Chapter 1: Introduction to Anatomy & Physiology

1. Definitions and Relationships

Anatomy and physiology are foundational sciences in understanding the human body. Anatomy is the study of body structure, while physiology focuses on function. These disciplines are closely related because structure often determines function.

• Anatomy: The study of the structure and shape of the body and its parts.

• Physiology: The study of how the body and its parts work or function.

• Relationship: Structure (anatomy) enables function (physiology); for example, the shape of the heart allows it to pump blood.

• Importance: Studying both together helps us understand how the body works as a whole.

2. Hierarchy of Structural Organization

The human body is organized in a hierarchical manner, from the smallest chemical level to the entire organism.

• Chemical level: Atoms and molecules

• Cellular level: Cells and their organelles

• Tissue level: Groups of similar cells

• Organ level: Contains two or more types of tissues

• Organ system level: Organs that work closely together

• Organismal level: All organ systems combined to make the whole organism

3. Necessary Life Functions

For something to be considered alive, it must perform certain functions.

• Maintaining boundaries (e.g., cell membranes)

• Movement (muscular system, movement of substances)

• Responsiveness (ability to sense and respond to stimuli)

• Digestion (breakdown of ingested food)

• Metabolism (all chemical reactions in the body)

• Excretion (removal of wastes)

• Reproduction (cellular and organismal levels)

• Growth (increase in size and number of cells)

4. Basic Needs for Survival

The body requires certain factors from the environment to survive.

• Nutrients (for energy and cell building)

• Oxygen (for metabolic reactions)

• Water (most abundant chemical in the body)

• Normal body temperature (for proper metabolic reactions)

• Appropriate atmospheric pressure (for gas exchange in the lungs)

5. Homeostasis and Feedback Mechanisms

Homeostasis is the maintenance of a stable internal environment. Feedback mechanisms help maintain homeostasis.

• Homeostasis: The body's ability to maintain relatively stable internal conditions despite changes in the external environment.

• Positive feedback: Enhances the original stimulus (e.g., blood clotting, labor contractions).

• Negative feedback: Reduces or shuts off the original stimulus (e.g., regulation of body temperature, blood glucose levels).

6. Regional and Directional Terms

Understanding anatomical terminology is essential for describing locations and relationships in the body.

• Directional terms: Superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep.

• Regional terms: Used to designate specific areas (e.g., brachial for arm, femoral for thigh).

• Body cavities: Dorsal (cranial and vertebral), ventral (thoracic and abdominopelvic).

Chapter 2: Basic Chemistry and Biochemistry

1. Energy and Its Forms

Energy is the capacity to do work. It exists in various forms in the body.

• Potential energy: Stored energy (e.g., chemical bonds).

• Kinetic energy: Energy of motion (e.g., movement of muscles).

• Forms of energy: Chemical, electrical, mechanical, radiant.

2. Atoms, Elements, and Isotopes

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

• Proton: Positively charged particle in the nucleus.

• Neutron: Neutral particle in the nucleus.

• Electron: Negatively charged particle orbiting the nucleus.

• Atomic number: Number of protons.

• Atomic weight: Sum of protons and neutrons.

• Isotopes: Atoms with the same number of protons but different numbers of neutrons.

3. Solutions, Colloids, and Suspensions

Mixtures are combinations of two or more substances.

• Solution: Homogeneous mixture (e.g., salt water).

• Colloid: Heterogeneous mixture with intermediate particle size (e.g., cytosol).

• Suspension: Heterogeneous mixture with large particles that settle out (e.g., blood).

4. Chemical Bonds and Reactions

Chemical bonds hold atoms together. Chemical reactions involve making or breaking these bonds.

• Ionic bonds: Transfer of electrons (e.g., NaCl).

• Covalent bonds: Sharing of electrons; can be polar or nonpolar.

• Hydrogen bonds: Weak attractions between polar molecules.

• Decomposition reaction: AB → A + B

• Synthesis reaction: A + B → AB

• Exchange reaction: AB + CD → AD + CB

• Redox reactions: Involve electron transfer (oxidation and reduction).

• Hydrolysis: Addition of water to break bonds.

5. Water, Acids, Bases, and Buffers

Water is vital for life. Acids and bases affect pH, and buffers help maintain pH balance.

• Water: Universal solvent, high heat capacity, important for chemical reactions.

• Acid: Proton donor, increases H+ concentration.

• Base: Proton acceptor, decreases H+ concentration.

• pH scale: Measures hydrogen ion concentration; 7 is neutral, below 7 is acidic, above 7 is basic.

• Buffers: Resist changes in pH (e.g., bicarbonate buffer system in blood).

6. Organic Molecules: Carbohydrates, Lipids, Proteins, Nucleic Acids

Organic molecules are essential for structure and function in the body.

• Carbohydrates: Sugars and starches; monomers are monosaccharides (e.g., glucose).

• Lipids: Fats, oils, phospholipids, steroids; important for energy storage and cell membranes.

• Proteins: Made of amino acids; function as enzymes, structural components, etc.

• Nucleic acids: DNA and RNA; store and transmit genetic information.

7. Factors Affecting Chemical Reactions

Chemical reaction rates are influenced by several factors.

• Temperature: Higher temperature increases reaction rate.

• Concentration: Higher concentration increases reaction rate.

• Particle size: Smaller particles increase reaction rate.

• Catalysts: Enzymes speed up reactions without being consumed.

Chapter 3: The Cell

1. Cell Theory and Structure

The cell is the basic unit of life. All living things are composed of cells.

• Three features of all cells: Plasma membrane, cytoplasm, nucleus.

• Extracellular materials: Substances outside the cell (e.g., interstitial fluid, blood plasma).

2. Plasma Membrane and Transport

The plasma membrane controls what enters and leaves the cell.

• Structure: Phospholipid bilayer with embedded proteins.

• Functions: Selective permeability, communication, cell recognition.

• Diffusion: Movement of molecules from high to low concentration.

• Osmosis: Diffusion of water across a membrane.

• Facilitated diffusion: Uses carrier proteins.

• Active transport: Moves substances against concentration gradient using ATP.

• Endocytosis: Cell takes in material by forming vesicles.

• Exocytosis: Cell expels material using vesicles.

3. Cell Interactions and Organelles

Cells interact with each other and their environment through direct and indirect means. Organelles perform specialized functions.

• Direct interactions: Cell junctions (tight, desmosomes, gap junctions).

• Indirect interactions: Chemical signaling.

• Organelles:

  • Mitochondria: ATP production.

  • Ribosomes: Protein synthesis.

  • Endoplasmic reticulum: Smooth (lipid synthesis), rough (protein synthesis).

  • Golgi apparatus: Modifies and packages proteins.

  • Lysosomes: Digestive enzymes.

  • Peroxisomes: Detoxification.

  • Cytoskeleton: Structural support.

4. Cellular Extensions and Cell Cycle

Cells may have extensions for movement or absorption. The cell cycle includes phases of growth and division.

• Cellular extensions: Microvilli (increase surface area), cilia (movement), flagella (movement).

• Cell cycle phases: Interphase (growth), mitosis (division), cytokinesis (cytoplasm division).

• Mitosis stages: Prophase, metaphase, anaphase, telophase.

5. Protein Synthesis, Autophagy, and Apoptosis

Cells synthesize proteins and regulate their own survival and death.

• Protein synthesis: Transcription (DNA to RNA), translation (RNA to protein).

• Autophagy: Self-digestion of cell components.

• Apoptosis: Programmed cell death.

Chapter 4: Tissues and Organ Systems

1. Epithelial Tissue

Epithelial tissue covers body surfaces and lines cavities.

• Functions: Protection, absorption, filtration, secretion.

• Classification: By cell shape (squamous, cuboidal, columnar) and layers (simple, stratified).

• Glands: Endocrine (secrete hormones), exocrine (secrete onto surfaces).

2. Connective Tissue

Connective tissue supports, protects, and binds other tissues.

• Components: Cells, fibers (collagen, elastic, reticular), ground substance.

• Types: Loose, dense, cartilage, bone, blood.

3. Muscle Tissue

Muscle tissue is responsible for movement.

• Types: Skeletal (voluntary), cardiac (heart), smooth (walls of organs).

4. Nervous Tissue

Nervous tissue transmits electrical impulses for communication.

• Cells: Neurons (transmit signals), neuroglia (support neurons).

• Function: Control and communication within the body.

5. Membranes

Body membranes line cavities and cover surfaces.

• Cutaneous membrane: Skin; dry, protective.

• Mucous membrane: Lines body cavities open to the exterior; moist.

• Serous membrane: Lines closed body cavities; produces serous fluid.