Chapter 5: Tissues - Living Communities Vocabulary

Comprehensive vocabulary flashcards generated from lecture notes on tissue types, gland classifications, membrane structures, and tissue healing.

Four types of tissues

Epithelial, connective, muscle, nerve

Epithelial Tissue

Sheets of cells that cover and line other tissues, functioning to protect core and line, filters biochemical substances, absorbs nutrients , provide sensory input, and manufacture secretions and excretions.

Characteristics of epithelia

Organized into tightly packed groups that form sheets, celli are polar, apical surface faces lumen or is exposed to outside world, basal surface is attached to basement membrane, lateral surface connects to neighboring cells, avascular, innervated (provide sensory info)

Tight Junctions

fusion of the outermost area of plasma membranes of adjoining cells to create a leak-proof seal.

Desmosomes

Strong mechanical couplings between cells involving plaque and tonofilaments, found in tissues undergoing repeated tension and stretching.

Gap Junctions

Cell junctions linked by tubular channel proteins called connexons that allow exchange of ions and nutrients and fast transport of electrical signals.

Basement Membrane

A nonliving, avascular network of fibers (also called basal lamina) serving as a foundation that cements epithelial cells to underlying tissue, varies in thickness, partial barrier to underlying tissue, allows diffusion of nutrients, waste

Apical surface specialization

Varies depending on epithelial location and role in the function of the tissue (smooth, microvilli, cilia, keratin)

Classification of epithelia

1) number of cell layers: simple, stratified

2)cell shape: squamous, cuboidal, columnar

3) presence of surface specialization: cilia, keratin

Simple Squamous Epithelium

A single layer of delicate, thin, flat, and smooth cells found lining surfaces involved in the passage of gas or liquid (lungs, kidneys), can have regional name (endothelium lines inside of vessel walls)

Stratified Squamous Epithelium

Multilayered, relatively flat epithelium that protects underlying tissues in areas subject to mechanical and chemical stresses (mouth, rectum), outer layer continually soughed away, replaced at equal rate by dividing cells in deeper layers, only stratum basale attached to basement membrane

Simple Cuboidal Epithelium

A single layer of cube-shaped cells with nuclei aligned in a single row, found in glandular ducts and renal tubules for secretion and absorption.

Simple Columnar Epithelium

Tall, elongated, closely packed cells with nuclei aligned at the base, associated with absorption and secretion in the GI tract.

Pseudostratified Columnar Epithelium

A single layer of epithelial cells with nuclei at varying levels that give the appearance of stratification, not all cells reach luminal surface but all cells attached to basement membrane, most are ciliated, located in respiratory tract and reproductive tract

Transitional Epithelium

Epithelium featuring a basal layer of cuboidal or columnar cells and a superficial layer that flattens when stretched, providing a leak-proof membrane in expandable regions (bladder)

Endocrine Glands

Multicellular glands that do not have ducts or tubules and secrete hormones directly into the bloodstream.

Exocrine Glands

Glands possessing ducts (except for unicellular goblet cells) that discharge secretions directly into local areas.

Goblet Cell

A unicellular exocrine gland modified from a columnar epithelial cell that secretes mucin.

Multicellular exocrine glands

Composed of a secretory unit and a duct

Merocrine Glands

Exocrine glands whose secretory cells remain intact while secretions are manufactured, packaged, and released via exocytosis.

Apocrine Glands

Glands that store their secretions and release the apical (top) aspect of the cell into the duct system.

Holocrine Glands

Glands that store their secretions and release the entire cell into the duct system.

Three types of secretion

Sebaceous (oily, waxy), serous (watery, high concentration of enzymes), mucous (thick, composed of glycoproteins, mixed endocrine glands

Connective Tissue

The most abundant tissue by weight, providing metabolic and structural connections, protection, insulation, energy storage, structural support, and transport, most is vascularized (fat, cartilage, bone)

Ground Substance

An amorphous, homogeneous medium in connective tissue through which cells exchange nutrients and waste with circulation.

Collagenous Fibers (type of extracellular fiber)

Strong, thick bundles composed of the protein collagen, located in varying densities in tendons and ligaments.

Reticular Fibers (extracellular fibers)

Thin, delicate, branched networks of collagen that provide structural support for cellular organs.

Elastic Fibers (extracullar fibers)

Networks of coiled microfibrils composed primarily of the protein elastin that occur in tissues subjected to stretching (vocal chords, lungs, skin)

Fixed Cells

Connective tissue cells that remain within the tissue and are involved in the production and maintenance of the extracellular matrix.

Transient Cells

Connective tissue cells (wandering cells) that move in and out of connective tissue by diapedesis to assist in immune response and repair.

Areolar Tissue (type of loose connective tissue)

The most common connective tissue in the body, consisting of a tangle of random fibers suspended in a thick ground substance high in hyaluronic acid, functions: surrounds and supports, provides nutrients found primarily in submucosal and subcutaneous layers, can be the side of edema, pitting edema

Adipose Tissue

A loose connective tissue that serves as an energy storehouse, thermal insulator, and mechanical shock absorber, it is fat, two main types are adipose and brown adipose

Reticular Tissue

Loose connective tissue composed of thin reticular fibers and fibroblasts that forms the framework (stroma) for organs.

Dense Regular Connective Tissue

Tightly packed parallel collagen fibers with rows of fibroblasts that form relatively avascular structures like tendons and ligaments.

Dense Irregular Connective Tissue

Thick collagen bundles interwoven into a single sheet with scattered fibroblasts, found in the dermis and organ capsules.

Elastic connective tissue

Type of dense connective tissue in body regions that require stretching, some ligaments, walls of arteries, stomach, bronchi, bladder, heart

What are the three types of specialized connective tissue

Cartilage (3 types), bone, blood

Cartilage

More rigid than dense connective tissue but more flexible than bone, no innervation and avascular, fixed cells are chondroblasts/chondrocytes, located in joint surfaces, ear, nose, vocal cords, framework for skeletal bone formation

Hyaline Cartilage

The most common and most rigid cartilage type, composed of closely packed collagen fibers enclosed within a perichondrium. Located in most of embryonic skeleton, tracheal rings, articular cartilage, growth plates of long bones

Elastic Cartilage

Flexible cartilage containing dense, branching bundles of elastic fibers that withstands repeated bending, epiglottis of larynx, external ears of animals (pinnae)

Fibrocartilage

designed to withstand strong compression forces, between vertebrae of spine (intervertebral discs), between bones in pelvis, stifle joint (meniscus)

Bone

The hardest and most rigid connective tissue, comprising an extracellular matrix of organic collagen fibers and inorganic calcium salts, fixed cells osteoblast/cyte, well vascularized and innervated, makes up the skeletal frame

Blood

Fluid connective tissue, extracellular matrix, ground substance is plasma (mostly water), fibrous component is proteins, erythrocytes are red, leukocytes are white, thrombocytes are platelets

What is a membrane and 4 common types

Thin, protective layers of tissues linked together and an epithelial sheet bound to underlying connective tissue. 4 types are mucous, serous, cutaneous, synovial

Mucous Membranes

Membranes lining organs with connections to the outside environment, consisting of an epithelial layer and an underlying lamina propria.

Serous Membranes

Membranes lining closed body cavities and organs, composed of a simple squamous epithelial sheet bound to loose areolar connective tissue.

Transudate

Normal, small amounts of watery serosal fluid produced in body cavities to reduce friction.

Effusion

Excessive production of fluid within a body cavity.

Exudate

Fluid containing abnormally high cell numbers or protein content, commonly produced during inflammation.

Cutaneous Membrane

The skin (integument), composed of an outer keratinized stratified squamous epithelium (epidermis) and an underlying dense irregular connective tissue layer (dermis).

Synovial Membranes

Specialized non-epithelial membranes lining joint cavities that produce and filter synovial fluid.

Skeletal Muscle

Voluntary, striated muscle tissue consisting of large multinucleate cells that attach to bone.

Smooth Muscle

Involuntary, nonstriated muscle tissue made of small, spindle-shaped single-nucleus cells located in the walls of hollow organs.

Cardiac Muscle

Involuntary, striated muscle tissue found only in the heart, consisting of branching single-nucleus cells connected by intercalated disks.

Neurons

The primary functional cells of nervous tissue designed to receive and transmit electrical signals, consisting of a perikaryon, dendrites, and an axon.

Neuroglial Cells

Supportive cells in nervous tissue that isolate, insulate, nourish, and protect neurons without transmitting impulses.

Inflammation

The initial nonspecific response to tissue injury aimed at limiting damage, characterized by vasoconstriction followed by vasodilation, edema, clot formation, and phagocytosis.

Granulation Tissue

Newly formed tissue during the organization step of healing, composed of newly branched capillaries and collagen fibers.

First-Intention Healing

Wound healing classification where the wound edges are in close apposition, resulting in minimal granulation tissue formation and scarring.

Second-Intention Healing

Wound healing classification where wound edges are separated, requiring granulation tissue formation and resulting in scarring.