central nervous system

(noun)

In vertebrates, the part of the nervous system comprising the brain, brainstem, and spinal cord.

Related Terms

Examples of central nervous system in the following topics:

  • Development of the Central Nervous System

    • The CNS originally develops from a longitudinal groove on the neural plate that forms the rudimentary nervous system.
    • The central nervous system (CNS) consists of the brain and the spinal cord.
    • It is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except radially symmetric animals such as sponges and jellyfish.
    • Together with the peripheral nervous system, it has a fundamental role in the control of behavior.
    • During early development of the vertebrate embryo, a longitudinal groove on the neural plate gradually deepens and the ridges on either side of it (the neural folds) become elevated and ultimately meet, transforming the groove into a closed tube, the ectodermal wall of which forms the rudiment of the nervous system.

  • Regeneration of Nerve Fibers

    • The peripheral nervous system is able to repair and regenerate itself, but the central nervous system is incapable of doing so.
    • Neuroregeneration differs between the peripheral nervous system (PNS) and the central nervous system (CNS) by the functional mechanisms and especially by the extent and speed.
    • The nervous system is divided into two parts: the central nervous system, which consists of the brain and spinal cord, and the peripheral nervous system, which consists of cranial and spinal nerves along with their associated ganglia.
    • There is simply not enough knowledge about regeneration in the central nervous system.
    • Unlike peripheral nervous system injury, injury to the central nervous system is not followed by extensive regeneration.

  • Subdivisions of the Nervous System

    • The nervous system is comprised of two major subdivisions, the central nervous system (CNS) and the peripheral nervous system (PNS).
    • The PNS is further subdivided into the autonomic nervous system (ANS) and the somatic nervous system.
    • The enteric nervous system (ENS) controls the gastrointestinal system and is sometimes considered part of the autonomic nervous system.
    • The central nervous system (2) is a combination of the brain (1) and the spinal cord (3).
    • The brain and the spinal cord are the central nervous system (CNS) (shown in yellow).

  • Cholinergic Neurons and Receptors

    • Acetylcholine is a neurotransmitter in the central and peripheral nervous systems affecting plasticity, arousal, and reward.
    • Acetylcholine (often abbreviated ACh) is an organic, polyatomic ion that acts as a neurotransmitter in both the peripheral nervous system (PNS) and central nervous system (CNS) in many organisms including humans.
    • Acetylcholine has functions both in the peripheral nervous system (PNS) and in the central nervous system (CNS) as a neuromodulator.
    • In the central nervous system, acetylcholine and the associated neurons form the cholinergic system.
    • In the central nervous system, ACh has a variety of effects as a neuromodulator of plasticity, arousal, and reward.

  • Preganglionic Neurons

    • In the autonomic nervous system (ANS), nerve fibers that connect the central nervous system to ganglia are known as preganglionic fibers.
    • In the autonomic nervous system (ANS), fibers from the central nervous system to the ganglion are known as preganglionic fibers.
    • All preganglionic fibers, whether they are in the sympathetic nervous system (SNS) or in the parasympathetic nervous system (PSNS), are cholinergic - that is, these fibers use acetylcholine as their neurotransmitter - and are myelinated.
    • Another major difference between the two ANS systems is divergence, or the number of postsynaptic fibers a single preganglionic fiber synapses with.
    • The site of synapse formation and this divergence for both the sympathetic and parasympathetic preganglionic neurons does however, occur within ganglia situated within the Peripheral 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.

  • Organization of the Nervous System

    • A nervous system is what allows us to react to the changing environment around us.
    • Central to the functioning of the nervous system is an extensive network of specialized cells called neurons.
    • In most animals, including humans, the nervous system consists of two parts: central and peripheral.
    • The central nervous system (CNS) is composed of the brain, spinal cord, and retina.
    • 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.
    • These sensory input is sent into the central nervous system which has the ability to determine an appropriate response.

  • 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 specialized tissue found in the 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.

  • 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.
    • It normally communicates with the central nervous system (CNS) through the parasympathetic (e.g., via the vagus nerve) and sympathetic (e.g., via the prevertebral ganglia) nervous systems.
    • An illustration of neural control of the gut wall by the autonomic nervous system and the enteric nervous system.