Anatomy & Physiology: Foundational Concepts and Chemistry Review

Anatomy & Physiology Overview

Introduction to Anatomy & Physiology

Anatomy and Physiology (A&P) is the study of the structure and function of the human body. Understanding both the organization of the body and the chemical principles underlying biological processes is essential for success in this course.

• Anatomy: The study of body structure; includes gross (macroscopic) and microscopic anatomy.

• Physiology: The study of body function; focuses on how body parts work and carry out life-sustaining activities.

• Types of Anatomy: Systemic (by organ system), regional (by body region), surface (external features), and others.

Organization of the Human Body

Levels of Organization

The human body is organized into several hierarchical levels, each building upon the previous one.

• Chemical level: Atoms and molecules

• Cellular level: Cells and their organelles

• Tissue level: Groups of similar cells

• Organ level: Contains two or more types of tissues

• Organ system level: Organs that work closely together

• Organismal level: All organ systems combined to make the whole organism

Organ Systems

There are eleven major organ systems in the human body, each with specific functions.

• Examples: Integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, reproductive

Anatomical Terminology

Directional Terms and Body Planes

Directional terms and body planes are used to describe locations and sections of the body.

• Directional terms: Anterior/posterior, dorsal/ventral, superior/inferior, medial/lateral, proximal/distal, superficial/deep

• Body planes: Sagittal (left/right), frontal (anterior/posterior), transverse (superior/inferior)

Body Cavities and Membranes

The body contains several cavities that house organs and are lined by membranes.

• Dorsal cavity: Cranial and vertebral cavities

• Ventral cavity: Thoracic (pleural, pericardial, mediastinum) and abdominopelvic (abdominal, pelvic) cavities

• Serous membranes: Pleura (lungs), pericardium (heart), peritoneum (abdominopelvic organs)

Homeostasis

Definition and Mechanisms

Homeostasis is the maintenance of a stable internal environment. It is essential for normal body function and survival.

• Feedback mechanisms: Negative feedback (most common; reverses a change), positive feedback (amplifies a change)

• Examples: Regulation of body temperature, blood glucose levels

Cell Communication

Electrical and Chemical Signaling

Cells communicate using electrical and chemical signals to coordinate body functions.

• Electrical communication: Involves changes in membrane potential (e.g., nerve impulses)

• Chemical communication: Involves neurotransmitters, hormones, and other signaling molecules

Basic Chemistry for Anatomy & Physiology

Atoms, Elements, and Compounds

Chemistry is fundamental to understanding physiological processes. Atoms, elements, and compounds form the basis of all matter.

• Atom: Smallest unit of matter; consists of protons, neutrons, and electrons

• Element: Pure substance made of only one kind of atom; defined by atomic number

• Compound: Substance formed from two or more elements chemically combined

• Isotope: Atoms of the same element with different numbers of neutrons

• Periodic table: Organizes elements by atomic number and properties

Chemical Bonds and Reactions

Atoms combine to form molecules through chemical bonds. Chemical reactions involve making or breaking these bonds.

• Ionic bonds: Transfer of electrons between atoms

• Covalent bonds: Sharing of electrons between atoms

• Hydrogen bonds: Weak attractions between polar molecules

• Reversible vs. irreversible reactions: Some reactions can go both directions; others cannot

• Energy: Exists as potential or kinetic; required for chemical reactions

Solutions and Concentrations

Solutions are mixtures where one substance is dissolved in another. Concentration describes the amount of solute in a solution.

• Solvent: Substance that dissolves the solute (e.g., water)

• Solute: Substance dissolved in the solvent

• Concentration: Amount of solute per unit volume of solution

Acids, Bases, and pH

Acids and bases are important in maintaining the body's pH balance.

• Acid: Releases hydrogen ions (H+) in solution

• Base: Accepts hydrogen ions or releases hydroxide ions (OH-)

• pH scale: Measures hydrogen ion concentration; ranges from 0 (acidic) to 14 (basic), with 7 as neutral

• Buffer: Substance that minimizes changes in pH

• Electrolyte: Substance that conducts electricity when dissolved in water

Organic Molecules

Organic molecules are carbon-based and essential for life. They include carbohydrates, lipids, proteins, and nucleic acids.

• Carbohydrates: Sugars and starches; provide energy

• Lipids: Fats, oils, and steroids; energy storage and cell membranes

• Proteins: Made of amino acids; structural and functional roles

• Nucleic acids: DNA and RNA; store and transmit genetic information

Enzymes and Metabolism

Enzymes are biological catalysts that speed up chemical reactions. Metabolism includes all chemical reactions in the body.

• Enzyme: Protein that lowers activation energy of a reaction

• Metabolism: Sum of all chemical reactions in the body

• Anabolic reactions: Build complex molecules from simpler ones

• Catabolic reactions: Break down complex molecules into simpler ones

• Oxidation-reduction (redox) reactions: Transfer of electrons between molecules

Nucleic Acids and Genetic Information

Nucleic acids store and transmit genetic information. DNA and RNA are the two main types.

• DNA (deoxyribonucleic acid): Double helix; stores genetic information

• RNA (ribonucleic acid): Single-stranded; involved in protein synthesis

• Nucleotides: Building blocks of nucleic acids; consist of a sugar, phosphate group, and nitrogenous base

• Bases: Adenine (A), Thymine (T), Cytosine (C), Guanine (G) in DNA; Uracil (U) replaces Thymine in RNA

• ATP (adenosine triphosphate): Main energy currency of the cell

Table: Comparison of Major Organic Molecules

Type	Monomer	Main Function	Examples
Carbohydrates	Monosaccharides	Energy source	Glucose, starch, glycogen
Lipids	Fatty acids, glycerol	Energy storage, membranes	Triglycerides, phospholipids
Proteins	Amino acids	Structure, enzymes	Hemoglobin, enzymes
Nucleic acids	Nucleotides	Genetic information	DNA, RNA

Genetic Processes

Genetic information is expressed through transcription and translation.

• Transcription: DNA is used to make RNA

• Translation: RNA is used to make proteins

Additional info: Some explanations and examples have been expanded for clarity and completeness based on standard Anatomy & Physiology curricula.