Spinal chord = extension of brain responsible for reflex actions
Peripheral: transmits messages to and from NS.
Somatic NS – controls muscle movement and receives info from sensory
receptors.
Autonomic nervous system – controls the body’s involuntary activities.
Sympathetic NS – prepares body to expend energy. Dilate pupils, inhibit
salvation, increase heartbeat.
Parasympathetic NS – conserves body energy. Slows heartbeat, constrict pupils,
stimulate salvation.
Noise is transmitted from somatic NS to the brain. The brain recognises what
the sound means e.g. pack up, sends to spinal cord. Motor messages carried by
the Peripheral nervous system to the skeletal muscles.