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Anatomy & Physiology Key Concepts

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Terms in this set (27)

  • Anatomical position
    A standard body position where a person stands upright, facing forward, feet flat and directed forward, arms at the sides with palms facing forward.
  • Homeostasis
    The body's ability to maintain a stable internal environment despite external changes.
  • Negative feedback
    A feedback mechanism that reverses a change in a controlled condition to maintain homeostasis.
  • Positive feedback
    A feedback mechanism that amplifies a change, often to complete a process.
  • Levels of structural organization in the human body
    Chemical, cellular, tissue, organ, organ system, and organism levels.
  • Serous membranes
    Thin membranes lining body cavities and covering organs, producing serous fluid to reduce friction.
  • Plasma membrane structure
    A fluid mosaic of lipids, proteins, and carbohydrates that controls substance movement in and out of cells.
  • Osmosis
    The diffusion of water across a selectively permeable membrane from low to high solute concentration.
  • Isotonic solution effect on cells
    No net water movement; cells retain their normal shape.
  • Hypertonic solution effect on cells
    Water moves out of cells causing them to shrink.
  • Hypotonic solution effect on cells
    Water moves into cells causing them to swell and possibly burst.
  • Dehydration synthesis
    A chemical reaction that joins monomers into polymers by removing water.
  • Hydrolysis
    A chemical reaction that breaks down polymers into monomers by adding water.
  • Four levels of protein structure
    Primary (sequence), secondary (folds), tertiary (3D shape), and quaternary (multiple polypeptides).
  • ATP hydrolysis reaction
    ATP + H2O → ADP + Pi + energy; provides energy for cellular processes.
  • Functions of the skeletal system
    Support, protection, movement, mineral storage, blood cell production, and fat storage.
  • Compact bone structure
    Dense bone with osteons containing central canals surrounded by concentric lamellae.
  • Synovial joint
    A freely movable joint with a fluid-filled cavity between articulating bones.
  • Agonist muscle
    The primary muscle responsible for a specific movement.
  • Antagonist muscle
    The muscle that opposes the action of the agonist.
  • Sliding-filament mechanism
    Muscle contraction process where actin filaments slide over myosin filaments to shorten sarcomeres.
  • Resting membrane potential
    The electrical charge difference across the plasma membrane of a resting cell, typically -70 mV.
  • Action potential phases
    Depolarization, repolarization, and hyperpolarization phases that propagate nerve impulses.
  • Neurotransmitter
    A chemical messenger released at synapses to transmit signals between neurons or to effector cells.
  • Blood-brain barrier
    A selective barrier that protects the brain by restricting passage of substances from blood to CNS tissue.
  • Upper motor neurons
    Neurons in the CNS that initiate voluntary movement by synapsing on lower motor neurons.
  • Reflex arc
    The neural pathway that mediates a reflex, including sensory input, integration, and motor output.