In biology, a stimulus is a change in an organism's surroundings that causes the organism to change its behavior in order to make the environment more satisfactory. For instance, hunger motivates animals to seek food, predators stimulate prey to run away or hide, and falling temperatures encourage creatures to seek shelter or find warmth in other ways.
When something in the environment stimulates an animal, its central nervous system, the brain and spinal cord, organizes the response. The stimulus is sensed by the animal, and its sensory neurons carry that information to the central nervous system. This directs the motor neurons to respond in a specific way, and the animal carries out that order.Learn More
The niche that an organism occupies is the opening in the environment that the organism fills to make a living. A species' niche is its place in an ecosystem relative to the other organisms present.Full Answer >
A biologic stimulus is any external change in the environment that can be detected by an organism. The ability to respond to a stimulus is called irritability and is a necessary condition for life.Full Answer >
Voluntary behavior refers to thoughts and actions aimed at or resulting from choice in nature by individuals. The opposite behavior is called reflexive or involuntary behavior. As of 2014, the existence and nature of voluntary behavior is a matter of some debate amongst neuroscientists, psychiatrists and psychologists.Full Answer >
Narcissists are capable of change, though it may require changes in their environment as well as associates dedicated to making change possible. It is important to keep in mind that the individual's issues are beyond their diagnosis, and no two cases of narcissistic personality disorder can be approached similarly.Full Answer >