Ultimate Histology Notes Flashcards

Vocabulary flashcards generated from the Ultimate Histology Notes covering tissue types, cell shapes, layers, surface modifiers, and histological structures across epithelial, connective, muscle, and nervous tissues.

Histology

The study of tissues and how their structure supports their function.

Squamous

A cell shape term referring to squashed, flat, and thin cells.

Cuboidal

A cell shape term referring to cube shaped cells.

Columnar

A cell shape term referring to tall, rectangular cells.

Simple Epithelium

An epithelial tissue layer classification indicating a single layer of cells.

Stratified Epithelium

An epithelial tissue layer classification indicating multiple layers of cells.

Pseudostratified Epithelium

An epithelial tissue layer classification meaning falsely layered; it appears to have multiple layers but is actually a single layer touching the basement membrane.

Ciliated

A modifier describing cells that have hair-like projections called cilia on their surface.

Keratinized

A modifier describing cells that contain a surface layer of the protective protein keratin.

Transitional Epithelium

A specialized epithelial tissue whose cells can stretch and recoil without tearing.

Simple Squamous Epithelium

Tissue consisting of ONE layer of very thin, flat cells designed for rapid diffusion, gas exchange, and filtration.

Endothelium

Simple squamous epithelium that lines the inside of blood vessels.

Endocardium

Simple squamous epithelium that lines the inside of the heart.

Mesothelium

Simple squamous epithelium that lines body cavities.

Stratified Squamous Epithelium

Tissue composed of MANY layers of cells, with flat cells at the apical surface and rounded cells near the basement membrane, serving as a protective barrier against abrasion.

Keratinized Stratified Squamous Epithelium

Stratified squamous epithelium with a dry, tough surface layer of dead cells filled with keratin and lacking nuclei.

Non-Keratinized Stratified Squamous Epithelium

Stratified squamous epithelium without a keratin layer, containing alive surface cells with nuclei to maintain a moist, flexible surface.

Simple Cuboidal Epithelium

ONE layer of cube shaped cells as tall as they are wide, with round, centered nuclei; functions in secretion and absorption.

Lumen

The hollow space or clear opening inside a tube, duct, or organ.

Stratified Cuboidal Epithelium

A rare tissue with two or more layers of cube shaped cells, providing extra protection and structural support for large gland ducts.

Simple Columnar Epithelium

ONE layer of tall, rectangular cells with oval or elongated nuclei lined up near the basement membrane.

Goblet Cells

Pale or empty-looking cells interspersed between epithelial cells that secrete protective mucus.

Microvilli

Projections on the apical surface of simple columnar cells (forming a brush border) that increase surface area for absorption.

Pseudostratified Columnar Epithelium

ONE layer of tall, thin cells with nuclei staggered at different heights, often featuring cilia and goblet cells to trap and sweep particles.

Umbrella Cells

Giant, dome-shaped cells on the apical surface of relaxed transitional epithelium that expand and flatten out when stretched.

Loose (Areolar) Connective Tissue

A loose, web-like connective tissue containing thick pink collagen fibers and thin dark elastic fibers running in various directions with scattered cells.

Fibroblasts

The most common cell type in connective tissue, featuring small, dark purple, oval nuclei and responsible for rebuilding tissue structures.

Ground Substance

The clear space between fibers and cells in loose connective tissue.

Loose (Reticular) Connective Tissue

A dark, net-like loose connective tissue made of thin branching reticular fibers that form a supportive skeleton holding lymphocytes.

Lymphocytes

Dark purple immune cells anchored within reticular connective tissue meshwork.

Adipose Tissue

A connective tissue composed of large, tightly packed fat cells (adipocytes) appearing as empty white bubbles with nuclei pushed to the edges.

Adipocytes

Fat-storing cells that provide long-term energy storage, thermal insulation, and shock absorption around organs.

Dense Regular Connective Tissue

Connective tissue made of wavy, thick collagen fibers tightly packed in parallel running in ONE direction to resist strong pulling forces.

Dense Irregular Connective Tissue

Connective tissue made of thick collagen fiber bundles arranged in MULTIPLE directions, allowing it to withstand pulling and stretching from any angle.

Elastic Connective Tissue

Dense tissue rich in thin, dark, squiggly elastic fibers running in wavy patterns to provide passive stretch and recoil.

Hyaline Cartilage

The most common cartilage, identified by its smooth, glassy extracellular matrix and chondrocytes located in lacunae in pairs or small clusters.

Chondrocytes

Mature cartilage cells residing inside small matrix cavities called lacunae.

Lacunae

Small circular cavities or spaces within the matrix of cartilage and bone that house cells.

Elastic Cartilage

A flexible cartilage containing a dense, busy network of dark elastic fibers packed around chondrocytes in lacunae.

Fibrocartilage

The strongest cartilage type, featuring rows of chondrocytes in lacunae separated by dense, wavy bundles of Type I collagen fibers.

Compact Bone

Hard, dense bone tissue organized into repeating circular units called osteons.

Osteon

The circular structural unit of compact bone, containing concentric lamellae surrounding a central Haversian canal.

Central (Haversian) Canal

A dark central opening in an osteon that houses blood vessels and nerves.

Concentric Lamellae

Concentric rings of hard, mineralized bone matrix surrounding the central canal of an osteon.

Osteocytes

Mature bone cells located inside lacunae between lamellae.

Canaliculi

Tiny cracks or channel networks radiating from lacunae that allow nutrients, gases, and wastes to pass between osteocytes and blood vessels.

Spongy Bone

Porous, lightweight bone tissue composed of an irregular network of thin bone branches called trabeculae with spaces filled with red bone marrow.

Trabeculae

Irregular branching beams or thin pieces of bone that form the structural framework of spongy bone.

Blood

A fluid connective tissue consisting of red blood cells, white blood cells, and platelets floating in a liquid matrix called plasma.

Erythrocytes

Pale pink, round red blood cells lacking a nucleus that transport oxygen.

Leukocytes

White blood cells with irregular purple nuclei that function in immune defense against pathogens.

Platelets

Tiny cell fragments in blood that initiate clotting at injury sites.

Plasma

The clear liquid matrix of blood that carries nutrients, waste products, proteins, and hormones.

Skeletal Muscle

A voluntary, striated muscle tissue made of long, parallel cylindrical fibers containing multiple nuclei pushed to the outer edges.

Striations

Repeating light and dark bands running perpendicular across skeletal and cardiac muscle fibers.

Cardiac Muscle

An involuntary, striated muscle tissue found only in the heart, consisting of short branching fibers with single central nuclei and intercalated discs.

Intercalated Discs

Dark, thick lines located where cardiac muscle cells connect end-to-end to coordinate electrical signals and contraction.

Smooth Muscle

An involuntary, non-striated muscle tissue made of tightly packed spindle-shaped cells with a single elongated nucleus in the center.

Neurons

Large, star-shaped cells in nervous tissue with branching extensions (dendrites and axons) that receive and transmit electrical signals.

Neuroglia

Small, dark, round support cells surrounding neurons that insulate, protect, and maintain the chemical environment for nerve signaling.