Question

Which signals sent through the central nervous system travel faster than others? Is there a particular hormone that intrigues or fascinates you? Which one(s)? Why?

Answer 1

Many things influence the speed at which information flows through the nervous sytem, but the most important factor would be, Neuron characteristics This is because they have two special characteristics that allow them send information very quickly, a large diameter, and a myelin sheath.

The speed at which a neuron transmits information depends upon how much myelination a neuron has, some nerve cells have myelin cells that wrap around the neuron to provide a type of insulation sheath. The myelin sheath isn’t completely continuous along a neuron; there are small gaps in which the nerve cell is exposed, the spaces between the myelin sheaths are known as the nodes of Ranvier, nerve signals effectively jump from these nodes of ranvier  instead of traveling the full extent of the neuronal surface, It almost looks like the signal jumps from node to node, in a process known as saltatory conduction. So signals move much faster in neurons that have myelin sheaths than in neurons that have no myelin sheath. Neurons travel at a speed of 268 miles per hour along an alpha motor neuron in the spinal cord, the fastest such transmission in the human body, while the sensory receptors in the skin travel at a low speed of about 1 miles per hour, since they do not have myelin.

The human body is home to more than 50 types of hormones,Different hormones have different effects on the shape of the body. Some of these hormones work quickly to start or stop a process and some will continually work over a long period of time to perform their functions. They help in body growth, development, metabolism, sexual function, reproduction etc, but among these the most important hormone for our body functions would be the thyroid hormones,, thyroid hormones affect every cell and all the organs of the body, they help  in controlling the metabolism of our body, can slow down or speed up the heartbeat, regulate body temperature, Influence the rate at which food moves through the digestive tract, control the way muscles contract.,Control the rate at which dying cells are replaced. Normal body temperature is maintained at a very small range, from 97.6–99.6°F, even few degree difference between these ranges can be very fatal, the unique feature of this system is that, whether we are at Himalyas, where the temperature can be very low ( as low as -15 degree celsius) or at the Sahara dessert, where the temperature can be very high,( as high as 50 degree celsius) our internal body temperature is maintained within these tiny range. it is the thyroid hormone which is responsible for maintaining body temperature.