Anonymous asked in Science & MathematicsZoology · 9 years ago

How brain and other organs formed in Non-Chordates?

They lack Notochord, which is responsible for the formation of brain in chordates. So. How to they develop these vital organs in absence of Notochord.

2 Answers

  • 9 years ago
    Favorite Answer

    The simplest brains are just a collection of nerve cells connected together through synapses. The notochord is just a bundle of nerves that runs down the length of the body. It is not necessary for brain formation. the nervous system consists of nerve cells that sense the environment, called sensor neurons, and nerve cells that control the body's muscles in the various parts of the body, called motor neurons. The brain, or central nervous system, simply receives input from the sensory neuron, and then makes a decision based on the nature of the input and the decision then results in signals being send to the body's motor neurons, which then instruct which particular muscle cells within the body as to what to do. If the sensory neuron detects danger, then the central nervous system may decide to escape, or it may decide to freeze. Simiarly, when the sensory system detects the presence of odors indicating food, the brain may then trigger the motor neurons to move towards the food. As long as there are neurons that can be connected to each other anywhere in the body, it can become a nervous system that can make decisions.

    Research on the round worm has provided insight on how brains work. See link below.

  • 9 years ago


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