Nervous system

What is the nervous system?

The nervous system helps all parts of the body communicate with each other - it is divided into two main components

• the central nervous system (CNS)

• the peripheral nervous system (PNS)

What is the central nervous system?

• Includes the spinal cord and the brain

• Main function - processing sensory information

• It synthesizes sensory input to compute an appropriate motor response, or output

What does the brain do (CNS)?

The brain provides conscious awareness and is involved in all psychological processes. The brain consists of many regions, which are responsible for different functions

1. Frontal lobe - associated with higher-order functions, including planning, abstract reasoning and logic

2. Parietal lobe - integrates sensory information and therefore plays an important role in spatial navigation

3. Temporal lobe - auditory information processing

4. Occipital lobe - visual information proessing

The brain stem connects the brain and spinal cord and controls involuntary processes, including our heartbeat, breathing and consciousness

What does the spinal cord do (CNS)?

• Role of spinal cord is to transfer messages to and from the brain and the rest of the body

• spinal cord is responsible for simple reflex actions that do not involve the brain e.g. jumping out you chair if you sit on a pin

What is the Peripheral Nervous System?

Role of the PNS is to relay messages (nerve impulses) from the CNS to the rest of the body

Consists of two main components

1. somatic nervous system

2. autonomic nervous system

What is the role of the Somatic Nervous System (PNS)?

Connects the CNS and the senses

• made of sensory receptors that carry information to the spinal cord and brain

• made of motor pathways that allow the brain to control movement - under conscious control/voluntary

Provides muscle responses via the motor pathways

What is the role of the Autonomic Nervous System (PNS)?

Plays an important role in homeostasis (e.g. regulating body temperature) which maintains internal processes - it is involuntary/not under conscious control

• Only consists of motor pathways and has two components

1. sympathetic nervous system

2. parasympathetic nervous system

What is the role of the Parasympathetic Nervous System (PNS)?

To relax the body and return us to our normal resting state

• e.g. slows down our heart rate and breathing rate and reduces our blood pressure

• any functions that were previously slowed down during a fight or flight reaction are started again (e.g. digestion)

• brings the body back to its normal, resting state

What is the role of the Sympathetic Nervous System (PNS)?

Involved in responses that prepare the body for fight or flight response

• impulses travel from the sympathetic nervous system to organs in the body to help us prepare for action when we are faced with a dangerous situation

• e.g. our heart rate, blood pressure and breathing rate increase

• less important functions functions like digestion, salivation are suppressed