Answer to Question #119128 in Human Anatomy and Physiology for Brittney

Question

Sense organs receive stimuli at different intensities. How do neurones transmit this information?

Answer 1

A neuron is the main functional element of the nervous system, it consists of the body of a nerve cell and its processes. There are two types of processes: axons and dendrites. Axon is a long process covered with myelin sheath, designed to transmit a nerve impulse over long distances. Dendrite is a short, branching process, due to which there is a relationship with many neighboring cells.

Neurons can vary greatly in shape, size and configuration, despite this, there is a fundamental similarity of the nervous tissue in different parts of the nervous system, and there are no serious evolutionary differences. The nerve cell of the mollusk Aplisia can secrete the same neurotransmitters and proteins as the human cell.

Three types of neurons are distinguished depending on the configuration:

a) receptor, centripetal, or afferent neurons, these neurons have a centripetal axon, at the end of which there are receptors, receptor or afferent endings. These neurons can be defined as elements that transmit external signals to the system.

b) interneurons (intercalary, contact, or intermediate) neurons that do not have long processes, but only have dendrites. There are more such neurons in the human brain than others. This type of neuron is the main element of the reflex arc.

c) motor, centrifugal, or efferent, they have a centripetal axon, which has efferent endings that transmit excitation to muscle or glandular cells. Efferent neurons are used to transmit signals from the nervous environment to the external environment.

 When neurons are stimulated they produce nerve impulse. Nerve impulse is nothing but mild electric potential or current which gets transmitted. The nerve impulse or the current generated is due to unequal distribution of ions across the nerve membrane. Transmission of this current along the length of the nerve is called nerve impulse.