anat ch 4 tissues week 2

Vocabulary flashcards covering key terms, definitions, and concepts from the Tissue: The Living Fabric lecture notes.

Histology

Study of tissues—the science focused on the microscopic structure and organization of tissues.

Tissue

Groups of cells similar in structure that perform related functions to maintain homeostasis.

Four basic tissue types

Epithelial, connective, muscle, and nervous tissue.

Epithelial tissue (epithelium)

A sheet of cells that covers body surfaces or lines cavities; also forms glands.

Connective tissue

Tissue that binds, supports, protects, and insulates; includes four main classes: proper, cartilage, bone, blood.

Muscle tissue

Tissues responsible for movement; three types: skeletal, cardiac, and smooth.

Nervous tissue

Tissue that regulates and controls body functions; composed of neurons and glial cells.

Apical surface

The exposed (top) surface of epithelial cells facing the body exterior or a body cavity.

Basal surface

The bottom surface of epithelial cells that faces inward toward the body and attaches to the basal lamina.

Basal lamina

An adhesive sheet that anchors the basal surface of epithelial cells to underlying tissue.

Basement membrane

Composite layer of basal and reticular lamina that reinforces epithelial sheets and resists tearing.

Avascular but innervated

Epithelial tissue lacks blood vessels but contains nerve fibers.

Regeneration

Replacement of damaged tissue with the same kind of tissue to restore function.

Simple epithelia

Epithelium with a single cell layer, typically for absorption, secretion, or filtration.

Stratified epithelia

Epithelium with two or more cell layers, typically for protection in high-abrasion areas.

Squamous

Flat, scale-like cell shape.

Cuboidal

Cube-shaped cell type.

Columnar

Tall, column-like cell shape.

Simple squamous epithelium

Single layer of flattened cells; rapid diffusion/filtration; includes endothelium and mesothelium.

Endothelium

Lining of lymphatic vessels, blood vessels, and the heart.

Mesothelium

Simple squamous epithelium lining serous membranes in the ventral body cavity.

Simple cuboidal epithelium

Single layer of cube-like cells; secretion and absorption; lines kidney tubules and some glands.

Simple columnar epithelium

Single layer of tall cells; involved in absorption and secretion; may have microvilli or goblet cells.

Goblet cell

Unicellular mucous-secreting gland cell within epithelia.

Pseudostratified columnar epithelium

Single-layered with different cell heights; often ciliated; contains goblet cells.

Transitional epithelium

Epithelium that stretches; lines hollow urinary organs; basal cells cuboidal/columnar.

Stratified squamous epithelium

Multi-layered epithelium; protects underlying tissues; keratinized or nonkeratinized.

Keratinized

Surface cells filled with keratin; typically dry, found in skin.

Nonkeratinized

Moist epithelium without keratin on the surface.

Stratified cuboidal epithelium

Rare multi-layered epithelium found in some sweat and mammary glands.

Stratified columnar epithelium

Rare multi-layered epithelium with apical columnar cells; occurs at transition areas.

Glandular epithelium

Epithelium that forms glands which secrete aqueous fluids.

Endocrine glands

Ductless glands that secrete hormones into interstitial fluid for transport by blood or lymph.

Exocrine glands

Glands that secrete products onto body surfaces or into cavities via ducts.

Unicellular exocrine glands

Individual secretory cells (e.g., goblet cells) within epithelia.

Multicellular exocrine glands

Glands composed of a duct and a secretory unit; may be simple or compound.

Merocrine secretion

Secretion by exocytosis as secretions are produced; most common type.

Holocrine secretion

Secretions accumulate until the cell ruptures; example: sebaceous glands.

Apocrine secretion

Secretions accumulate at the apex and that portion pinches off; mammary glands cited as example (controversial in humans).

Connective tissue proper

Subclass of connective tissue; includes loose and dense tissues.

Cartilage

Rigid, yet flexible connective tissue; avascular; chondroblasts/chondrocytes in lacunae.

Bone (osseous tissue)

Rigid connective tissue with mineralized matrix; osteoblasts/osteocytes; organized into osteons.

Blood

Fluid connective tissue with plasma, cells (RBCs, WBCs), and platelets; transports substances.

Areolar connective tissue

Widely distributed loose connective tissue; packing material with ground substance and fibers.

Adipose tissue

Loose connective tissue for energy storage; white fat stores nutrients; brown fat generates heat.

Reticular connective tissue

Loose connective tissue with reticular fibers supporting lymphoid organs.

Dense regular connective tissue

Dense CT with parallel collagen fibers; great tensile strength; found in tendons and ligaments.

Dense irregular connective tissue

Dense CT with interwoven collagen fibers; resists stress from multiple directions; dermis.

Elastic connective tissue

Dense CT with elastic fibers; allows recoil; found in elastic arteries and some ligaments.

Hyaline cartilage

Most common cartilage; glossy; found at tips of long bones, nose, trachea; perichondrium.

Elastic cartilage

Cartilage with many elastic fibers; found in external ear and epiglottis.

Fibrocartilage

Strong cartilage with thick collagen; found in intervertebral discs and knee menisci.

Osteoblasts

Bone-forming cells that synthesize the bone matrix.

Osteocytes

Mature bone cells that maintain bone matrix; reside in lacunae.

Osteon

Structural unit of compact bone surrounding a central canal.

Blood components

Red blood cells, white blood cells, platelets, and plasma.

Skeletal muscle

Voluntary, striated muscle attached to bones; multinucleated fibers.

Cardiac muscle

Involuntary muscle of the heart; striated, single nucleus per cell, branched with intercalated discs.

Smooth muscle

Involuntary muscle found in hollow organs; non-striated, spindle-shaped cells.

Neurons

Nerve cells that transmit electrical signals; possess dendrites and axons.

Glial cells (neuroglia)

Supportive cells that protect, insulate, and nourish neurons.

Membranes

Coverings/linings of the body: cutaneous, mucous, serous membranes.

Cutaneous membrane

Skin; dry membrane composed of keratinized epidermis and dermis.

Mucous membranes (mucosae)

Line cavities open to exterior; epithelium over lamina propria; often mucus-secreting.

Serous membranes (serosae)

Moist membranes lining closed ventral body cavities; parietal and visceral layers with serous fluid in between.

Mesothelium

Epithelium that lines serous membranes.

Parietal serosa

Serous membrane lining the cavity walls.

Visceral serosa

Serous membrane covering the organs.

Serous fluid

Lubricating fluid between parietal and visceral layers of serosae.

Tissue repair

Process to restore tissue after injury, involving inflammation, organization, and regeneration/fibrosis.

Inflammation

Initial response with vascular dilation and increased permeability to clot the wound.

Organization (tissue repair)

Replacement of clot with granulation tissue; reepithelialization; fibroblast collagen deposition.

Regeneration and fibrosis

Final repair phase: epithelial regeneration with scar tissue formation; function may be restored or reduced.

Embryonic germ layers

Ectoderm, mesoderm, and endoderm—layers from which tissues develop.

Nerve tissue origin

Nerve tissue arises from the ectoderm.

Muscle and connective tissue origin

Muscle and connective tissues arise from the mesoderm.

Epithelial tissue origin

Epithelial tissues arise from all three germ layers.