Exam II- Bio 208

33 Questions | Total Attempts: 69

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Exam II- Bio 208 - Quiz

Questions and Answers
  • 1. 
    Arrange the following stpes involved inthe generation of an action potential into their proper sequence: a. Sodium channels are inactived b. Potassium channels open and potassium oves out of the cell c. Sodium channels regain their normal properties d. Graded depolarization brings area of excitable membrane to threshold e. A temperary hyperpolarization occurs f. Sodium channel activation occurs g. Sodium ions enter the cell and depolarization occurs
    • A. 

      D,f,g,c,b,e,a

    • B. 

      E,g,d,a,b,c,f

    • C. 

      B,d,f,g,a,c,e

    • D. 

      D,f,g,a,b,c,e

    • E. 

      D,b,e,f,g,c,a

  • 2. 
    During salatory conduction, (APs=action potentials)
    • A. 

      APs move in all directions along an axon

    • B. 

      Local currents depolarize adjacent areas of membrane so that APs continue to form along the membrane

    • C. 

      APs produce a local current that is strong enough to spread along the length of the axon

    • D. 

      Local potentials produce a continuous outward flow of potassium ions

    • E. 

      APs occur between successive nodes along the length of stimulated axon

  • 3. 
    Multiple Sclerosis (MS) is associated with a loss of myelin. MS may then involve:
    • A. 

      Oligodendrocytes

    • B. 

      Astrocytes

    • C. 

      Microglia

    • D. 

      Ependymal

    • E. 

      Reshaw neruons

  • 4. 
    The later part of the rising (depolarizing) phase of the action potential is mediated by a(n) )____ ion membrane channel
    • A. 

      Ligand- gated

    • B. 

      Voltage-gated

    • C. 

      Leak

    • D. 

      Active pump

    • E. 

      Facilitated diffusion

  • 5. 
    Which of the following is TRUE of a graded potential?
    • A. 

      The potential is propagated with a constant magnitude

    • B. 

      The potential is all-or-none

    • C. 

      Stimulus causes ion channels to open changing membrane permeability

    • D. 

      No summation of potentials occurs

    • E. 

      The potential has a refractory period

  • 6. 
    Opening of Na+ channels in the membrane of a neuron normally results in
    • A. 

      Hyperpolarization

    • B. 

      Repolarization

    • C. 

      Depolarization

    • D. 

      Increased negative charge inside neuron

    • E. 

      None of these

  • 7. 
    A resting (trans) membrane potential of a cell has a valuue of approximatly
    • A. 

      -9 V

    • B. 

      +9 V

    • C. 

      0 mV

    • D. 

      +70 mV

    • E. 

      -70 mV

    • F. 

      -80 mV

  • 8. 
    What prevents an action potential from traveling in both directions down an axon?
    • A. 

      The resting potential

    • B. 

      Ligand-gated channels

    • C. 

      Graded potentials

    • D. 

      The refractory period

    • E. 

      Leak channels

  • 9. 
    A person whose genetic makeup or training makes then a better SPRINTER than a marathon runner probably has ____ in their leg muslces
    • A. 

      More red muscle fibers

    • B. 

      More white muscle fibers

    • C. 

      More noncontractile fibers

    • D. 

      Equal amounts of read and white m.fibers

    • E. 

      Less myoglobin than hemoglobin

  • 10. 
    The smooth but steady increase in muscle tension (submaximally) produced by increasing the number of active motor units is called:
    • A. 

      Recruitment

    • B. 

      Tetany

    • C. 

      A twitch

    • D. 

      Relaxation

    • E. 

      Recovery

  • 11. 
    ____ is involved in BOTH synaptic transmission and excitation-contraction coupling?
    • A. 

      Myosin

    • B. 

      Chloride

    • C. 

      Calcium

    • D. 

      Tropomyosin

    • E. 

      T-tubules

  • 12. 
    Which striated muscle band is directly adjacent to the Z-line?
    • A. 

      A-band

    • B. 

      H-band

    • C. 

      T-band

    • D. 

      M-band

    • E. 

      I-band

  • 13. 
    During relaxation, muscles return to their original length NOT because of
    • A. 

      Renshaw inhibition

    • B. 

      Elastic forces

    • C. 

      The pull of gravity

    • D. 

      The contraction of opposing muscles

    • E. 

      The elastic nature of the sarcrolemma

  • 14. 
    At rest, active sites on the actin are blocked by
    • A. 

      Myosin molecules

    • B. 

      Calcium ions

    • C. 

      ATP molecules

    • D. 

      Troponin molecules

    • E. 

      Tropomyosin molecules

  • 15. 
    Tropomyosin wraps itself around which other muscle element?
    • A. 

      Myosin

    • B. 

      F-actin

    • C. 

      Troponin

    • D. 

      Titin

    • E. 

      H-band

  • 16. 
    The 'powerstroke' in skeletal muslce contraction is directly associated with:
    • A. 

      Myosin head pivots at joint pulling action

    • B. 

      AP movement down t-tubule

    • C. 

      Calcium release from SR

    • D. 

      AP movement along sacrolemma

    • E. 

      Calcium binding to troponin

  • 17. 
    We can distinguish between sensation orginating in different body areas because
    • A. 

      Receptors from each body region synapse in specific brain regions

    • B. 

      Snesory neurons carry only one type of information

    • C. 

      Incoming sensory information is first assessed by the thalamus

    • D. 

      Different types of sensory receptors produce different types of AP's

    • E. 

      Sensory neurons in different parts of the body

  • 18. 
    Diffusion across the Arachnoid Granulations returns excess CSF to
    • A. 

      The third ventricle

    • B. 

      Arterial circulation

    • C. 

      Venous circulation

    • D. 

      The fourth ventricle

    • E. 

      The central canal

  • 19. 
    Soon after a person dies (and loses all ATPs), their skeletal muscles:
    • A. 

      Flex with significant force

    • B. 

      Stiffen from actin and myosin binding

    • C. 

      Extend with significant force

    • D. 

      Get smaller in volume

    • E. 

      Get larger in volume

  • 20. 
    Each of the following are characteristics of smooth muscles EXCEPT
    • A. 

      Have small diameters and lengths compared with skeletal muscles

    • B. 

      Have actin and myosin

    • C. 

      Have autorhythmicity

    • D. 

      Have striations

    • E. 

      Little fatigue with prolong contraction

  • 21. 
    Which of the following is responsible for reciprocal inhibition?
    • A. 

      Sensory neurons

    • B. 

      Interneurons in the spinal cord

    • C. 

      Extensor neurons

    • D. 

      Motor neurons

    • E. 

      None of these

    • F. 

      All of these

  • 22. 
    Arrange the following steps involved in a reflex arc into their proper sequence: a. activation of a sensory neuron b. activation of a motor neuron c.response by an effector d.arrival of a stimulus e.information processing
    • A. 

      D,a,e,b,c

    • B. 

      D,e,c,a,b

    • C. 

      A,c,d,e,b

    • D. 

      C,a,d,e,b

    • E. 

      D,c,a,e,b

  • 23. 
    People perceive different intensities of light when their brains recieve different ___.
    • A. 

      Action potentials send to various regions of the brain

    • B. 

      Shapes of action potentials

    • C. 

      Sizes of action potentials

    • D. 

      Wavelengths of light

    • E. 

      Rates of action potentials

  • 24. 
    Part of the brian most closely associated with emotions is:
    • A. 

      Cerebrum

    • B. 

      Thalamus

    • C. 

      Hypothalamus

    • D. 

      Cerebellum

    • E. 

      Medulla oblongata

  • 25. 
    Overseeing the postural muscles of teh body and making rapid adjustments to maintain balance and equilibrium are functions of the
    • A. 

      Cerebrum

    • B. 

      Midbrain

    • C. 

      Pons

    • D. 

      Cerebellum

    • E. 

      Medulla

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