Cellular Physiology & Pathophysiology

A comprehensive set of vocabulary flashcards covering cell structure, function, metabolism, transport, signaling, adaptations, injury, and aging as presented in the Cellular Physiology lecture.

Cell Membrane (Plasma Membrane)

Outer boundary of the cell that protects, activates, transports, and allows cell-to-cell interaction.

Cytoplasm

Aqueous solution between nucleus and plasma membrane that houses organelles.

Nucleus

Central organelle that controls genetic information, DNA replication, and ribosome synthesis.

Ribosome

Nucleoprotein particle, free or bound, that serves as the site of protein synthesis.

Endoplasmic Reticulum (ER)

Network of tubular channels specializing in synthesis and transport of proteins and lipids.

Rough Endoplasmic Reticulum

ER studded with ribosomes; synthesizes and transports proteins.

Smooth Endoplasmic Reticulum

ER lacking ribosomes; synthesizes lipids and steroid hormones.

Golgi Complex

Flattened membranes that process, package, and direct proteins and lipids in secretory vesicles.

Lysosome

Saclike organelle containing digestive enzymes for intracellular digestion and autophagy.

Peroxisome

Membrane-bound organelle with oxidative enzymes that generate and degrade hydrogen peroxide.

Mitochondria

Double-membrane organelle that produces ATP via oxidative phosphorylation; cell’s power plant.

Cytoskeleton

Network of microtubules and filaments that maintains cell shape and internal organization.

Microtubules

Rigid cytoskeletal components that move organelles and aid nerve impulse transport.

Microfilaments

Fine filaments involved in cell locomotion, growth regulation, and shape maintenance.

Movement (Chief Cellular Function)

Ability of muscle cells to contract and produce motion.

Conductivity

Function of nerve cells to transmit electrical impulses.

Metabolic Absorption

Uptake of nutrients and fluids by all cells, notably intestine and kidney cells.

Secretion

Release of substances such as mucus by specialized cells.

Respiration (Cellular)

Process by which cells use oxygen to produce energy.

Reproduction (Cellular)

Formation of new cells through division of most cell types.

Communication (Cellular)

Cell-to-cell signaling needed for tissue function.

Excretion

Removal of metabolic waste products from the cell.

Prokaryote

Simple single-celled organism without nucleus or membrane-bound organelles.

Eukaryote

Cell with well-defined nucleus, organelles, and histones; single- or multicellular.

Passive Transport

Energy-free movement from high to low concentration across membranes.

Active Transport

Energy-requiring movement, often against a concentration gradient.

Mediated Transport

Membrane crossing that uses a specific channel or carrier; may be active or passive.

Diffusion

Passive movement of solute from high to low concentration.

Osmosis

Passive movement of water across a semipermeable membrane toward higher solute concentration.

Endocytosis (Phagocytosis)

Cellular ingestion of large particles or organisms by engulfment (cell ‘eating’).

Pinocytosis

Endocytosis of fluids and dissolved substances (cell ‘drinking’).

Exocytosis

Process of secreting substances from the cell by vesicle fusion with the membrane.

Depolarization

Opening of sodium channels causing membrane potential to become less negative.

Repolarization

Restoration of negative membrane potential via potassium efflux after depolarization.

Hyperpolarization

Transient increase in membrane negativity, making the cell less excitable.

Sodium-Potassium Pump

Active transporter exchanging 3 Na⁺ out for 2 K⁺ in, maintaining membrane potential.

Adenosine Triphosphate (ATP)

Universal energy currency that stores and provides cellular energy.

Anaerobic Metabolism

ATP production without oxygen via glycolysis; yields 2 ATP.

Aerobic Metabolism

Oxygen-dependent ATP production through citric acid cycle and oxidative phosphorylation; yields 32 ATP.

Growth Factors (Cytokines)

Peptides that signal cell growth, proliferation, and development.

Atrophy

Decrease in cell size leading to reduced organ size.

Hypertrophy

Increase in cell size causing enlargement of the affected organ.

Hyperplasia

Increase in cell number due to accelerated cell division.

Metaplasia

Reversible replacement of one mature cell type by another.

Dysplasia

Abnormal changes in cell size, shape, and organization.

Hypoxic Injury

Cell damage caused by oxygen deprivation leading to ATP depletion and ion pump failure.

Free Radical

Unstable molecule with an unpaired electron that initiates damaging chain reactions.

Apoptosis

Programmed, non-inflammatory cell death characterized by cellular condensation.

Necrosis

Uncontrolled cell death with membrane rupture, swelling, and inflammation.

Protease

Enzyme that breaks down proteins by hydrolyzing peptide bonds.

Proteolytic Cascade

Sequential activation of proteases in processes like apoptosis, coagulation, and complement.

Ligand

Molecule that binds to a specific cellular receptor to trigger signaling.

Channel-Linked Receptor

Membrane receptor that opens or closes an ion channel upon ligand binding.

G Protein–Linked Receptor

Receptor that activates intracellular G proteins to relay signals.

Paracrine Signaling

Local chemical communication affecting nearby cells.

Autocrine Signaling

Cell releases a messenger that acts on itself.

Hormonal Signaling

Endocrine cells release hormones into bloodstream to act on distant targets.

Synaptic Signaling

Neurotransmitter-mediated communication between adjacent neurons across synapses.

Neurohormonal Signaling

Neurons release hormones into blood for distant action.

Telomere Attrition

Progressive shortening of chromosome ends associated with aging.

Cellular Senescence

Permanent loss of cell division potential contributing to aging.