Introduction to Anatomy & Physiology

This study guide covers foundational concepts in anatomy and physiology, including body organization, homeostasis, cell structure, membrane transport, tissues, and more. Each topic is expanded with definitions, examples, and key points to support exam preparation.

Organization of the Human Body

Levels of Organization

• Chemical Level: Atoms and molecules essential for life.

• Cellular Level: Basic structural and functional units of life.

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

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

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

• Organismal Level: The complete living being.

Major Organ Systems and Their Functions

• Integumentary System: Protection, temperature regulation, sensation.

• Skeletal System: Support, movement, protection, blood cell production.

• Muscular System: Movement, posture, heat production.

• Nervous System: Rapid internal communication, coordination, motor control.

• Endocrine System: Hormone production, internal chemical communication.

• Cardiovascular System: Transport of nutrients, gases, wastes.

• Lymphatic System: Immunity, fluid balance.

• Respiratory System: Gas exchange.

• Digestive System: Nutrient breakdown and absorption.

• Urinary System: Waste elimination, water balance.

• Reproductive System: Production of offspring.

Homeostasis

Definition and Importance

• Homeostasis: The maintenance of a stable internal environment despite external changes.

• Vital for normal cell function and overall health.

• Organ systems such as the nervous and endocrine systems play key roles in maintaining homeostasis.

Feedback Mechanisms

• Negative Feedback: Reverses a change to keep a variable within a normal range (e.g., body temperature regulation).

• Positive Feedback: Enhances or amplifies a change (e.g., blood clotting, childbirth contractions).

• Example: When blood glucose rises, insulin is released to lower it (negative feedback).

Anatomical Terminology and Body Organization

Anatomical Position

• Standard reference position: standing upright, facing forward, arms at sides, palms facing forward.

Body Cavities

• Dorsal Cavity: Cranial and vertebral cavities.

• Ventral Cavity: Thoracic and abdominopelvic cavities.

• Each cavity contains specific organs (e.g., heart in thoracic cavity).

Abdominal Quadrants

• Four quadrants: right upper, left upper, right lower, left lower.

• Used to localize pain or abnormalities.

Body Membranes

• Serous Membranes: Line body cavities not open to the outside (pleural, pericardial, peritoneal).

• Mucous Membranes: Line cavities open to the exterior (digestive, respiratory tracts).

• Cutaneous Membrane: The skin.

• Synovial Membranes: Line joint cavities.

Chemistry of Life

Atomic Structure

• Subatomic Particles: Protons (+), neutrons (0), electrons (-).

• Atomic Number: Number of protons.

• Atomic Mass: Protons + neutrons.

Forms of Energy

• Chemical Energy: Stored in bonds of molecules.

• Electrical Energy: Movement of charged particles.

• Mechanical Energy: Directly involved in moving matter.

• Radiant Energy: Energy that travels in waves (e.g., light).

Chemical Bonds

• 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.

Chemical Reactions

• Synthesis: Building larger molecules from smaller ones.

• Decomposition: Breaking down molecules.

• Exchange: Parts of molecules are switched.

• Example: (synthesis), (decomposition).

Properties of Water

• High heat capacity, solvent properties, reactivity, cushioning.

• Water is a universal solvent, important for transport and chemical reactions.

Solutions and Concentrations

• Solvent: Substance present in greatest amount (usually water).

• Solute: Substance dissolved in solvent.

• Solution: Homogeneous mixture of solute and solvent.

• pH Scale: Measures hydrogen ion concentration; scale from 0 (acidic) to 14 (basic).

Biomolecules

Macromolecules

• Carbohydrates: Energy source; monosaccharides, disaccharides, polysaccharides.

• Lipids: Energy storage, insulation; triglycerides, phospholipids, steroids.

• Proteins: Structure, enzymes, transport; made of amino acids.

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

DNA vs. RNA

• DNA: Double-stranded, deoxyribose sugar, stores genetic code.

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

Cell Structure and Function

Cell Membrane

• Phospholipid Bilayer: Hydrophilic heads, hydrophobic tails.

• Selective Permeability: Allows some substances to pass while restricting others.

• Factors affecting permeability: size, charge, solubility, presence of transport proteins.

Membrane Proteins

• Transport, receptors, enzymes, cell recognition, attachment.

Membrane Transport

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

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

• Vesicular Transport: Endocytosis (phagocytosis, pinocytosis), exocytosis.

• Osmosis: Diffusion of water across a membrane.

• Sodium-Potassium Pump: Maintains cell potential by moving Na+ out and K+ in.

Cell Junctions

• Tight Junctions: Prevent leakage between cells.

• Desmosomes: Anchor cells together.

• Gap Junctions: Allow communication between cells.

Tissues

Epithelial Tissue

• Functions: protection, absorption, filtration, secretion.

• Types: simple, stratified, squamous, cuboidal, columnar.

• Specialized cells: goblet cells (secrete mucus).

• Locations: skin, lining of GI tract, glands.

Glands

• Endocrine Glands: Ductless, secrete hormones into blood (e.g., thyroid, pituitary).

• Exocrine Glands: Secrete products via ducts (e.g., sweat, salivary glands).

• Goblet Cells: Unicellular exocrine glands that secrete mucus, found in respiratory and digestive tracts.

Connective Tissue

• Functions: support, protection, insulation, transport.

• Types: loose, dense, cartilage, bone, blood.

• Fibers: collagen (strength), elastic (flexibility), reticular (support).

• Distinguishing features: extracellular matrix, varying vascularity.

Muscle Tissue

• Types: skeletal (voluntary movement), cardiac (heart, involuntary), smooth (walls of organs, involuntary).

• Functions: movement, posture, heat production.

• Control: voluntary (skeletal) vs. involuntary (cardiac, smooth).

Nervous Tissue

• Functions: transmit electrical impulses, process information.

• Components: neurons, neuroglia.

Tissue Repair and Inflammation

Tissue Repair

• Steps: inflammation, organization, regeneration, and fibrosis.

• Five signs of inflammation: redness, heat, swelling, pain, loss of function.

Summary Table: Types of Tissues and Their Functions

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