Neurons Flashcards
What are neurons?
They are the basic building blocks of the nervous system and process and transmit messages through electrical and chemical signals.
What are the 3 main types of neuron?
Motor, sensory and relay neurons.
What are sensory neurons?
They carry messages from the PNS to the CNS.
What are relay neurons?
They connect sensory neurons to the motor neurons or other relay neurons
What are motor neurons?
They connect the CNS to effectors such as muscles or glands.
What is the structure of a neuron?
There is a cell body with a nucleus, containing the genetic information. Dendrites protrude from the cell body, carrying impulses towards the cell body. The axon carries impulses along the neuron and in a sensory and motor neuron is covered by a myelin sheath to protect the axon and speed up the transmission of the impulse. There are gaps in the myelin sheath called nodes of ranvir to increase the speed and at the end of the neuron there are terminal buttons to communicate with the next neuron.
How are electrons transmitted?
When a neuron is in a resting state, the inside of the cell is negatively charged compared to the outside. When a neuron is activated by a stimulus, the inside of the cell becomes positively chraged for a split second, causing an action potential to occur.
