Anatomy, Physiology, and Cellular Biology Flashcards

Vocabulary flashcards covering foundational concepts in human anatomy, physiology, body organization, cellular structure, membrane transport mechanisms, cell replication, and stem cell differentiation.

Anatomy

The study of the structure and shape of the body and its parts, as well as their relationships to one another (derived from Greek words meaning to cut apart).

Physiology

The scientific study of the chemistry and physics of body structures and how they work together to support the functions of life.

Microscopic Anatomy

The study of body structures that require magnification to be seen, including cytology and histology.

Gross Anatomy

The study of large, visible body structures without the use of magnification.

Regional Anatomy

An approach to anatomical study that focuses on all the structures within a specific region of the body, such as the abdomen.

Systemic Anatomy

An approach to anatomical study that looks at the structures that make up a discrete organ system, such as the muscular system.

Flow

The movement of materials from one region to another within the body, which is always driven by a gradient.

Gradient

A difference in a particular variable (such as concentration, electrical charge, or pressure) between two regions.

Concentration Gradient

A difference in solute concentration between two areas that drives the diffusion of individual molecules from higher to lower concentration.

Pressure Gradient

A difference in pressure between two regions that drives the flow of fluids and gases, generated by mechanisms like heart pumping or diaphragm contraction.

Homeostasis

The state of dynamic stability of the body's internal environment, maintained through active regulation of conditions around a set point.

Set Point

The physiological value around which the normal range of a regulated variable fluctuates (e.g., approximately $37^\circ\text{C}$ or $98.6^\circ\text{F}$ for body temperature).

Negative Feedback Loop

The primary mechanism of homeostasis that resists or reduces deviations from a set point using a sensor, control center, and effector.

Positive Feedback Mechanism

A physiological system that intensifies or amplifies a deviation from normal body conditions to achieve a specific outcome before an interruption stops it.

Chemical Level

The simplest level of organization in the body, consisting of atoms and molecules (such as collagen) that combine to form organelles and cells.

Cellular Level

The level of biological organization comprising cells, which are the smallest independent units of life in the human organism.

Tissue Level

A level of organization consisting of groups of similar cells working together to perform a specific function (the four basic types are epithelial, connective, muscle, and nervous).

Organ Level

A level of biological organization formed when two or more different tissue types work together to perform a specific function.

Organ System Level

A group of organs that cooperate to accomplish a common purpose, such as the cardiovascular or urinary system.

Integumentary System

The organ system that creates a barrier protecting the body from pathogens and fluid loss, and functions in sensory reception.

Lymphatic System

The organ system that regulates fluid balance in the body and houses immune cells to defend against pathogens.

Anatomical Position

The standard reference position in which an individual stands erect, feet parallel and shoulder-width apart with toes pointing forward, upper limbs at the sides, and palms facing forward.

Prone

An anatomical position term describing a face-down body orientation.

Supine

An anatomical position term describing a face-up body orientation.

Superior (Cranial)

A directional term meaning towards the head end or upper part of a structure or the body; above.

Inferior (Caudal)

A directional term meaning away from the head end or toward the lower part of a structure or the body; below.

Anterior (Ventral)

A directional term meaning towards or at the front of the body.

Posterior (Dorsal)

A directional term meaning towards or at the back of the body.

Medial

A directional term meaning towards or at the midline of the body.

Lateral

A directional term meaning away from the midline of the body.

Proximal

A directional term meaning closer to the origin of the body part or the point of attachment of a limb to the body trunk.

Distal

A directional term meaning farther from the origin of a body part or the point of attachment of a limb to the body trunk.

Superficial (External)

A directional term meaning towards or at the body surface.

Deep (Internal)

A directional term meaning away from the body surface; more internal.

Parietal

A positional term pertaining to the outer wall of a body cavity.

Visceral

A positional term pertaining to the organs located within a body cavity.

Sagittal Plane

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

Midsagittal (Median) Plane

A specific sagittal plane running directly down the middle of the body, dividing it into equal right and left halves.

Frontal (Coronal) Plane

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

Transverse (Horizontal) Plane

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

Mediastinum

The central portion of the thoracic cavity between the lungs, containing the heart, thymus, esophagus, trachea, and major blood vessels.

Serous Membrane

A double-layered membrane consisting of parietal and visceral layers separated by fluid, lining closed body cavities and covering internal organs.

Fluid Mosaic Model

A structural model describing the plasma membrane as a dynamic, fluid arrangement composed of a mosaic of phospholipids, proteins, and carbohydrates.

Phospholipid Bilayer

The core double-layered barrier of the plasma membrane, composed of amphipathic phospholipid molecules with hydrophilic heads facing outward and hydrophobic tails facing inward.

Amphipathic

Describing a molecule (like a phospholipid) that possesses both hydrophilic ("water-loving") and hydrophobic ("water-fearing") regions.

Integral Proteins

Membrane proteins embedded directly within the lipid bilayer, often spanning the entire membrane as transmembrane proteins.

Peripheral Proteins

Membrane proteins loosely attached to the inner or outer surface of the lipid bilayer rather than embedded within it.

Glycocalyx

A carbohydrate-rich "sugar coat" on the extracellular surface of the plasma membrane formed by glycoproteins and glycolipids, functioning in cell recognition, adhesion, and protection.

Passive Transport

The movement of substances across a cell membrane down their concentration gradient without requiring cellular energy ($\text{ATP}$).

Simple Diffusion

Passive transport where small, nonpolar molecules move directly across the lipid bilayer down their concentration gradient.

Facilitated Diffusion

Passive transport where ions or polar molecules cross the membrane down their concentration gradient with the aid of transmembrane channel or carrier proteins.

Osmosis

The diffusion of water molecules across a semipermeable membrane down its concentration gradient toward an area of higher solute concentration.

Isotonic Solution

A solution in which the solute concentration outside the cell equals the solute concentration inside the cell, resulting in no net water movement or cell volume change.

Hypotonic Solution

A solution with a lower solute concentration than the cytoplasm, causing water to enter the cell and making it swell or burst.

Hypertonic Solution

A solution with a higher solute concentration than the cytoplasm, causing water to move out of the cell and making it shrink or crenate.

Primary Active Transport

An energy-dependent transport process that directly consumes $\text{ATP}$ to pump substances against their concentration gradient (e.g., the sodium-potassium pump).

Secondary Active Transport

An active transport process that utilizes the energy stored in an existing electrochemical gradient (established by primary active transport) to move a second substance against its concentration gradient.

Symporter

A cotransporter protein involved in secondary active transport that moves two different substances in the same direction across the membrane.

Antiporter

A cotransporter protein involved in secondary active transport that moves two different substances in opposite directions across the membrane.

Phagocytosis

A form of endocytosis ("cell eating") in which a cell engulfs large particles, debris, or microorganisms into a membrane-bound phagosome.

Pinocytosis

A non-selective form of endocytosis ("cell drinking") in which a cell takes in small droplets of extracellular fluid and dissolved solutes in small vesicles.

Receptor-Mediated Endocytosis

A highly selective form of endocytosis where specific extracellular ligands bind to cell-surface receptor proteins, triggering invagination and vesicle formation.

Exocytosis

A vesicular transport mechanism in which intracellular materials packaged in vesicles are released into the extracellular fluid upon vesicle fusion with the plasma membrane.

Cytosol

The fluid, jelly-like component of the cytoplasm primarily made of water that surrounds the organelles.

Rough Endoplasmic Reticulum (RER)

A membrane network studded with ribosomes on its cytosolic surface, responsible for synthesizing, folding, and modifying proteins destined for membranes or secretion.

Smooth Endoplasmic Reticulum (SER)

A ribosome-free membrane network involved in lipid and steroid synthesis, detoxification of medications and poisons, and calcium ion storage.

Golgi Apparatus

An organelle consisting of flattened membranous cisternae that sorts, modifies, and packages proteins and lipids received from the RER into vesicles.

Lysosomes

Membrane-bound organelles originating from the Golgi apparatus that contain powerful digestive enzymes to break down waste, foreign materials, and unneeded cellular components.

Peroxisomes

Membrane-bound organelles containing enzymes for fatty acid breakdown and chemical detoxification, producing hydrogen peroxide ($H_2O_2$) and subsequently neutralizing it into $H_2O$ and $O_2$ via catalase.

Mitochondria

Double-membrane bound organelles containing folded inner membranes (cristae) that generate cellular $\text{ATP}$ via cellular respiration.

Microtubules

The thickest cytoskeletal elements, composed of tubulin subunits forming rigid hollow tubes that support cell structure, form centrioles and spindle fibers, and construct cilia and flagella.

Microfilaments

The thinnest cytoskeletal elements, composed of actin subunits, responsible for cell movement, muscle contraction, cleavage furrow formation, and microvilli structural support.

Intermediate Filaments

Ropelike cytoskeletal elements made of fibrous protein subunits (like keratin) that provide mechanical strength, maintain organelle placement, and offer durable structural integrity.

Microvilli

Tiny, non-motile projections on the cell membrane supported internally by actin microfilaments, functioning to dramatically increase surface area for absorption.

Cilia

Motile, hair-like projections extending from cell surfaces composed of microtubules that beat in unison to propel materials along the cell surface.

Flagellum

A long, motile cellular projection built of microtubules that propels an entire cell, uniquely found on sperm cells in humans.

Nucleolus

A dense region within the nucleus that serves as the site for ribosomal RNA (rRNA) synthesis and ribosome assembly.

Chromatin

The diffuse, uncoiled form of DNA wrapped around histone proteins present when a cell is in interphase and not actively dividing.

Sister Chromatids

Two identical copies of a duplicated chromosome joined together at a centromere prior to cell division.

Stem Cell

An unspecialized cell capable of self-renewal through repeated division and able to differentiate into specialized cell types under specific conditions.

Cell Differentiation

The process by which an unspecialized cell undergoes regulated changes in gene expression to acquire a specific structure and specialized function.

Pluripotent

Stem cell potency describing the ability to give rise to any cell type in the human body, characteristic of embryonic stem cells.

Multipotent

Stem cell potency describing a restricted ability to differentiate only into specific cell lineages or groups, characteristic of adult stem cells.