PNSPrint - Peripheral Nervous System Stress and rage we all experience it Maybe bioespresso or your favorite web site renders a message like this

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Peripheral Nervous System Stress and rage, we all experience it. Maybe, bioespresso or your favorite web site renders a message like this or something else causes you stress. Whatever the cause, stress is a result of the peripheral nervous system and a reaction to the external and internal environment.
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Peripheral Nervous System What is the overall role of the nervous system? In multicellular organisms such as vertebrates, most functions depend on the precise coordination of individual cells. For example, reading this page requires eye movement as well as hand movement to scroll down as you read. In order to coordinate cellular functions there must be communication between the different cells. This is the role for the nervous system . Its job is to collect information, process that information and then respond to the gathered information. The nervous system is continuously gathering information from the environment as well as from inside the body. Briefly, the role of the nervous system can be divided into three functions which will be discussed in more detail: sensory input, integration, and motor output . This is illustrated in Figure 1. Sensory input is collected by receptors and conveyed through the peripheral nervous system (PNS) to the brain and spinal cord which comprise the central nervous system (CNS) . Within the CNS the sensory input is integrated, a process which interprets input and associates it with appropriate responses. Integration is a continuous process defined in the diagram by a circular arrow. A response is then generated by the CNS and carried through the PNS to effector tissues in the form of motor output signal. Sensory and motor communication between the CNS and tissues is conducted through the
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Figure 2 . The overall organization of the PNS Table 1. Example of sensory receptors PNS by nerves , bundles of neuron extensions (or axons), which carry the input and output signals. Introduction to the peripheral nervous system (PNS) Since the previous e-module covered the CNS, here we will focus on the PNS which by definition is any part of the nervous system outside of the brain and spinal cord. As mentioned previously, the PNS is responsible for collecting sensory input from external or internal stimuli and conveying the information to the CNS via afferent, sensory neurons (Figure 2). It is also responsible for conveying information using efferent motor neurons from the CNS back to the effector tissues (glands and muscle). There are two sets of nerves which make up the PNS: cranial and spinal nerves . Most of these nerves are bundles that contain both sensory and motor neurons. Cranial nerves innervate organs in the head while spinal nerves innervate the rest of the body. We have 12 pairs of cranial nerves and 31 pairs of spinal nerves. Motor neurons in PNS can be divided into two branches: the somatic nervous system, which regulates movements that can be under voluntary control and mainly responds to external stimuli, and the
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This note was uploaded on 04/21/2008 for the course BIOL 100 taught by Professor Lee during the Winter '07 term at San Diego State.

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PNSPrint - Peripheral Nervous System Stress and rage we all experience it Maybe bioespresso or your favorite web site renders a message like this

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