Chapter 3: Cells and Tissues - Vocabulary Flashcards

Vocabulary-style flashcards covering the key terms and concepts from the lecture notes on cells, organelles, transport, cell cycle, tissues, and basic physiology.

Cell

The basic unit of life; carries out all chemical activities needed to sustain life and is the building block of all living things.

Tissue

Group of cells similar in structure and function.

Nucleus

Control center of the cell; contains genetic material (DNA).

Nuclear membrane

Barrier around the nucleus; double phospholipid membrane with nuclear pores for exchange.

Nucleolus

Sites of ribosome production; ribosomes migrate to the cytoplasm through nuclear pores.

Chromatin

DNA-protein material in the nucleus; condenses to form chromosomes during cell division.

Plasma membrane

Barrier for cell contents; composed of a double phospholipid layer with hydrophilic heads and hydrophobic tails; contains proteins, cholesterol, and glycoproteins.

Cytoplasm

Material outside the nucleus and inside the plasma membrane; includes cytosol, organelles, and inclusions.

Cytosol

Fluid that suspends organelles and elements within the cytoplasm.

Ribosome

Sites of protein synthesis; made of protein and RNA; free or attached to rough ER.

Rough endoplasmic reticulum (RER)

Ribosome-studded ER; site where membrane and secretory proteins are synthesized.

Smooth endoplasmic reticulum (SER)

ER lacking ribosomes; functions in lipid/cholesterol synthesis, fat metabolism, and detoxification.

Golgi apparatus

Modifies and packages proteins; produces secretory vesicles and membrane components.

Lysosome

Contain enzymes that digest nonusable materials within the cell.

Peroxisome

Membranous sacs with oxidase enzymes; detoxify harmful substances and break down free radicals.

Mitochondrion

The cell’s powerhouses; produce ATP through cellular respiration.

Cytoskeleton

Internal framework of the cell made of microfilaments, intermediate filaments, and microtubules.

Microfilaments

Smallest cytoskeletal elements involved in cell movement and shape.

Intermediate filaments

Cytoskeletal components providing mechanical support.

Microtubules

Hollow tubes that determine cell shape and enable organelle movement.

Centrioles

Rod-shaped microtubule structures that direct mitotic spindle formation during cell division.

Cilia

Hair-like projections that move substances across the cell surface.

Flagellum

Long projection that propels the cell.

Microvilli

Finger-like extensions that increase surface area for absorption.

Tight junctions

Junctions that prevent leakage between adjacent cells.

Desmosomes

Strong junctions that anchor cells together to resist tearing.

Gap junctions

Communicating junctions that allow ions and small molecules to pass between cells.

Extracellular fluid

The watery environment outside the cell.

Interstitial fluid

Fluid that surrounds cells in tissues (outside the bloodstream).

Intracellular fluid

Fluid located inside cells; includes nucleoplasm and cytosol.

Diffusion

Movement of solutes from high to low concentration (down a concentration gradient).

Simple diffusion

Unassisted diffusion of lipid-soluble or very small particles through the membrane.

Osmosis

Diffusion of water across a selectively permeable membrane.

Facilitated diffusion

Diffusion that requires a carrier protein to move substances down their concentration gradient.

Filtration

Movement of water and solutes through a membrane due to a hydrostatic pressure gradient.

Active transport

Movement of substances against a concentration gradient; requires energy (ATP).

Solute pumping

Active transport using protein carriers energized by ATP (e.g., Na+/K+ pump).

Bulk transport

Exocytosis and endocytosis; movement of large particles or volumes across the membrane in vesicles.

Exocytosis

Vesicles fuse with the plasma membrane to secrete contents outside the cell.

Endocytosis

Extracellular substances are engulfed by the plasma membrane forming vesicles.

Phagocytosis

Cell eating; ingestion of large particles.

Pinocytosis

Cell drinking; ingestion of fluids and dissolved solutes.

Interphase

The cell’s metabolic period of growth and replication before division.

DNA replication

Duplication of genetic material in preparation for cell division.

Mitosis

Nuclear division producing two identical daughter nuclei.

Prophase

First stage of mitosis; chromosomes condense and centromeres move to poles.

Metaphase

Chromosomes align along the cell’s equator; spindle fibers attach to centromeres.

Anaphase

Sister chromatids separate and move toward opposite poles; cell elongates.

Telophase

Daughter nuclei form; chromatin lengthens; the cell prepares for cytokinesis.

Cytokinesis

Division of the cytoplasm resulting in two separate daughter cells.

DNA

Deoxyribonucleic acid; genetic material that stores the instructions for building proteins.

RNA

Ribonucleic acid; essential for protein synthesis; various forms include mRNA, tRNA, and rRNA.

Transcription

Process of copying a DNA base sequence into a complementary mRNA sequence.

Translation

Process by which the base sequence of mRNA is read to build a polypeptide (protein).

mRNA

Messenger RNA; carries genetic instructions from DNA to the ribosome.

tRNA

Transfer RNA; delivers appropriate amino acids to the ribosome; has an anticodon.

rRNA

Ribosomal RNA; forms the core of ribosome structures and catalyzes protein synthesis.

Codon

Three-nucleotide sequence on mRNA that specifies a particular amino acid.

Anticodon

Three-nucleotide sequence on tRNA complementary to a codon.

Amino acids

Building blocks of proteins; joined by peptide bonds.

Protein synthesis

Process of building proteins from amino acids via transcription and translation.

Gene

DNA segment that provides the blueprint for building a protein.

Protein

A molecule with many functions; acts as enzymes, structural components, and more.

Epithelial tissue

Tissue that covers body surfaces, lines body cavities, and forms glands; functions include protection, absorption, filtration, and secretion.

Epithelium characteristics

Cells fit closely; one free surface; basement membrane; avascular; regenerates easily with nourishment.

Simple epithelium

One cell layer thick; includes squamous, cuboidal, and columnar types.

Stratified epithelium

Two or more cell layers; includes squamous, cuboidal, columnar, and transitional types.

Simple squamous

Single layer of flat cells; lines membranes, lungs, and capillaries.

Simple cuboidal

Single layer of cube-like cells; lines kidney tubules and glands.

Simple columnar

Single layer of tall cells; often with goblet cells; lines digestive tract.

Pseudostratified epithelium

Single layer that looks stratified; often ciliated; lines respiratory tract.

Stratified squamous

Many layers; cells at the free edge are flattened; protective covering in skin, mouth, esophagus.

Stratified cuboidal

Two layers of cuboidal cells; rare; found in ducts of large glands.

Stratified columnar

Surface cells are columnar; rare; found in ducts of large glands.

Transitional epithelium

Shape changes with stretching; lines urinary system organs.

Glandular epithelium

Glandular tissue formed by secreting cells; endocrine (ductless) and exocrine (ducts).

Endocrine gland

Ductless gland; secretes hormones into the blood.

Exocrine gland

Gland that secretes to the epithelial surface via ducts (e.g., sweat, oil glands).

Connective tissue

Found throughout the body; binds, supports, protects; most abundant and distributed tissue.

Extracellular matrix

Non-living material surrounding living cells; composed of ground substance and fibers.

Ground substance

Water-rich medium with adhesion proteins and polysaccharides.

Collagen fibers

Fibers providing tensile strength in connective tissue.

Elastic fibers

Fibers that provide elasticity to tissues.

Reticular fibers

Fine network fibers that support organs.

Bone tissue (osseous tissue)

Bone cells in lacunae; hard matrix of calcium salts; collagen fibers; protects and supports.

Hyaline cartilage

Most common cartilage; rubbery matrix with collagen; fetal skeleton is hyaline.

Elastic cartilage

Cartilage that provides elasticity (e.g., external ear).

Fibrocartilage

Highly compressible cartilage; cushions between vertebrae.

Dense connective tissue

Matrix rich in collagen fibers; fibroblasts; includes tendons and ligaments.

Areolar connective tissue

Widely distributed; soft, pliable tissue; contains all fiber types; soaks up fluid.

Adipose tissue

Fat tissue; adipocytes store lipid; insulates, protects organs, and stores fuel.

Reticular connective tissue

Delicate network of reticular fibers; forms supporting stroma in lymphoid organs.

Blood

Blood cells in a fluid matrix; fibers visible during clotting; transport vehicle for materials.

Muscle tissue

Tissue that produces movement; three types: skeletal, cardiac, smooth.

Skeletal muscle

Voluntary, attached to bones, striated, multiple nuclei per cell.

Cardiac muscle

Heart muscle; pumps blood; involuntary; striated; intercalated disks.

Smooth muscle

Involuntary muscle; surrounds hollow organs; no visible striations; single nucleus.

Nervous tissue

Neurons and supporting cells; conducts impulses; irritability and conductivity.

Tissue repair: Regeneration

Replacement of damaged tissue by the same kind of cells.

Fibrosis

Repair by dense fibrous connective tissue (scar tissue).