Anatomy & Physiology: Foundations, Chemistry, and Biochemistry Study Guide

Chapter 1: Introduction to Anatomy & Physiology

Defining Anatomy and Physiology

Anatomy is the study of the structure of body parts, while physiology is the study of the function of those parts. Understanding both is essential for comprehending how the human body operates as an integrated whole.

• Anatomy: Examines the physical structure of organisms, from cells to organ systems.

• Physiology: Focuses on the processes and functions carried out by anatomical structures.

• Example: The structure of the heart (anatomy) enables it to pump blood (physiology).

Relationship Between Structure and Function

The structure of a body part is closely related to its function. This principle is fundamental in anatomy and physiology.

• Example: The thin, flat shape of red blood cells increases their surface area for gas exchange.

• Additional info: Phospholipids in cell membranes have hydrophilic heads and hydrophobic tails, forming a bilayer that is selectively permeable.

Levels of Structural Organization

The human body is organized into 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

Homeostasis

Homeostasis is the maintenance of a stable internal environment despite changes in external conditions. It is vital for normal body functioning and survival.

• Components of a feedback system: Stimulus, receptor, control center, effector, and response.

• Negative feedback: Reduces the effect of the stimulus (e.g., regulation of body temperature).

• Positive feedback: Enhances the effect of the stimulus (e.g., blood clotting).

• Homeostatic imbalance: Can lead to disorders, disease, or death.

• Signs vs. Symptoms: Signs are objective and measurable (e.g., fever), while symptoms are subjective (e.g., pain).

Chapter 2: Chemistry of Life

Elements, Atoms, and Chemical Bonds

All matter is composed of elements, which are made up of atoms. Atoms consist of protons, neutrons, and electrons.

• Major elements in the body: Oxygen, carbon, hydrogen, nitrogen

• Trace elements: Required in small amounts (e.g., iron, iodine)

• Atomic number: Number of protons in the nucleus

• Mass number: Sum of protons and neutrons

• Isotopes: Atoms with the same number of protons but different numbers of neutrons

• Electron shells: Electrons are arranged in shells around the nucleus; the outermost shell determines chemical reactivity.

Chemical Bonds

Atoms form bonds to achieve stability. The main types of chemical bonds are ionic, covalent, and hydrogen bonds.

• Ionic bonds: Transfer of electrons from one atom to another, forming ions (e.g., NaCl).

• Covalent bonds: Sharing of electrons between atoms (e.g., H2O).

• Hydrogen bonds: Weak attractions between polar molecules, important in water and DNA structure.

• Single, double, triple bonds: Refers to the number of shared electron pairs.

Water, Acids, Bases, and Buffers

Water is essential for life due to its unique properties. Acids, bases, and buffers help maintain pH balance in the body.

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

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

• pH scale: Measures hydrogen ion concentration; 7 is neutral, below 7 is acidic, above 7 is basic.

• Buffers: Substances that minimize changes in pH by accepting or donating H+ ions.

Organic Compounds

Organic compounds contain carbon and are vital to life. The four major classes are carbohydrates, lipids, proteins, and nucleic acids.

• Carbohydrates: Provide energy; monomers are monosaccharides (e.g., glucose).

• Lipids: Include fats, oils, and steroids; important for energy storage and cell membranes.

• Proteins: Made of amino acids; function as enzymes, structural components, and more.

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

Monomers and Polymers

Many biological molecules are polymers, made by joining monomers through dehydration synthesis.

• Dehydration synthesis: Removes water to form a bond between monomers.

• Hydrolysis: Adds water to break bonds between monomers.

• Examples: Polysaccharides (carbohydrates), polypeptides (proteins), nucleic acids (DNA/RNA).

Enzymes and Chemical Reactions

Enzymes are biological catalysts that speed up chemical reactions without being consumed.

• Specificity: Each enzyme acts on a specific substrate.

• Active site: Region where the substrate binds.

• Activation energy: Minimum energy required to start a reaction.

• Enzyme activity: Affected by temperature, pH, and substrate concentration.

• Lock-and-key model: Describes enzyme-substrate interaction.

Types of Chemical Reactions

Chemical reactions in the body include synthesis, decomposition, exchange, reversible, and oxidation-reduction reactions.

• Synthesis (anabolic): Building larger molecules from smaller ones.

• Decomposition (catabolic): Breaking down molecules into smaller units.

• Exchange: Parts of molecules are exchanged between reactants.

• Reversible: Reactions that can proceed in both directions.

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

Energy in Biological Systems

Energy is required for all life processes. The body uses chemical energy stored in molecules like ATP.

• Potential energy: Stored energy (e.g., in chemical bonds).

• Kinetic energy: Energy of motion.

• Law of conservation of energy: Energy cannot be created or destroyed, only transformed.

• ATP (adenosine triphosphate): The primary energy carrier in cells.

Table: Comparison of Intracellular and Extracellular Fluid

Property	Intracellular Fluid	Extracellular Fluid
Location	Inside cells	Outside cells (includes plasma and interstitial fluid)
Major Ions	K+, Mg2+, phosphate	Na+, Cl-, Ca2+
Protein Content	High	Low (except plasma)
Function	Cellular processes	Transport, nutrient delivery, waste removal

Table: Types of Chemical Bonds

Bond Type	Description	Example
Ionic	Transfer of electrons	NaCl
Covalent	Sharing of electrons	H2O
Hydrogen	Weak attraction between polar molecules	Between water molecules

Key Equations

• pH calculation:

$\text{pH} = -\log_{10}[\text{H}^+]$

• ATP hydrolysis:

$\text{ATP} + \text{H}_2\text{O} \rightarrow \text{ADP} + \text{P}_i + \text{energy}$

• Law of Conservation of Energy:

$\text{Energy}_{\text{initial}} = \text{Energy}_{\text{final}}$

Additional info:

• Some content was inferred and expanded for clarity and completeness, especially regarding feedback systems, chemical bonds, and the properties of water.

• Tables were constructed to summarize comparisons and classifications mentioned in the original material.