Coordination in animals br Nervous Coordination br Elements of Nervous system br 1. Neurons br The chief structural and functional units of the Nervous system are Neurons. br Neuroglia br Types of Neurons. br 1. The Sensory Neurons. br 2. Associative Neurons. br 3. Motor Neurons. br Structure of Neurons. br Dendron br cell body br Axons br Variety of Neurons types in human being br 2. Receptors br They detect changes in the environment of the animal br Classification of Receptors br a) Chemoreceptor br b) Mechanoreceptor br c) Photoreceptor br d) Thermoreceptor br e) Nociceptor br 3. Effectors br Coordination and Control br Chapter No.