nervous system

(noun)

The organ system that coordinates the activities of muscles, monitors organs, constructs and processes data received from the senses and initiates actions.

Related Terms

Examples of nervous system in the following topics:

  • Comparing the Somatic and Autonomic Nervous Systems

    • The peripheral nervous system (PNS, see ) is divided into the somatic nervous system and the autonomic nervous system.
    • The somatic nervous system (SoNS) is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles.
    • The somatic nervous system consists of three parts:
    • It is classically divided into two subsystems: the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS).
    • The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system.

  • Organization of the Nervous System

    • A nervous system is what allows us to react to the changing environment around us.
    • The nervous system is an organ system that coordinates our actions by transmitting signals between different parts of our bodies.
    • The central nervous system (CNS) is composed of the brain, spinal cord, and retina.
    • Along with neurons, the nervous system relies on the function of other specialized cells called glial cells, or glia, that provide structural and metabolic support to the nervous system.
    • Gross organization of the nervous system, with the peripheral nervous system, the spinal, and the cortical levels.

  • Functions of the Nervous System

    • The primary function of the nervous system is to coordinate and control the various functions of our body.
    • The nervous system has three overlapping functions.
    • The nervous system is a highly integrated system.
    • Nervous system processes and interprets sensory input and decides what should be done at the each moment.
    • The nervous system activates effector organs such as muscles and glands to cause a response called the motor input.

  • Parasympathetic Responses

    • The parasympathetic nervous system regulates organ and gland function during rest and is considered a slowly activated, dampening system.
    • The parasympathetic nervous system (PSNS, or occasionally PNS) is one of the two main divisions of the autonomic nervous system (ANS) (shown in ).
    • The autonomic nervous system (ANS, or visceral nervous system, or involuntary nervous system) is the part of the peripheral nervous system that acts as a control system, functioning largely below the level of consciousness and controlling visceral functions.
    • The sympathetic nervous system can be considered a quick response, mobilizing system; and the parasympathetic a more slowly activated dampening system.
    • The parasympathetic nervous system, shown in blue, is a division of the autonomic nervous system.

  • Divisions of the Autonomic Nervous System

    • The autonomic nervous system (ANS) contains two subdivisions; the parasympathetic (PSNS) and sympathetic (SNS) nervous systems.
    • The autonomic nervous system (ANS) is classically divided into two subsystems (see : the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS).
    • The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system.
    • In the autonomic nervous system, preganglionic neurons connect the CNS to the ganglion.
    • Distinguish between the parasympathetic and sympathetic subsystems of the autonomic nervous system

  • Autonomic Nervous System (ANS)

    • The autonomic nervous system is a part of the peripheral nervous system that controls visceral functions such as heart rate and digestion.
    • The autonomic nervous system (ANS or visceral nervous system or involuntary nervous system) is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness and controls visceral functions .
    • It is classically divided into two subsystems: the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS).
    • The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system.
    • An illustration of neural control of the gut wall by the autonomic nervous system and the enteric nervous system.

  • Enteric Nervous System

    • The enteric nervous system (ENS) is a subdivision of the autonomic nervous system (ANS) that directly controls the gastrointestinal system.
    • The gastrointestinal (GI) system has its own nervous system, the enteric nervous system (ENS).
    • Neurogastroenterology is the study of the enteric nervous system, a subdivision of the autonomic nervous system (ANS) that directly controls the gastrointestinal system.
    • The enteric nervous system is embedded in the lining of the gastrointestinal system.
    • An illustration of neural control of the gut wall by the autonomic nervous system and the enteric nervous system.

  • Development of the Peripheral Nervous System

    • The peripheral nervous system develops from two strips of tissue called the neural crest, running lengthwise above the neural tube.
    • In vertebrates, the first sign of the nervous system is the appearance of a thin strip of cells along the center of the back, called the neural plate.
    • The inner portion of the neural plate (along the midline) is destined to become the central nervous system (CNS), the outer portion the peripheral nervous system (PNS).
    • Subsequently, neural crest cells from the roof plate of the neural tube undergo an epithelial to mesenchymal transition, delaminating from the neuroepithelium and migrating through the periphery where they differentiate into varied cell types, including pigment cells and the cells of the peripheral nervous system.
    • The neural tube will give rise to the central nervous system, while the neural crest will give rise to the peripheral nervous system.

  • Comparing the Nervous and Endocrine Systems

    • The nervous system and endocrine system both use chemical messengers to signal cells, but the speed of transmission is different.
    • The nervous and endocrine systems both work to bring about this adaptation, but their response patterns are different.
    • Both the nervous system and the endocrine system use chemical messengers to signal cells, but the speed at which these messages are transmitted is different.
    • The nervous system responds rapidly to stimuli by sending electrical action potentials along neurons, which in turn transmit these action potentials to their target cells using neurotransmitters, the chemical messenger of the nervous system.
    • The response to stimuli by the nervous system is near instantaneous.

  • Characteristics of Nervous Tissue

    • Nervous tissue is the main component of the nervous system, which includes the brain, spinal cord, and nerves.
    • Nervous tissue is one of four major classes of tissues.
    • It is the specialized tissue that is found in  central nervous system and the peripheral nervous system.
    • The nervous system is responsible for the control of the body and the communication among its parts.
    • In the peripheral nervous system, Schwann cells are neuroglia cells that support neuronal function by increasing the speed of  impulse propagation.