Final answer:
The statement is true; conduction velocity increases with a higher space constant, which is facilitated by myelination of axons. Myelin allows for faster transmission of electrical impulses, while demyelination results in decreased conduction velocity and disrupted signal transmission.
Step-by-step explanation:
The statement is true; conduction velocity is indeed increased when the space (length) constant is increased. This is the reason why myelination of axons is essential for rapid signal transmission. Myelin sheaths act as insulators, allowing the electrical impulse to jump between gaps in the myelin called nodes of Ranvier, in a process known as saltatory conduction. The increased space constant via myelination leads to a greater distance that the membrane potential can passively spread. Consequently, when an axon is demyelinated, its space constant decreases, resulting in slower conduction velocity due to the disruption of the insulating layer.
Demyelination diseases, such as Multiple Sclerosis, exemplify the effects of decreased space constant on conduction velocity, contributing to neurological symptoms due to delayed signal transmission.