Study guide

• Homeostasis


  Body maintaining stable life parameters
• Steady state


  System equilibrium with energy input
• Fluid categories


  Intracellular, interstitial, plasma with varying compositions
• Set point


  Optimal physiological value maintained around
• Negative feedback


  Prevents deviation from set point in regulatory systems
• Acclimatization


  Reversible set point change, involving epigenetic mechanisms
• Biological rhythms


  Regulated processes with regular interval changes
• Biological membranes


  Composed of phospholipids, critical for compartmentalization
• Flux


  Passive movement of small molecules across membranes
• Na+K+ ATPase


  Maintains internal/external Na+ and K+ concentrations
• Water transport


  Passive diffusion and aquaporin-mediated large volume transport
• Axonal transport


  Movement of cellular components via vesicles along microtubules
• Neuron classes


  Afferent, interneurons, efferent neurons
• Ion channels


  Ligand-gated, voltage-gated, ungated (leak channels)
• Forces on ions


  Ion gradient and membrane/electrical potential
• Flux rate calculation


  J = D(Co-Ci) for substance movement across membrane
• Nernst equation


  Determines equilibrium potential for ions (Eion = 61/z log)
• Membrane potential


  Accounts for ion potentials and permeabilities
• Resting potential


  Membrane potential of fully polarized excitatory cells
• Graded vs. action potentials

  Graded not propagated fully, action reaches synapse
• Depolarization threshold


  Voltage for opening of sodium channels in neurons
• Afterhyperpolarization


  Membrane potential drop post action potential due to K+ movement
• Refractory periods


  Relative due to K+ permeability, absolute due to Na+ inactivation gates
• Absolute Refractory Period


  Due to Na+ inactivation gate closure
• Conduction Velocity Mechanisms


  Myelination and increased axon diameter
• Multiple Sclerosis Pathology


  Autoimmune antibodies against myelinating cell proteins
• Synapse


  Junction between neurons or neuron/muscle/gland
• Types of Synapses


  Chemical and electrical
• Graded Potential Effects


  Depolarization or hyperpolarization from spatial/temporal summation
• Major Neurotransmitters


  Acetylcholine, Norepinephrine, Dopamine, GABA, Glycine, Glutamate
• Presynaptic Neurotransmitter Release


  Action potential, calcium channel opening, fusion for release
• Postsynaptic Receptors


  Ion channel coupled and G protein coupled
• Nicotinic vs. Glycine Receptors

  ACh excitatory, glycine inhibitory via ion channels
• Excitatory vs. Inhibitory Potentials

  Involving sodium or chloride ions
• Long vs. Short Term Potentiation

  LTP: days/weeks upregulation, STP: minutes calcium accumulation
• Drug Actions on Neurotransmitters

  Mimic, block binding/reuptake/degradation
• Muscle Cell Types


  Skeletal, smooth, cardiac muscle distinctions
• Neuromuscular Junction vs. Synapse

  Excitatory, one neuron to muscle cell
• Muscle Fiber Definitions


  Muscle cell, myofibril, sarcomere
• Sarcomere Proteins


  Actin and myosin for filaments, titin, nebulin, dystrophin for structure