Tissues – Lecture Vocabulary

Vocabulary flashcards covering major terms and definitions from the tissue lecture, including organization, epithelial, connective, muscular, and nervous tissue concepts.

molecules → cells → tissues → organs → organ systems → organism

Levels of Organization - Hierarchy of the human body:

Tissue

Group of cells working together to perform a common function

Epithelial, Connective, Muscular, Nervous

Four Tissue Types

Histology

Study of tissues using thin stained sections viewed under a microscope

Stem Cell

Multipotent precursor cell capable of giving rise to various specialized cell types

Asymmetric Division

Stem-cell division producing two daughter cells with different fates

Chemotaxis

Cell migration guided by soluble chemical signals

Contact Guidance

Cell movement directed by physical cues in the extracellular matrix

Adhesion (cellular)

Attachment of cells to each other and to the extracellular matrix

Lumen

Innermost open space of a hollow organ or tube

Basement Membrane

Thin extracellular layer anchoring epithelium to underlying connective tissue

Apical Surface

Free, unattached top surface of an epithelial cell layer

Basolateral Surface

Deep surface of epithelium bound to the basement membrane

Avascular

Lacking blood vessels; nutrients diffuse from surrounding tissues

High Regeneration Capacity

Ability of epithelial cells to divide rapidly and replace lost cells

Protection, permeability control, absorption, secretion, filtration, sensation

Epithelial Tissue Functions

Simple Epithelium

One layer of epithelial cells

Stratified Epithelium

Two or more layers of epithelial cells

Squamous Cell Shape

Flattened, scale-like epithelial cells

Cuboidal Cell Shape

Cube-shaped epithelial cells with round central nucleus

Columnar Cell Shape

Tall, rectangular epithelial cells with oval nucleus

Simple Squamous Epithelium

Single layer of flat cells for diffusion, filtration; lines alveoli, heart, Bowman’s capsule, serous membranes

Stratified Squamous Epithelium

Many layers; apical cells flat; protects against abrasion; found in skin, mouth, esophagus, rectum, vagina

Simple Cuboidal Epithelium

Single layer of cube-like cells; secretion & absorption; kidney tubules, glandular ducts, ovary surface

Stratified Cuboidal Epithelium

Two layers of cuboidal cells; rare; secretion in sweat gland ducts

Simple Columnar Epithelium

Single layer of tall cells, often with goblet cells; absorption & secretion; digestive tract, gallbladder, uterine tubes

Stratified Columnar Epithelium

Multiple layers, apical columnar cells; secretion; large ducts such as salivary glands

Pseudostratified Columnar Epithelium

Single disorganized layer appearing stratified; may have cilia & goblet cells; secretion & propulsion; upper respiratory tract, male urethra

Transitional Epithelium

Multiple layers that change shape from cuboidal to squamous; stretches to allow distension; ureters, bladder, renal pelvis

Gland

One or more epithelial cells that produce secretions

Endocrine Gland

Ductless gland releasing hormones into surrounding tissue & bloodstream

Exocrine Gland

Gland with ducts that secrete substances onto body surface or into lumen

Merocrine Secretion

Exocytosis of secretory vesicles from cell without cell damage

Apocrine Secretion

Apical portion of cell pinches off with secretory product

Holocrine Secretion

Entire cell ruptures to release accumulated secretions

Connective Tissue

Tissue with cells plus extracellular matrix providing support, binding, storage, transport, immune protection

Extracellular Matrix

Non-living material around connective-tissue cells; composed of ground substance and protein fibers

Ground Substance

Fluid or gel portion of matrix that fills space between fibers and cells

Collagen Fibers

Strong, thick protein fibers providing tensile strength

Elastic Fibers

Stretchable protein fibers allowing recoil

Reticular Fibers

Thin branching fibers forming supportive networks

Areolar Connective Tissue

Loose CT with all fiber types; cushions organs, holds fluids; widely distributed under epithelia

Adipose Tissue

Loose CT of adipocytes storing fat; insulation, cushioning, energy reserve; under skin, around organs

Reticular Connective Tissue

Loose CT with reticular fiber network supporting blood-cell-rich organs; spleen, lymph nodes, bone marrow, liver

Dense Regular Connective Tissue

Parallel collagen bundles; resists one-direction stress; forms tendons and ligaments

Dense Irregular Connective Tissue

Random collagen bundles; resists multidirectional stress; dermis, joint capsules

Elastic Connective Tissue

Dense CT rich in elastic fibers; allows stretch & recoil; walls of large arteries, certain ligaments

Hyaline Cartilage

Most common cartilage; glassy matrix; supports & cushions; nose, costal cartilage, articular surfaces, trachea

Elastic Cartilage

Cartilage with abundant elastic fibers; flexible support; external ear, epiglottis

Fibrocartilage

Cartilage with thick collagen; resists compression; intervertebral discs, menisci, pubic symphysis

Osseous Tissue (Bone)

Connective tissue with hard calcium-phosphate matrix and collagen; structural support, protection, muscle attachment

Blood

Fluid connective tissue with plasma matrix; transports gases, nutrients; contains red cells, white cells, platelets

Lymph

Fluid connective tissue in lymphatic system; returns interstitial fluid to bloodstream, immune surveillance

Skeletal Muscle

Voluntary, striated, multinucleate muscle attached to bones for body movement

Cardiac Muscle

Involuntary, striated muscle of heart; branching cells with single nucleus and intercalated discs

Smooth Muscle

Involuntary, non-striated muscle of hollow organs and vessels; spindle-shaped cells with single nucleus

Neural Tissue

Tissue specialized for electrical communication; located in brain, spinal cord, nerves

Neuron

Excitable nervous-system cell that generates and transmits electrical signals

Neuroglia

Supporting cells of nervous system; include astrocytes, oligodendrocytes, ependymal cells, microglia, Schwann cells, satellite cells

Adventitia/Fascia/Capsule

Outermost connective-tissue coverings surrounding organs or tissues