Introduction to Anatomy & Physiology

This study guide covers foundational concepts in anatomy and physiology, including organ systems, basic chemistry, cell structure, and molecular biology. Understanding these topics is essential for success in a college-level A&P course.

Organ Systems and Homeostasis

Functions of Organ Systems

• Organ Systems: Groups of organs that work together to perform major functions in the body (e.g., digestive, respiratory, circulatory systems).

• Organ Overlap: Some organs belong to more than one system (e.g., pancreas in digestive and endocrine systems; thymus in lymphatic and endocrine systems; testes/ovaries in reproductive and endocrine systems; bone marrow in skeletal and immune systems; heart in circulatory system).

Homeostasis

• Definition: The maintenance of a stable internal environment despite external changes.

• Importance: Essential for normal cell function and overall health.

Feedback Mechanisms

• Positive Feedback: Enhances or amplifies changes; tends to move a system away from its equilibrium state (e.g., blood clotting, childbirth).

• Negative Feedback: Counteracts changes; returns a system to its set point (e.g., regulation of body temperature, blood glucose levels).

• Stimulus: Any change in the environment that elicits a response from the body.

Example: In blood glucose regulation, increased blood sugar stimulates insulin release (negative feedback) to lower glucose levels.

Basic Chemistry for Anatomy & Physiology

Key Terms and Definitions

• Ion: An atom or molecule with a net electric charge due to the loss or gain of electrons.

• Cation: A positively charged ion.

• Anion: A negatively charged ion.

• Electrolyte: A substance that produces ions when dissolved in water and conducts electricity.

• Salt: An ionic compound formed from the neutralization reaction of an acid and a base.

• Atomic Number: The number of protons in the nucleus of an atom.

• Atomic Weight: The average mass of atoms of an element, measured in atomic mass units (amu).

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

• Polar Molecule: A molecule with an uneven distribution of charge, resulting in positive and negative ends (e.g., water).

• Non-polar Molecule: A molecule with an even distribution of charge.

Chemical Bonds

• Ionic Bond: Formed when electrons are transferred from one atom to another, creating ions.

• Covalent Bond: Formed when atoms share electrons.

• Hydrogen Bond: A weak bond between a hydrogen atom and an electronegative atom (e.g., between water molecules).

Acids, Bases, and Buffers

• Acid: A substance that releases hydrogen ions (H+) in solution.

• Base: A substance that accepts hydrogen ions or releases hydroxide ions (OH-).

• Buffer: A solution that resists changes in pH when acids or bases are added.

• pH: A measure of hydrogen ion concentration.

• Strong Acid: Completely dissociates in water (e.g., HCl).

• Weak Acid: Partially dissociates in water (e.g., acetic acid).

Example: Buffer system: (carbonic acid-bicarbonate buffer in blood)

Redox Reactions

• Oxidation: Loss of electrons.

• Reduction: Gain of electrons.

• Example: (hydrogen peroxide decomposition)

Molecular and Structural Formulas

• Molecular Formula: Shows the number and type of atoms in a molecule (e.g., ).

• Structural Formula: Shows the arrangement of atoms within the molecule.

• Water: Each molecule of water contains 2 hydrogen atoms and 1 oxygen atom; 5 molecules of water: .

Biological Macromolecules

Monomers and Polymers

• Carbohydrates: Monomer = monosaccharide (e.g., glucose)

• Proteins: Monomer = amino acid

• Lipids: Monomer = fatty acids and glycerol

• Nucleic Acids: Monomer = nucleotide

Saturated vs. Unsaturated Lipids

• Saturated: No double bonds between carbon atoms; solid at room temperature (e.g., butter).

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

Enzymes

• Definition: Biological catalysts that speed up chemical reactions without being consumed.

• Denaturation: Loss of enzyme structure and function due to extreme conditions (e.g., high temperature, pH).

• Temperature Effect: Enzyme activity increases with temperature up to an optimum, then decreases due to denaturation.

• Factors Increasing Reaction Rate: Higher temperature (to a point), increased substrate concentration, optimal pH, presence of cofactors.

Protein Structure

• Primary Structure: Sequence of amino acids.

• Secondary Structure: Local folding (alpha helices, beta sheets).

• Tertiary Structure: 3D shape of a single polypeptide.

• Quaternary Structure: Association of multiple polypeptide chains.

Cell Structure and Function

Organelles and Their Functions

• Nucleus: Contains genetic material (DNA).

• Mitochondria: Site of ATP production.

• Ribosomes: Protein synthesis.

• Endoplasmic Reticulum: Protein and lipid synthesis.

• Golgi Apparatus: Modifies and packages proteins.

Cell Membrane

• Components: Phospholipid bilayer, proteins, cholesterol, carbohydrates.

• Functions: Selective barrier, communication, transport.

• Membrane Proteins: Transport, receptors, enzymes, structural support.

Transport Across Membranes

• Passive Transport: Movement of substances without energy (e.g., diffusion, osmosis).

• Active Transport: Requires energy (e.g., sodium-potassium pump).

• Endocytosis: Uptake of materials (phagocytosis = "cell eating", pinocytosis = "cell drinking").

• Osmosis: Movement of water across a membrane.

• Hypertonic Solution: Higher solute concentration outside cell; cell shrinks (crenation).

• Hypotonic Solution: Lower solute concentration outside cell; cell swells (lysis).

• Isotonic Solution: Equal solute concentration; no net water movement.

Cell Surface Structures

• Microvilli: Increase surface area for absorption; found in intestines.

• Cilia: Move substances across cell surface; found in respiratory tract.

Cell Division and Genetic Material

Mitosis

• Purpose: Cell division for growth and repair.

• Stages (PMAT):

  • Prophase: Chromosomes condense, nuclear envelope dissolves.

  • Metaphase: Chromosomes align at cell equator.

  • Anaphase: Sister chromatids separate.

  • Telophase: Nuclear envelopes reform, chromosomes decondense.

• Interphase: Cell grows, DNA replicates, prepares for division.

Transcription and Translation

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

• Translation: mRNA is decoded by ribosomes to synthesize proteins.

• Key Components: mRNA, tRNA, ribosomes, introns, exons.

DNA, Genes, and Chromosomes

• DNA: Deoxyribonucleic acid; stores genetic information.

• Monomer: Nucleotide (composed of a sugar, phosphate, and nitrogenous base).

• Gene: A segment of DNA that codes for a protein.

• Chromosome: A structure composed of DNA and proteins that contains many genes.

• Complimentary DNA Strand: Base pairing rules: A-T, C-G.

Tissues

Types and Examples

• Connective Tissue: Supports and binds other tissues (e.g., tendons, ligaments).

• Muscle Tissue: Responsible for movement.

• Epithelial Tissue: Covers body surfaces and lines cavities.

• Nervous Tissue: Transmits electrical impulses.

Example: Tendons and ligaments are composed of dense regular connective tissue.

Summary Table: Key Chemical Terms

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