*See picture*, do neurons make up a nervous pathway? (Length of neurons)

That is actually true. There are neurons that span a very long distance especially those related to our skeletal muscles. As for the sensory neurons, it actually depends from where the sensation is transmitted and to which vertebral column. They may be as an estimation less than 1m, say 70 or 80 if we are speaking of fingertips to cervical vertebrae. If from toes to sacral vertebrae, then they may vary depending on how tall the person is. if they are taste neurons, they could be very short such that they need to travel from the tongue to the hypothalamus in the brain. 

and yes, there would be many little neurons. Neurons and nerves are the most abundant innervations in our bodies. They connect everything together, such that in 1m, you would find a huge number of neurons maybe not even sensory, they may be motor, they may be pseudounipolar or bipolar, they may be modulatory, etc etc.
I hope this clarifies =)

Thank you!
So the 'sensory neuron' is a pathway of lots of other neurons, basically?

I'll go read up on some of those types of neurons that you mentioned.

Not really. The sensory neuron is a pathway of only sensory neurons.. There are many others around it, but when they emphasize sensory neurons in diagrams, it is usually a way of simplifying the concept they are trying to convey. So here in the picture, the sensory neuron is one specialized to convey say pain, or touch, or temperature so on and so forth.

you're welcome anytime Let me know if you need more info

Thanks again,

Is this little diagram correct:
                     (Sensory neuron, 1m, signal )
Receptor (PNS)|--------------------------------------------------------------------------------------| Spinal cord (CNS)
              /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
            (Lots of little sensory neurons within the 1m long neuron)


Are there be lots of long ~1m sensory neurons as well? Do both long sensory neurons and smaller sensory neurons both have myelin sheath?

That's right. And yes there are many long sensory. Remember, if say we are talking about receptors in our hand, we don't only have one neuron for one finger tip. We have many! And of different receptor types. They all meet at the dorsal ganglion outside the spinal cord before going in.
As for myelination, it depends. Some are myeinated, some are not. For example, pain C fibers are unmyelinated. But there are A fibers that are fast conducting and so have myelin.