A ganglion (: ganglia) is a group of neuron cell bodies in the

peripheral nervous system The peripheral nervous system (PNS) is one of two components that make up the nervous system of Bilateria, bilateral animals, with the other part being the central nervous system (CNS). The PNS consists of nerves and ganglia, which lie outside t ...

. In the

somatic nervous system The somatic nervous system (SNS), also known as voluntary nervous system, is a part of the peripheral nervous system (PNS) that links brain and spinal cord to skeletal muscles under conscious control, as well as to sensory receptors in the skin ...

, this includes dorsal root ganglia and trigeminal ganglia among a few others. In the

autonomic nervous system The autonomic nervous system (ANS), sometimes called the visceral nervous system and formerly the vegetative nervous system, is a division of the nervous system that operates viscera, internal organs, smooth muscle and glands. The autonomic nervo ...

, there are both sympathetic and parasympathetic ganglia which contain the cell bodies of postganglionic sympathetic and parasympathetic neurons respectively. A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies.

Structure

Ganglia are primarily made up of somata and dendritic structures, which are bundled or connected. Ganglia often interconnect with other ganglia to form a complex system of ganglia known as a plexus. Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the

peripheral A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core compo ...

and central nervous systems. Among vertebrates there are three major groups of ganglia: * Dorsal root ganglia (also known as the spinal ganglia) contain the cell bodies of sensory (afferent)

neurons A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

. * Cranial nerve ganglia contain the cell bodies of cranial nerve neurons. * Autonomic ganglia contain the cell bodies of autonomic nerves. In the autonomic nervous system, fibers from the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

to the ganglia are known as preganglionic fibers, while those from the ganglia to the effector organ are called postganglionic fibers.

Basal ganglia

The term "ganglion" refers to the

. However, in the brain (part of the

), the

basal ganglia The basal ganglia (BG) or basal nuclei are a group of subcortical Nucleus (neuroanatomy), nuclei found in the brains of vertebrates. In humans and other primates, differences exist, primarily in the division of the globus pallidus into externa ...

are a group of nuclei interconnected with the

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of Neuron, neural integration in the central nervous system, and plays ...

thalamus The thalamus (: thalami; from Greek language, Greek Wikt:θάλαμος, θάλαμος, "chamber") is a large mass of gray matter on the lateral wall of the third ventricle forming the wikt:dorsal, dorsal part of the diencephalon (a division of ...

, and

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is conti ...

, associated with a variety of functions: motor control, cognition, emotions, and learning. Partly due to this ambiguity, the '' Terminologia Anatomica'' recommends using the term 'basal nuclei' instead of 'basal ganglia'; however, this usage has not been generally adopted.

Pseudoganglion

A pseudoganglion is a localized thickening of the main part or trunk of a nerve that has the appearance of a ganglion but has only nerve fibers and no nerve cell bodies. Pseudoganglia are found in the teres minor muscle and radial nerve.

References

External links

* {{Authority control Neurohistology

Structure

Basal ganglia

Pseudoganglion

See also

References

External links