BIOL 233 Anatomy and Physiology – Lecture Notes (Ch. 1 & 2A) Key Terms

A vocabulary set covering anatomy, physiology, homeostasis, and foundational chemistry concepts from the lecture notes.

Anatomy

Study of the structure of body parts and their relationships.

Physiology

Study of the function of body parts; how they work to carry out life-sustaining activities.

Gross (macroscopic) anatomy

Study of large, visible structures.

Regional anatomy

Looks at all structures in a particular area of the body.

Systemic anatomy

Looks at just one system (e.g., cardiovascular, nervous, muscular).

Cytology

Microscopic study of cells.

Histology

Microscopic study of tissues.

Developmental anatomy

Study of anatomical and physiological development.

Surface anatomy

Looks at internal structures as they relate to overlying skin; visible surface features.

Microscopic anatomy

Deals with structures too small to be seen by naked eye.

Embryology

Study of developments before birth.

Organ systems

11 organ systems in the human body that work closely together.

Complementarity of structure and function

Function reflects structure; what a structure can do depends on its form.

Homeostasis

Maintenance of relatively stable internal conditions despite environmental changes.

Receptor

Sensor that detects changes in the environment.

Control center

Determines the set point and appropriate response.

Effector

Organelle or gland that acts to restore homeostasis.

Negative feedback

Output reduces or shuts off the original stimulus.

Positive feedback

Output enhances the original stimulus; usually for infrequent, rapid events.

Afferent pathway

From receptor to control center.

Efferent pathway

From control center to effector.

Nervous system

Uses electrical impulses to communicate.

Endocrine system

Uses hormones to communicate.

Receptor (in feedback context)

Detects changes in variables (e.g., temperature, glucose).

Diabetes mellitus (Type 1 & Type 2)

Type 1: pancreas cannot produce insulin; Type 2: insulin is produced but cells don’t respond.

Hypoglycemia

Abnormally low blood glucose.

Glycogen

Storage form of glucose in liver and muscles.

Negative feedback in physiology (examples)

Regulation by insulin and body temperature control are classic examples.

Positive feedback examples

Labor contractions (oxytocin), platelet plug formation and blood clotting.

Organismal level

All organ systems together; the whole human being.

Human being

The living organism composed of organ systems.

ATP

Adenosine triphosphate; the basic energy currency of cells.

Carbohydrates

Major source of energy; stored in liver and muscles.

Proteins (as energy source)

Not stored for energy; used for energy mainly when carbs are deficient.

Fat (adipose tissue)

Stored energy reserve.

Oxygen

Essential for release of energy from foods.

Nutrients

Chemicals for energy and cell building (carbs, proteins, fats, minerals, vitamins).

Water

Most abundant chemical; required for reactions and as a solvent.

Matter

Anything that has mass and occupies space; weight includes gravity’s effect.

Energy

Capacity to do work or move matter; comes in multiple forms.

States of matter

Solid (definite shape/volume), liquid (definite volume), gas (no fixed shape/volume).

Kinetic energy

Energy in action or motion.

Potential energy

Stored energy that can be released.

Forms of energy

Chemical, electrical, mechanical, radiant (electromagnetic).

Energy transformations

Energy can change from one form to another (e.g., electrical to light).

Element

Substance that cannot be broken down by ordinary chemical methods; bulk body matter is mainly four elements.

Major body elements (bulk)

Carbon, Oxygen, Hydrogen, Nitrogen.

Atomic number

Number of protons in the nucleus (and electrons in a neutral atom).

Mass number

Total number of protons and neutrons in the nucleus.

Isotopes

Structural variations of the same element with different neutron numbers.

Radioisotopes

Isotopes that decompose to more stable forms; emit radiation.

Radioactivity

Energy released as radioactive decay occurs.

Molecule

Two or more atoms bonded together.

Compound

A molecule with two or more different kinds of atoms bonded together.

Mixtures

Two or more components physically intermixed.

Solution

Homogeneous mixture where solute particles are tiny and evenly distributed.

Solvent

Substance present in greatest amount; water is the body’s chief solvent.

Solute

Substance dissolved in solvent.

Concentration

Relative amount of solute in solvent; expressions include percent, mg/dL, and molarity.

Molarity

Moles of solute per liter of solvent; a precise concentration unit.

Avogadro’s number

6.02 x 10^23; number of particles per mole.

Colloids (emulsions)

Heterogeneous mixtures with larger solute particles that scatter light.

Suspensions

Heterogeneous mixtures with large particles that settle out.

Sol-gel

Transformation from solution to gel; cytosol is a sol-gel.

Electrons

Negatively charged subatomic particles orbiting the nucleus.

Electron shells (energy levels)

Levels around the nucleus that hold electrons; up to 7 shells.

Valence shell

Outermost electron shell; most responsible for bonding.

Octet rule

Atoms tend to have eight electrons in their valence shell (except H, He).

Ionic bonds

Transfer of electrons; formation of cations and anions with electrostatic attraction.

Covalent bonds

Sharing of electrons between atoms; can be single, double, or triple bonds.

Nonpolar covalent bonds

Equal sharing of electrons; electrically balanced molecules.

Polar covalent bonds

Unequal sharing of electrons; creates dipole moments in molecules.

Hydrogen bonds

Weak forces between electropositive H and electronegative atoms; important in water and biomolecules.

Electronegativity

Attraction of an atom for electrons in a bond.

Electropositive

Atoms with lower attraction for electrons in a bond.

Dipole

Molecule with two opposite charges forming a polar molecule.

Ionic bonds vs covalent bonds

Ionic: transfer of electrons; Covalent: sharing of electrons.

Molecular formulas vs formulas with subscripts and prefixes

Molecular formulas show types and numbers of atoms; subscripts indicate bonded atoms.

Chemical reactions

Processes where bonds are formed, rearranged, or broken.

Reactants

Substances entering into a reaction.

Products

Resulting substances of a reaction.

Synthesis (anabolic) reactions

Atoms or molecules combine to form larger, more complex molecules.

Decomposition (catabolic) reactions

Molecule breaks down into smaller units.

Exchange (displacement) reactions

Parts of molecules are rearranged; bonds are formed and broken.

Redox reactions (oxidation-reduction)

Reactions involving transfer of electrons; reduction gains electrons, oxidation loses them.

Exergonic reactions

Release energy; products have less energy than reactants.

Endergonic reactions

Absorb energy; products have more energy than reactants.

Enzymes

Biological catalysts that speed up chemical reactions.

Temperature, concentration, particle size (rate factors)

Factors that influence how fast reactions occur.