Body Tissues and Cells (Tissus du corps et cellules)

Comprehensive vocabulary flashcards covering cell structure and organelles, membrane transport, metabolism, primary tissue types, vascularization, lymphatics, cutaneous immunity, wound healing, and cellular aging.

Cell (Cellule)

The basic structural and functional unit of the human body, composed of three constant elements: a plasma membrane, cytoplasm, and a nucleus.

Mature Red Blood Cell (Globule rouge mature)

A notable exception among human cells that is devoid of a nucleus.

Plasma Membrane (Membrane plasmique)

A selectively permeable lipid bilayer composed of phospholipids embedded with proteins that delimits the cell and controls exchanges with the external environment.

Cytoplasm (Cytoplasme)

The internal liquid medium (cytosol) of the cell where cellular metabolism takes place and organelles are suspended.

Nucleus (Noyau)

The organelle that contains DNA, carries genetic information, and directs cellular activity, but cannot manufacture proteins entirely on its own.

Mitochondria (Mitochondries)

The energy powerhouse organelles of the cell that produce cellular energy in the form of ATP.

Endoplasmic Reticulum (Réticulum endoplasmique)

The organelle responsible for manufacturing proteins and lipids, which are subsequently routed toward the Golgi apparatus.

Golgi Apparatus (Appareil de Golgi)

The organelle that modifies, sorts, and packages proteins prior to their cellular export (such as collagen secreted by fibroblasts).

Lysosomes (Lysosomes)

Organelles that digest cellular waste and worn-out structures, whose efficiency declines with advancing age.

Ribosomes (Ribosomes)

Granular structures located on the endoplasmic reticulum or free in the cytoplasm that assemble proteins from the genetic code carried by mRNA.

Cytoskeleton (Cytosquelette)

An internal network of filaments providing shape to the cell and enabling cellular movement and division.

Messenger RNA / mRNA (ARN messager)

The nucleic acid that transcribes genetic instructions from nuclear DNA and transports them out into the cytoplasm to the ribosomes.

Phospholipid Bilayer (Double couche phospholipidique)

The structural arrangement of the cell membrane, consisting of hydrophilic heads facing exterior and interior fluids and hydrophobic tails facing each other in the center.

Selective Permeability (Perméabilité sélective)

The essential property of the cell membrane that regulates and chooses which substances enter and leave the cell.

Simple Diffusion (Diffusion simple)

The spontaneous, energy-free passage of molecules (such as oxygen and carbon dioxide) from a concentrated zone toward a dilute zone.

Osmosis (Osmose)

The passive diffusion of water across a membrane from a less concentrated solution toward a more concentrated solute solution.

Active Transport (Transport actif)

The movement of substances across a membrane against their concentration gradient, requiring energy consumption in the form of ATP.

Sodium-Potassium Pump (Pompe sodium-potassium)

A membrane transport mechanism that consumes mitochondrial ATP to move ions against their natural concentration gradient.

500 Dalton Rule (Règle des 500 daltons)

An indicative benchmark in cosmetology, rather than an absolute physical law, representing the approximate molecular weight threshold for crossing the skin barrier.

Cellular Metabolism (Métabolisme cellulaire)

The totality of chemical reactions that sustain cellular life, comprising the synthesis of cellular structures and the breakdown of molecules for energy.

Anabolism (Anabolisme)

The energy-consuming metabolic process of constructing complex molecules from simpler ones, such as collagen synthesis by a fibroblast.

Catabolism (Catabolisme)

The energy-releasing metabolic process of breaking down complex molecules, such as the breakdown of glucose to yield ATP.

Mitosis (Mitose)

The somatic cell division process where a parent cell duplicates its DNA and divides into two daughter cells identical to each other and to the parent cell.

Meiosis (Méiose)

Specialized cell division restricted to reproductive cells (gametes), distinct from somatic renewal mechanisms.

Epithelial Tissue (Tissu épithélial)

A covering and lining tissue composed of closely joined cells devoid of its own blood vessels.

Stratified Squamous Keratinized Epithelium (Épithélium stratifié pavimenteux kératinisé)

The histological classification of the epidermis: multilayered for abrasion resistance, flattened at the surface for waterproofing, and loaded with keratin.

Keratin (Kératine)

A tough, fibrous protein that fills surface epidermal cells, nails, and hair, imparting structural resistance.

Avascularity (Avascularité)

The complete absence of intrinsic blood vessels in epithelial tissue, requiring nutrients and oxygen to diffuse across the dermo-epidermal junction from the dermis.

Connective Tissue (Tissu conjonctif)

A supportive and filling tissue characterized by sparse, widely spaced cells embedded in an abundant extracellular matrix, exemplified by the dermis.

Extracellular Matrix (Matrice extracellulaire)

The non-cellular component of connective tissue consisting of structural protein fibers and ground substance.

Ground Substance (Substance fondamentale)

A gel rich in water and hyaluronic acid in which the cells and protein fibers of connective tissue are embedded.

Fibroblast (Fibroblaste)

The principal cell of the dermis that synthesizes collagen, elastin, and hyaluronic acid.

Collagen (Collagène)

A braided, woven structural protein fiber that provides mechanical firmness, strength, and resistance to stretching.

Elastin (Élastine)

A spring-like structural protein fiber that imparts suppleness, elasticity, and the ability of the skin to return to its original shape.

Hyaluronic Acid (Acide hyaluronique)

A water-retaining component of connective tissue ground substance (not a protein fiber) capable of binding volumes of water far exceeding its own weight.

Papillary Dermis (Derme papillaire)

The thin, loose connective tissue layer situated directly beneath the epidermis, rich in capillaries and sensory nerve endings.

Reticular Dermis (Derme réticulaire)

The deeper, thicker, and denser connective tissue layer of the dermis, heavily packed with collagen and elastin fibers to provide mechanical resistance.

Adipose Tissue (Tissu adipeux)

A specialized connective tissue found in the hypodermis, composed of adipocytes that store fat for energy reserve, thermal insulation, and mechanical shock absorption.

Adipocyte (Adipocyte)

A specialized connective tissue cell capable of storing lipid reserves in the form of a large lipid droplet.

Hypodermis (Hypoderme)

The deepest layer of the skin, composed predominantly of adipose tissue that provides insulation, cushioning, and nutritional storage.

Cellulite (Cellulite)

A non-histological, colloquial term describing a dimpled skin surface appearance caused by adipose tissue bulging between vertical connective tissue septa.

Skeletal Striated Muscle (Muscle strié squelettique)

Striated muscle tissue under voluntary conscious control, attached to bones and including facial mimic muscles.

Cutaneous Facial Muscles (Muscles peauciers du visage)

Specialized skeletal striated muscles inserted directly into the skin rather than bone-to-bone, whose contractions generate facial expressions and expression lines.

Cardiac Striated Muscle (Muscle strié cardiaque)

Striated muscle tissue located exclusively in the heart that operates involuntarily.

Smooth Muscle (Muscle lisse)

Non-striated, involuntary muscle tissue found in the walls of blood vessels and hollow visceral organs.

Muscle Tone (Tonus musculaire)

The continuous, slight state of involuntary contraction maintained in resting muscles by constant nerve impulses, which helps preserve facial contours.

Neuron (Neurone)

The functional cell of nervous tissue specialized in information transmission via electrical and chemical signals, consisting of a cell body, dendrites, and an axon.

Synapse (Synapse)

The junctional relay between neurons, or between a neuron and a target cell, where transmission occurs chemically through neurotransmitters.

Neurotransmitters (Neurotransmetteurs)

Chemical messenger molecules released at axon terminals to bridge synaptic gaps and transmit impulses between cells.

Autonomic Nervous System (Système nerveux autonome)

The involuntary branch of the nervous system that regulates background bodily functions such as heart rate, sweating, and vascular caliber.

Cutaneous Sensory Receptors (Récepteurs cutanés)

Specialized dermal nerve endings that detect specific modalities of stimuli, including light touch, firm pressure, pain, heat, and cold.

Artery (Artère)

A blood vessel that transports blood away from the heart toward body tissues (classified strictly by flow direction rather than oxygen level).

Vein (Veine)

A blood vessel that transports blood from peripheral tissues back toward the heart.

Capillary (Capillaire)

A microscopic vessel with a wall only one cell layer thick that connects arteries and veins, serving as the site of nutrient, gas, and metabolic waste exchange.

Pulmonary Artery (Artère pulmonaire)

The anatomical exception to the oxygenation rule: an artery that carries deoxygenated blood away from the heart to the lungs.

Vasodilation (Vasodilatation)

The relaxation of vascular smooth muscle resulting in vessel widening, increased local blood flow, cutaneous redness, and warmth.

Vasoconstriction (Vasoconstriction)

The contraction of vascular smooth muscle resulting in vessel narrowing, reduced local blood flow, and skin pallor.

Lymphatic System (Système lymphatique)

A one-way open vascular network lacking a central pump that drains excess interstitial fluid from tissues back into the venous circulation.

Lymph Nodes (Ganglions lymphatiques)

Encapsulated lymphatic structures that filter lymph and mount immune defenses against nearby pathogens.

Edema (Œdème)

Tissue swelling resulting from the abnormal accumulation of interstitial fluid when fluid leakage from capillaries exceeds the drainage capacity of the lymphatic system.

Manual Lymphatic Drainage (Drainage lymphatique manuel)

A specialized aesthetic massage technique utilizing gentle, rhythmic maneuvers directed toward regional lymph nodes to assist natural lymph progression.

Langerhans Cells (Cellules de Langerhans)

First-line immune surveillance cells situated specifically in the epidermis that capture foreign antigens and migrate to alert the wider immune system.

Keratinocyte (Kératinocyte)

The predominant structural cell of the epidermis that produces keratin, forms the epidermal barrier, and renews itself through continuous differentiation.

Melanocyte (Mélanocyte)

An epidermal cell responsible for producing melanin pigment to provide skin coloration and natural photoprotection.

Cardinal Signs of Inflammation (Signes cardinaux de l'inflammation)

The four classic visible manifestations of acute tissue inflammation: redness (erythema), heat, swelling (edema), and pain.

Hemostasis (Hémostase)

The initial phase of wound healing lasting minutes, characterized by blood coagulation and cessation of bleeding.

Proliferation Phase (Phase de prolifération)

The intermediate phase of wound healing spanning several weeks, characterized by the formation of new connective tissue and new capillaries.

Remodeling Phase (Phase de remodelage)

The prolonged final phase of wound healing lasting months, characterized by the reorganization and maturation of collagen fibers long after the wound appears closed.

Primary Intention Healing (Cicatrisation de première intention)

Rapid wound healing with minimal scarring, occurring in clean injuries with sharp, closely approximated edges.

Secondary Intention Healing (Cicatrisation de seconde intention)

Slower wound healing occurring in wounds with separated edges or tissue loss, requiring extensive tissue reconstruction and carrying a higher risk of visible scarring.

Hypertrophic Scar (Cicatrice hypertrophique)

A thick, raised scar resulting from excessive, poorly organized collagen that remains strictly confined within the boundaries of the original wound.

Keloid Scar (Cicatrice chéloïde)

An abnormal, raised scar formed by excessive collagen production that expands beyond the original injury boundaries and continues growing over time.

Telomeres (Télomères)

Protective structures located at the ends of chromosomes that progressively shorten with each cell division until division ceases.

Oxidative Stress (Stress oxydatif)

Cellular damage caused by an accumulation of unstable free radical molecules that degrade DNA, proteins, and cell membranes over time.