Anatomy & Physiology Study Guide: Foundations, Chemistry, Cells, and Biomolecules

Introduction to Anatomy & Physiology

Organ Systems and Their Functions

Anatomy and Physiology is the study of the structure and function of the human body. Understanding organ systems and their associated organs is foundational.

• Organ System: A group of organs that work together to perform a specific function.

• Examples:

  • Pancreas: Digestive and endocrine systems

  • Thymus: Immune system

  • Testis/Ovaries: Reproductive and endocrine systems

  • Bone marrow: Skeletal and immune systems

  • Heart: Cardiovascular system

Additional info: Some organs participate in multiple systems, reflecting the body's complexity.

Homeostasis

Homeostasis is the maintenance of a stable internal environment despite external changes.

• Definition: The body's ability to maintain equilibrium by adjusting physiological processes.

• Example: Regulation of body temperature, blood glucose levels.

Feedback Mechanisms

Feedback mechanisms help regulate homeostasis.

• Positive Feedback: Enhances or amplifies changes; moves a system away from equilibrium. Example: Blood clotting, childbirth contractions.

• Negative Feedback: Counteracts changes; maintains stability. Example: Regulation of blood sugar by insulin.

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

Basic Chemistry for Anatomy & Physiology

Key Terms and Concepts

Chemistry underpins many physiological processes. Understanding basic chemical terms is essential.

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

• Cation: Positively charged ion.

• Anion: Negatively charged ion.

• Electrolyte: Substance that produces ions in solution and conducts electricity.

• Salt: Compound formed from the reaction of an acid and a base.

• Atomic Number: Number of protons in an atom's nucleus.

• Atomic Weight: Average mass of atoms of an element.

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

• Polar Molecule: Molecule with unequal distribution of charges.

• Non-polar Molecule: Molecule with equal sharing of electrons and no charge separation.

Chemical Bonds

• Ionic Bond: Transfer of electrons between atoms, forming ions.

• Covalent Bond: Sharing of electrons between atoms.

  • Polar Covalent: Unequal sharing of electrons (e.g., H2O).

  • Non-polar Covalent: Equal sharing of electrons (e.g., O2).

• Hydrogen Bond: Weak attraction between a hydrogen atom and another electronegative atom (e.g., between water molecules).

Acids, Bases, and Buffers

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

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

• Buffer: Solution that resists changes in pH when acid or base is added.

• pH: Measure of hydrogen ion concentration; scale from 0 (acidic) to 14 (basic).

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

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

Example Buffer Equation:

$\mathrm{H}_2\mathrm{CO}_3 \rightleftharpoons \mathrm{HCO}_3^- + \mathrm{H}^+$

Reduction and Oxidation

• Reduction: Gain of electrons.

• Oxidation: Loss of electrons.

Molecular and Structural Formulas

• Molecular Formula: Shows the number and type of atoms (e.g., H2O).

• Structural Formula: Shows arrangement of atoms.

Water Molecule: Each H2O contains 1 oxygen and 2 hydrogen atoms; 5 H2O means 5 molecules.

Biomolecules and Chemical Reactions

Dehydration vs. Hydrolysis

• Dehydration Synthesis: Formation of larger molecules by removal of water.

• Hydrolysis: Breakdown of molecules by addition of water.

Monomers of Biomolecules

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

• Proteins: Monomer is amino acid.

• Lipids: Monomer is fatty acid and glycerol.

• Nucleic Acids: Monomer is nucleotide.

Saturated vs. Unsaturated Lipids

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

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

Enzymes and Reaction Rates

• Enzyme: Biological catalyst that speeds up chemical reactions.

• Factors Increasing Reaction Rate:

  1. Higher temperature

  2. Increased enzyme concentration

  3. Optimal pH

  4. Substrate concentration

• Denaturation: Loss of enzyme structure and function due to extreme conditions.

• Temperature Effect: High temperatures can denature enzymes; low temperatures slow reaction rates.

Protein Structure

• Primary Structure: Sequence of amino acids.

• Secondary Structure: Alpha helices and beta sheets formed by hydrogen bonding.

• Tertiary Structure: 3D folding due to side chain interactions.

• Quaternary Structure: Multiple polypeptide chains forming a functional protein.

Cell Biology

Cell Organelles and Their Functions

• Nucleus: Contains genetic material (DNA).

• Mitochondria: Produces ATP (energy).

• Ribosomes: Site of protein synthesis.

• Endoplasmic Reticulum: Protein and lipid synthesis.

• Golgi Apparatus: Modifies and packages proteins.

Transcription and Translation

• Transcription: DNA is copied into mRNA.

• Translation: mRNA is used to synthesize proteins.

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

Cell Division: Mitosis and Interphase

• Purpose of Mitosis: Cell division for growth and repair.

• Stages of Mitosis (PMAT):

  1. Prophase: Chromosomes condense, spindle forms.

  2. Metaphase: Chromosomes align at cell equator.

  3. Anaphase: Sister chromatids separate.

  4. Telophase: Nuclear membranes reform.

• Interphase: Cell grows, DNA replicates.

Cell Membrane and Transport

• Components: Phospholipid bilayer, proteins, cholesterol.

• Functions of Membrane Proteins: Transport, signaling, structural support.

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

• Endocytosis: Phagocytosis (cell eating), pinocytosis (cell drinking).

• Sodium-Potassium Pump: Active transport mechanism; moves Na+ out, K+ in.

• Crenation: Shrinking of cells in hypertonic solution.

• Lysis: Bursting of cells in hypotonic solution.

DNA, Genes, and Chromosomes

• DNA: Stores genetic information; composed of nucleotides.

• Gene: Segment of DNA coding for a protein.

• Chromosome: Structure containing DNA and proteins; humans have 46 chromosomes.

Tissues and Examples

Tissue Types

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

• Epithelial Tissue: Covers body surfaces and lines cavities.

• Muscle Tissue: Enables movement.

• Nervous Tissue: Transmits electrical signals.

Example: Tendons and ligaments are made of dense connective tissue.

Cell Surface Structures

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

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

Transport Type	Energy Required?	Example
Passive Transport	No	Diffusion, Osmosis
Active Transport	Yes	Sodium-Potassium Pump
Endocytosis	Yes	Phagocytosis, Pinocytosis

Additional info: This study guide covers foundational concepts in anatomy, physiology, and biochemistry, suitable for exam preparation.