Cells and Tissues

Cell

Basic unit of living structure in organisms.

Cell organelles

Membrane-bound functional structures within a cell.

Cell membrane

Lipoprotein layer retaining cell structure.

Lipoprotein

Composed of lipids and proteins.

Pseudopod

Temporary arm-like projection for cell movement.

Nuclear membrane

Porous membrane regulating nuclear molecule passage.

Nucleoplasm

Substance within the nucleus containing chromatin.

Nucleolus

RNA mass forming ribosomal RNA for protein synthesis.

Cytoplasm

Substance excluding the nucleus containing organelles.

Rough endoplasmic reticulum

Flattened ER with ribosomes for protein synthesis.

Smooth endoplasmic reticulum

ER synthesizing lipids and storing calcium ions.

Ribosomes

Sites of protein synthesis from amino acids.

Golgi complex

Packages secretory products for export or use.

Mitochondrion

Energy-producing structure through oxygen and digestion.

Vacuoles

Transport vehicles merging with other structures.

Lysosomes

Enzyme-filled structures digesting microorganisms and nutrients.

Centriole

Microtubule bundle aiding in cell division.

Microtubules

Cytoskeleton components providing structural support.

Cytoskeleton

Network of filaments giving cells shape and support.

Microfilaments

Actin filaments for membrane alteration and movement.

Endocytosis

Process of bringing substances into the cell.

Exocytosis

Process of exporting substances from the cell.

Mitosis

Cell duplication and division process.

Interphase

Longest phase of the cell reproductive cycle.

Chromatids

Paired sub-units of chromosomes during cell division.

Centrioles

Paired structures that divide in the centrosome.

Prophase

Chromatin condenses into visible chromosomes.

Centromere

Region where two chromatids are joined.

Metaphase

Chromatids align at the cell's equatorial plane.

Anaphase

Chromatids move to opposite poles of the cell.

Daughter chromosomes

Separated chromatids that reach cell poles.

Telophase

Formation of two daughter cells from one parent.

Epithelial tissue

Covers surfaces, cavities, and forms glands.

Basement membrane

Connects epithelium to underlying connective tissue.

Simple epithelia

Single layer of cells for filtration and absorption.

Simple squamous epithelia

Thin cells lining blood vessels and cavities.

Simple cuboidal epithelia

Secretory cells in glands and kidney tubules.

Simple columnar epithelia

Lines gastrointestinal tract for secretion and absorption.

Microvilli

Finger-like projections on epithelial cell surfaces.

Myoepithelial cells

Contractile cells aiding secretion in glands.

Cell junctions

Structures connecting adjacent epithelial cells.

Pseudostratified columnar epithelium

Single layer of cells appearing stratified.

Cilia

Move surface material with undulating strokes.

Stratified epithelial tissue

Tissue with more than one cell layer.

Squamous cell

Flat cells, may be keratinized or not.

Transitional stratified epithelia

Cells stretch or contract with urine volume changes.

Glandular epithelia

Produce and secrete various materials like hormones.

Exocrine glands

Secrete through ducts to free surfaces.

Endocrine glands

Secrete hormones directly into the bloodstream.

Connective tissue proper

Variable cells and fibers in a viscous matrix.

Loose areolar connective tissue

Irregular fiber arrangement with a viscous fluid matrix.

Fibroblast

Cells that secrete fibers in connective tissue.

Collagen fibers

Main fibrous support composed of elastin protein.

Reticular fibers

Support small cell groups in blood and lymph tissues.

Mobile macrophages

Engulf debris and microorganisms in tissues.

Adipose tissue

Fat cells aggregating for energy storage and insulation.

Plasma cells

Secrete antibodies in response to infections.

Mast cells

Involved in inflammatory and allergic responses.

Superficial fascia

Loose connective tissue in mucous and serous membranes.

Dense regular connective tissue

Parallel fibers forming strong ligaments and tendons.

Dense irregular connective tissue

Interwoven fibers forming capsules and dermis.

Matrix

Ground substance where connective tissue cells function.

Cartilage

Flexible connective tissue with chondrocytes in lacunae.

Chondrocytes

Cells maintaining and producing cartilage matrix.

Extracellular Matrix (ECM)

Network providing structural and biochemical support.

Hyaline Cartilage

Most common cartilage, smooth and strong.

Elastic Cartilage

Contains elastic fibers, supports flexible structures.

Fibrous Cartilage

Dense fibers provide strength and flexibility.

Avascular Cartilage

Lacks blood vessels, relies on diffusion for nutrients.

Perichondrium

Dense tissue surrounding cartilage, aiding nutrition.

Bone

Mineralized matrix providing structural support and protection.

Compact Bone

Dense outer layer, weight-bearing and impact-resistant.

Cancellous Bone

Spongy bone, found at ends of long bones.

Osteons

Structural units of compact bone with Haversian canals.

Haversian Canal

Central canal containing blood vessels in bone.

Volkmann's Canals

Connect Haversian canals, allowing blood flow.

Osteocytes

Mature bone cells residing in lacunae.

Osteoblasts

Bone-forming cells located in periosteum.

Osteoclasts

Multinucleated cells that resorb bone matrix.

Trabeculae

Irregular beams of bone in spongy bone.

Skeletal Muscle

Striated, multinucleated muscle for voluntary movement.

Myofibrils

Bundles of filaments responsible for muscle contraction.

Sarcolemma

Cell membrane surrounding muscle fibers.

Innervation

Nerve supply required for muscle contraction.

Muscle Belly

Contractile portion of a muscle between attachments.

Skeletal Muscle Contraction

Rapid, brief shortenings generating considerable force.

Denervation

Lack of nerve supply causing muscle atrophy.

Muscle Tone

Involuntary maintenance of skeletal muscle contraction.

Myoblasts

Cells that regenerate skeletal muscle after injury.

Skeletal Muscle Hypertrophy

Growth of muscle size from training/exercise.

Cardiac Muscle

Branched, striated cells forming heart muscle.

Intercalated Discs

Junctional complexes connecting cardiac muscle cells.

Rhythmic Contractions

Strong, regulated contractions of cardiac muscle.

Autonomic Nervous System

Mediates cardiac muscle contraction rates.

Smooth Muscle Cells

Long, nonstriated cells in visceral organs.

Plasmalemma

Cell membrane surrounding smooth muscle cells.

Myofilaments

Thick and thin filaments in muscle cells.

Sarcoplasmic Reticulum (SR)

Regulates calcium ion distribution in myofibrils.

Sarcomere

Contractile unit composed of myofilaments.

Z Line

Separates adjacent sarcomeres in myofibrils.