Human Anatomy & Physiology - Chapter 4: Tissue

Flashcards covering key vocabulary and concepts from the Human Anatomy and Physiology Eleventh Edition Chapter 4 Lecture on Tissue.

Tissues

Groups of cells similar in structure that perform a common or related function.

Histology

The study of tissues.

Four Basic Tissue Types

Epithelial, Connective, Muscle, and Nervous.

Epithelial Tissue

Forms boundaries between different environments, protects, secretes, absorbs, and filters.

Connective Tissue

Supports, protects, and binds other tissues together.

Muscle Tissue

Contracts to cause movement.

Nervous Tissue

Internal communication.

Fixed (Microscopy)

Tissue is preserved with solvent.

Sectioned (Microscopy)

Cut into slices thin enough to transmit light or electrons.

Stained (Microscopy)

Used to enhance contrast in microscopy.

Artifacts

Distortions that detract from what the sample looks like in living tissues

Epithelial Tissue (Epithelium)

Sheet of cells that covers body surfaces or cavities.

Covering and Lining Epithelia

On external and internal surfaces (example: skin).

Glandular Epithelia

Secretory tissue in glands (example: salivary glands).

Main Functions of Epithelial Tissue

Protection, absorption, filtration, excretion, secretion, and sensory reception.

Apical Surface

Upper free side, is exposed to surface or cavity.

Basal Surface

Lower attached side, faces inwards toward body.

Basal Lamina

Adhesive sheet that holds basal surface of epithelial cells to underlying cells.

Reticular Lamina

Deep to basal lamina and consists of network of collagen fibers.

Basement Membrane

Made up of basal and reticular lamina; reinforces epithelial sheet, resists stretching and tearing, and defines epithelial boundary.

Regeneration

Epithelial cells that have high regenerative capacities.

Simple Epithelia

A single layer thick.

Stratified Epithelia

Two or more layers thick and involved in protection (example: skin).

Squamous

Flattened and scale-like.

Cuboidal

Box-like, cube.

Columnar

Tall, column-like.

Endothelium

Lining of lymphatic vessels, blood vessels, and heart.

Mesothelium

Serous membranes in the ventral body cavity.

Pseudostratified Columnar Epithelium

Cells vary in height and appear to be multi-layered and stratified, but tissue is in fact single-layered simple epithelium.

Gland

One or more cells that makes and secretes an aqueous fluid called a secretion.

Endocrine

Internally secreting (example: hormones).

Exocrine

Externally secreting (example: sweat).

Mucous Cells and Goblet Cells

The only important unicellular glands.

Mucin

A sugar-protein that can dissolve in water to form mucus, a slimy protective, lubricating coating.

Merocrine

Most secrete products by exocytosis as secretions are produced (sweat, pancreas).

Holocrine

Accumulate products within, then rupture (sebaceous oil glands).

Apocrine

Accumulate products within, but only apex ruptures (maybe mammary cells).

Connective Tissue

The most abundant and widely distributed of primary tissues – binding and support, protecting, insulating, storing reserve fuel, and transporting substances (blood).

Four Main Classes of Connective Tissue

Connective tissue proper, cartilage, bone, and blood.

Common Embryonic Origin of Connective Tissues

All arise from mesenchyme tissue as their tissue of origin.

Extracellular Matrix (ECM)

Protein-sugar mesh in which cells are suspended/embedded.

Ground substance & Fibers

The two elements (ground substance and fibers) together make up the extracellular matrix.

Ground Substance

Unstructured gel-like material that fills space between cells.

Collagen Fibers

Strongest and most abundant type of connective tissue fiber; tough and provides high tensile strength.

Elastic Fibers

Networks of long, thin, elastin fibers that allow for stretch and recoil.

Reticular Fibers

Short, fine, highly branched collagenous fibers; branching forms networks that offer more 'give'.

Blast Cells

Immature form of cell that actively secretes ground substance and ECM fibers.

Cyte Cells

Mature, less active form of 'blast' cell that now becomes part of and helps maintain health of matrix.

Fat Cells

Store nutrients.

White Blood Cells

Neutrophils, eosinophils, lymphocytes; tissue response to injury.

Mast Cells

Initiate local inflammatory response against foreign microorganisms they detect.

Macrophages

Phagocytic cells that 'eat' dead cells, microorganisms; function in immune system.

Connective Tissue Proper

Consists of all connective tissues except bone, cartilage, and blood.

Areolar Connective Tissue

Most widely distributed connective tissue; supports and binds other tissues; universal packing material between other tissues.

Adipose Tissue

Similar to areolar tissue but greater nutrient storage; cells are called adipocytes.

Reticular Connective Tissue

Resembles areolar tissue, but fibers are thinner reticular fibers; fibroblast cells are called reticular cells.

Dense Regular Connective Tissue

Very high tensile strength; can withstand high tension and stretching; example: tendons and ligaments.

Dense Irregular Connective Tissue

Same elements as dense regular, but bundles of collagen are thicker and irregularly arranged; resists tension from many directions; found in dermis.

Elastic Connective Tissue

Some ligaments are very elastic; example: ligaments connecting adjacent vertebrae; also found in walls of many large arteries.

Cartilage

Matrix secreted from chondroblasts (during growth) and chondrocytes (adults); chondrocytes found in cavities called lacunae; avascular.

Chondroblasts

Secrete matrix in cartilage.

Chondrocytes

Mature cartilage cells that reside in Lacunae.

Hyaline Cartilage

Most abundant cartilage; 'gristle'; found at tips of long bones, nose, trachea, larynx, and cartilage of the ribs.

Elastic Cartilage

Similar to hyaline but with more elastic fibers; found in ears and epiglottis.

Fibrocartilage

Properties between hyaline and dense regular tissue; strong, so found in areas such as intervertebral discs and knee.

Bone (Osseous Tissue)

Supports and protects body structures; stores fat and synthesizes blood cells in cavities; has more collagen compared to cartilage; has inorganic calcium salts.

Osteoblasts

Produce bone matrix.

Osteocytes

Maintain matrix of bone, reside in lacunae.

Osteons

Individual structural units of bone.

Blood

Most atypical connective tissue because it is fluid; consists of cells surrounded by matrix (plasma); functions in transport.

Muscle Tissue

Highly vascularized; responsible for most types of movement; muscle cells possess myofilaments made up of actin and myosin proteins that bring about contraction.

Skeletal Muscle Tissue

Attached to and causes movement of bones; also called voluntary muscle; cells are called muscle fibers.

Cardiac Muscle Tissue

Found only in walls of heart; involuntary muscle; contains striations; cells have only one nucleus; intercalated discs are special joints where cardiac cells are joined.

Smooth Muscle Tissue

Found mainly in walls of hollow organs (other than heart); involuntary muscle; has no visible striations; spindle-shaped cells with one nucleus.

Nervous Tissue

Main component of nervous system (brain, spinal cord, nerves); regulates and controls body functions.

Neurons

Specialized nerve cells that generate and conduct nerve impulses.

Neuroglia

Supporting cells that support, insulate, and protect neurons.

Covering and Lining Membranes

Composed of at least two primary tissue types: an epithelium bound to underlying connective tissue proper layer.

Cutaneous Membranes

Another name for skin; keratinized stratified squamous epithelium (epidermis) attached to a thick layer of connective tissue (dermis); a dry membrane.

Mucous Membranes

Line body cavities that are open to the exterior; moist membranes bathed by secretions (or urine); epithelial sheet lies over layer of loose connective tissue called lamina propria; may secrete mucus.

Serous Membranes

Found in closed ventral body cavities; constructed from simple squamous epithelium (called mesothelium) resting on thin areolar connective tissue; cavity between layers is filled with slippery serous fluid, so these are moist membranes.

Regeneration (Tissue Repair)

Same kind of tissue replaces destroyed tissue, so original function is restored.

Fibrosis (Tissue Repair)

Connective tissue replaces destroyed tissue, and original function lost.

Epithelial tissues, bone, areolar connective tissue, dense irregular connective tissue, blood-forming tissue

Tissue that regenerates extremely well.

Smooth muscle and dense regular connective tissue

Tissue with moderate regenerating capacity.

Cardiac muscle and nervous tissue of brain and spinal cord

Tissues with virtually no functional regenerative capacity.

Primary Germ Layers

Superficial to deep: ectoderm, mesoderm, and endoderm; formed early in embryonic development; specialize to form the four primary tissues.