Exam 1 Study Guide: Essentials of Anatomy & Physiology

Basics of Anatomy & Physiology

What is Anatomy & 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.

• Both fields are interrelated: structure determines function.

Ways to Study A&P and Branches

• Anatomy branches: Gross (macroscopic), Microscopic (histology, cytology), Developmental (embryology).

• Physiology branches: Cell physiology, Organ physiology, Systemic physiology, Pathophysiology.

Structural Hierarchy of the Human Body

Levels of Organization

• Chemical level: Atoms and molecules.

• Cellular level: Cells, the basic unit of life.

• Tissue level: Groups of similar cells performing a common function.

• Organ level: Structures composed of at least two types of tissues.

• Organ system level: Organs working together for a common purpose.

• Organismal level: The living human being.

Body Systems and Their Main Functions

• Integumentary System: Protection, temperature regulation, sensation.

• Muscular System: Movement, posture, heat production.

• Skeletal System: Support, protection, movement, blood cell production.

• Nervous System: Control, communication, integration of body functions.

Necessary Life Functions

• Maintaining boundaries: Plasma membrane regulates entry/exit of substances.

• Movement: Muscular system enables movement.

• Responsiveness: Ability to sense and respond to stimuli.

• Digestion: Breakdown of food for absorption.

• Metabolism: All chemical reactions in the body.

• Excretion: Removal of wastes.

• Reproduction: Cellular and organismal reproduction.

• Growth: Increase in size and number of cells.

Homeostasis & Biological Control Systems

Components of Control Systems

• Sensor (Receptor): Detects changes (e.g., thermoreceptors).

• Control Center: Processes information and determines response (e.g., brain).

• Effector: Carries out the response (e.g., sweat glands).

Examples

• Walking outside in heat: Thermoreceptors (sensor) detect temperature, hypothalamus (control center) initiates sweating (effector).

Feedback Mechanisms

Negative vs. Positive Feedback

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

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

Anatomical Position and Directional Terms

• Anatomical Position: Standing, facing forward, arms at sides, palms forward.

• Directional Terms: Medial, lateral, proximal, distal, superior, inferior, anterior, posterior.

Abdominopelvic Quadrants and Regions

Quadrants and Organs

• Right Upper Quadrant (RUQ): Liver, gallbladder.

• Left Upper Quadrant (LUQ): Stomach, spleen.

• Right Lower Quadrant (RLQ): Appendix.

• Left Lower Quadrant (LLQ): Descending colon.

Regions

• Spleen: Left hypochondriac region.

• Stomach: Epigastric and left hypochondriac regions.

Anatomical Planes

• Sagittal: Divides body into left and right.

• Frontal (Coronal): Divides body into anterior and posterior.

• Transverse: Divides body into superior and inferior.

Internal Cavities

• Dorsal cavity: Contains brain and spinal cord.

• Ventral cavity: Contains thoracic and abdominopelvic cavities.

Energy and Its Forms

• Kinetic energy: Energy of motion.

• Potential energy: Stored energy.

• Energy conversion: Chemical energy (ATP) to mechanical energy (muscle contraction).

Elements and Their Properties

• Protons: Positive charge, determine element identity.

• Neutrons: No charge, contribute to mass.

• Electrons: Negative charge, involved in chemical bonds.

• Major body elements: Oxygen, carbon, hydrogen, nitrogen.

• Elements differ by number of protons.

Isotopes

• Isotopes are atoms of the same element with different numbers of neutrons.

Mixtures

• Solutions: Homogeneous, e.g., salt water.

• Colloids: Heterogeneous, particles do not settle, e.g., cytosol.

• Suspensions: Heterogeneous, particles settle, e.g., blood.

Chemical Bonds

• Bonds are relationships between electrons of atoms.

• Ionic bonds: Transfer of electrons.

• Covalent bonds: Sharing of electrons.

• Hydrogen bonds: Weak attractions between polar molecules.

Chemical Reactions

• Synthesis: Building larger molecules.

• Decomposition: Breaking down molecules.

• Rate affected by temperature, concentration, catalysts.

pH and Buffer Systems

• pH: Measure of H+ concentration.

• More acidic = more H+ = low pH.

• Bicarbonate buffer: Helps maintain pH by neutralizing acids and bases.

• Acid: Donates H+.

• Base: Accepts H+.

$\mathrm{CO_2 + H_2O \leftrightarrow H_2CO_3 \leftrightarrow H^+ + HCO_3^-}$

Macromolecules: Carbohydrates, Fats, Proteins

• Carbohydrates: Energy source, e.g., glucose.

• Fats (Lipids): Energy storage, insulation.

• Proteins: Structure, enzymes, transport.

Enzymes

• Proteins that catalyze reactions.

• Optimal temperature and pH required.

• Denaturation: Loss of function due to changes in environment.

DNA vs. RNA

• DNA: Double-stranded, stores genetic information.

• RNA: Single-stranded, involved in protein synthesis.

Plasma Membrane

• Composed of phospholipid bilayer, proteins, cholesterol.

• Regulates entry and exit of substances.

Cell Junctions

• Tight junctions: Prevent leakage.

• Desmosomes: Provide strength.

• Gap junctions: Allow communication.

Transport Across Membranes

• Passive transport: No energy required (diffusion, osmosis, facilitated diffusion).

• Active transport: Requires energy (pumps, endocytosis, exocytosis).

Tonicity

• Hypotonic: Lower solute concentration outside cell; cell swells.

• Hypertonic: Higher solute concentration outside cell; cell shrinks.

Endocytosis and Exocytosis

• Endocytosis: Cell takes in material (phagocytosis, pinocytosis, receptor-mediated).

• Exocytosis: Cell expels material.

Resting Membrane Potential

• Inside of cell is negative relative to outside.

• Maintained by ion gradients and membrane permeability.

$\mathrm{Na^+/K^+}$ pump maintains resting potential.

Ligands and Receptors

• Ligands: Molecules that bind to receptors.

• Receptors: Proteins that receive signals.

Parts of the Cell

• Nucleus: Contains DNA.

• Mitochondria: Powerhouse, ATP production.

• Ribosomes: Protein synthesis.

• Endoplasmic reticulum: Synthesis and transport.

• Golgi apparatus: Packaging and distribution.

• Lysosomes: Digestion.

• Extensions: Cilia, flagella.

Cell Cycle

• DNA replication: Semiconservative process.

• Mitosis: Division of nucleus (prophase, metaphase, anaphase, telophase).

• If DNA is ATG, complementary DNA strand is TAC.

Protein Synthesis

• Transcription: DNA to RNA.

• Translation: RNA to protein.

• If DNA is ATG, RNA strand is UAC.

• Central dogma: DNA → RNA → Protein.

$\mathrm{DNA \rightarrow RNA \rightarrow Protein}$