OpenStax Anatomy & Physiology 2e — Chapters 1-4: Intro to the Human Body, Chemical Level, Cellular Level, Tissues

Vocabulary flashcards covering key terms from Chapters 1–4: introduction to the human body, chemical level, cellular level, and tissues.

Levels of Organization

Chemical, cellular, tissue, organ, organ system, and organism—levels from small to complex in the human body.

Characteristics of Life

Organization, metabolism, responsiveness, movement, development, and reproduction.

Homeostasis

Maintenance of stable internal conditions; regulated by negative feedback (e.g., temperature) and positive feedback (e.g., childbirth).

Anatomy

Study of the structure of body parts.

Physiology

Study of the function of body parts and systems.

Anterior

Front of the body.

Posterior

Back of the body.

Superior

Upper, toward the head.

Inferior

Lower, away from the head.

Medial

Toward the midline of the body.

Lateral

Away from the midline; toward the sides.

Proximal

Near the point of attachment or origin on a limb.

Distal

Farther from the point of attachment or origin on a limb.

Superficial

Near the surface of the body.

Deep

Away from the body surface; more internal.

Sagittal Plane

Vertical plane that divides the body into left and right portions (midsagittal vs parasagittal).

Transverse Plane

Horizontal plane that divides the body into superior and inferior parts.

Frontal (Coronal) Plane

Vertical plane that divides the body into anterior and posterior portions.

Dorsal Body Cavities

Cranial and spinal cavities.

Ventral Body Cavities

Thoracic, abdominal, and pelvic cavities.

Cranial Cavity

Cavity within the skull that houses the brain.

Spinal Cavity

Cavity within the vertebral column that houses the spinal cord.

Thoracic Cavity

Contains the heart, lungs, and others; protected by the rib cage.

Abdominal Cavity

Contains digestive organs; liver, stomach, intestines, etc.

Pelvic Cavity

Contains reproductive and some urinary/intestinal organs.

Matter

Anything with mass that occupies space.

Element

Pure substance; essential elements include oxygen, carbon, hydrogen, and nitrogen.

Atomic Number

Number of protons in the nucleus of an atom.

Atomic Mass

Total number of protons and neutrons in the nucleus.

Isotopes

Atoms with the same number of protons but different numbers of neutrons.

Ions

Atoms that carry a net electric charge due to loss or gain of electrons.

Isomers

Molecules with the same formula but different structural arrangements; mirror images in some cases.

Ionic Bonds

Bonds formed by transfer of electrons between atoms.

Covalent Bonds

Bonds formed by sharing electrons between atoms; can be polar or nonpolar.

Polar Covalent Bonds

Unequal sharing of electrons; results in partial charges (e.g., water).

Nonpolar Bonds

Equal sharing of electrons; common in lipids.

Hydrogen Bonds

Weak attractions between polar molecules, such as between water molecules.

Synthesis

Chemical reaction that builds larger molecules (anabolic; endergonic); dehydration synthesis is an example.

Decomposition

Chemical reaction that breaks down molecules (catabolic; exergonic); hydrolysis is an example.

Exchange Reactions

Chemical reactions that rearrange atoms to produce new molecules.

Water’s Importance

Solvent; high heat capacity; participates in hydrolysis and dehydration synthesis.

Carbohydrates

Energy source; includes monosaccharides, disaccharides, polysaccharides; glycosidic bonds.

Monosaccharides

Glucose, fructose, galactose (hexoses); deoxyribose and ribose (pentoses).

Disaccharides

Sucrose, lactose, maltose.

Polysaccharides

Amylose, amylopectin, glycogen, cellulose (fiber).

Glycosidic bonds

Chemical bonds linking monosaccharide units in carbohydrates.

Lipids

Energy storage and structural roles; include triglycerides, phospholipids, steroids; cholesterol is a steroid.

Proteins

Polymers built from amino acids; functions include enzymes, transport, and support.

Monosaccharides

(Repeated entry for emphasis) Glucose, fructose, galactose; ribose and deoxyribose.

Polysaccharides (continued)

Complex carbohydrates like glycogen in animals and starch/amylose in plants.

Peptide Bonds

Covalent bonds linking amino acids in proteins.

Nucleic Acids

DNA and RNA; built from nucleotides.

pH

Measure of acidity/alkalinity on a 0–14 scale; neutral is 7.

Buffers

Substances that maintain stable pH by neutralizing acids or bases.

Functional Groups

Specific molecular groups like hydroxyl, methyl, phosphate, and amino that determine chemical properties.

Dehydration Synthesis

Chemical reaction that builds larger molecules by removing water.

Hydrolysis

Chemical reaction that breaks bonds by adding water.

Cell Theory

All living things are composed of cells; cells are the basic unit of life.

Plasma Membrane

Phospholipid bilayer with embedded proteins; regulates movement of substances.

Cytoplasm

Cytosol plus organelles.

Nucleus

Control center; stores DNA.

Mitochondria

Powerhouse of the cell; produces ATP.

Ribosomes

Site of protein synthesis.

Endoplasmic Reticulum (ER)

Smooth ER: lipid synthesis; Rough ER: protein processing.

Golgi Apparatus

Modifies, sorts, and packages proteins.

Lysosomes

Break down waste and cellular debris.

Cytoskeleton

Provides structural support and transport; composed of microfilaments, intermediate filaments, and microtubules.

Diffusion

Movement of particles from high to low concentration; passive transport.

Osmosis

Diffusion of water across a semipermeable membrane.

Facilitated Diffusion

Passive transport using carrier or channel proteins.

Sodium-Potassium Pump

Active transport that moves Na+ and K+ against their gradients.

Endocytosis

Bulk transport into the cell; includes phagocytosis and pinocytosis.

Exocytosis

Bulk transport out of the cell.

Phagocytosis

Cell eating; endocytosis of large particles.

Pinocytosis

Cell drinking; uptake of extracellular fluid.

Receptor-Mediated Endocytosis

Endocytosis that requires a ligand to bind to a receptor.

Mitosis

Division of somatic (body) cells with stages: Prophase, Metaphase, Anaphase, Telophase, Cytokinesis.

Meiosis

Cell division that produces gametes with half the number of chromosomes.

DNA Replication

Copying DNA prior to cell division; occurs in S phase of interphase.

Transcription

DNA is transcribed into mRNA.

Translation

mRNA is translated into protein at ribosomes.

DNA Nucleotides

Adenine, Guanine, Thymine, Cytosine; in RNA, Thymine is replaced by Uracil; A pairs with T or U, G pairs with C.

RNA Nucleotides

Adenine, Guanine, Uracil, Cytosine.

Epithelial Tissue

Lines body surfaces and cavities; protective barrier; involved in absorption, secretion, and sensation.

Avascular

Lacking blood vessels; epithelia rely on underlying tissues for nutrients.

Regenerative

Tissues that can be replaced continually by new cells of the same type.

Simple Epithelium

One cell layer thick.

Stratified Epithelium

Multiple cell layers thick.

Squamous

Flat, scale-like cells.

Cuboidal

Cube-shaped cells.

Columnar

Tall, column-like cells.

Simple Squamous Epithelium

One-layer, flat epithelium; e.g., lining blood vessels and alveoli.

Stratified Squamous Epithelium

Multiple layers; e.g., skin and mucous membranes.

Simple Columnar Epithelium

One layer of tall cells; lines digestive tract.

Connective Tissue

Supports and connects other tissues; has extracellular matrix.

Extracellular Matrix

Fibers and ground substance that surround connective tissue cells.

Loose Connective Tissue

Areolar, adipose, and reticular tissues; provide cushioning and energy storage.

Dense Connective Tissue

Dense regular (tendons/ligaments) and dense irregular (dermis); provides tensile strength.

Cartilage

Flexible connective tissue: hyaline, elastic, fibrocartilage.

Bone

Rigid connective tissue that supports, protects, and stores minerals.