Histology and Tissue Types Vocabulary

A complete set of vocabulary flashcards covering the primary tissue types, histology, epithelial classification, connective tissues, muscle, nervous tissue, membranes, and tissue repair.

Histology

The study of living tissues and their cellular structure.

Tissue

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

Epithelial Tissue

A primary tissue type consisting of sheets of cells that cover body surfaces, line body cavities, form boundaries, and constitute glands.

Connective Tissue

The most abundant primary tissue type, consisting of cells in an extracellular matrix; functions in binding, supporting, protecting, insulating, storing reserve fuel, and transporting substances.

Muscle Tissue

A highly vascularized primary tissue type responsible for movement through contraction; includes skeletal, cardiac, and smooth muscle tissues.

Nervous Tissue

A primary tissue type found in the brain, spinal cord, and nerves that regulates and controls bodily functions by generating and transmitting electrical signals.

Simple Epithelium

Epithelial tissue composed of a single layer of cells, primarily involved in absorption, secretion, and filtration.

Stratified Epithelium

Epithelial tissue composed of two or more stacked cell layers, primarily functioning in protection against abrasion.

Squamous Cells

Flattened and scale-like epithelial cells containing flattened nuclei.

Cuboidal Cells

Boxlike epithelial cells that are as tall as they are wide, featuring round central nuclei.

Columnar Cells

Tall, column-shaped epithelial cells containing elongated nuclei located near the basal surface.

Simple Squamous Epithelium

extremely thin & permeable; Functions in diffusion, filtration, and secretion of lubricating substances in serosae; in lungs and kidneys

Simple Cuboidal Epithelium

Functions in secretion and absorption within kidney tubules and small gland ducts.

Simple Columnar Epithelium

Functions in the absorption and secretion of mucus and enzymes in the digestive tract and bronchi.

Pseudostratified Columnar Epithelium

A single layer of cells of differing heights with nuclei at different levels that appears stratified; functions in mucus secretion and propulsion by ciliary action in the upper respiratory tract (trachea)

Stratified Squamous Epithelium

Protects underlying tissues subjected to abrasion.

Transitional Epithelium

A stratified epithelium with dome-shaped surface cells that stretch and flatten when filled, lining hollow urinary organs such as the bladder.

Endocrine Glands

Ductless glands that secrete hormones directly into surrounding blood or lymph to reach specific target organs.

Exocrine Glands

Glands that release their secretions through ducts onto body surfaces or into body cavities, such as sweat, oil, mucous, and salivary glands.

Extracellular Matrix

The nonliving matrix surrounding living cells in connective tissue, composed of ground substance and protein fibers, enabling tissue to bear weight and withstand tension.

Ground Substance

Unstructured material filling the space between cells in connective tissue; composed of interstitial fluid, cell adhesion proteins, and proteoglycans.

Collagen Fibers

The strongest and most abundant connective tissue fibers, made of collagen protein, providing high tensile strength.

Elastic Fibers

Long, thin, branching connective tissue fibers containing elastin that allow tissues to stretch and recoil.

Reticular Fibers

Short, fine, highly branched collagenous fibers that form delicate networks (stroma) supporting soft organs and blood cells.

Fibroblasts

Immature primary cells of connective tissue proper that actively secrete fibers and ground substance.

Chondroblasts

Immature cartilage cells that actively secrete matrix in growing cartilage.

Osteoblasts

Immature bone cells that produce the organic component of bone matrix.

Chondrocytes

Mature cartilage cells located in small spaces within the matrix called lacunae.

Osteocytes

Mature bone cells located in lacunae that maintain the bone matrix.

Areolar Connective Tissue

A loose connective tissue with a gel-like matrix containing all three fiber types; wraps and cushions organs and holds body fluids.

Adipose Connective Tissue

A loose connective tissue dominated by adipocytes storing fat droplets; functions in reserve fuel storage, thermal insulation, and shock absorption.

Reticular Connective Tissue

A loose connective tissue consisting of reticular fibers forming a soft internal skeleton (stroma) to support blood cells in lymphoid organs.

Dense Regular Connective Tissue

Dense connective tissue consisting primarily of parallel collagen fiber bundles; withstands tensile stress in one direction, found in tendons and ligaments.

Dense Irregular Connective Tissue

Dense connective tissue with thick, irregularly arranged collagen fiber bundles; withstands multidirectional tension, found in dermis and joint capsules.

Elastic Connective Tissue

Dense connective tissue containing a high proportion of elastic fibers; allows tissue recoil after stretching in large artery walls and bronchial tubes.

Hyaline Cartilage

The most abundant cartilage type, featuring a firm matrix with imperceptible collagen fibers; provides pliable support and absorbs compressive stress at joints.

Elastic Cartilage

Cartilage containing a high density of elastic fibers in its matrix; maintains structural shape while allowing great flexibility in the external ear and epiglottis.

Fibrocartilage

Cartilage with thick collagen fiber bands alternating with chondrocyte rows; absorbs compressive shock and withstands heavy pressure.

Bone Tissue

Hard, calcified connective tissue matrix containing collagen fibers and osteocytes in lacunae; functions in structural support, protection, and mineral storage.

Blood Tissue

An atypical fluid connective tissue consisting of blood cells (erythrocytes, leukocytes, platelets) in a fluid extracellular matrix called plasma.

Skeletal Muscle

Voluntary muscle tissue made of long, cylindrical, multinucleate cells with obvious striations; attached to bones or skin to cause movement.

Cardiac Muscle

Involuntary muscle tissue found in the heart wall, featuring branching, striated, generally uninucleate cells connected by intercalated discs.

Smooth Muscle

Involuntary muscle tissue composed of nonstriated, spindle-shaped cells with central nuclei; propels substances along internal passageways in hollow organs.

Cutaneous Membrane

The dry epithelial covering of the body, commonly referred to as the skin.

Mucous Membranes

Moist epithelial membranes that line body cavities open to the exterior, such as the digestive, respiratory, and urinary tracts.

Serous Membranes

Moist membranes lining closed ventral body cavities and covering organs (pleurae, pericardium, peritoneum).

Regeneration

A tissue repair process where destroyed tissue is replaced by the same kind of tissue, restoring original function.

Fibrosis

A tissue repair process where destroyed tissue is replaced by dense connective scar tissue, resulting in a loss of original function.

Primary Germ Layers

The three embryonic cell layers (ectoderm, mesoderm, endoderm) that give rise to all four primary tissue types in the body.

erythrocytes

Red blood cells responsible for transporting oxygen and carbon dioxide in the bloodstream

leukocytes

White blood cells that are part of the immune system, helping to defend the body against infections and foreign invaders.

5 key characteristics of epithelial tissue

polar (have apical & basal side), have continuous sheets with tight junctions, supported by connective tissue, avascular BUT innervated, are able to regenerate quickly via mitosis

how shape of stratified epithelium determined?

morphology of the cells at the apical (top) surface, not the basal layer

origin of epithelial tissue

arises from all three germ layers: ectoderm, mesoderm, and endoderm.

mast cells

initiate inflammatory response against foreign organisms

macrophages

phagocytic cells that eat dead cells/bacteria/other foreign molecules & microorganisms

how does cartilage receive nutrients?

through diffusion from the membrane surrounding it

hematopoiesis

The process of blood cell formation occurring in the bone marrow.

nerve tissue originates from…

ectoderm

muscle tissue originates from..

mesoderm

Connective tissue & muscle tissue originate from..

mesoderm