Cell Structure, Function, and Tissue Types

Vocabulary flashcards covering cell morphology, membrane structure, organelles, primary germ layers, and histology.

Squamous

Flat, thin cell shape.

Polygonal

Cell shape having many sides.

Discoidal

Disc-shaped cell shape.

Cuboidal

Cube-shaped cell shape.

Stellate

Star-shaped cell shape.

Fusiform

Spindle-shaped cell shape.

Columnar

Tall, column-shaped cell shape.

Spheroidal

Round, spherical-shaped cell shape.

Fibrous

Long, thin cell shape.

Phospholipid Bilayer

Plasma membrane arrangement with hydrophilic heads facing the watery environment inside and outside, and hydrophobic tails facing away from water.

Selective Permeability

Property of the plasma membrane that controls the passage and movement of materials into and out of the cell.

Cell-Adhesion Molecules (CAMs)

Membrane proteins responsible for intracellular joining.

Second Messengers

Intracellular signaling molecules activated after a first messenger binds a surface receptor and relays a signal via a G protein and effector enzyme.

Microvilli

Membrane extensions $1\text{ to }2\text{ }\frac{1}{1000}\text{ mm}$ ($1\text{ to }2\text{ }\frac{1}{1000}\text{ mm}$ long, or $1\text{ to }2\text{ }\frac{1}{1000}\text{ mm}$) forming a brush border to increase surface area for absorption.

Motile Cilia

Hair-like processes $7\text{ to }10\text{ }\frac{1}{1000}\text{ mm}$ ($7\text{ to }10\text{ }\frac{1}{1000}\text{ mm}$) long found in the respiratory tract and uterine tubes that beat in waves to propel materials.

Nuclear Envelope

Double membrane perforated by nuclear pores that surrounds the cell nucleus.

Nucleoplasm

Material enclosed within the nucleus containing chromatin and nucleoli.

Ribosomes

Small granules of RNA and protein consisting of large and small subunits that synthesize proteins.

Rough Endoplasmic Reticulum

System of membrane channels covered with ribosomes functioning in protein synthesis and cell membrane production.

Smooth Endoplasmic Reticulum

System of tubular and branched membrane channels functioning in lipid synthesis, detoxification, and calcium storage.

Golgi Complex

Organelle that synthesizes carbohydrates and packages proteins from the rough ER into membrane-bound vesicles.

Mitochondria

Double membrane-enclosed organelles specialized for synthesizing ATP.

Cristae

Folds of the inner mitochondrial membrane containing enzymes that synthesize ATP.

Ectoderm

Outer primary germ layer of embryonic tissue that develops into the epidermis and nervous system.

Mesoderm

Middle primary germ layer of embryonic tissue consisting of branching cells in a matrix, giving rise to cardiac muscle, bone, and blood.

Endoderm

Inner primary germ layer of embryonic tissue that gives rise to mucous membranes and digestive glands.

Basement Membrane

Structure that anchors epithelial tissue to the underlying connective tissue.

Simple Epithelia

Epithelial tissue composed of a single layer of cells with all cells touching the basement membrane.

Pseudostratified Epithelia

Epithelial tissue where all cells touch the basement membrane, but not all cells reach the apical surface.

Stratified Epithelia

Epithelial tissue consisting of $2\text{ to }20$ layers of cells.

Urothelium (Transitional Epithelium)

Epithelium unique to the urinary tract that allows tissue to stretch and relax.

Collagenous Fibers

Tough, flexible fibers made of collagen that resist stretching, found in tendons, ligaments, and dermis.

Reticular Fibers

Thin collagen fibers coated with glycoprotein forming a mesh-like framework in organs such as the spleen and lymph nodes.

Elastic Fibers

Coiled fibers made of elastin coated with glycoprotein that allow stretching and recoil in skin, lungs, and arteries.

Areolar Tissue

Loose connective tissue containing collagen and elastin fibers that binds epithelia to deeper tissues.

Dense Regular Connective Tissue

Connective tissue with densely packed parallel collagen fibers that connects bone to bone and muscle to bone.

Dense Irregular Connective Tissue

Connective tissue with densely packed collagen fibers in random orientation that withstands stress in unpredictable directions.

Adipose Tissue

Tissue dominated by adipocytes specialized for energy storage, insulation, and cushioning.

Hyaline Cartilage

Cartilage tissue with a clear, glassy matrix that eases joint movement and holds airways open.

Fibrocartilage

Cartilage tissue containing large bundles of collagen fibers that resists compression and absorbs shock.

Elastic Cartilage

Cartilage tissue containing elastic fibers providing flexible, elastic support.

Osteocytes

Bone cells residing in lacunae located between concentric calcified matrix layers called lamellae.

Canaliculi

Tiny channels connecting lacunae in bone tissue.

Neurons

Nervous tissue cells specialized for transmitting signals rapidly to other cells.

Neuroglia

Glial cells in nervous tissue that protect and assist neurons.

Skeletal Muscle Tissue

Muscular tissue composed of long, thin, multinucleated cells displaying striations.

Cardiac Muscle Tissue

Striated, involuntary muscle tissue limited to the heart composed of short, branched cells connected by intercalated discs.

Smooth Muscle Tissue

Non-striated, involuntary muscle tissue composed of fusiform cells located in visceral organs and blood vessels.