DPT 708 FINAL EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
motor unit
LMN and all the muscle fibers it innervates
afferent neurons
sensory neurons traveling to spinal cord/brain
efferent neurons
motor neurons sending signal to muscles
what do muscle spindles and golgi tendon organs provide
speed and size of muscle length change
muscle position
muscle tension
limb orientation with respect to gravity (proprioception)
membrane potential
concentration of difference of ions across membranes can create potential
What is the resting membrane potential?
[Na+] outside > [Na+] inside
,more permeable to movement of K+
can vary from -20 to -200 mV
nerst potential
Na+ diffuses into cell making the potential (-) and more (+) on the inside -> membrane
potential rises high enough to block further diffusion of Na+ = +60mV inside cell
what does it mean for nerve and muscle cells to be excitable
they are capable of generating rapid electrochemical impulses at membranes
how do other cells control cell function with membrane potential
they use local changes in MP and signal downstream within the cell
membrane potential
unequal distribution of ions across membrane
electrical dipole layer
charge along membrane
outside is (+) and inside is (-) due to ratio of ions outside vs inside the cell
RMP of large nerve cells
-80 to -90 mV
the electric potential inside the cell is 80 to 90mV more negative than the charge outside
the cell
what is the origin of the RMP
, diffusion of K+ out and minimal Na+ in (leaky channels)
Na+/K+ pump
what does Na+/K+ pump do
maintains concentration gradient by rapid movement of Na+ to the outside of the cell to
make the inside more (-)
3 Na+ OUT for every 2 K+ IN
more (+) ions pumped out develops a (-) charge along the inside of the cell membrane
RMP of Na+ only
+65 mV
RMP of K+ only
-94 mV
action potentials
rapid changes in local membrane potential that spread rapidly along nerve
membrane threshold
potential it takes to activate voltage gated sodium channels to discharge AP across
entire cell
3 stages of APs
resting = RMP is -90 mV (polarized)
depolarization: inside becomes less (-) Na+/K+ pump turns on
COMPLETE SOLUTIONS VERIFIED
motor unit
LMN and all the muscle fibers it innervates
afferent neurons
sensory neurons traveling to spinal cord/brain
efferent neurons
motor neurons sending signal to muscles
what do muscle spindles and golgi tendon organs provide
speed and size of muscle length change
muscle position
muscle tension
limb orientation with respect to gravity (proprioception)
membrane potential
concentration of difference of ions across membranes can create potential
What is the resting membrane potential?
[Na+] outside > [Na+] inside
,more permeable to movement of K+
can vary from -20 to -200 mV
nerst potential
Na+ diffuses into cell making the potential (-) and more (+) on the inside -> membrane
potential rises high enough to block further diffusion of Na+ = +60mV inside cell
what does it mean for nerve and muscle cells to be excitable
they are capable of generating rapid electrochemical impulses at membranes
how do other cells control cell function with membrane potential
they use local changes in MP and signal downstream within the cell
membrane potential
unequal distribution of ions across membrane
electrical dipole layer
charge along membrane
outside is (+) and inside is (-) due to ratio of ions outside vs inside the cell
RMP of large nerve cells
-80 to -90 mV
the electric potential inside the cell is 80 to 90mV more negative than the charge outside
the cell
what is the origin of the RMP
, diffusion of K+ out and minimal Na+ in (leaky channels)
Na+/K+ pump
what does Na+/K+ pump do
maintains concentration gradient by rapid movement of Na+ to the outside of the cell to
make the inside more (-)
3 Na+ OUT for every 2 K+ IN
more (+) ions pumped out develops a (-) charge along the inside of the cell membrane
RMP of Na+ only
+65 mV
RMP of K+ only
-94 mV
action potentials
rapid changes in local membrane potential that spread rapidly along nerve
membrane threshold
potential it takes to activate voltage gated sodium channels to discharge AP across
entire cell
3 stages of APs
resting = RMP is -90 mV (polarized)
depolarization: inside becomes less (-) Na+/K+ pump turns on
