Anatomy and Physiology: Study Guide Notes (Chapters 1–5)

I. Introduction to Anatomy and Physiology

Characteristics of Living Things

• Definition: Living things are organisms that exhibit certain characteristics distinguishing them from non-living matter.

• Key Characteristics:

  • Organization (cellular structure)

  • Metabolism (chemical reactions for energy and growth)

  • Responsiveness (ability to sense and respond to stimuli)

  • Growth and development

  • Reproduction

  • Homeostasis (maintaining internal balance)

  • Adaptation through evolution

• Essential Elements for Life: Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur are the most essential elements found in living organisms.

Levels of Organization in the Human Body

• Levels: Chemical → Cellular → Tissue → Organ → Organ System → Organism

• Animal Kingdom Classification: Humans are classified as Homo sapiens in the animal kingdom, phylum Chordata, class Mammalia.

Definitions

• Anatomy: The study of the structure of body parts and their relationships to one another.

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

Bodily Functions and Cavities

• Bodily Functions: Include processes such as respiration, digestion, circulation, excretion, and movement.

• Main Cavities of the Upper Torso:

  • Thoracic cavity: Contains the heart and lungs.

  • Abdominal cavity: Contains digestive organs.

  • Pleural cavities: Surround each lung.

  • Pericardial cavity: Surrounds the heart.

II. Basic Chemistry

Atoms, Elements, and Molecules

• Compound: A substance formed when two or more elements are chemically bonded.

• Element: A pure substance consisting of only one type of atom.

• Molecule: Two or more atoms bonded together (e.g., O2, H2O).

• Subatomic Particles: Protons (positive), neutrons (neutral), electrons (negative).

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

• Ions: Atoms or molecules with a net electric charge due to loss or gain of electrons. Cations are positively charged; anions are negatively charged.

Chemical Bonds

• Main Types:

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

  • Covalent bonds: Sharing of electrons (e.g., H2O).

  • Hydrogen bonds: Weak attractions between polar molecules (important in water and DNA structure).

Properties of Water and Chemical Reactions

• Water: Universal solvent, high heat capacity, participates in chemical reactions.

• Hydrolysis: Breaking down molecules by adding water.

• Dehydration Synthesis: Building larger molecules by removing water.

Acids and Bases

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

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

• pH Scale: Measures acidity or alkalinity; ranges from 0 (most acidic) to 14 (most basic), with 7 being neutral.

Macromolecules

• Polymers: Large molecules made of repeating units called monomers.

• Monomer Examples:

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

  • Proteins: Monomer is amino acid.

  • Nucleic acids: Monomer is nucleotide.

  • Lipids: Not true polymers, but fatty acids and glycerol are building blocks.

• Phosphate Group: Important in nucleic acids and energy transfer (e.g., ATP).

III. Cells and Tissues

Cell Structure and Function

• Cell: The basic structural and functional unit of life.

• Tissue: A group of similar cells performing a specific function.

• Phospholipid Bilayer: The fundamental structure of the cell membrane, composed of two layers of phospholipids with hydrophilic heads and hydrophobic tails.

Cell Types and Tissues

• Major Tissue Types:

  • Epithelial tissue (covers surfaces)

  • Connective tissue (supports and binds)

  • Muscle tissue (movement)

  • Nervous tissue (control and communication)

Cell Cycle and Mitosis

• Cell Cycle: The series of events that cells go through as they grow and divide.

• Mitosis: The process of cell division that results in two genetically identical daughter cells.

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

Cytoplasm and Cytosol

• Cytoplasm: The material within a cell, excluding the nucleus, containing organelles and cytosol.

• Cytosol: The fluid portion of the cytoplasm.

Cell Organelles

• Primary Organelles and Functions:

  • Nucleus: Contains genetic material (DNA).

  • Mitochondria: Site of ATP (energy) production.

  • Endoplasmic Reticulum (ER): Synthesis of proteins (rough ER) and lipids (smooth ER).

  • Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

  • Lysosomes: Digestive enzymes for waste breakdown.

  • Ribosomes: Protein synthesis.

IV & V. Skin and Membranes

Structure and Function of the Skin

• Skin: The largest organ of the body, providing protection, sensation, and regulation of temperature.

• Layers of the Skin:

  • Epidermis: Outermost layer, provides barrier and creates skin tone.

  • Dermis: Middle layer, contains connective tissue, hair follicles, and sweat glands.

  • Hypodermis (subcutaneous layer): Deepest layer, made of fat and connective tissue.

Appendages and Membranes

• Appendages of the Skin: Hair, nails, sweat glands, and sebaceous (oil) glands.

• Membranes Associated with Skin:

  • Cutaneous membrane: The skin itself.

  • Mucous membranes: Line body cavities open to the exterior.

  • Serous membranes: Line closed body cavities.

Melanin and Skin Color

• Melanin: A pigment produced by melanocytes in the epidermis; responsible for skin color and protection against UV radiation.

• Role of Melanin: Absorbs harmful UV rays, reducing DNA damage and risk of skin cancer.

Table: Comparison of Skin Layers

Layer	Main Components	Functions
Epidermis	Keratinocytes, melanocytes	Protection, barrier, skin tone
Dermis	Connective tissue, blood vessels, nerves, hair follicles	Support, sensation, thermoregulation
Hypodermis	Adipose tissue, connective tissue	Insulation, energy storage, cushioning

Additional info:

• Some details, such as the specific names of tissue types and the functions of organelles, were expanded for academic completeness.

• Examples and definitions were added to clarify brief points from the original study guide.