What are the applications of human nervous cells?
the nervous system is responsible for sending, receiving and interpreting signals from all over the body and coordinates its action. it processes and intergrates information on a variety of levels, and directs the body to respond appropriately. the nervous cell system consists of neurons, endothelial cells, pericytes, smooth muscle cells, fibroblasts, schwann cells, epithelial cells, meningeal cells and microglia. when the nervous cells grow abnormally, the development of disorders starts such as cerebrovascular disease, alzheimer’s disease, parkinson’s disease, multiple sclerosis, mental illness, and huntington’s disease.

The human body is made up of trillions of cells. Cells of the nervous system, called nerve cells or neurons, are specialized to carry "messages" through an electrochemical process. The human brain has approximately 86 billion neurons. To learn how neurons carry messages, read about the action potential.

Neurons come in many different shapes and sizes. Some of the smallest neurons have cell bodies that are only 4 microns wide. Some of the biggest neurons have cell bodies that are 100 microns wide. (Remember that 1 micron is equal to one thousandth of a millimeter!).

Neurons are similar to other cells in the body because:

Neurons are surrounded by a cell membrane.

Neurons have a nucleus that contains genes.

Neurons contain cytoplasm, mitochondria and other organelles.

Neurons carry out basic cellular processes such as protein synthesis and energy production.

However, neurons differ from other cells in the body because:

Neurons have specialize cell parts called dendrites and axons. Dendrites bring electrical signals to the cell body and axons take information away from the cell body.

Neurons communicate with each other through an electrochemical process.

Neurons contain some specialized structures (for example, synapses) and chemicals (for example, neurotransmitters).

The Neuron

neuron

One way to classify neurons is by the number of extensions that extend from the neuron's cell body (soma).

bipolar neuron

Bipolar neurons have two processes extending from the cell body (examples: retinal cells, olfactory epithelium cells).

Pseudounipolar cells (example: dorsal root ganglion cells). Actually, these cells have 2 axons rather than an axon and dendrite. One axon extends centrally toward the spinal cord, the other axon extends toward the skin or muscle.

Multipolar neurons have many processes that extend from the cell body. However, each neuron has only one axon (examples: spinal motor neurons, pyramidal neurons, Purkinje cells).

Neurons can also be classified by the direction that they send information.

Sensory (or afferent) neurons: send information from sensory receptors (e.g., in skin, eyes, nose, tongue, ears) TOWARD the central nervous system.

Motor (or efferent) neurons: send information AWAY from the central nervous system to muscles or glands.

Interneurons: send information between sensory neurons and motor neurons. Most interneurons are located in the central nervous system.

Check out the Gallery of Neurons to see some pictures of real neurons or "Sidewalk Cells" to see photographs of neurons on the street.

Hear It

"Neuron" | "Axon" | "Dendrite" |

"Nissl" | "Mitochondria" | "Endoplasmic reticulum"

There are several differences between axons and dendrites:

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.