Chapter 1: Introduction to Anatomy & Physiology

Defining Anatomy and Physiology

Anatomy and physiology are foundational sciences in understanding the human body. Anatomy focuses on the structure of body parts, while physiology explores their functions.

• Anatomy: The study of the structure and relationships between body parts.

• Physiology: The study of how body parts function and work together.

• Relationship: Structure determines function; for example, the shape of bones allows for movement.

Scientific Method in Anatomy & Physiology

Scientific inquiry in anatomy and physiology uses hypotheses, facts, laws, and theories to explain biological phenomena.

• Hypothesis: A testable statement or prediction.

• Fact: An observation that has been repeatedly confirmed.

• Law: A statement based on repeated experimental observations that describes some aspect of the world.

• Theory: A well-substantiated explanation of some aspect of the natural world.

• Example: The cell theory is a foundational theory in biology.

Levels of Human Structure: Most complex to simplest

• Organism → Organ Systems → Organs→ Tissues → Cells → Organelles → Molecules → Atoms

Characteristics and processes of Living Things

All living things share certain characteristics and processes.

Characteristics of Life:

• Cells: Cells are the smallest parts of organisms. All living things are composed of cells.

• Organization: All living things have a structural arrangement more complex

  than non-living things.

• Responsiveness: Ability to sense and react to stimuli.

• Regulation: Living things have mechanisms to maintain a relatively stable

  internal environment. This stabilizing process is called homeostasis.

• Growth and Development: Growth is an increase

  in size, and it occurs as part of development. Development is

  the natural progression in physical maturation, such as a seed

  becoming a plant.

• Reproduction: The process by which organisms produce offspring

• Metabolism: All chemical reactions in the body.

Processes of Life:

• Respiration: A fundamental process of life involving

  energy production.

• Digestion: The mechanical and chemical process that

  converts the nutrients in ingested food into simpler

  substances the body can use.

• Circulation: The internal movement and distribution

  of oxygen, cellular wastes, and the products of

  digestion

• Excretion: The process in which undigested food and

  the wastes of metabolism are eliminated.

Homeostasis

Homeostasis is the process by which the body maintains a stable internal environment.

Why is the concept of Homeostasis central to physiology?

What happens if we don't maintain Homeostasis? Failure to maintain homeostasis soon leads to illness or even death. We maintain homeostasis through negative and positive feedback

• Negative Feedback: Mechanism that reverses a change to keep conditions stable (e.g., body temperature regulation). Example: Sweating to cool the body is negative feedback. Importance: It counteracts or reverses changes in the bodies internal environment to return the body to homeostasis.

• Positive Feedback: Mechanism that amplifies a change. Example: Blood Clotting. Positive feedback can be beneficial because of it's quick and decisive actions to return homeostasis. It's drawbacks is that the responses can be quite extreme which can cause instability.

Anatomical Position and Directional Terms

Standard anatomical position and directional terms are used to describe locations and relationships of body parts.

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

• Supine: Face upward on your back.

• Prone: Face down on your belly.

Directional Terms: Used to describe relative positions.

• Caudal: Toward the tail.

• Cephalic: Toward the head.

• Anterior: The front surface.

• posterior: The back surface.

• superior: Above; at a higher level

• inferior: Lower; at a lower level

• Planes: Sagittal, frontal (coronal), transverse, oblique.

• Proximal: Toward the point of attachment of the trunk

• Distal: Away from the point of attachment of the trunk

• Medial: Toward the midline

• Lateral: Away from the midline

  Planes

• Frontal or coronal (Brain) plane: Separates front (anterior) and back (posterior) planes.

• Sagittal: Separates the body into right and left sides. Midsagittal separates into equal right and left sides. Parasagittal separates into unequal right and left sides.

• Transverse: Separates superior and inferior sides.

• Oblique: Separates the body at an angle.

Chapter 2: Chemistry of Life

Properties of Water

Water is essential for life due to its unique chemical and physical properties.

• Cohesion: Water molecules stick together.

• Adhesion: Water molecules stick to other surfaces.

• High Heat of Vaporization: Water requires much energy to change from liquid to gas.

• How do hydrogen bond relate to the properties of water? Hydrogen bonds give water its high heat of vaporization because breaking these bonds requires a significant amount of energy which prevents water molecules from separating into gas easily.

Atoms and Elements

Atoms are the basic units of matter, composed of subatomic particles.

• Elements: A pure substance that cannot be broken down into simpler chemical substances by ordinary means.

• Protons: Positively charged particles in the nucleus.

• Neutrons: Neutral particles in the nucleus.

• Electrons: Negatively charged particles orbiting the nucleus.

• Atomic Number: Number of protons in an atom.

• Mass Number: Sum of protons and neutrons.

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

Molecules and Chemical Bonds

Molecules are formed by atoms bonded together; the type of bond affects molecular properties.

• Ionic Bonds: Transfer of electrons between atoms.

• Covalent Bonds: Sharing of electrons between atoms.

• Polar vs. Nonpolar: Polar molecules have unequal sharing of electrons; nonpolar have equal sharing.

Acids, Bases, and Buffers

Acids and bases affect pH; buffers help maintain pH stability in biological systems.

• Acid: Substance that releases hydrogen ions ().

• Base: Substance that accepts hydrogen ions.

• Buffer: Substance that minimizes changes in pH.

• pH Scale: Measures acidity/alkalinity;

Organic Molecules

Organic molecules contain carbon and are essential for life.

• Carbohydrates: Provide energy; made of monosaccharides.

• Lipids: Store energy, form cell membranes.

• Proteins: Made of amino acids; perform various functions.

• Nucleic Acids: DNA and RNA; store genetic information.

Macromolecules and Their Functions

Macromolecules are large, complex molecules with specific functions.

• Carbohydrates: Energy source; structure in plants.

• Lipids: Energy storage; insulation; cell membrane structure.

• Proteins: Enzymes, structural support, transport.

• Nucleic Acids: Genetic information storage and transfer.

Dehydration Synthesis and Hydrolysis

Macromolecules are formed and broken down by specific chemical reactions.

• Dehydration Synthesis: Joining molecules by removing water.

• Hydrolysis: Breaking molecules by adding water.

Protein Structure

Proteins have four levels of structure that determine their function.

• Primary: Sequence of amino acids.

• Secondary: Alpha helices and beta sheets.

• Tertiary: 3D folding of the polypeptide.

• Quaternary: Multiple polypeptides joined together.

• Denaturation: Loss of structure and function due to environmental changes.

Hydrophilic vs. Hydrophobic

Molecules can be hydrophilic (water-loving) or hydrophobic (water-fearing), affecting their behavior in biological systems.

• Hydrophilic: Attracted to water; often polar.

• Hydrophobic: Repelled by water; often nonpolar.

Chapter 3: Cellular Structure and Function

Cell Theory

The cell theory is a fundamental concept in biology describing the properties of cells.

• All living things are composed of cells.

• Cells are the basic units of structure and function in living things.

• All cells come from pre-existing cells.

Cell Membrane Structure

The cell membrane is a dynamic structure that controls the movement of substances in and out of the cell.

• Phospholipid Bilayer: Main component; hydrophilic heads and hydrophobic tails.

• Proteins: Integral and peripheral; involved in transport and signaling.

• Other Structures: Microvilli (increase surface area), cilia (movement), flagella (locomotion).

Membrane Transport

Cells use various mechanisms to move substances across membranes.

• Passive Transport: No energy (ATP) required; Includes diffusion, facilitated diffusion, osmosis.

• Diffusion: Movement of ions/molecules in the air or water, does not require membrane

• Facilitated Diffusion: Movement of ions/molecules across a membrane through protein channels

• Osmosis: Movement of water across a membrane.

• Active Transport: Requires energy (ATP); includes pumps, endocytosis, exocytosis.

• Pumps:

• Endocytosis:

• Exocytosis:

Cell Organelles

Organelles are specialized structures within cells that perform specific functions.

• Cytoplasm: Gel-like substance where organelles are suspended.

• Membranous Organelles: Nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus.

• Non-membranous Organelles: Ribosomes, cytoskeleton.

Protein Synthesis

Protein synthesis involves transcription and translation, converting genetic information into functional proteins.

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

• Translation: mRNA is used to assemble amino acids into proteins at ribosomes.

Cell Cycle and Mitosis

The cell cycle describes the life stages of a cell, including division by mitosis.

• Main Phases: Interphase (growth, DNA replication), Mitosis (division).

• Mitosis Stages: Prophase, Metaphase, Anaphase, Telophase.

• Chromosomes: Structures containing DNA; number varies between mitosis and meiosis.

• Centromere: Region where sister chromatids are joined.

Cancer and Cell Division

Cancer results from uncontrolled cell division; understanding cell cycle regulation is key to understanding cancer.

• Benign: Non-cancerous growth.

• Malignant: Cancerous, invasive growth.

• Metastasis: Spread of cancer cells to other parts of the body.

DNA Replication

DNA replication is the process by which DNA makes a copy of itself before cell division.

• Occurs during: Interphase, before mitosis.

• Ensures: Each daughter cell receives an identical set of DNA.

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