Anatomy & Physiology Study Guide: Foundations, Chemistry, Cells, and Tissues

Chapter 1: Introduction to Anatomy & Physiology

Levels of Organization

The human body is organized in a hierarchical structure, from the simplest to the most complex levels.

• Atom: The smallest unit of matter.

• Molecule: Two or more atoms bonded together.

• Organelle: Specialized structures within cells.

• Cell: The basic unit of life.

• Tissue: Groups of similar cells performing a common function.

• Organ: Structures composed of two or more tissue types.

• Organ System: Groups of organs working together for a common purpose.

• Organism: The complete living being.

Organ Systems Overview

Each organ system has a specific overall function essential for maintaining homeostasis and survival.

• Examples: Nervous system (control), cardiovascular system (transport), etc.

Homeostasis

Homeostasis is the maintenance of a stable internal environment despite external changes.

• Components: Receptor (detects change), control center (processes information), effector (carries out response).

• Feedback Mechanisms:

  • Negative Feedback: Reduces the effect of the stimulus (e.g., body temperature regulation).

  • Positive Feedback: Enhances the effect of the stimulus (e.g., blood clotting).

Anatomical Terminology

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

• Regional Terms: Refer to specific areas (e.g., brachial for arm).

• Directional Terms: Describe positions (e.g., anterior/posterior, superior/inferior).

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

Additional info: Mastery of terminology is often tested early in anatomy courses.

Chapter 2: Basic Chemistry for Anatomy & Physiology

Atomic Structure

Atoms are composed of subatomic particles: protons, neutrons, and electrons.

• Atomic Number: Number of protons in the nucleus.

• Mass Number: Sum of protons and neutrons.

• Use atomic number and mass number to determine the number of each subatomic particle.

Electron Shells and Bonding

Electrons are arranged in shells around the nucleus. The number of electrons in the outer shell determines bonding behavior.

• Ionic Bonds: Transfer of electrons from one atom to another.

• Covalent Bonds: Sharing of electrons between atoms.

• Polarity: Covalent bonds can be polar (unequal sharing) or nonpolar (equal sharing).

Properties of Water

Water is essential for life due to its unique properties.

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

• Hydrogen Bonding: Leads to cohesion, adhesion, and high specific heat.

Inorganic and Organic Compounds

• Inorganic Compounds: Do not contain carbon-hydrogen bonds (e.g., water, salts).

• Organic Compounds: Contain carbon-hydrogen bonds (e.g., carbohydrates, lipids, proteins, nucleic acids).

Acids, Bases, and pH

The pH scale measures the concentration of hydrogen ions in a solution.

• Acids: Release H+ ions (pH < 7).

• Bases: Accept H+ ions (pH > 7).

• Neutral: pH = 7.

Hydrolysis and dehydration synthesis are chemical reactions involved in breaking down and building macromolecules, respectively.

Macromolecules

Organic compounds essential for life include:

• Carbohydrates: Provide energy (e.g., glucose).

• Lipids: Store energy, form cell membranes (e.g., triglycerides, phospholipids).

• Proteins: Perform various functions, including catalysis (enzymes), structure, and transport.

• Nucleic Acids: Store and transmit genetic information (DNA, RNA).

Denaturation is the loss of protein structure and function due to environmental changes.

DNA contains instructions for building proteins.

Chapter 3: The Cell

Membrane Structure and Function

The plasma membrane is composed of phospholipids, proteins, and cholesterol, providing a barrier and regulating transport.

• Membrane Junctions: Tight junctions, desmosomes, gap junctions.

Membrane Transport

• Passive Transport: No energy required.

  • Diffusion: Movement from high to low concentration.

  • Facilitated diffusion: Uses a carrier or channel protein.

  • Osmosis: Diffusion of water across a membrane.

• Active Transport: Requires energy (ATP).

  • Moves substances against their concentration gradient.

• Vesicular Transport: Endocytosis (into cell), exocytosis (out of cell).

Tonicity

Tonicity describes the effect of a solution on cell volume.

• Isotonic: No net water movement.

• Hypertonic: Water leaves the cell; cell shrinks.

• Hypotonic: Water enters the cell; cell swells.

Organelles and Cytoskeleton

Organelles perform specialized functions within the cell.

• Nucleus: Contains genetic material.

• Mitochondria: Produce ATP (energy).

• Endoplasmic Reticulum: Synthesizes proteins and lipids.

• Golgi Apparatus: Modifies and packages proteins.

• Lysosomes: Digest cellular waste.

• Cytoskeleton: Provides structure and facilitates movement (microfilaments, intermediate filaments, microtubules).

Cell Cycle and Division

The cell cycle includes interphase (growth and DNA replication) and mitosis (cell division).

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

• Cytokinesis: Division of the cytoplasm.

DNA Replication and Protein Synthesis

• DNA Replication: Produces two identical DNA molecules before cell division.

• Transcription: DNA is used to make mRNA.

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

Genetic Code: Each set of three nucleotides (codon) codes for one amino acid.

Example: If the DNA sequence is ATG-CAG, the mRNA sequence is UAC-GUC, and the corresponding amino acids are determined by the genetic code.

Cell Specialization and Tissues

Cells differentiate to perform specific functions, forming tissues.

• Epithelial Tissue: Covers surfaces, lines cavities.

• Connective Tissue: Supports and binds other tissues.

• Muscle Tissue: Produces movement.

• Nervous Tissue: Transmits electrical signals.

Chapter 4: Tissues and the Integumentary System

Body Membranes

Body membranes cover surfaces, line cavities, and form protective sheets.

• Types: Cutaneous (skin), mucous, serous, synovial.

• Serous Membranes: Consist of parietal and visceral layers.

Skin Structure and Function

The skin is composed of two main layers: epidermis and dermis.

• Epidermis: Stratified squamous epithelium; contains keratinocytes, melanocytes, dendritic cells, tactile cells.

• Dermis: Connective tissue; provides strength and elasticity.

• Functions: Protection, sensation, temperature regulation, vitamin D synthesis.

Hair and Nails

• Hair Structure: Shaft, root, bulb; composed of keratinized cells.

• Nail Structure: Free edge, body, root; protects fingertips.

Glands of the Skin

• Sudoriferous (Sweat) Glands: Eccrine (thermoregulation), apocrine (odor).

• Sebaceous (Oil) Glands: Secrete sebum to lubricate skin and hair.

Skin Disorders and Cancer

• Homeostatic Imbalances: Infections, allergies, burns.

• Skin Cancer: Basal cell carcinoma, squamous cell carcinoma, melanoma.

• ABCDE Rule: Asymmetry, Border, Color, Diameter, Evolving (used to identify melanoma).

Burns

• Types: First-degree (epidermis), second-degree (epidermis and part of dermis), third-degree (full thickness).

• Rule of Nines: Used to estimate the percentage of body surface area affected by burns.