##### Asked by: Jeannetta Leistra

asked in category: General Last Updated: 25th May, 2020# Does myelination increase length constant?

**myelinated**axons will have longer

**length constants**than thinner, unmyelinated axons, which means that graded potentials can travel over longer distances in large,

**myelinated**axons before dying out.

Hereof, does myelination increase time constant?

In textbooks, it says that **myelination** doesn't really affect the **time constant** as tau=RC where R **is** the membrane resistance and C **is** the membrane capacitance. **Myelin increases** membrane resistance while decreasing membrane capacitance so there isn't really an overall effect on the **time constant**.

Similarly, how do you find length constant? This means that the **length constant** is the distance at which 63% of V_{max} has been reached during the rise of voltage. Setting for x= λ for the fall of voltage sets V(x) equal to . 37 V_{max}, meaning that the **length constant** is the distance at which 37% of V_{max} has been reached during the fall of voltage.

Herein, how does myelination affect time constant?

Explain how the effects of **myelin** on the **time constant affect** AP speed and the effects of **myelin** on the length **constant affect** AP failure. - Decreases capacitance which leads to smaller **time constant** and increase in speed - Increased membrane resistance which leads to longer length **constant** and less voltage decay 9.

What is the membrane time constant?

**Membrane time constant** is the **time** for the potential to fall from the resting to a fraction (1-l/e), or 63%, of its final value in the charging curve during the application of a small negative current pulse.