Anatomy & Physiology Study Guide: Foundations, Cells, Membranes, and Skin

Chapter 1: Introduction to Anatomy & Physiology

Definitions and Scope

Anatomy and physiology are foundational sciences for understanding the structure and function of the human body. This section introduces key terms and concepts.

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

• Physiology: The study of the function of body parts and how they work to carry out life-sustaining activities.

• Body Regions: Examples include cephalic (head), popliteal (back of knee), umbilical (navel), brachial (arm), olecranal (elbow), and antecubital (front of elbow).

• Body Cavities: Spaces within the body that contain vital organs (e.g., cranial, thoracic, abdominal cavities).

Homeostasis

Homeostasis is the process by which the body maintains a stable internal environment despite changes in external conditions.

• Controlling Systems: The nervous and endocrine systems are the two main systems that regulate homeostasis.

• System/Organismal Level: Homeostasis can be maintained at both the cellular and whole-body levels.

Chapter 2: Chemical Foundations and Water

Major Elements and Atomic Structure

The human body is composed of four major elements: oxygen, carbon, hydrogen, and nitrogen. Understanding atomic structure is essential for grasping chemical interactions in physiology.

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

• Planetary/Orbital Model: Electrons orbit the nucleus in defined energy levels.

Compounds, Molecules, and Ions

Chemical substances in the body can be classified as elements, compounds, molecules, or ions.

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

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

• Molecule: Two or more atoms bonded together.

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

Chemical Bonds and Reactions

Chemical bonds hold atoms together, and chemical reactions transform substances.

• Types of Chemical Bonds: Ionic, covalent, and hydrogen bonds.

• Synthesis Reaction: Two or more substances combine to form a more complex substance.

• Organic vs. Inorganic Molecules: Organic molecules contain carbon and hydrogen; inorganic molecules do not.

Properties of Water

Water is vital for life due to its unique properties.

• Polarity: Water is a polar molecule, allowing it to dissolve many substances.

• Hydrogen Bonding: Responsible for water's high specific heat and surface tension.

• Solvent: Water dissolves ionic and polar substances.

• Dehydration Synthesis: A reaction where water is removed to form a bond.

• Hydrolysis: A reaction where water is added to break a bond.

Acids, Bases, and pH

Acids and bases are important for maintaining physiological pH.

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

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

• pH Scale: Measures hydrogen ion concentration; ranges from 0 (acidic) to 14 (basic), with 7 as neutral.

Macromolecules

Macromolecules are large, complex molecules essential for life.

• Polymer: A large molecule made of repeating subunits (monomers).

• Carbohydrates: Classified by size and complexity: monosaccharides, disaccharides, polysaccharides.

• Lipids: Three most abundant types: triglycerides, phospholipids, steroids.

Chapter 3: Cell Structure and Function

Cell Theory and Cell Types

Cells are the basic units of life. The cell theory states that all living things are composed of cells, and all cells arise from pre-existing cells.

• Three Main Pieces of the Cell: Plasma membrane, cytoplasm, nucleus.

• Fluid Mosaic Model: Describes the structure of the plasma membrane as a mosaic of proteins floating in or on the fluid lipid bilayer.

Membrane Structure and Transport

Cell membranes regulate the movement of substances in and out of cells.

• Phospholipid Bilayer: Composed of hydrophilic heads and hydrophobic tails, creating a semipermeable barrier.

• Types of Membrane Transport: Passive (diffusion, osmosis, facilitated diffusion) and active (pumps, endocytosis, exocytosis).

• Osmosis: Movement of water across a semipermeable membrane.

• Isotonic, Hypotonic, Hypertonic: Terms describing the relative concentration of solutes in solutions.

• Sodium-Potassium Pump: Active transport mechanism moving $Na^+$ out and $K^+$ into the cell.

Cell Junctions and Organelles

Cells are connected and communicate through specialized junctions and contain organelles that perform specific functions.

• Types of Cell Junctions: Tight junctions, desmosomes, gap junctions.

• Organelles: Nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, etc.

Chapter 4: Cell Division and Genetics

Mitosis and Meiosis

Cell division is essential for growth, repair, and reproduction.

• Mitosis: Division of a somatic cell into two identical daughter cells. Phases: prophase, metaphase, anaphase, telophase.

• Interphase: Period of cell growth and DNA replication between divisions.

• Cytokinesis: Division of the cytoplasm, usually following mitosis.

DNA and RNA Structure and Function

Genetic information is stored in DNA and expressed through RNA.

• DNA: Double helix structure, organized into chromosomes. Contains genes.

• RNA: Single-stranded, involved in protein synthesis.

• Complementary Base Pairs: In DNA: Adenine-Thymine (A-T), Cytosine-Guanine (C-G). In RNA: Adenine-Uracil (A-U), Cytosine-Guanine (C-G).

• Example: DNA sequence: TACCTTGC, RNA sequence: AUGGAACG.

Protein Synthesis

Proteins are synthesized through transcription and translation.

• Transcription: DNA is copied into messenger RNA (mRNA).

• Translation: mRNA is decoded by ribosomes to assemble amino acids into a protein.

• Gene: Segment of DNA coding for a protein.

• Triplet Code: Three-nucleotide sequence in DNA or mRNA that codes for an amino acid.

• Ribosome: Organelle where protein synthesis occurs.

Chapter 5: Membranes and Skin

Types and Functions of Membranes

Membranes protect and compartmentalize body structures.

• Serous Membranes: Line body cavities not open to the outside; secrete serous fluid.

• Mucous Membranes: Line cavities open to the exterior; secrete mucus.

• Cutaneous Membrane: The skin; protects the body and prevents water loss.

Skin Structure and Function

The skin is the largest organ, providing protection, sensation, and thermoregulation.

• Hypodermis: Subcutaneous layer; stores fat and anchors skin.

• Fibrous Protein: Collagen provides strength; keratin provides waterproofing.

• Strata of Epidermis: Five layers: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (in thick skin), stratum corneum.

• Dermis: Contains connective tissue, blood vessels, nerves, and glands.

• Dermal Papillae: Projections that increase surface area for exchange and form fingerprints.

Skin Color and Glands

Skin color is determined by pigments and glandular activity.

• Pigmentation: Melanin, carotene, and hemoglobin contribute to skin color.

• Epidermal Dendritic Cells: Immune cells in the skin.

• Sebaceous Glands: Secrete sebum; found near hair follicles.

• Sudoriferous (Sweat) Glands: Two types: eccrine (thermoregulation) and apocrine (active at puberty, found in axillary/genital areas).

• Cold Sores: Caused by herpes simplex virus.

• Impetigo: Bacterial skin infection.

Lab Practical: Tissue Types and Body Regions

Identification of tissues and body regions is essential for practical exams.

• Cardiac/Smooth/Skeletal Muscle: Found in heart, hollow organs, and attached to bones.

• Adipose Tissue: Stores fat, insulates, and protects.

• Bone: Rigid connective tissue.

• Tendon: Dense regular connective tissue.

• Keratinized Stratified Squamous Epithelium: Found in skin.

• Nerve Tissue: Found in nervous system.

• Transitional Epithelium: Found in bladder and urinary tract.

Study Tip: Review the locations, functions, and identifying features of each tissue type and organelle for lab practicals.