Question

A characteristic ganglia is
A. Hollow cluster of nervous tissue
B. Nervous tissue devoid of tissue sheath
C. Solid cluster of nervous tissue surrounded by its sheath
D. Found inside the central nervous system

Answer 1

Hint: A ganglion is generally known as the cluster of interconnecting neurons or nerve cells that are found in the peripheral nervous system or the PNS or outside the brain.

Complete Answer:
- Ganglion also known as ganglia are a dense group of nerve cell bodies seen in most animals above the level of cnidarians. In flatworms example planaria two lateral neuronal cords bear impulses to and from a pair of ganglia on the head of the animal.
- In more higher organisms for instance earthworms and arthropods, pairs of ganglia at intervals all along the body mostly control the actions of each body segment in addition to a larger pair in the head. This latter pair of ganglia is considered as the brain in these more advanced invertebrates which inhibits responses moderately than directing them. In the case vertebrates the ganglion is a cluster of neural bodies situated outside the central nervous system.
- A spinal ganglion for example is a cluster of nerve bodies to be found along the spinal cord at the dorsal and ventral roots of a spinal nerve. The dorsal root ganglia is composed of the cell bodies of afferent nerve fibres that are those carrying impulses toward the central nervous system, efferent neurons that carry motor impulses away from the central nervous system and are present in the ventral root ganglia.
- Basal ganglia is a group of nuclei or we can say it as clusters of neurons in the brain that are situated deep underneath the cerebral cortex which is the highly convoluted outer layer of the brain. The basal ganglia concentrate in giving out information on movement and in modification of the activity of brain circuits that decide the best probable response in a given situation . It is an intermediate structure between the central (CNS) and peripheral nervous systems (PNS).
- The Ganglion tissues are generally made up of cell bodies, dendrites and satellite glial cells. The satellite glial cells line the exterior surface of nerve cells in the peripheral nervous system and they enclose nerve cell bodies within ganglia.

Therefore, the correct answer for this question is option C, Solid cluster of nervous tissue surrounded by tissue sheath.

Note: Basal ganglia are important structures that play an important role in setting up actions that are needed to achieve a particular goal in executing well practiced habitual actions and also in learning new actions in fresh situations.