Action potential: Electric current generated to carry a signal in your cells.
Synapse: Where one nerve has to pass the signal across a gap to another nerve
Thalamus: Part of brain that splits pain signals to different parts of the brain.
Somatosensory cortex: Part of brain that identifies a pain signal and determines where it hurts.
Limbic system: Registers emotional component of pain.
Frontal cortex: Thinks and makes decision about a pain.
Explanation:
The sensation of pain involves sensory neurons that contain nocireceptors. These are receptors specialized to sense pain.
Nocireceptors receive a pain stimulus and generate an action potential through ligand gated channels such as the Na+/K+ pump which are ion channels responsible for generating a nerve impulse.
The neuron is the cell of the nervous system that conducts nerve impulses towards and away from the brain.
Two neurons are connected through synapses. A synapse, also called a neuronal junction, is the gap between two neurons that allows the exchange of electrical and chemical signals between them. This synapse can exist between two neurons or a neuron and a muscle in which case it is called a neuromuscular junction.
Crossing the synapse and following the afferent pathway (signaling towards the central nervous system), the nerve impulse reaches the thalamus in the brain. The thalamus is a sensory gate in the brain that distinguishes between different pain signals and relays them to the appropriate part of the brain.
The thalamus then sends the signal to the somatosensory cortex that determines which part of the body is affected.
The somatosensory cortex then forwards the signal to the frontal cortex that decides the course of action.
The efferent nerve impulse i.e. signaling away from the CNS then carries the signal to motor neurons that respond to the pain stimulus.
