Questions tagged [central-nervous-system]

The complex of nerve tissues including the brain and spinal cord, but excluding the peripheral nervous system.

Filter by
Sorted by
Tagged with
9 votes
3 answers
2k views

How do our eyes detect light at different frequencies?

Here is my confusion: we can see colored light of different wavelengths: form red to violet. To my understanding, these stimuli cause a confirmational change in the photoreceptors in our eyes and ...
Confusedbyeverything's user avatar
63 votes
4 answers
9k views

Are there organisms with fewer than 1000 neurons?

I'm developing neural networks comprised of just 3 to 10 layers of virtual neurons and I'm curious to know if there are any insect brains out there with fewer than a thousand neurons? Are there any ...
J.Todd's user avatar
  • 1,881
6 votes
3 answers
7k views

Do lobsters possess a nervous system to feel pain?

I was reading an article, which it mentions that lobsters do not have a nervous system: Lobsters have very poor eyesight and no nervous system. They walk slowly on the sea floor but are capable ...
Johansson's user avatar
  • 705
7 votes
2 answers
1k views

Is the bipolar neuron of the retina considered a sensory neuron?

Any neuron that participates in sending impulses from receptors to the CNS are referred as sensory neurons. But I often see bipolar neurons of the eye (which according to the above definition should ...
deechitpoudel's user avatar
5 votes
2 answers
128 views

Neurons during Numb feeling

We become numb when there is short supply of blood to some parts, as mentioned here. If that is the reason, why don't neurons and other cells die at that part if they don't receive oxygen and other ...
Ram Keswani's user avatar
3 votes
0 answers
70 views

CNS lymphatic vessels around ventricles lat et 4th?

I am searching for precise locations of the lymphatic vessels of the CNS based on the applications of the article here. However, I did not find any when having a focus on the immediate region around ...
Léo Léopold Hertz 준영's user avatar
3 votes
1 answer
184 views

Photoreceptors and light with mixed frequencies

I am interested in how the activation of a, say, blue cone depends on the incident light. Wikipedia tells me this: , which describes how strong the activation of the blue cone is for light with a ...
Erik Aas's user avatar
  • 133
2 votes
2 answers
311 views

At what stage is the nervous system developed enough to interpret neuronal signals as 'pain'?

According to this article in Live Science, one of the reasons the fetus can't feel pain until 19 weeks is because the nervous system isn't fully developed. But according to this article, the heart ...
Pablo's user avatar
  • 2,787