the physiology of the nervous system
cognitive psychology uses the information-processing approach. unlike a computer we can process information in the past, present and future and make assumptions on this and make little errors whereas a computer would make much more.both computers and humans use electricity. we work by a system of electrochemical changes, caused by external stimuli and by changes in our bodies.
the structure of the nervous system
the nervous system includes the central nervous system (CNS) which is the brain and spinal chord.this is the centeral control for all the activities of the body, where information is recieved and processed and there is coordination of actions and reactions, both concious and unconcious. the nervous system also includes the peripheral nervous system (PNS), which consists of a network of neurons which are located around the whole body and are responisble for carrying information from the world to the CNS, and from the CNS back to the different parts of the body. the PNS can also be subdivided into the somatic nervous system (SNS) and the automic nervous system (ANS).
the somatic nervous system is the part that is generally concious of the responses it is making. for example the sensory nervous of the somatic system carry information about external stimulation from the different receptors to the CNS. the information is decoded and messages are carried back from the CNS to the muscles of the body, where action is then taken in resonse. therefore the somatic part of the nervous system is responsible for all the muscles we use to make voluntary movements, as well as involuntary adjustments to posture and balance.
the nervous of the automic system run to and from the internal organs and are affected generally by information from inside the body (although occasionally they may respond to external infomation). the message transmitted by the ANS regulate the function of these internal organs, such as the heart rate, speed of respiration and digestion.it is called the automatic nervous system because many of the activities it controls are autonomous and self-regulating, and these continue to take place even if a person is asleep or unconcious.
the ANS can be futher subdivided into the sympathetic division and the parasympathetic division:
- the sympathetic division is the mechanism that speeds bodily systems up and prepares the organism for activity- it has an excitatory function. it is the fight/flight mechanism which prepares the body for a response. for example by speeding up the heart rate, dialating the arteries of the essential organs and constricting the arteries of the less essential organs, such as the skin and digestive organs.
- the parasympathetic division is responsible for returning the body to normal by slowing it down again and allowing bodily functions to return to their original state- it is inhibitory.
- in order for these reactions to occur, neuronal fibres from both the sympathetic and parasympathetic divisions supply most organs, and the normal state of the body is maintained by a balance between these two…