Neurons and synaptic transmission Flashcards
Neuron
Basic building blocks of the nervous system. They are nerve cells that process and transmit messages through electrical and chemical signals.
Sensory neurons
Carry messages from the PNS to the CNS
Relay neurons
Connect to sensory neurons to the motor or other relay neurons
Motor neurons
Connect the CNS to effectors such as muscles and glands
Synaptic transmission
The process by which neighbouring neurons communicate with each other by sending chemical messages across the gap that separates them
Neurotransmitter
Brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another. Neurotransmitters can be broadly divided into those that perform an excitatory function and those that perform an inhibitory function
Excitation
When a neurotransmitter such as adrenaline increases the positive charge of the post-synaptic neuron. This increases the likelihood that the neuron will re and pass on the electrical impulse.
Inhibition
When a neurotransmitter such as serotonin increases the negative charge of the post-synaptic neuron. This decreases the likelihood that the neuron will re and pass on the electrical impulse.
Cell body
Includes the nucleus which contains the genetic material of the cell and has dendrites branching off it
Axon
Long extension from the cell body. The nerve impulse travels down the axon. Nearly all the axons are covered with a myelin sheath.
Myelin sheath
Protects axon from damage as well as speeding up nervous impulse transmission along the axon
Terminal button
The end of the axon. This is how axons send signals to an adjacent cell. This cell may be another neuron or muscle cell.
Dendrite
If the adjacent cell is another neuron, the dendrites receive the impulse or signal from the adjacent neuron
