The paired cranial and spinal nerves constitute the peripheral nervous system. The autonomic nervous system is a part of the peripheral nervous system that controls the involuntary functions of the body. Cranial nerves: The cranial or cerebral nerves are paired, originate in the nuclei in the brain, pass out of the cranium through passages in it and terminate in the [...]
In this article we will discuss about the invertebrate nervous system. This will also help you to draw the structure and diagram of invertebrate nervous system. Beginning from a primitive nerve net system, the evolution of nervous system has progressed towards aggregation of ganglia (cephalization) giving rise to a controlling and coordinating centre, the brain, towards the anterior end of [...]
Here is a List of receptors and sense organs found in animals. Invertebrate Receptors: 1. Mechanoreceptors: Four types of mechanoreceptors are present in invertebrates: i. Tactile receptors: The tactile (touch) receptor is a phasic receptor. In cnidaria the tactile receptors cnidocils are present (Fig. 14.1) in the cnidocytes (cnidoblasts). The cnidocil being touched, the cnidocyte contracts violently discharging the nematocyst. [...]