Biopsychology: CNS & PNS - Similarities and Differences

Here are some key similarities and differences when comparing the CNS (Brain & spinal cord) and PNS (somatic/autonomic & sympathetic/parasympathetic).

CENTRAL NERVOUS SYSTEM (brain & spinal cord)

Similarities:

The brain stem and spinal cord both control involuntary processes (e.g. the brain stem controls breathing and the spinal cord controls involuntary reflexes).

Differences:

The brain provides conscious awareness and allows for higher-order thinking, while the spinal cord allows for simple reflex responses.

The brain consists of multiple regions responsible for different functions, whereas the spinal cord has one main function.

PERIPHERAL NERVOUS SYSTEM (somatic/autonomic & sympathetic/parasympathetic)

Similarities:

The sympathetic nervous system (part of the autonomic nervous system) and the somatic nervous system respond to external stimuli. The sympathetic nervous system responds to external stimuli by preparing the body for fight or flight and the somatic nervous system responds to external stimuli (by carrying information from sensory receptors to the spinal cord and brain).

Differences:

The autonomic nervous system consists of two sub-components, whereas the somatic nervous system only has one.

The somatic nervous system has sensory and motor pathways, whereas the autonomic nervous system only has motor pathways.

The autonomic nervous system controls internal organs and glands, while the somatic nervous system controls muscles and movement.

The brain consists of multiple regions responsible for different functions, whereas the spinal cord has one main function.