Question

Do nerves grow out from within or in from the skin? Thoughts: My guess is outwards. However, I have a vague memory of a study involving frogs that I read about in a pop science book - I forgot which - that took skin from the back & chest of a bunch of frogs, swapped them, then tested their reactions.IfI remember correctly, some of the frogs wiped their chest when the skin on their back was stimulated (and/or vice versa). That would suggest that they grow inward from the skin. Some vaguely formed hypotheses: Nerves grow inwards from skin.Nerves grow outwards from, say, the brain.Some combination of 1. and 2. Background: I have no formal training in biology. I read a handful of textbooks on evolution for fun though, like99% Ape,Why Evolution is True, and some of Dawkins' work, includingThe Selfish Gene.

Answer 1

Nerves grow out from the skin. Spinal nerves contain afferent axons from sensory receptors in the periphery and transmit sensory information to the central nervous system. Motor neurons have cell bodies in the spinal cord and their axons project to muscles.

Step-by-step explanation:

The nerves grow out from the skin. Spinal nerves contain afferent axons from sensory receptors in the periphery, such as from the skin, and transmit sensory information to the central nervous system. The dorsal root of the spinal nerve contains only the axons of sensory neurons that enter the spinal cord through the dorsal nerve root. On the other hand, motor neurons have cell bodies in the ventral gray matter of the spinal cord and their axons project to muscles through the ventral root, causing muscle contractions in their target regions.