Biopsychology: Divisions of the Nervous System
THE NERVOUS SYSTEM.
The nervous system is a specialised system of up to 1 trillion neurones which allow signals to move between the brain and the body. The nervous system as many people know it is broken down into two main systems: the central nervous system, and the peripheral nervous system.
THE CENTRAL NERVOUS SYSTEM.
The central nervous system is the most significant part of the nervous system which is composed of the brain and the spinal cord. There are various protective structures surrounding the brain and spinal cord which involve the skull and the spinal vertebrae.
THE BRAIN.
The brain provides conscious awareness and is involved in all psychological processes. It consists of many regions which are each involved in different functions. The brain consists of the frontal lobe, temporal lobe and the occipital lobe, along with the hypothalamus and other smaller areas. The brain stem handles involuntary responses such as breathing, heartbeat and blinking.
THE SPINAL CORD.
The role of the spinal cord is to transfer messages to and from the brain and the rest of the body. It is also responsible for simple reflex actions which do not involve the brain. These may include removing your hand from a stimulus that causes pain.
THE PERIPHERAL NERVOUS SYSTEM.
The peripheral nervous system maintains communication between the CNS and the outside world. It is a large portion of the overall nervous system as it includes pretty much all of the nerves in your arms, legs, fingers and toes as well as the rest of the body. It is split into two systems:
THE SOMATIC NERVOUS SYSTEM.
The somatic nervous system is made up of sensory receptors that carry information to the spinal cord and to the brain. It is also composed of motor pathways (and neurons) that allow the brain to control movement of our muscles.
THE AUTONOMIC NERVOUS SYSTEM.
The autonomic nervous system controls homeostasis (the maintenance of a constant internal environment). This system has only motor pathways. This part is composed of two systems:
THE SYMPATHETIC NERVOUS SYSTEM.
The sympathetic nervous system is typically involved in responses that prepare the body for fight or flight. Impulses travel from the sympathetic nervous system to the organs to help us prepare for action when we are faced with a dangerous situation.
THE PARASYMPATHETIC NERVOUS SYSTEM.
The role of this system is to relax the body of return us to our normal resting state. It slows down our heart and breathing rates, as well as reducing blood pressure.
