(MOS) Nervous System Lesson

Nervous System Lesson

Made up of the brain, the spinal cord, and an extensive network of nerves that are woven throughout the body, the nervous system is the body's control center. The brain gathers and responds to information it receives from nerves to coordinate all actions and reactions. Listen to the following presentation to learn more about how the Nervous System makes it possible for humans to learn.

 

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The nervous system helps you maintain homeostasis by responding and acting to the world around you. It receives information about what is going on inside and outside your body. Then the nervous system determines what types of changes must be made in response to this information. For example, if a mosquito lands on your arm, your response will be to swat it before it bites you. An annoying itching sensation will let you know it was too late. The nervous system gives you the ability to move, think, and feel pain.  

 A neuron is a specialized nerve cell that carries information throughout the nervous system. Billions of nerve impulses travel within your body every day. Motor neurons send nerve impulses to a muscle or gland and they will react to this response by usually moving. A sensory neuron receives a nerve impulse from an external or internal environment. The nerve impulse is sent to an interneuron in the brain or spinal cord. The interneuron transfers nerve impulses one neuron to another. Therefore a sensory neuron can send information to a motor neuron. For example, when the mosquito lands on your arm, the receptors under the skin receive stimuli from the environment. The stimulus is converted into a nerve impulse by the sensory neurons. The nerve impulse travels to interneurons in the brain. Your brain decides that you should remove the mosquito from your arm. Nerve impulses travel to motor neurons. The muscle in your hand receives the information from the motor neuron. The muscle in your hand carries out the response and you will squash the mosquito. 

The nervous system is divided into two divisions: central and peripheral. The brain and spinal cord make up the central nervous system. It controls the activities of the body. The peripheral nervous system consists of a network of nerves, even the ones that extend from the central nervous system. It carries messages between the CNS and the rest of the body. The PNS can be further divided into the somatic and autonomic nervous systems. The nerves in the somatic nervous system control the voluntary actions in your body. For example, brushing your hair and opening a door. The autonomic nervous system as it name implies controls involutionary actions. For example, the autonomic nervous system controls your heartbeat and breathing.

The amount of monitoring and adjusting that goes on in the human body at any given time is astounding. Thankfully, it's automatic. Our nervous system keeps up with everything so we never have to think about it. In the interactive feature below, every change in activity requires us to make adjustments in respiration, heart rate, or energy delivery.  An adjustment to one system often changes the balance in some other system. Remember homeostasis? Can we do as good a job maintaining the harmony in this virtual body as our nervous system does in us?

 

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