Ans: The nervous system is a complex and vital part of the human body responsible for controlling and coordinating various physiological functions and behaviors. It is a highly specialized network of cells, tissues, and organs that transmit signals in the form of electrical impulses and chemical messages. The nervous system has two main components: the central nervous system (CNS) and the peripheral nervous system (PNS).
a). Central Nervous System (CNS):
The CNS consists of the brain and the spinal cord. It serves as the command center of the body and is responsible for processing and integrating information received from sensory organs and the peripheral nervous system.
The brain is the seat of consciousness, intelligence, emotions, and higher-order functions. It controls voluntary movements, cognitive processes, and emotional responses.
The spinal cord serves as a relay system, transmitting signals between the brain and the rest of the body. It also plays a critical role in reflex actions.
b). Peripheral Nervous System (PNS):
The PNS includes all the nerves and ganglia (clusters of nerve cell bodies) outside the CNS.
It is further divided into the somatic nervous system (SNS) and the autonomic nervous system (ANS).
The Nervous System controls the body function, in the following ways:
a). Sensory Input: Sensory receptors in the body detect changes in the internal and external environment, such as temperature, pressure, light, and chemicals. These receptors convert sensory information into electrical signals called action potentials.
b). Integration: The CNS, particularly the brain, processes and integrates the incoming sensory information. It interprets the data and makes decisions based on previous experiences and learned behaviors.
c). Motor Output: After processing sensory input, the CNS generates appropriate motor commands. These commands are transmitted as electrical signals along motor neurons to effector organs, which can be muscles, glands, or other tissues.
d). Response: The motor commands lead to specific actions or responses. For example, if you touch a hot object, sensory receptors signal the CNS, which quickly sends motor commands to contract muscles, causing your hand to withdraw from the heat source.
e). Feedback: The nervous system constantly receives feedback about the body’s internal and external conditions, allowing it to adjust and fine-tune its responses to maintain homeostasis, the body’s stable internal environment.