Key Concept 4: Organisation of the nervous system Flashcards
Nervous system
A complex network of cells in the human body. It is our internal communication system. It collects, processes and responds to information in the environment. It coordinates different organs and cells in the body.
The Central nervous system (CNS)
The Central nervous system (CNS) is made up of the brain and the spinal cord.
The brain - the center of our conscious awareness, it is divided into two hemispheres, the right side of the brain controls the left side of the body etc. The brain is covered by an outer layer called the cortex - this is where higher level thinking processes occur such as problem solving. At the bottom of the brain is the brain stem which controls basic functions such as breathing and connects the brain to the spinal cord.
The spinal cord - A tube like structure that runs like a cable from the brain and down the middle of the spine. It controls reflexes and passes messages to and from the brain and the rest of the body via the Autonomic nervous system (ANS).
Autonomic nervous system (ANS) - a collection of nerves that send and receive signals between the spinal cord and the body organs. It is autonomic because it operates automatically. It controls functions that are vital for survival and do not require our conscious attention (we don’t have to think about it) e.g. breathing and heart rate. It plays a key role in the fight or flight response.
Sympathetic division
This activates physiological arousal e.g. increases heart rate, prepares the body for fight or flight.
Parasympathetic division
This activates rest (stops arousal/fight or flight) and brings the body back to its normal resting state after the stress has passed e.g. slows down heart rate.
