Sci Bio

Peripheral Nervous System

Made up of dual pathways: Afferent Pathway (sensory) and Efferent Pathway that branch off into two subdivisions: Somatic nervous system and Autonomic Nervous System

Somatic Nervous System

Contains nerves that carry sensory signals from the body to the central nervous system (CNS) and that carry motor signals from the CNS to skeletal muscles. Associated with voluntary movement. Eg picking up a pencil.

Autonomic Nervous System

Sometimes called the involuntary nervous system and regulates the internal environment of the body. It carries signals from internal organs to the CNS and from the CNS to the internal organs. Can also be split into two subdivisions of nerve fibres: Sympathetic and Parasympathetic.

Sympathetic Nervous System

Stimulates and moblisies energy resources (Increases energy) Often known as fight or flight responses

Parasympathetic Nervous System

A network of nerves that calms your body (Conserves energy) often described as being involved in rest and digest reponses

Afferent pathway (sensory)

Carries sensory information toward the CNS from receptors in the body. These receptors detect changes like touch, temperature, pain, light and sound Eg touching a hot surface sends sensory signals to the CNS.
body → CNS (incoming information)

Efferent pathway (motor)

Carries motor commands away from the CNS (brain and Spinal cord) to muscles and glands. It allows the body to actually act on the information it received
CNS → body (outgoing commands)