Biology Forums - Study Force

Hoping someone can assist -
The final question in this Activity asks what is the main reason for differences in velocity between myelinated and unmylinated nerves?

Any help would be much appreciated!
Thanks!

You gotta be more specific...

which activity are you doing and what number?

It is Exercise 3, Activity 8  - the final question. 
Thanks.

This is all I have for that section. There is also a chart.

Activity 8: Measuring Nerve Conduction Velocity (pp. 38–40)

11. The earthworm has the slowest conduction velocity.
The speed of the earthworm nerve was about 8.85 m/sec.
Rat nerve 2 had the fastest conduction velocity.
The speed of rat nerve 2 was about 46.74 m/sec.
The larger the nerve, the faster the conduction velocity.
Conduction velocity is faster if the nerve is myelinated than if it is not.
In myelinated nerves, conduction velocity is faster as the action potential jumps from node
of Ranvier (internode) to node of Ranvier and does not travel along the cell membrane.

wheres the chart?

The chart for activity 8

Nerve                   Earthworm                     Frog                      Rat Nerve 1              Rat Nerve 2
Threshold
voltage                     5.0 V                          3.0 V                          2.5 V                         3.0 V

Elapsed time
from stimulation         about                       about                         about                        about
to action potential    4.86 msec             1.56 msec                  2.5 msec                 0.92 msec

Conduction                about                        about                         about                        about
velocity                  8.85 m/sec              27.56 m/sec              17.2 m/sec                46.74 m/sec

thx Rit727!

thank you so much

You guys a're awesome, looking forward to contributing

anyone have physioex 8.0, exercise 5B, activity 3 ( simulating osmotic pressure ) I need to do a lab report on this exercise.  I can't get my simulator to ad Nacl concentration to 8.0 it would only go to 5.0. I went in thru my mastering a&p lecture code, maybe it has something to do with accessing the correct simulator.  Can anyone offer any help with my lab report for this exercise?

6. Using the 20 MWCO membrane results in an osmotic pressure increase using any of the solutes. The 50 and 100 MWCO membranes caused osmotic pressure increase with albumin and glucose. Only albumin caused osmotic pressure increase using the 200 MWCO membrane. NaCl appeared in the right beaker with all membranes except the 20 MWCO membrane.

8. Increasing the number of non-diffusible particles increases osmotic pressure. If solutes are able to diffuse, then equilibrium will be established and osmotic pressure will not be generated. Osmotic pressure would be zero if albumin concentration was the same on both sides of the membrane.

If you increased (or doubled) the concentration of albumin, osmotic pressure will increase (or double). Glucose is freely diffusible using the 200 MWCO membrane and therefore has no effect
on osmotic pressure. The 100 MWCO membrane does not allow glucose to pass and therefore glucose will generate an osmotic influence. Because albumin concentration in the left beaker is 9.00 mM and glucose concentration in the right beaker is 10.00 mM (1.00 mM higher than the left), the small gradient dictates that an osmotic pressure increase will appear in the right beaker.

Thanks guys!! :)

anyone has physio ex 9.0 Exercise 8 Review sheet (Chemical & physical processes of digestion) Thanks!

physio ex is excruciating