5. Control & Coordination
Structure of Nerve Cell
Structure of Nerve Cell :
Neuron or nerve cell is a structural and functional unit of nervous system that is specialised to receive, conduct and transmit impulses. It is very long, sometimes reaching 90-100 cm. A neuron has three parts— cell body, dendrites and axon. The term neurites is used for both dendrites and axon Reflex action :
A reflex may be defined as an immediate and rapid response given without our awarness by an effector organ on the arrival of some external or internal stimulus. Reflex actions may be of two types : Simple Reflex :
It is an in born, inherited or unlearned response to a stimulus Ex. Nest budding. Conditioned Reflex :
It is the response acquired as a result of training or experience to a stimulus that originally failed to evoke the reaction. Father is I.P. Pavlov Ex. Writing, Driwing etc.