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Biology-Related Homework Help Anatomy and Physiology Topic started by: les4212 on Jul 25, 2012



Title: Neurophysiology of Nerve Impulses Activity
Post by: les4212 on Jul 25, 2012
Can someone please help me with the following questions?
1. Excitability is the ability to transit nerve impulses to other neurons. (Points : 1) 
       True
       False
 
   
2. When a neuron is stimulated, the membrane becomes more permeable to Na+ ions, which diffuse into the cell, causing ___. (Points : 1) 
       depolarization
       hyperpolarization
       repolarization
 
   
3. As an action potential progresses, the permeability to Na+ decreases and the permeability to ____ increases. (Points : 1) 
       Ca2+
       K+
       Na+
 
   
4. The period of time when the neuron is totally insensitive to further stimulation and cannot generate another action potential is the ____. (Points : 1) 
       absolute refractory period
       membrane potential
       repolarization
       threshold
 
   
5. The resting membrane potential is the potential difference (electrical charge difference) between the inside of the cell and the outside of the cell across the cell membrane (Points : 1) 
       True
       False
 
   
6. What is the approximate concentration of K+ inside a typical cell? (Points : 1) 
       150 mM
       5 mM
       10 mM
       15 mM
 
   
7. What is the approximate concentration of K+  outside a typical cell? (Points : 1) 
       150 mM
       5 mM
       10 mM
       15 mM
 
   
8. What is the approximate concentration of Na+ inside a typical cell? (Points : 1) 
       150 mM
       5 mM
       10 mM
       15 mM
 
   
9. What is the approximate concentration of Na+ outside a typical cell? (Points : 1) 
       150 mM
       5 mM
       10 mM
       15 mM
 
   
10. In Activity 1, the intracellular voltage of the resting (control) neuron is _____ compared to the extracellular voltage. (Points : 1) 
       0
       -70
       -40
       + 10
 
   
11. Having a negative intracellular charge means that there are more negative charges than there are positive charges just inside the neuronal cell membrane. (Points : 1) 
       True
       False
 
   
12. Which of the following caused a change in membrane potential from -70 (in the control) to -40 in the cell body. (Points : 1) 
       an increase in extracellular K+
       a decrease in extracellular K+
       an increase in extracellular Na+
       a decrease in extracellular Na+
 
   
13. The end of the axon where it contacts the target is called the _____. (Points : 1) 
       cell body
       myelin sheath
       axon terminal
       nucleus
 
   
14. Neurotransmitter is released into the synaptic gap by ___. (Points : 1) 
       exocytosis
       voltage-gated neurotransmitter channels
       muscle contraction
       the postsynaptic membrane of the target cell
 
   
15. Exocytosis of neurotransmitter from the axon terminal is triggered by an increase of in the intracellular concentration of ___. (Points : 2) 
       Na+
       K+
       Ca2+
       none of the above
 
   
16. Neurotransmitter that has been released into the synpatic gap reaches the target by ___. (Points : 1) 
       exocytosis
       diffusion
       muscle contraction
       conduction down the axon
 
   
17. At the target, neurotransmitter _____. (Points : 1) 
       binds to receptor proteins
       causes membrane channels to open or close
       causes a change in membrane potential
       does all of the above
 


Title: Re: Neurophysiology of Nerve Impulses Activity
Post by: fbihansip on Aug 14, 2012
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Title: Re: Neurophysiology of Nerve Impulses Activity
Post by: etolson on Aug 16, 2012
Thanks this is really helpful. Much appreciated.