An Introduction to Anatomy, Physiology, and the Chemical & Cellular Levels of Organization

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Chapter 1: An Introduction to Anatomy and Physiology

Key Concepts

Anatomy and Physiology: Anatomy is the study of body structures, while physiology is the study of how those structures function. These disciplines are closely integrated, with structure determining function (the principle of complementarity).
Levels of Organization: The human body is organized from the simplest to the most complex: chemical, cellular, tissue, organ, organ system, and organism levels.
Medical Terminology: Understanding word roots, prefixes, and suffixes is crucial for comprehending anatomical and physiological terms. Eponyms are often replaced by more precise terms.
Anatomical Terminology: Standard terms are used to describe body regions, sections, and relative positions (e.g., anatomical position, supine, prone, abdominopelvic quadrants/regions, sectional planes like frontal, sagittal, and transverse).
Body Cavities: Fluid-filled spaces protect organs and allow for changes in their size and shape. Major cavities include the thoracic cavity (pleural and pericardial cavities, mediastinum) and the abdominopelvic cavity (abdominal and pelvic cavities, peritoneal cavity).
Homeostasis: The body's ability to maintain a stable internal environment. This involves homeostatic regulation through autoregulation (local response) and extrinsic regulation (nervous and endocrine systems). A homeostatic regulatory mechanism includes a receptor, control center, and effector.

Vocabulary List

Anatomy: Study of internal and external body structures and their physical relationships among other body parts.
Physiology: Study of how living organisms perform their vital functions.
Principle of complementarity of structure and function: All specific functions are performed by specific structures, and the form of a structure relates to its function.
Surface anatomy: Anatomy of body surface.
Regional anatomy: Anatomy of specific body areas.
Sectional anatomy: Understanding the relationship of body structures by examining cross sections.
Systemic anatomy: Anatomy of organ systems.
Clinical anatomy: Anatomy as used in clinical practice.
Pathological anatomy: Anatomical changes during illness.
Radiologic anatomy: Anatomical structures seen using imaging techniques.
Surgical anatomy: Anatomical landmarks important in surgery.
Developmental anatomy: Anatomical changes from fertilization to adulthood.
Embryology: Study of early developmental processes.
Cytology: Study of the structure of cells.
Histology: Study of the structure of tissues.
Cell physiology: Study of the function of cells and their chemical processes.
Organ physiology: Study of the function of specific organs.
Systemic physiology: Study of function of organ systems.
Pathological physiology: Study of effects of diseases on organs or systems.
Signs: Objective disease indications (such as a fever).
Symptoms: Subjective disease indications (such as tiredness).

Levels of Organization

Chemical level: Atoms and molecules.
Cellular level: Cells, the smallest living units.
Tissue level: Groups of similar cells performing a common function.
Organ level: Two or more tissue types performing specific functions.
Organ system level: A group of organs interacting for a particular function.
Organism level: An individual life form.

Medical Terminology and Anatomical Reference

Medical terminology: Involves using word roots, prefixes, suffixes, and combining forms to build terms related to the body in health and disease.
Eponyms: Commemorative names (such as names based on names of discoverer of a structure or disease).
Anatomical position: Standard anatomical reference position with hands at the sides, palms facing forward and feet together.
Anterior view: Body in anatomical position from the front.
Posterior view: Body in anatomical position from the back.
Supine: Body lying face up.
Prone: Body lying face down.

Body Regions, Planes, and Cavities

Abdominopelvic quadrants: Divide the abdominopelvic region in four quadrants.
Abdominopelvic regions: Divide the abdominopelvic region in nine specific regions.
Section: A slice through a three-dimensional object.
Sectional plane: A single view or slice along a two-dimensional flat surface.
Frontal (coronal) plane: A vertical plane that divides the body or organ into anterior and posterior portions.
Sagittal plane: A vertical plane that divides the body or organ into left and right portions.
Midsagittal plane: Lies in the middle of the sagittal plane.
Parasagittal plane: Offset from the middle of the sagittal plane.
Transverse (horizontal) plane: A horizontal plane that divides the body or organ into superior and inferior portions.
Body cavities: Closed, fluid-filled cavities that are lined by a thin serous membrane; contain the vital organs (viscera) of the trunk.

Major Body Cavities and Membranes

Serous fluid: Moistens membranes and reduces friction.
Thoracic cavity: Deep to the chest wall of the thoracic region; divided from the abdominopelvic cavity by the diaphragm.
Pleural cavities: Surround the lungs.
Pericardial cavity: Surrounds the heart.
Mediastinum: A mass of connective tissue that stabilizes the trachea, esophagus, thymus, and largest vessels of the heart; also contains the pericardial cavity.
Abdominopelvic cavity: Deep to the abdominal and pelvic walls; extends from the diaphragm to the pelvis.
Superior abdominal cavity: Upper part of the abdominopelvic cavity.
Inferior pelvic cavity: Lower part of the abdominopelvic cavity.
Peritoneal cavity: Space within the abdominopelvic cavity lined with peritoneum.
Parietal peritoneum: Lines the internal body wall.
Visceral peritoneum: Covers the organs.
Retroperitoneal space: Area between the parietal peritoneum and the back of the muscular body wall.
Infraperitoneal: Organs which extend inferior to the peritoneal cavity.

Homeostasis and Regulation

Homeostasis: The continuous physiological processes that establish a relatively stable internal environment.
Homeostatic regulation: The adjustment of physiological systems to preserve homeostasis.
Autoregulation: Automatic, local response to an environmental change in a cell, tissue, or organ.
Extrinsic regulation: Responses of organ systems controlled by the nervous system (through electrical signals) or the endocrine system (through chemical messengers).
Receptor: A sensor that detects the stimulus or change.
Control center: Receives and processes the information supplied by the receptor.
Effector: Responds to the commands of the control center and opposes or enhances the stimulus.

Chapter 2: The Chemical Level of Organization

Key Concepts

Atoms and Atomic Structure: Matter is composed of atoms, which consist of subatomic particles (protons, neutrons, electrons). The atomic number defines an element, and isotopes are variations with different numbers of neutrons. Electrons occupy shells, and the valence shell determines chemical reactivity.
Molecules and Compounds: Atoms combine to form molecules and compounds through chemical bonds. These include ionic bonds (transfer of electrons, forming ions), covalent bonds (sharing of electrons), and hydrogen bonds (weak attractions between polar molecules).
Chemical Reactions: These involve the formation or breaking of chemical bonds. Types include decomposition reactions (catabolism, release energy), synthesis reactions (anabolism, consume energy), and exchange reactions. Many biological reactions are reversible and seek equilibrium.
Enzymes: These are biological catalysts that speed up biochemical reactions by lowering the activation energy without being consumed in the process.

Vocabulary List

Chemistry: The science that deals with the structure of matter.
Matter: Anything that takes up space and has mass.
Atom: The smallest stable unit of matter.
Subatomic particles: Protons, neutrons, and electrons.
Protons: Positively charged particles found in the nucleus.
Neutrons: Neutral particles found in the nucleus.
Electrons: Negatively charged particles that orbit the nucleus.
Electron shell: Two-dimensional representation of an electron cloud.
Element: A pure substance composed of atoms of one kind, which cannot be broken down into simpler substances by ordinary physical means.
Isotopes: Versions of an element that have different numbers of neutrons.
Mass number: The number of protons plus the number of neutrons of an atom.
Radioisotopes: Isotopes that have unstable or radioactive nuclei.
Radioactive decay: The breakdown of the nucleus of a radioisotope.
Half-life: The time required for half of a given amount of isotope to decay.
Atomic weight: An average of the different atomic masses and proportions of different isotopes.
Atomic mass: The actual mass of an atom, taking into account the masses of its protons, neutrons and electrons.
Mole (mol): A specific quantity that has a weight in grams equal to the atomic weight of the element.
Avogadro's number: The number of atoms in one mole of a given element.
Valence shell: The outermost electron shell, determining the chemical properties of an element.
Inert elements: Elements with a full valence shell that are not reactive.
Chemical reactions: Result in the formation of new bonds or the breaking of existing bonds.
Molecule: Two or more atoms joined by shared electrons.
Compound: Two or more atoms of different elements.
Molecular weight: The sum of the atomic weights of its atoms.

Chemical Bonds and Reactions

Covalent bonds: Strong bonds created when atoms share electrons.
Single covalent bond: Sharing one pair of electrons.
Double covalent bond: Sharing two pairs of electrons.
Triple covalent bond: Sharing three pairs of electrons.
Nonpolar covalent bonds: Equal sharing of electrons between two atoms.
Polar covalent bonds: Unequal sharing of electrons between two atoms.
Polar molecules: Molecules in which one side is partially positive and the other partially negative due to unequal sharing of electrons.
Hydrogen bonds: Weak electrical attractions between the partial positive charge of a hydrogen atom in a polar covalent bond and the partial negative charge of an atom of oxygen, nitrogen or fluorine in another polar covalent bond.
States of matter: Solid, liquid, and gas.
Reactants: The reacting substances that enter a chemical reaction.
Products: The resulting substances at the end of a chemical reaction.
Metabolism: All chemical reactions that are occurring in the cells and tissues of the body at any given time.
Work: The movement of an object or a change in the physical structure of matter.
Energy: The capacity to do work.
Kinetic energy: The energy of motion.
Potential energy: Stored energy an object possesses because of its position or its physical or chemical structure.
Decomposition reactions: Break molecules into smaller fragments.
Hydrolysis reactions: Decomposition reactions which involve water.
Synthesis reactions: Combine smaller molecules into larger ones.
Dehydration synthesis: Synthesis reaction that removes water to form a bond.
Exchange reactions: Parts of the reacting molecules are shuffled to produce new products.
Reversible reactions: Reactions that can proceed in both directions to reach equilibrium.
Equilibrium: The state where the rates of the forward and reverse reactions are balanced.
Activation energy: The amount of energy required to start a reaction.
Enzymes: Catalysts that lower the activation energy of reactions and therefore speed up the reaction.

Chapter 3: The Cellular Level of Organization

Key Concepts

Cell Theory: Cells are the fundamental building blocks of all organisms. All cells come from the division of preexisting cells, and each cell maintains homeostasis at the cellular level.
Cellular Components: Cells contain a plasma membrane (outer boundary), cytoplasm (intracellular fluid), and organelles (specialized structures with specific functions).
Plasma Membrane Functions: Provides physical isolation, regulates exchange with the environment, is sensitive to environmental changes, and offers structural support. The membrane is a phospholipid bilayer with embedded proteins (integral, peripheral, anchoring, recognition, enzymes, receptor, carrier, and channel proteins) and carbohydrates (glycocalyx).
Organelles and Their Functions:
- Ribosomes: Synthesize proteins (free and fixed types).
- Proteasomes: Break down proteins for recycling.
- Endoplasmic Reticulum (ER): Network of membranes for synthesis, storage, and transport. Smooth ER synthesizes lipids and carbohydrates; Rough ER processes and packages proteins.
- Golgi Apparatus: Modifies, packages, and stores proteins and lipids.
- Lysosomes: Digestive organelles containing enzymes.
- Peroxisomes: Break down organic compounds and neutralize hydrogen peroxide.
- Mitochondria: Produce ATP through aerobic metabolism.

Vocabulary List

Cell: The smallest living unit in the human body.
Cytology: Study of the structure of cells.
Sex cells (germ cells): Reproductive cells (sperm and oocytes).
Somatic cells: All body cells except sex cells.
Plasma membrane: The cell membrane that forms the outer boundary of the cell and allows for selective transport of substances.
Phospholipid bilayer: The structure of the plasma membrane with hydrophilic heads facing outward and hydrophobic tails facing inward.
Cholesterol: Makes the plasma membrane less fluid and less permeable.
Integral proteins: Proteins within the membrane.
Transmembrane proteins: Integral proteins that span the width of the membrane.
Peripheral proteins: Proteins bound to either the inner or outer surface of the membrane.
Anchoring proteins: Attach the plasma membrane to other structures and stabilize its position.
Recognition proteins (antigens): Label cells as normal or abnormal.
Enzymes: Catalyze reactions.
Receptor proteins: Bind and respond to ligands (ions, hormones).
Carrier proteins: Transport specific solutes through the membrane.
Channels: Permit water and small solutes to move across the membrane.
Glycocalyx: Carbohydrate layer on the outer surface of the plasma membrane for protection and recognition.
Cytoplasm: Intracellular fluid containing water, ions, proteins, and waste products.
Organelles: Internal structures with specific functions.
Nonmembranous organelles: Not completely enclosed by membranes (e.g., cytoskeleton, centrioles, ribosomes, proteasomes).
Membranous organelles: Surrounded by phospholipid membranes (e.g., ER, Golgi apparatus, lysosomes, peroxisomes, mitochondria).
Cytoskeleton: Network of protein filaments for cell shape, strength, and movement.
Microfilaments: Smallest cytoskeletal elements, composed of actin, provide mechanical strength.
Intermediate filaments: Medium-sized filaments, strengthen the cell and help maintain its shape.
Microtubules: Largest cytoskeletal components, anchor organelles, and are involved in cell division and movement.
Centrosome: Region near the nucleus that organizes microtubules.
Cilia: Short, hair-like projections for movement of substances across the cell surface.
Flagella: Longer projections for cell movement (e.g., sperm cell).
Free ribosomes: In the cytoplasm, manufacture proteins for the cell.
Fixed ribosomes: Attached to the ER, manufacture proteins for export.
Proteasomes: Organelles that contain enzymes to break down proteins.
Endoplasmic reticulum (ER): Network of intracellular membranes for synthesis and transport.
Smooth ER: Synthesizes lipids and carbohydrates.
Rough ER: Has ribosomes attached; synthesizes proteins and glycoproteins.
Golgi apparatus: Modifies and packages secretions and renews the plasma membrane.
Lysosomes: Vesicles containing digestive enzymes for breakdown of materials.
Peroxisomes: Vesicles containing enzymes that break down organic compounds and neutralize toxic compounds.
Mitochondria: Produce ATP through aerobic metabolism.

pH and Buffers

pH: A measure of hydrogen ion concentration. A neutral solution has equal hydrogen and hydroxide ions (pH 7). Acids release hydrogen ions, bases release hydroxide ions. Buffers help maintain stable pH in body fluids.

Osmotic Behavior

Isotonic solution: Solution with the same solute concentration as the cell; no net movement of water.
Hypotonic solution: Solution with lower solute concentration than the cell; water moves into the cell, causing swelling and possible lysis.
Hypertonic solution: Solution with higher solute concentration than the cell; water moves out of the cell, causing shrinkage (crenation).

Genetic Information and Protein Synthesis

DNA: Stores genetic information, composed of nucleotides (five-carbon sugar, nitrogenous base, phosphate group). Pyrimidines (thymine, cytosine) and purines (adenine, guanine) form complementary base pairs (A-T, C-G) joined by hydrogen bonds.
DNA Replication: The process by which DNA makes new copies, with each new copy containing one strand from the original DNA molecule.
Codon/Anticodon: Sequence of three bases (codon) on mRNA specifies an amino acid; anticodon on tRNA is complementary to the mRNA codon.

Cell Cycle and Differentiation

Cell cycle: The series of events that take place in cells leading to division and duplication. Includes interphase (G1, S, G2 phases) and M phase (mitosis and cytokinesis). G0 phase is a resting phase where cells are not dividing.
Cell differentiation: The process by which cells become specialized in structure and function. Different cell types have the same genes, but different sets of genes are active in each type.

Key Equations and Concepts

Atomic mass number:
Mole concept:
pH calculation:
General chemical reaction:

Table: Major Body Cavities and Their Contents

Body Cavity	Location	Major Organs	Membrane
Thoracic cavity	Chest	Lungs, heart	Pleura (lungs), Pericardium (heart)
Abdominal cavity	Abdomen	Digestive organs, kidneys	Peritoneum
Pelvic cavity	Pelvis	Bladder, reproductive organs	Peritoneum (partial)

Table: Types of Chemical Bonds

Bond Type	Description	Strength	Example
Ionic	Transfer of electrons between atoms	Moderate	NaCl (table salt)
Covalent	Sharing of electrons between atoms	Strong	H2O (water)
Hydrogen	Attraction between polar molecules	Weak	Between water molecules