Anatomy and Physiology: Chemical and Cellular Foundations

Comprehensive vocabulary flashcards covering anatomical terminology, chemical foundations of life, metabolic energetics, and cellular organelles and physiology.

Anatomy

The study of the physical form and structure of the body.

Physiology

The study of the physical and chemical functions of living systems.

Gross Anatomy

The branch of anatomy dealing with structural features visible to the naked eye.

Systemic Anatomy

The anatomical approach focused on the structure of specific organ systems.

Pathophysiology

The study of how diseases or pathogens alter normal physiological processes in a healthy system.

Interstitial Fluid

The extracellular fluid that fills the microscopic spaces between tissue cells.

Homeostasis

A condition of equilibrium in the body's internal environment maintained by regulatory processes.

Receptor (Feedback System)

A body structure that monitors changes in a controlled condition and sends input signals to a control center.

Control Center

A component of a feedback system that sets the physiological operating range, evaluates receptor input, and generates output commands.

Effector

A body structure that receives output commands from the control center and produces an adjusted response.

Negative Feedback System

A regulatory feedback loop that operates to reverse or counteract a deviation from a controlled physiological condition.

Positive Feedback System

A regulatory feedback loop that operates to reinforce or amplify a change occurring in a controlled condition.

Anatomical Position

A standard reference posture in which the subject stands erect facing forward, head level, feet flat on the floor, and arms at the sides with palms facing forward (ventral).

Prone Position

The anatomical orientation describing a body lying in a face-down position.

Supine Position

The anatomical orientation describing a body lying in a face-up position.

Sagittal Plane

A vertical plane that divides the body or an organ into right and left sides.

Frontal (Coronal) Plane

A vertical plane that divides the body or an organ into anterior (front) and posterior (back) portions.

Transverse Plane

A horizontal cross-sectional plane that divides the body or an organ into superior (upper) and inferior (lower) portions.

Mediastinum

A broad anatomical partition between the pleural cavities extending from the sternum to the vertebral column, containing all thoracic organs except the lungs.

Serous Membrane

A double-layered, slippery membrane lining closed body cavities and covering the organs residing within them.

Parietal Layer

The superficial sheet of a serous membrane that lines the interior cavity walls.

Visceral Layer

The deep sheet of a serous membrane that adheres directly to the viscera inside a body cavity.

Isotopes

Atoms of the same element that have the same number of protons but differ in atomic mass due to varying numbers of neutrons.

Ion

An atom or molecule that carries an electrical charge due to an unequal count of protons and electrons.

Cation

A positively charged ion formed when a neutral atom loses one or more electrons.

Anion

A negatively charged ion formed when a neutral atom gains one or more electrons.

Molecule

A chemical particle composed of two or more atoms of the same or different elements held together by chemical bonds.

Compound

A chemical substance composed of molecules containing two or more distinct chemical elements.

Valence Shell

The outermost electron shell of an atom containing the electrons available to participate in chemical bonding.

Octet Rule

The chemical principle stating that atoms interact via bond formation to achieve a stable arrangement of eight electrons in their valence shell.

Ionic Bond

A chemical bond formed by the electrostatic attraction between oppositely charged ions following the complete transfer of electrons.

Electrolyte

An ionic compound that dissociates into positive and negative ions when dissolved in an aqueous solution.

Covalent Bond

A strong chemical bond formed when two atoms share one or more pairs of valence electrons.

Polar Covalent Bond

A covalent bond in which shared electrons are drawn closer to the more electronegative atom, resulting in unequal charge distribution.

Non-polar Covalent Bond

A covalent bond in which bonding electrons are shared equally between atoms with identical or similar electronegativities.

Hydrogen Bond

A weak electrostatic attraction between an electropositive hydrogen atom of one polar molecule and an electronegative atom of another molecule.

Metabolism

The sum of all biochemical reactions occurring within an organism.

Exergonic Reaction

A chemical reaction where the bonds broken release more energy than is required to form product bonds, releasing net energy typically as heat.

Endergonic Reaction

A chemical reaction that consumes net energy, requiring an input (usually from $ATP$) to form new chemical bonds.

Activation Energy

The minimum collision energy required to destabilize existing chemical bonds and initiate a chemical reaction.

Anabolism

Metabolic synthesis pathways that build larger, complex biomolecules from smaller precursors; generally endergonic.

Catabolism

Metabolic decomposition pathways that break down complex molecules into simpler subunits; generally exergonic.

Exchange Reaction

A chemical reaction (displacement reaction) in which both bond cleavage and bond formation occur ($AB + C \rightarrow AC + B$).

Hydrolysis Reaction

A catabolic decomposition reaction in which water acts as a reactant to break complex covalent bonds.

Dehydration Synthesis

An anabolic condensation reaction in which two smaller molecules join covalently with the simultaneous elimination of a water molecule.

Heat Capacity (Water)

The ability of water to absorb or release substantial quantities of thermal energy with minimal change in its own temperature due to extensive hydrogen bonding.

Heat of Vaporization

The quantity of heat energy required to convert a liquid into a gas.

Monosaccharide

A simple monomeric sugar containing three to seven carbon atoms conforming to the general formula $(CH_2O)_n$.

Glycogen

The principal storage polysaccharide in the human body, composed of branched chains of glucose and stored primarily in the liver and skeletal muscles.

Triglyceride

A neutral lipid formed from a single three-carbon glycerol molecule esterified to three fatty acid chains.

Phospholipid

An amphipathic structural membrane lipid consisting of a glycerol backbone, a charged polar phosphate head group, and two nonpolar fatty acid tails.

Steroid

A class of lipids characterized by a core carbon skeleton composed of four fused interlocking hydrocarbon rings.

Eicosanoids

A group of lipid signaling molecules derived from the 20-carbon fatty acid arachidonic acid, including prostaglandins and leukotrienes.

Peptide Bond

A covalent bond formed via dehydration synthesis between the amino group ($-NH_3^+$) of one amino acid and the carboxyl group ($-COO^-$) of an adjacent amino acid.

Denaturation

The irreversible loss of a protein's specific three-dimensional conformation and biological function induced by extremes of heat, pH, or salt concentration.

Holoenzyme

A complete, catalytically active enzyme composed of an apoenzyme (protein portion) bound to a non-protein cofactor or coenzyme.

Nucleotide

A monomeric subunit of nucleic acids composed of a five-carbon sugar (ribose or deoxyribose), one or more phosphate groups, and a nitrogenous base.

Adenosine Triphosphate (ATP)

The primary cellular energy currency, composed of an adenine base, ribose sugar, and three phosphate groups joined by high-energy bonds.

Cytology

The branch of cell biology dedicated to the study of cellular structure.

Fluid Mosaic Model

A structural model describing the plasma membrane as a dynamic lipid bilayer containing freely drifting phospholipids, glycolipids, cholesterol, and proteins.

Diffusion

The passive net dispersion of solute particles from an area of higher concentration to one of lower concentration driven by thermal kinetic energy.

Facilitated Diffusion

A passive transmembrane transport mechanism wherein solutes move down their concentration gradient assisted by specific carrier or channel proteins.

Transport Maximum

The saturation threshold that limits the rate of carrier-mediated facilitated diffusion when all transport protein binding sites are fully occupied.

Osmosis

The passive net movement of solvent (water) molecules through a selectively permeable membrane toward the region with a higher solute concentration.

Tonicity

The capability of an extracellular solution to alter cell shape and volume by driving osmotic water exchange across the plasma membrane.

Primary Active Transport

The movement of solutes against an electrochemical gradient powered directly by the hydrolysis of $ATP$ (exemplified by the $\text{Na}^+/\text{K}^+$ ATPase pump).

Secondary Active Transport

The transport of a solute against its gradient powered by potential energy stored in an established ionic concentration gradient (such as $\text{Na}^+$ or $H^+$).

Endocytosis

A vesicular transport process by which large molecules or extracellular fluids are internalized through plasma membrane invagination and vesicle formation.

Exocytosis

A vesicular export process in which membrane-bound secretory vesicles fuse with the plasma membrane to discharge their contents into the extracellular fluid.

Microfilaments

Thin cytoskeletal elements composed predominantly of actin that generate mechanical support and drive cellular movement.

Intermediate Filaments

Tough protein filaments of the cytoskeleton that withstand mechanical stress and stabilize the positions of organelles like the nucleus.

Microtubules

Hollow cylindrical cytoskeletal polymers composed of tubulin dimers that guide organelle transport, define cell shape, and segregate chromosomes.

Peroxisomes

Membrane-bound organelles containing catalases and oxidases that neutralize toxic free radicals and decompose hydrogen peroxide into water and oxygen.

Mitochondria

Double-membraned cellular organelles containing the metabolic machinery for the Krebs cycle and oxidative phosphorylation to produce $ATP$.

Homologous Chromosomes

The matched maternal and paternal pairs of chromosomes within a diploid cell that possess identical gene loci.

Diploid Cell

A somatic cell that contains a complete homologous complement of chromosomes ($2N = 46$ in humans).

Haploid Cell

A gametic cell that contains only a single set of unpaired chromosomes ($N = 23$ in humans).

Mitosis

The orderly division of a cell's somatic nuclear genome into two identical sets distributed into separate daughter nuclei.

Cytokinesis

The physical partitioning of the cytoplasm and associated organelles following karyokinesis to yield two individual daughter cells.

Transcription

The enzyme-mediated biological process in which base sequences from a $DNA$ template strand are copied into a complementary $mRNA$ transcript.

Translation

The ribosomal process wherein the triplet codon sequence of an $mRNA$ molecule is decoded to synthesize a specific chain of amino acids.