Human Body Anatomy, Physiology, and Cellular Biology Flashcards

A set of vocabulary flashcards covering key definitions, principles, and diagrams from Chapters 1-3 on anatomy, physiology, chemical organization, and cell biology.

Anatomy

The scientific study of body structures and their physical relationships to one another.

Physiology

The scientific study of the functions of body parts, focusing heavily on cellular and molecular events.

Principle of Complementarity of Structure and Function

States that function is entirely dependent on structure; a body part's form dictates what it can do.

Levels of Structural Organization

The hierarchy of structural complexity in the human body, organized across six distinct levels: Chemical, Cellular, Tissue, Organ, Organ System, and Organismal.

Maintaining Boundaries

A necessary life function that preserves separate internal and external environments, or isolates distinct internal chemical environments.

Responsiveness (Irritability)

The necessary life function of detecting changes (stimuli) in the internal or external environment and mounting an appropriate response.

Metabolism

The sum total of all internal chemical reactions that occur within the human body.

Excretion

The continuous process of filtering and removing metabolic waste products from the human body.

Homeostasis

The dynamic ability of the body to maintain a relatively stable internal environment despite constant external changes.

Receptor

A homeostatic control sensor that monitors environmental changes and sends input data to the control center.

Control Center

A homeostatic component that determines the optimal set point for a variable, analyzes incoming input, and coordinates the proper response.

Effector

A homeostatic structure that executes the physical response commanded by the control center.

Negative Feedback Mechanisms

Homeostatic controls that drive a variable in a direction opposite to the initial change to prevent sudden, severe physiological shifts.

Positive Feedback Mechanisms

Homeostatic controls that cause a variable to deviate further from its original set point in the same direction, managing self-perpetuating, rare events.

Matter

Anything that has mass and takes up physical space, existing as a solid, liquid, or gas.

Energy

The capacity to do physical work or put matter into motion, existing as active kinetic energy or stored potential energy.

Major Elements of the Human Body

The four elements comprising roughly $96\,\%$ of human body mass: Oxygen (O), Carbon (C), Hydrogen (H), and Nitrogen (N).

Octet Rule

The rule governing chemical bonding which states that atoms gain, lose, or share electrons to fill their outermost valence shell with $8$ electrons.

Ionic Bonds

Chemical bonds formed by the complete transfer of valence electrons from one atom to another, creating charged particles called ions.

Covalent Bonds

Chemical bonds formed by the sharing of two or more valence shell electrons, which can be nonpolar (equal sharing) or polar (unequal sharing).

Hydrogen Bonds

Weak attractive forces between an electropositive hydrogen atom of one molecule and an electronegative atom (like O or N) of another molecule.

Relative Bond Strength Rank

A hierarchy ranking triple bonds as stronger than double and single bonds, and ionic bonds as stronger than covalent and hydrogen bonds.

Mixture Types

The three classes of physical intermixtures: solutions (homogeneous), colloids (heterogeneous with non-settling solutes), and suspensions (heterogeneous with settling solutes).

Solution

A transparent, homogeneous mixture in which solute particles do not settle out, such as atmospheric air or seawater.

Colloid

A translucent or milky, heterogeneous mixture containing large solutes that do not settle and undergo sol-gel shifts, such as cytosol.

Suspension

A heterogeneous mixture containing large, visible solutes that actively settle out over time, such as whole blood.

Inorganic Compounds

Molecules that do not contain carbon (with exceptions including $\text{CO}_2$ and $\text{CO}$), such as water, salts, acids, and bases.

Organic Compounds

Large, covalently bonded molecules containing carbon that are unique to living systems, including carbohydrates, lipids, proteins, and nucleic acids.

Buffers

Chemical solutions that resist sudden shifts in pH by converting strong acids or bases into weak ones.

Adenosine Triphosphate (ATP)

An adenine-containing RNA nucleotide with two extra phosphate groups that drives cellular work via phosphorylation.

Fluid Mosaic Model

A structural description of the plasma membrane as a dynamic, constantly shifting bimolecular layer of lipids embedded with mobile proteins.

Plasma Membrane Lipids

Membrane components consisting of $75\,\%$ phospholipids, $5\,\%$ glycolipids, and $20\,\%$ cholesterol.

Integral Proteins

Membrane proteins firmly inserted into the phospholipid bilayer, most of which are transmembrane.

Peripheral Proteins

Membrane proteins loosely attached to integral proteins on the surface of the lipid bilayer.

Active vs. Passive Transport

Passive processes move substances down concentration gradients without ATP, whereas active processes move substances against gradients requiring ATP.

Simple Diffusion

Passive transport process where nonpolar, lipid-soluble substances pass directly through the phospholipid bilayer down their concentration gradient.

Facilitated Diffusion

Passive transport of lipophobic or polar molecules crossing the plasma membrane via specific, regulatable, and saturable transport proteins.

Osmosis

Net diffusion of a solvent (water) through aquaporins or the lipid bilayer, driven by total solute concentration (osmolarity).

Tonicity

The ability of a surrounding solution to alter a cell's internal water volume, categorized into isotonic, hypertonic, and hypotonic.

Primary Active Transport

Active transport mechanism where the hydrolysis of ATP directly alters the shape of a transport pump protein, such as the Sodium-Potassium Pump ($\text{Na}^+\text{-K}^+$ ATPase).

Secondary Active Transport

Transport mechanism that uses potential energy stored in ionic gradients created by primary active transport to indirectly drive the transport of other solutes.

Vesicular Transport

An ATP-dependent transport mechanism that uses membranous sacs to move large particles and fluids via endocytosis and exocytosis.

Organelles

The specialized metabolic machinery of the cell located within the cytoplasm, suspended alongside cytosol and inclusions.

Mitochondria

Membranous organelles that act as the powerhouse of the cell, generating the majority of ATP via aerobic cellular respiration and containing unique DNA and RNA.

Rough Endoplasmic Reticulum (Rough ER)

Ribosome-studded membranous organelle that synthesizes secreted proteins, integral membrane proteins, and phospholipids.

Smooth Endoplasmic Reticulum (Smooth ER)

Network of tubules that metabolizes lipids/cholesterol, synthesizes steroid hormones, and stores/releases calcium.

Golgi Apparatus

Flattened membranous sacs that modify, concentrate, and package lipids and proteins arriving from the rough ER.

Lysosomes

Spherical membranous bags containing acid hydrolases to digest bacteria, toxins, and worn-out organelles.

Semiconservative Replication

DNA synthesis process during S phase where helicase unwinds DNA and DNA polymerase builds a leading strand continuously and a lagging strand discontinuously via segments joined by DNA ligase.

Mitosis

The nuclear division phase of cell division comprising four sequential stages: Prophase, Metaphase, Anaphase, and Telophase.

Transcription

The nuclear process of transferring DNA gene sequences into a complementary mRNA format using RNA polymerase.

Translation

The cytoplasmic process where mRNA codons are bound by matching tRNA anticodons to assemble an amino acid sequence at the ribosome.

Protein Synthesis

The multi-step process consisting of nuclear transcription of DNA into mRNA and cytoplasmic translation of mRNA into a polypeptide chain at the ribosome.