CNS 2 PDF - Nervous System

Central Nervous system Classification of CNS Central/peripheral Nerve cell structure A synapse is a junction between two neurons or between a neuron and another cell, where the transmission of nerve impulses occurs. This involves the release of neurotransmitters that facilitate communication acros...

Central Nervous system Classification of CNS Central/peripheral Nerve cell structure A synapse is a junction between two neurons or between a neuron and another cell, where the transmission of nerve impulses occurs. This involves the release of neurotransmitters that facilitate communication across the synaptic cleft, allowing signals to be passed and processed in the nervous system. Receptors are specialized neural structures that detect specific types of stimuli, such as light, sound, temperature, and pressure. These receptors convert physical energy from the environment into neural signals, which are then interpreted by the brain as sensations. Sensation is the process of receiving stimuli through the senses—vision, hearing, taste, touch, and smell— and conveying that information to the central nervous system for processing Motor function refers to the ability of the nervous system to control and coordinate the muscles to produce movement. It includes simple reflexes to complex movements, and is crucial for tasks such as walking, writing, and balance. Upper motor neurons (UMNs) are nerve cells that originate in the brain and send signals to lower motor neurons (LMNs) in the spinal cord, controlling voluntary movements. Lower motor neurons, on the other hand, directly innervate skeletal muscles and are responsible for executing these movements. Damage to UMNs can lead to conditions like spasticity, while damage to LMNs can result in weakness and atrophy of muscles.