Images

The autonomic nervous system regulates involuntary bodily functions through two complementary divisions: the sympathetic nervous system and the parasympathetic nervous system.

The cell bodies of efferent pathways (motor and autonomic) lie in the spinal cord of the central nervous system (CNS) and peripheral nerves contain axons from these neuronal cell bodies as well as those situated in peripheral ganglia.

Receptors are crucial for transducing chemical, mechanical, thermal or light stimuli into signals that the rest of the nervous system will understand.

The receptive field of a neuron usually coincides with its perceptive field – the area from which a sensation is perceived to arise. The overlapping of receptive fields of individual neurons allows for perception to smoothly move from one sensory neuron to the next.

Slowly adapting receptors’ respond to prolonged and constant stimulation, and generate action potentials throughout the entire stimulation period; ‘rapidly adapting receptors’ fire only at the beginning and at the end of a stimulus, and stop firing in response to stimulation whose frequency does not change.

Sensory information used to control actions is processed in neural pathways separate from the afferent pathways that contribute to conscious perception.