Introduction to neural cell types
This video provides an introduction to the cell types of the nervous system. By Matt Jensen. Created by Matthew Barry Jensen.
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- Do we actually use 10% of our brain? It does not seem possible to me.(26 votes)
- As mentioned, we do not just use ten percent of our brains, but actually use every single part of it - for the senses, hormonal control, memory, speech, and so on. The "ten percent" myth actually came from the fact that, although we do use our entire brains, we do not use them to their fullest intellectual capacity. Many neurologists believe that the long-term memory is endless, and thus we could never use it to its fullest potential. That is where the saying that we only use ten percent of our brains came from.(27 votes)
- What is the ratio of glia cells to neuron cells?(13 votes)
- Depending on the source, the generally accepted estimates seem to number glial cells at 5-10 times the number of neurons. So there are a lot more of them than neurons. A commonly accepted number has the human brain made up about 90% of glia.(19 votes)
- What does cress (is that how you spell it?) Mean? Where was it derived from? Greek? Latin?(7 votes)
- In the video, he talks about "neural crest cells." They are part of the embryonic layer called the ectoderm and are named for their location at the dorsum of the neural tube, running as a crest along that tube (which tube eventually forms much of the central nervous system).(15 votes)
- What exactly does being ticklish mean? Is it your touch sensors being touched in a way so they conflict and send a weird message to your brain? Is it a warning sign to stop like when you get hurt? Or does it trigger a nerve like your funny bone?(9 votes)
- The tickle sensation involves signals from nerve fibers associated with both pain and touch. Endorphins released during tickling is also called karolin, by the name of Karolinska Institute. In 1939, Yngve Zotterman of the Karolinska Institute studied the knismesis type of tickle in cats, by measuring the action potentials generated in the nerve fibres while lightly stroking the skin with a piece of cotton wool. Zotterman found that the "tickling" sensation depended, in part, on the nerves that generate pain. Further studies have discovered that when the pain nerves are severed by surgeons, in an effort to reduce intractable pain, the tickle response is also diminished. However, in some patients that have lost pain sensation due to spinal cord injury, some aspects of the tickle response do remain. Tickle may also depend on nerve fibres associated with the sense of touch. When circulation is severed in a limb, the response to touch and tickle are lost prior to the loss of pain sensation.(7 votes)
- At0:19, it says that neurons cause consciousness. How do we know that? I thought we don't know what consciousness is yet?(6 votes)
- anesthetics causes desynchronisation of microtubules in nerve cells, which brings you in unconscious(7 votes)
- Do people with a certain diseases or disorders use 100% of their brain, because I've been hearing that if you have autism you use 100% of your brain.(3 votes)
- All healthy humans use 100% of their brains; if we did not use our entire brain then having such a large brain would be an evolutionary disadvantage. Statements suggesting we do not use our entire brain are not supported by scientific evidence.
- Can we find any unicellular organism carrying the same features as that of a neural cell?(5 votes)
- No, because neural cells depend entirely on being networked to other cells for their functionality, and must be supported at all times by other cells that help provide them with nourishment, myelination, and several other things.
Unicellular organisms must be able to survive on their own.(8 votes)
- is it true that the right side of our brains is the active part only?(1 vote)
- No that is not true we use our entire brain.(7 votes)
- What would happen if a nerve stem broke(3 votes)
- First of all, the event of a nerve stem breaking would be very painful and the chances of this are pretty low. However, the effects would differ depending on what it did. Motor neurons being torn would result in immobility of a joint, as one spinal nerve will connect to both of two opposing muscles. Sensory neurons being torn would result in loss of sensation in a long, narrow area(see: http://r2.emsworld.com/files/cygnus/image/EMSR/2014/MAR/1280x720/spinal-fig-1_11321840.jpg ) .(1 vote)
- What is happening when we dream?(3 votes)
- Good question! In short, when we dream, our brain is going over the events and information of the past day and processing it - deciding whether it is worth keeping or not. It forms stronger connections (called synapses) to store the information it wants to keep, and discards all the non-useful information, such as what you ate for lunch. This in turn, creates images or "hallucinations" that we call dreams.
Hope this helped!(1 vote)
In this video, I want to introduce the different types of neural cells. The word "neural" or the prefix "neuro" just refers to the nervous system, so that neural cells are cells of the nervous system. Neural cells work with all the other cell types of the body to produce the amazing range of functions of the nervous system, including consciousness, social interactions, cognition, emotion, movement, sensory perception, and regulation of other functions, such as circulation, respiration, and digestion. Neural cells are divided into two big categories. The first are neurons, which were traditionally called nerve cells. And the second are glia. Now, these can also be called neuroglia or glial cells. That all means the same thing. Neurons are named from a Greek word for nerve, while glia are named from a Greek word for glue, because they were once thought to do little except glue neurons together. The structure of the nervous system is divided into two main parts. The first part is mainly made up of the brain in the head and the spinal cord in the spine. And this part of the nervous system is called the central nervous system. The other part of the nervous system is called the peripheral nervous system. And that's made up mostly of nerves, these long, stringy structures that come out of the brain and the spinal cord. And they go all over the body, like down into the arms, and down into the legs, and into every part of the body. And we'll cover a lot more in detail about neuroanatomy in other videos. But I just need to bring up the central and peripheral nervous system because the neural cells are divided up differently amongst the different systems. Calling neurons nerve cells is a little problematic because these structures in the peripheral nervous system called nerves are made up of neurons. But they also contain glial cells. And they contain a number of other cells that aren't neural cells at all. However, you'll often hear people refer to neurons as nerve cells because that was the traditional name for them. Neurons are found both in the central nervous system, the brain and the spinal cord, and the peripheral nervous system, in the nerves. But the different types of glial cells are found only in one or the other. Most neural cells are derived from populations of cells called neural stem cells or neural crest cells. And both of those cell types arise early in development in the part of the embryo called the ectoderm. Most neurons and glia found in the central nervous system are derived from neural stem cells, while most neurons and glia found in the peripheral nervous system are derived from neural crest cells. Now, we'll go into a lot more detail about what neural stem cells are and neural crest cells in other videos, when we cover development of the nervous system. Most types of both neurons and glia share some structural features of the way their cell is shaped. Most of them have a main part to their cell called the soma or the cell body that contains the nucleus and most of the organelles. Coming out of the soma, most of these cell types have processes, long, thin extensions that come out of the soma. And the processes of the different neural cells vary in number and in length, in thickness, and degree of branching, because some of them will be unbranched, and some of them will have processes that branch, sometimes a little and sometimes a lot. They will also vary a lot in the terminal structures at the end of their processes and the function of these structures and the processes. The function of neurons is to process and transmit information. And the function of glia is to support them in a variety of ways. There are many structural and functional types of both the neurons and the glia. And there are large numbers of these cells making up the nervous system. There are billions of neurons that form trillions of connections in the adult human nervous system. And there even more glia than there are neurons. In subsequent videos, we'll go over the most common glia, which are astrocytes, microglia, ependymal cells, oligodendrocytes, and Schwann cells. There are also less common glia, such as satellite cells and olfactory and sheathing cells. But we'll just go over the most common types here.