PSYC106 Midterm1 Questions

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PSYC106 Midterm1 Questions
2014-04-24 01:31:17
PSYC106 Physiology

PSYC106 Physiology
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  1. Following an Action Potential, Potassium Channels open up driving membrane potential toward equilibrium. These voltage-gated Potassium channels differ from leak-potassium channels in that they are normally __________ during resting potential, but __________ in response to depolarization. (Thus the term "voltage-gated").
    • Closed
    • Open
  2. The "Undershoot" Phase following an Action Potential is caused by _____________.
  3. The tree-like branches of a neuron are called ______________
  4. The long thin structure of a neuron that carries information TO another cell is called the __________
  5. Which animal species have the longest axons?
    • Longest axons occur in the largest animals.
    • ex giraffes & elephants from spinal cord to feet, ~2 meters
  6. What is one major advantage of the blood brain barrier & one major disadvantage
    • Advantage: Toxins and viruses don't go to the brain
    • Disadvantage: Needed medications or nutrients don't get to brain
  7. Which chemicals cross the blood-brain barrier PASSIVELY?
    • Small, un-charged molecules:
    • water, oxygen, carbon dioxide, chemicals that dissolve in fats of membrane
  8. Which chemicals cross the blood-brain barrier via ACTIVE transport?
    Glucose, amino acids, purines, choline, some vitamins, (A & D), iron, some hormones
  9. Heroin exerts faster effects on the brain than morphine. What can we infer about those drugs?
    Heroin crosses the blood-brain barrier.
  10. When a neuron membrane is at rest, the sodium ions more concentrated __________ of the cell. The Potassium ions more concentrated __________ of the cell
    • Outside
    • Inside
  11. When the neuron membrane is at rest, what tends to drive the potassium ions OUT of the cell? What tends to draw them INTO the cell?
    • OUT: Concentration gradient (higher concentration inside, driving them out)
    • INTO: Electrical gradient (post-AP after cell is depolarized, opens K+ voltage-gate channels to send cell back to neutral)
    • Also, the sodium-potassium pump.
  12. What is the difference between HYPERPOLARIZATION and DEPOLARIZATION?
    • Hyperpolarization: Makes cell more NEGATIVE
    • Depolarization: Makes cell more POSITIVE (by decreasing amount of negative charge) (-/-) = (+)
  13. During the rise of the action potential, do sodium ions move INTO the cell or OUT of it? Why?
    • Move INTO it.
    • The voltage-dependent sodium gates open, so sodium can move freely. Sodium is attracted to the INSIDE of the cell by both an electrical and a concentration gradient
  14. As the membrane reaches the peak of the action potential, what brings it down to the original resting potential?
    Sodium Channels CLOSE- causing sodium levels to drop. Voltage-gated Potassium Channels OPEN - Potassium ions EXIT the cell, carrying a POSITIVE charge. Enough potassium ions leave to drive membrane BEYOND usual resting level to short hyperpolarization. Eventually, the sodium-potassium pump removes the higher amount of sodium and adds more potassium to bring back to normal resting level.
  15. What are the "3 Mantras"?
    • 1. Biology is NOT determinism
    • 2. Brains produce behavior AND behavior changes brains.
    • 3. Multiple approaches COMPLETE, not COMPETE
  16. In most cases, neuron cluster OUTSIDE the CNS is called a ganglion, & cluster INSIDE is called a nucleus. The exception to this is the __________  _____________, which is located IN the CNS.
    Basal Ganglion
  17. Name the 6 stages of Brain Development
    • 1. Neurogenesis (making neurons), mitosis (making cells)
    • 2. Migration
    • 3. Differentiation
    • 4. Synaptogenesis (hook up, make synapses)
    • 5. Cell Death (and apoptosis = programmed death)
    • 6. Rearrangement (constant/permanent)
  18. When will a dose-response curve look like a NORMAL distribution?
    • When EVEN MORE of the drug gives less effect
    • ex Quinelorane
    • Dopamine agonist-induced yawning in rates
  19. Spinal Cord arrangement:
    One branch on dorsal side: ___________ info COMING INTO spinal cord.
    One branch on ventral route: ___________ - nerve controls muscles.
    • MOTOR
  20. How many cranial nerves do we have?
  21. List the 3 Main functions of CSF
    • 1) cushion or "shock absorber
    • 2) vehicle for delivering nutrients to the brain and removing waste
    • 3) flow between cranium and spine & compensate for changes in amount of blood within the brain
  22. Myelin sheaths in the Periphery: ___________
    In the CNS: _______________
    • schwann cells
    • oligodendrocytes
  23. Receptors inhibit or excite depending on what _______ _____________ are altered.
    Ion channels
  24. Seven Processesin Neurotransmitter Action (and sites that drugs can act on)
    • Synthesis
    • Storage
    • Maintanance
    • Release
    • Feedback
    • Binding
    • Inactivation
  25. In sensitization, the DRC is pushed to the __________
  26. Which NT is released when a mouse presses a lever and is chooses to do that
    over food and sex and other things?
    Dopamine (DA)
  27. The type of genetics that can alter DNA (gene expression) through methylation is called: