Pharmacology

Nervous System It is the Central Processing Unit (CPU) of the human body. It controls all the activities of the body. It consists of two principal types of cells: neurons and neuroglia . Fig.1: Anatomy of a neuron Neuron: Also known as nerve cells These are Excitable cells Sensitive to various stimuli Convert stimuli into electrical signals ( Action Potentials ) or ( Nerve Impulse ) Action potentials can travel along the plasma membrane of a neuron due to the presence of specific voltage-gated ion channels Neuron conduct these Action potential to other neurons, to muscle tissue or to glands with the help of a chemical, called Neurotransmitter Classification of neurons Fig.2: Different types of neurons. A: Multipolar neuron; B: Bipolar neuron; C: Unipolar or pseudounipolar neuron Neuroglia or glia Initially, it was believed that these cells were the glue that held the nervous tissue together. Smaller than neurons, but 5-50 times more numerous Do not generate or propagate an action pot

The nervous system can be divided into two (depending on the location of the system associated organs in the body)       Central Nervous System (CNS) is present on the central longitudinal axis of the body and consists of Brain and Spinal cord .      Peripheral Nervous System (PNS) is present outside the central longitudinal axis and consists of Cranial nerves and Spinal nerves . The main function of PNS is to act as communication mechanism between the CNS and the body. The messages between the CNS and the body are received and sent via nerves . A nerve is a group of neurons which conveys the message from one site to another site. PNS can be further subdivided into two broad categories on the basis of functioning of the nerves i.e, Voluntary or Involuntary   Somatic Nervous System (SNS) is voluntary in nature, meaning it will work as per the will of the human. E.g, if you want to raise your hand you can simply do it. Whereas, Autonomic Nervous System (ANS) is invol