The Nervous System

Stimulus --> Receptor --> Coordinator --> Effector --> Response

Stimulus - change in the environment/imbalance/evade an opponent

Receptor - specialised receptor cells/eyes and ears

Coordinator - brain or spinal chord

Effector - muscle or glands

Response - movement/skill

Nervous system is divided into two main parts:

1. Central Nervous System (CNS): brain and spinal cord

--> processing and integrating information

1. Peripheral Nervous System (PNS): connect the CNS to the rest of the body through nerves

PNS is further divided into efferent pathways

Efferent pathways: carry signals from the CNS to effectors

• Motor neurone system

• Controls movement

• Muscle contraction

Efferent pathways include the somatic system and the autonomic system

Somatic system: controlling voluntary movements (skeletal muscles)

Autonomic system: regulating involuntary functions (heart rate)

The autonomic system is further divided into the sympathetic and parasympathetic system

Sympathetic system: activated fight or flight response + stimulate an 'increase' response

Parasympathetic system: promotes rest functions + stimulates a 'decrease' response

Central Nervous System:

Brain

Processes and interprets sensory information

Initiates and coordinates movement

Regulates the body's physiological functions

Spinal Chord

Enables information to travel between the brain and the rest of the body

Peripheral Nervous System

All the nerves outside of the CNS

--> carry messages to and from the brain and spinal cord

Sensory nerves inform CNS about what is going on within and outside the body

--> motor nerves (efferent nervous system) sends information from the CNS to the effectors