How many cells in a nervous system?

Answer 1

You could say there are 2, The Central Nervous System(CNS), & the Peripheral Nervous System (PNS).

To be more inclusive, here is a list of human nervous systems:

The Central Nervous System (CNS), the Peripheral Nervous System (PNS),

the Somatic Nervous System (SNS), the Autonomic Nervous System, the Sympathetic Nervous System, and the Parasympathetic Nervous System.

That would make a total of 6, although the Sympathetic and Parasympathetic are parts of the Autonomic Nervous system, which could mean a total of 4, and the Autonomic is itself a part of the Peripheral Nervous System, which would bring the total back to 2.

The Central Nervous System is comprised of the brain and the spinal cord;

the Peripheral Nervous System connects the CNS to other parts of the body, and is comprised of the Somatic Nervous System and the Autonomic Nervous System;

the Somatic Nervous System includes all the nerves controlling the body's muscular system, and sensory nerves;

the Autonomic Nervous System consists of motor neurons which control internal organs, and is comprised of two sub-systems, the Sympathetic Nervous System, and the Parasympathetic Nervous System;

the Sympathetic Nervous System is involved in the fight-or-flight response, and the Parasympathetic Nervous System is involved in relaxation.

Answer 2

Some recent research indicates that the human braincontains 86 billion neurons. This number is less than the usual number stated, which is usually 100 billion. (This new determination was made by Dr Suzana Herculano-Houzel, who turned a number of human brains into 'soup' and then took an average of the total count of the nuclei of just the neurons! One could wonder if she has had fantasies of marrying Dr. Hannibal Lector? :) )

And since there are about 10 times as many glial cells in the brain, that would bring the total number of cells in the brain to be 86,000,000,000 + 860,000,000,000, or 946,000,000,000, which is close to a trillion, which would seem to be a close approximation to the number of cells in the whole human nervous system.

Of course, the number of cells in the nervous system of other animals would likely be different, particularly for much smaller animals like starfish or worms.

Answer 3

The human nervous system contains billions of cells, including neurons and other supporting cells like glial cells. Neurons are specialized cells that transmit electrical and chemical signals within the nervous system, facilitating communication between different parts of the body.

Answer 4

There is one nervous system, it is subdivided into the central and the peripheral nervous systems.

Answer 5

100,000