates, and is highly vascularized.

White adipose tissue (WAT)

Fat tissue found in small amounts in adults; stores energy.

Brown adipose tissue (BAT)

Fat tissue in babies that generates heat to help regulate body temperature; decreases with age.

Reticular tissue

Connective tissue that forms the stroma (framework) of organs.

Dense regular connective tissue

Fibers (mainly collagen) arranged in the same direction; forms tendons and ligaments; strong and somewhat extensible.

Elastic tissue

Dense tissue with elastic fibers; allows stretch; connects structures such as vertebrae.

Dense irregular connective tissue

Fibers arranged in a mesh-like, irregular pattern; resists forces from multiple directions.

Cartilage

A tough, flexible connective tissue that provides support and absorbs compression; avascular; produced by chondroblasts.

Chondroblasts

Cartilage-forming cells that secrete the extracellular matrix.

Hyaline cartilage

Most common cartilage; glassy matrix with collagen; covers ends of bones in joints and provides smooth surfaces.

Elastic cartilage

Cartilage containing elastic fibers; flexible; found in the ear and epiglottis.

Fibrocartilage

Tough cartilage found in intervertebral discs and knee joints; withstands compression and tension.

Arthritis

Joint inflammation and cartilage wear that increases with age.

Bone tissue (osseous tissue)

Rigid, vascularized connective tissue that supports, protects, stores fat, and forms blood cells; composed of matrix and cells (osteoblasts).

Osteoblasts

Bone-forming cells that secrete the organic matrix of bone.

Central canals (Haversian canals)

Vertical channels in bone containing blood vessels and nerves within osteons.

Bone matrix

Organic matrix of bone (collagen and other components) prior to mineralization.

Red blood cells (erythrocytes)

Cells that transport oxygen and carbon dioxide in the blood.

White blood cells (leukocytes)

Immune cells that defend against infection.

Platelets (thrombocytes)

Cell fragments that participate in blood clotting.

Ground substance

Gel-like part of the extracellular matrix in connective tissue that fills space between cells and fibers.

Nervous tissue

Tissue of the brain, spinal cord, and nerves; specialized for electrical signaling.

Neuron

Nerve cell that transmits impulses via dendrites and axons.

Neuroglial cells

Supportive cells that maintain neuron structure, repair tissue, and provide metabolic support.

Dendrites

Neuron branches that receive electrical signals.

Axon

Long projection that conducts nerve impulses away from the cell body.

Skeletal muscle

Muscle tissue composed of muscle fibers; voluntary movement.

Cardiac muscle

Heart muscle (cardiomyocytes) connected by intercalated discs for coordinated contraction.

Intercalated discs

Cell junctions between cardiac muscle cells enabling synchronized contractions.

Smooth muscle

Non-striated muscle in the walls of hollow organs; contracts to move contents through organs.

Cutaneous membrane

Skin; outer covering of the body; provides a protective barrier and is keratinized.

Mucous membrane (mucosa)

Lines body cavities that open to the exterior; usually secretes mucus; often has lamina propria underneath the epithelium.

Lamina propria

Loose connective tissue layer underlying mucous membranes.

Serous membrane

Membranes lining closed body cavities (peritoneal, pleural, and pericardial) that secrete serous fluid to reduce friction.

Synovial membrane

Membrane lining joint cavities that secretes synovial fluid for lubrication.

Epidermis

Outer, avascular, stratified squamous keratinized epithelium of the skin.

Dermis

Thicker, vascular layer beneath the epidermis containing nerves, blood vessels, hair follicles, and glands; composed of papillary and reticular layers.

Hypodermis (subcutaneous layer)

Layer beneath the dermis; primarily adipose tissue; not a true skin layer but anchors skin to underlying tissues.

Keratinocytes

Most abundant epidermal cells; produce keratin; originate in the basal layer and move outward, progressively dying as they reach the surface.

Melanocytes

Cells that produce pigment melanin and transfer it to keratinocytes via melanosomes.

Melanin

Pigment produced by melanocytes; determines skin color and provides some UV protection.

Merkel cells

Touch-sensing cells at the epidermal-dermal border associated with nerve endings.

Langerhans' cells

Dendritic immune cells in the epidermis that present antigens; derived from bone marrow.

Granulosum (stratum granulosum)

Middle epidermal layer (3–5 cell layers) where keratohyalin and lamellated granules accumulate.

Stratum corneum

Outermost epidermal layer; composed of dead, flattened cells and provides a water barrier; thick in thick skin.

Papillary layer

Superficial dermal layer with projections (dermal papillae) that form fingerprints and increase surface area.

Dermal ridges / epidermal ridges (fingerprints)

Ridges formed by dermal papillae that create epidermal ridges and unique fingerprints.

Cleavage (tension) lines

Bundles of collagen fibers oriented parallel to skin surface; influence surgical incisions and scarring.

Flexure lines

Dermal folds where skin creases occur over joints.

Stretch marks (striae)

Tears in the dermis due to extreme stretching, resulting in white scars.

Thick skin

Skin with five epidermal layers, found on palms and soles.

Thin skin

Skin with four epidermal layers; covers most of the body.