BIO 259 Exam 1 Study Guide: Human Anatomy & Physiology Core Concepts

Course Introduction

Anatomy vs. Physiology

• Anatomy is the study of the structure of body parts and their relationships to one another.

• Physiology is the study of the function of the body’s structural machinery—how the body parts work and carry out their life-sustaining activities.

• Example of Form-Function Relationship: The structure of the heart’s muscular walls (form) enables it to pump blood (function) throughout the body.

Organization of the Human Body

Levels of Structural Organization

• From smallest to largest: Atoms → Molecules → Organelles → Cells → Tissues → Organs → Organ Systems → Organism

Anatomical Position

• The body is erect, facing forward, arms at the sides with palms facing forward, and feet slightly apart.

• Importance: Provides a standard reference for describing locations and directions on the body.

Directional Terms

• Cranial/Superior: Toward the head/upper part of a structure

• Caudal/Inferior: Away from the head/lower part of a structure

• Ventral/Anterior: Toward the front of the body

• Dorsal/Posterior: Toward the back of the body

• Medial: Toward the midline of the body

• Lateral: Away from the midline

• Proximal: Closer to the origin of the body part or point of attachment

• Distal: Farther from the origin or point of attachment

Body Cavities and Major Organs

Cavity	Main Organs
Dorsal Body Cavity	Brain, Spinal Cord
Thoracic Cavity	Heart, Lungs
Abdominopelvic Cavity	Digestive organs, Kidneys, Bladder, Reproductive organs
Pericardial Cavity	Heart
Pleural Cavity	Lungs

Organic Compounds

Carbon and Macromolecules

• Carbon forms four covalent bonds, allowing for a variety of stable, complex molecules essential for life.

Carbohydrates

• Monosaccharide: Simple sugar (e.g., glucose, fructose); basic unit of carbohydrates.

• Disaccharide: Two monosaccharides joined together (e.g., sucrose, lactose).

• Hexose: Six-carbon sugar (e.g., glucose, C6H12O6).

• Pentose: Five-carbon sugar (e.g., ribose, C5H10O5).

• Glucose as Energy: Easily oxidized to release energy for cellular processes.

• Hydrolysis: Breaking down a compound by adding water; e.g., splitting a disaccharide into two monosaccharides.

• Glycogen: Highly branched polysaccharide; structure allows rapid release of glucose units.

• Polysaccharide Functions: Energy storage (glycogen, starch), structural support (cellulose in plants).

Lipids

• Triglyceride Structure: Glycerol backbone + 3 fatty acids.

• Solid vs. Liquid: Saturated fats (no double bonds) are solid; unsaturated fats (one or more double bonds) are liquid at room temperature.

• Phospholipid Structure: Glycerol + 2 fatty acids + phosphate group; forms the basis of cell membranes due to hydrophilic head and hydrophobic tails.

• Steroids: Lipids with multiple hydrocarbon rings (e.g., cholesterol, hormones).

Proteins

• Amino Acid Function: Determined by the variable R group (side chain).

• Peptide Bond: Covalent bond linking amino acids in a protein.

• Protein Structure Levels:

  • Primary: Sequence of amino acids

  • Secondary: Alpha helices and beta sheets (hydrogen bonding)

  • Tertiary: 3D folding due to side chain interactions

  • Quaternary: Multiple polypeptide chains assembled together

• Fibrous Proteins: Collagen (connective tissue), Keratin (hair, nails, skin)

Nucleic Acids

• DNA: Double-stranded, deoxyribose sugar, stores genetic information

• RNA: Single-stranded, ribose sugar, involved in protein synthesis

Organelles of Cells

Determinants of Cell Function

• Cell function is determined by the types and abundance of organelles and proteins present.

Plasma (Cell) Membrane

• Defines cell boundary, regulates entry/exit of substances, and facilitates communication.

• Phospholipid Bilayer: Two layers of phospholipids with hydrophilic heads facing outward and hydrophobic tails inward; forms a semi-permeable barrier.

• Other Components: Proteins (transport, receptors), cholesterol (fluidity), carbohydrates (cell recognition).

Cytosol

• Fluid portion of cytoplasm where metabolic reactions occur.

Major Organelles and Functions

Organelle	Function
Mitochondria	ATP production via cellular respiration; inner membrane (cristae) is folded to increase surface area for energy production.
Rough ER	Protein synthesis (ribosomes attached)
Smooth ER	Lipid synthesis, detoxification
Golgi Apparatus	Modifies, sorts, and packages proteins/lipids
Microfilaments	Cell shape, movement
Microtubules	Cell structure, transport within cell
Nucleus	Contains genetic material (DNA), controls cell activities

• Ribosomes: Sites of protein synthesis

• Histones: Proteins that package and organize DNA in the nucleus

Membrane Transport

Passive vs. Active Transport

• Passive Transport: No energy required; substances move down their concentration gradient (e.g., diffusion, osmosis).

• Active Transport: Requires energy (ATP); substances move against their concentration gradient.

Diffusion

• Movement of particles from high to low concentration due to random molecular motion.

• Factors Affecting Rate: Temperature, concentration gradient, particle size, membrane permeability.

Simple vs. Facilitated Diffusion

• Simple Diffusion: Small, nonpolar molecules pass directly through the lipid bilayer.

• Facilitated Diffusion: Larger or polar molecules move via protein channels or carriers.

Osmosis

• Diffusion of water across a selectively permeable membrane.

• Requirements: Selectively permeable membrane and a difference in solute concentration.

Tonicity

Solution Type	Effect on Cell
Hypertonic	Cell shrinks (water leaves cell)
Isotonic	No net water movement; cell remains the same
Hypotonic	Cell swells (water enters cell)

Active Transport Types

• Primary Active Transport: Direct use of ATP to move substances (e.g., Na+/K+ pump).

• Secondary Active Transport (Cotransport): Uses energy from the movement of one substance down its gradient to move another substance against its gradient.

Vesicular Transport

• Endocytosis: Bringing substances into the cell

• Exocytosis: Expelling substances from the cell

• Phagocytosis: "Cell eating"—engulfing large particles

• Pinocytosis: "Cell drinking"—engulfing extracellular fluid

Cellular Respiration

Overview

• Majority occurs in the mitochondria.

• Inputs: Glucose, oxygen

• Byproducts: Carbon dioxide, water, ATP

Redox Reactions

• Involve the transfer of electrons; oxidation is loss, reduction is gain of electrons.

• Coenzymes (e.g., NAD+, FAD) carry electrons during cellular respiration.

ATP Structure and Energy

• Most energy is stored in the bonds between phosphate groups, especially the terminal phosphate bond.

Stages of Cellular Respiration

• Glycolysis: Occurs in cytosol; breaks glucose into 2 pyruvate, producing 2 ATP and 2 NADH.

• Transitional Phase: Pyruvate converted to acetyl-CoA in mitochondria, producing NADH and CO2.

• Citric Acid Cycle (Krebs Cycle): Occurs in mitochondrial matrix; for each glucose, produces 2 ATP, 6 NADH, 2 FADH2, and 4 CO2.

• Electron Transport Chain (ETC): Located in the inner mitochondrial membrane; uses electrons from NADH and FADH2 to create a proton gradient that powers ATP synthase.

ATP Synthase

• Enzyme that synthesizes ATP as protons flow down their gradient; powered by the proton motive force generated by the ETC.

Anaerobic Respiration

• When oxygen is low, cells convert pyruvate to lactate (lactic acid fermentation) to regenerate NAD+ and allow glycolysis to continue producing ATP.

Key Equations

• Overall Cellular Respiration:

$\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + 36-38~ATP}$

• ATP Hydrolysis:

$\mathrm{ATP + H_2O \rightarrow ADP + P_i + Energy}$

Additional info: Some explanations and tables were expanded for clarity and completeness based on standard introductory anatomy and physiology textbooks.