BIO 109: Study Guide for Exam 1 – Introduction to Anatomy, Physiology, and Chemistry of Life

Introduction to Anatomy and Physiology

Anatomical Terminology

Understanding anatomical terminology is essential for accurately describing locations and relationships of body parts. The anatomical position is the standard reference position for the body in the study of anatomy.

• Directional Terms: Used to describe the positions of structures relative to other structures or locations in the body.

  • Superior (cranial): Toward the head or upper part of a structure.

  • Inferior (caudal): Away from the head or toward the lower part of a structure.

  • Anterior (ventral): Toward the front of the body.

  • Posterior (dorsal): Toward the back of the body.

  • Medial: Toward the midline of the body.

  • Lateral: Away from the midline of the body.

  • Proximal: Closer to the point of attachment or origin.

  • Distal: Farther from the point of attachment or origin.

• Anatomical Position: The body is standing upright, facing forward, arms at the sides with palms facing forward.

Organ Systems Overview

The human body is organized into several organ systems, each with specific functions and components.

• Skeletal System: Provides support, protection, and aids in movement; includes bones and joints.

• Muscular System: Allows movement, maintains posture, and produces heat; includes skeletal muscles.

• Endocrine System: Regulates body functions through hormones; includes glands such as the pancreas, which also functions in the digestive system.

• Respiratory System: Facilitates gas exchange; includes lungs, trachea, and other airways.

• Pancreas: Functions in both the digestive (producing digestive enzymes) and endocrine (secreting insulin and glucagon) systems.

Body Cavities

Body cavities protect internal organs and allow for changes in organ shape and size.

• Dorsal Cavity: Contains the cranial cavity (brain) and vertebral cavity (spinal cord).

• Ventral Cavity: Contains the thoracic cavity (heart and lungs) and abdominopelvic cavity (digestive, urinary, and reproductive organs).

• Sub-cavities: Thoracic cavity includes pleural cavities (lungs) and pericardial cavity (heart).

Serous Membranes

Serous membranes line body cavities and cover organs, reducing friction from organ movement.

• Parietal Layer: Lines the cavity walls.

• Visceral Layer: Covers the organs within the cavity.

• Examples: Pleura (lungs), pericardium (heart), peritoneum (abdominal organs).

Homeostasis and Feedback Loops

Homeostasis is the maintenance of a stable internal environment. The body uses feedback mechanisms to regulate physiological processes.

• Negative Feedback: Reverses a change to maintain balance (e.g., body temperature regulation).

• Positive Feedback: Enhances or amplifies a change (e.g., blood clotting, labor contractions).

• Components: Receptor (detects change), control center (processes information), effector (produces response).

Gradients in Physiology

A gradient is a difference in concentration, pressure, or electrical charge between two regions. Gradients drive many physiological processes.

• Concentration Gradient: Difference in the concentration of a substance across a space.

• Pressure Gradient: Difference in pressure between two areas.

• Electrical Gradient: Difference in charge across a membrane.

Labeling Diagrams

Accurate labeling of anatomical diagrams is essential for understanding spatial relationships in the body. Practice identifying organs, cavities, and directional terms on diagrams.

The Chemistry of Life

Atomic Structure and Elements

Atoms are the basic units of matter, composed of protons, neutrons, and electrons.

• Atomic Number: Number of protons in the nucleus; defines the element.

• Protons: Positively charged particles in the nucleus.

• Neutrons: Uncharged particles in the nucleus.

• Electrons: Negatively charged particles orbiting the nucleus.

Chemical Bonds

Chemical bonds form when atoms interact to achieve stability.

• Ionic Bonds: Formed by the transfer of electrons from one atom to another, resulting in charged ions (e.g., NaCl).

• Covalent Bonds: Formed by the sharing of electrons between atoms (e.g., H2O).

Chemical Reactions

Chemical reactions involve the making or breaking of bonds, transforming reactants into products.

• Catabolic Reactions: Break down molecules and release energy (e.g., cellular respiration).

• Anabolic Reactions: Build complex molecules and consume energy (e.g., protein synthesis).

• Reactants: Substances that enter a reaction.

• Products: Substances produced by a reaction.

General chemical equation:

$\mathrm{Reactants} \rightarrow \mathrm{Products}$

Factors Affecting Reaction Rates

• Temperature: Higher temperatures increase reaction rates.

• Concentration: Higher concentrations of reactants increase reaction rates.

• Catalysts: Substances that speed up reactions without being consumed (e.g., enzymes).

pH and Solutions

The pH scale measures hydrogen ion concentration in a solution, ranging from 0 (acidic) to 14 (basic).

• pH Formula: $\mathrm{pH} = -\log_{10}[\mathrm{H}^+]$

• Acidic Solutions: pH < 7

• Neutral Solutions: pH = 7

• Basic Solutions: pH > 7

Biological Macromolecules

Macromolecules are large, complex molecules essential for life.

• Carbohydrates: Energy source; building blocks are monosaccharides (e.g., glucose).

• Lipids: Energy storage, insulation, and cell membrane structure; include fats, oils, and steroids.

• Proteins: Structure, enzymes, transport; building blocks are amino acids.

• Nucleic Acids: Store and transmit genetic information; building blocks are nucleotides (e.g., DNA, RNA).

Dehydration Synthesis and Disaccharide Formation

• Dehydration Synthesis: Reaction that joins two molecules by removing a water molecule.

• Disaccharide Formation: Two monosaccharides join to form a disaccharide (e.g., glucose + fructose = sucrose).

$\mathrm{Monosaccharide}_1 + \mathrm{Monosaccharide}_2 \xrightarrow{\text{Dehydration}} \mathrm{Disaccharide} + \mathrm{H}_2\mathrm{O}$

Lipids and Fatty Acids

• Saturated Fatty Acids: No double bonds; solid at room temperature (e.g., butter).

• Unsaturated Fatty Acids: One or more double bonds; liquid at room temperature (e.g., olive oil).

The Cell

Plasma Membrane Functions

The plasma membrane controls the movement of substances into and out of the cell, facilitates communication, provides structural support, and isolates the cell from its environment.

Cytosol and Intracellular Fluids

Cytosol is the fluid portion of the cytoplasm, containing dissolved substances and organelles. It is crucial for cellular processes and reactions.

Structure of the Plasma Membrane

• Phospholipid Bilayer: Composed of hydrophilic heads and hydrophobic tails, forming a selective barrier.

• Cholesterol: Stabilizes membrane fluidity and structure.

Diffusion and Osmosis

• Simple Diffusion: Movement of molecules from high to low concentration without energy input.

• Facilitated Diffusion: Movement of molecules via membrane proteins; no energy required.

• Osmosis: Diffusion of water across a selectively permeable membrane.

Cell Solutions: Tonicity

• Isotonic: Equal solute concentration inside and outside the cell; no net water movement.

• Hypotonic: Lower solute concentration outside; water enters cell, causing swelling.

• Hypertonic: Higher solute concentration outside; water leaves cell, causing shrinkage.

Cellular Organelles

• Mitochondria: Site of ATP (energy) production.

• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

• Endoplasmic Reticulum (ER): Rough ER synthesizes proteins; smooth ER synthesizes lipids and detoxifies.

• Peroxisomes: Break down fatty acids and detoxify harmful substances.

• Ribosomes: Synthesize proteins.

Endomembrane System

The endomembrane system includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, and plasma membrane. It coordinates the synthesis, modification, and transport of cellular materials.

Genetics: DNA Structure and Protein Synthesis

• DNA: Double helix structure; contains genes that code for proteins.

• Triplet Code: Sequence of three DNA bases codes for one amino acid.

• mRNA: Messenger RNA transcribes genetic code from DNA and carries it to ribosomes.

• tRNA: Transfer RNA brings amino acids to ribosomes during translation; anticodon pairs with mRNA codon.

Homologous Chromosomes

• Humans have 23 pairs of homologous chromosomes (46 total), carrying genes for the same traits.

Protein Synthesis

• Transcription: DNA is transcribed into mRNA in the nucleus.

• Translation: mRNA is translated into a protein at the ribosome, with tRNA bringing the correct amino acids.

Study Strategies

• Concept Mapping: Create diagrams to visualize relationships between concepts.

• Practice Questions: Test your understanding with sample questions.

• Group Study: Collaborate with peers to reinforce learning.

• Flashcards: Use for memorizing definitions and key terms.

• Regular Review: Space out study sessions for better retention.

• Utilize Resources: Supplement learning with textbooks, online materials, and videos.

Additional info: This guide covers foundational concepts from Chapters 1–3, including anatomical terminology, organ systems, body cavities, homeostasis, basic chemistry, cell structure, and genetics, as relevant to introductory anatomy and physiology courses.