facts about Nerve cells скачать в хорошем качестве

facts about Nerve cells

the nerves or neurons carry messages between the central nervous system and the rest of the body. a neuron usually has a number of dendrites and an axon. the gap between one neuron and the next is called the synapse. information enters the neuron at the dendrites and passes along the axon to the synapse. neurotransmitters take the message across the synapse to a neighbouring dendrite. the axon is wrapped in myelin its like the insulation on an electrical cable. this means the nerve impulse is protected from the message travel fast. the nerve jumps between gaps in the myelin. the gaps are called nodes of ranvier. if the myelin sheath is damaged the nerve impulses may slow down or fail to get to their destination. this kind of nerve damage is called demyelinanation. if demyelination persists the neuron will die. just as faulty insulation can cause problems for your wiring at home demyelination can cause all kinds of problems. it all depends where the nerve damage occurs. neurons are not usually replaced when they die. the disablities caused can be permenant.MS research and treatment aims to: reduce the the inflamammation that causes demyelination. grow new myelin before the damage neuron dies. protect the myelin that is still there. help the people learn how to work around impaired nerve function. There are more nerve cells in the human brain than there are stars in the Milky Way. If we lined up all the neurons in our body it would be around 965 km long. There are 100 billion neurons in your brain alone. A newborn baby's brain almost triples in size during the course of its first year.