Nerves, Neurons, Axons and Dendrites by Example

Question

Here is a simple diagram of a neuron:

A few (very closely related) questions:

• Where are receptors located (for pain, pressure, temperature, etc.): in the axon terminals or the dendrite tree?
• Please confirm: for sensory nerves, signals travel from axon terminal to dendrite tree, yes?
• According to Wikipedia, axons communicate with each other across synapses, and nerves are chained bundles of axons (basically forming a cable with each other). However, if sensory signals travel from axon to dendrite, then how can axons be chained together? In other words, if axons are a "male" recepticle, and dendrites are a "female" recepticle, then how can you have a chain of all-male recepticles?
• Please confirm: a nerve is just the cabling that houses bundles of long, individual strands of neurons, yes?

Answer 1

• Receptors are typically not located in a neuron. Instead, receptors generally synapse onto a primary neuron, and specifically on the primary neuron's dendrite;

• Within the neuron physiological signals are received in the dendrite and are transmitted uni-directionally via the axon to the axon terminal. Between neurons the signal is transmitted from axon to dendrite via the synapse (see figure).

• Although axo-axonal communication exists, it is not the typical way of neural communication (they are regulatory in nature and do not convey information as such). Typically, axons synapse onto another neuron via the dendrite of that second neuron.

The typical connection is the following:

• Nerves typically do not contain cell bodies, only the elongated parts of neurons, i.e. the axons. A nerve is a bundle of axons that contain closely related signals from closely related structures in the body.