Foundations of Anatomy & Physiology: Study Notes

Chapter 1: Introduction to Anatomy & Physiology

Distinguishing Anatomy and Physiology

Anatomy and physiology are foundational sciences in understanding the human body. Anatomy is the study of the structure and organization of living organisms, while physiology focuses on the functions and processes of those structures.

• Anatomy: Examines body parts, their locations, and relationships.

• Physiology: Explores how body parts work and interact to sustain life.

• Example: Studying the heart's chambers (anatomy) vs. understanding how the heart pumps blood (physiology).

Subfields of Human Biology

Human biology encompasses several subfields, each focusing on specific aspects of the body.

• Histology: Study of tissues.

• Cytology: Study of cells.

• Pathology: Study of disease.

• Embryology: Study of development from fertilization to birth.

Levels of Organization in the Human Body

The human body is organized into hierarchical levels, each building upon the previous.

• Chemical level: Atoms and molecules.

• Cellular level: Cells and their organelles.

• Tissue level: Groups of similar cells.

• Organ level: Structures composed of multiple tissue types.

• Organ system level: Groups of organs working together.

• Organismal level: The complete living being.

The 11 Organ Systems

The body is composed of 11 major organ systems, each with specific functions.

• Integumentary

• Skeletal

• Muscular

• Nervous

• Endocrine

• Cardiovascular

• Lymphatic

• Respiratory

• Digestive

• Urinary

• Reproductive

Anatomical Terms and Body Regions

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

• Body planes: Sagittal, frontal (coronal), transverse.

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

• Abdominopelvic regions: Nine regions (e.g., epigastric, umbilical, hypogastric).

Membranes and Organs in Body Cavities

Body cavities contain organs surrounded by specific membranes.

• Serous membranes: Line body cavities and cover organs (e.g., pleura, pericardium, peritoneum).

• Retroperitoneal organs: Located behind the peritoneum (e.g., kidneys).

Homeostasis and Feedback Mechanisms

Homeostasis is the maintenance of a stable internal environment. It is regulated by feedback loops.

• Negative feedback: Reduces deviation from a set point (e.g., body temperature regulation).

• Positive feedback: Amplifies changes (e.g., blood clotting, labor contractions).

• Homeostatic regulatory mechanism: Consists of receptor, control center, and effector.

Chapter 2: Chemical Foundations of Life

Atoms, Elements, Molecules, and Compounds

All matter is composed of atoms, which combine to form elements, molecules, and compounds.

• Atom: Smallest unit of an element, composed of protons, neutrons, and electrons.

• Element: Substance made of one type of atom.

• Molecule: Two or more atoms bonded together.

• Compound: Molecule containing different elements.

Subatomic Particles

Atoms consist of subatomic particles with distinct properties.

• Proton: Positive charge, found in nucleus.

• Neutron: No charge, found in nucleus.

• Electron: Negative charge, orbits nucleus.

Isotopes

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

• Example: Carbon-12 and Carbon-14.

Chemical Bonds

Atoms interact to form chemical bonds, which hold molecules together.

• Covalent bonds: Atoms share electrons; can be polar or nonpolar.

• Ionic bonds: Transfer of electrons between atoms.

• Hydrogen bonds: Weak attractions between polar molecules.

Properties of Water

Water is essential for life due to its unique properties.

• Polarity: Water is a polar molecule.

• Cohesion and adhesion: Water molecules stick to each other and other surfaces.

• High specific heat: Water resists temperature changes.

pH and Acids/Bases

pH measures the concentration of hydrogen ions in a solution.

• Acid: Releases H+ ions; pH < 7.

• Base: Accepts H+ ions; pH > 7.

• Neutral: pH = 7.

• Formula: $\text{pH} = -\log_{10}[\text{H}^+]$

Metabolism, Anabolism, and Catabolism

Metabolism is the sum of all chemical reactions in the body. It includes:

• Anabolism: Building complex molecules from simpler ones (requires energy).

• Catabolism: Breaking down complex molecules into simpler ones (releases energy).

• Condensation (dehydration synthesis): Forms bonds by removing water.

• Hydrolysis: Breaks bonds by adding water.

Kinetic vs. Potential Energy

Energy exists in two main forms:

• Kinetic energy: Energy of motion.

• Potential energy: Stored energy.

Enzymes

Enzymes are biological catalysts that speed up chemical reactions without being consumed.

• Function: Lower activation energy of reactions.

• Example: Amylase breaks down starch into sugars.

Biological Macromolecules

Monomers, Polymers, and Functions

Biological macromolecules are large molecules essential for life, composed of smaller units called monomers.

Biomacromolecule	Monomers (atom composition)	Polymers	Functions
Carbohydrates	Monosaccharides (C, H, O)	Cellulose, Starch, Glycogen	Energy storage, structural support
Nucleic Acids	Nucleotides (RNA, DNA)	RNA, DNA	Genetic information, protein synthesis
Proteins	Amino acids (C, H, O, N, S)	Polypeptides	Movement, speeding up reactions (enzymes), structural support
Lipids	Fatty acids, glycerol (C, H, O)	Triglycerides, phospholipids, steroids	Energy storage, membrane structure, signaling

Additional info: Amino acids undergo dehydration reactions to form peptide bonds.

The four levels of protein structure

The shape of a protein can be described by four levels of structure: primary, secondary, tertiary and quaternary.

Cell Structure and Function

DNA Organization in the Cell

DNA is organized into chromosomes within the nucleus. Chromatin is the complex of DNA and proteins.

• Chromosomes: Condensed DNA during cell division.

• Chromatin: Loosely packed DNA during interphase.

Saturated vs. Unsaturated Lipids

Lipids are classified based on the presence of double bonds in their fatty acid chains.

• Saturated lipids: No double bonds; solid at room temperature.

• Unsaturated lipids: One or more double bonds; liquid at room temperature.

Plasma Membrane Structure

The plasma membrane is a selectively permeable barrier composed of a phospholipid bilayer with embedded proteins.

• Integral proteins: Span the membrane; involved in transport.

• Peripheral proteins: Attached to the surface; involved in signaling and support.

Glycocalyx: Structure and Function

The glycocalyx is a carbohydrate-rich layer on the cell surface.

• Structure: Glycoproteins and glycolipids.

• Function: Cell recognition, protection, adhesion.

Cell Organelles and Their Functions

Cells contain specialized organelles, each with distinct functions.

• Nucleus: Contains genetic material.

• Mitochondria: Produce ATP via cellular respiration.

• Endoplasmic reticulum (ER): Protein and lipid synthesis.

• Golgi apparatus: Modifies and packages proteins.

• Lysosomes: Digest cellular waste.

• Ribosomes: Protein synthesis.

Flow of Genetic Information

Genetic information flows from DNA to RNA to protein.

• Transcription: DNA to RNA.

• Translation: RNA to protein.

Enzymes in DNA Replication

Several enzymes are involved in DNA replication.

• Helicase: Unwinds DNA.

• DNA polymerase: Synthesizes new DNA strands.

• Ligase: Joins DNA fragments.

Transport Across Biological Membranes

Cells transport substances across membranes via passive and active mechanisms.

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

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

• Carrier-mediated transport: Uses specific proteins to move substances.

• Vesicular transport: Uses vesicles for bulk transport (e.g., endocytosis, exocytosis).

Cell Cycle and Regulation

The cell cycle consists of stages that regulate cell growth and division.

• Interphase: Cell growth, DNA replication.

• Mitosis: Division of the nucleus.

• Cytokinesis: Division of the cytoplasm.

• Regulation: Controlled by checkpoints and regulatory proteins.

Unregulated Cell Division

Unregulated cell division can lead to diseases such as cancer.

• Example: Tumor formation due to loss of cell cycle control.