Central Nervous System

Definition

The central nervous system (CNS) is the primary control center of the body, consisting of the brain and spinal cord. It is responsible for processing sensory information, coordinating motor functions, and facilitating communication between different parts of the body, thus playing a critical role in maintaining homeostasis and enabling cognitive functions.

5 Must Know Facts For Your Next Test

1. The central nervous system is encased in protective layers known as meninges and is cushioned by cerebrospinal fluid.
2. Neurons in the CNS can be classified into three types: sensory neurons, motor neurons, and interneurons, each serving distinct functions.
3. The brain is divided into several regions including the cerebrum, cerebellum, and brainstem, each responsible for different aspects of processing and coordination.
4. Damage to the spinal cord can lead to significant impairments in movement and sensation, highlighting the importance of the CNS in controlling bodily functions.
5. The central nervous system plays a crucial role in higher-order functions such as memory, learning, emotion, and decision-making.

Review Questions

• How do the structures within the central nervous system interact to facilitate movement and coordination?
  • The central nervous system facilitates movement and coordination through a complex interaction between various structures. The brain processes information from sensory neurons, which detect stimuli from the environment. This information is then relayed to the motor neurons via interneurons within the spinal cord, leading to appropriate muscle responses. The cerebellum also plays a vital role in refining movements by ensuring balance and coordination based on feedback from sensory inputs.
• What is the role of neurotransmitters at synapses in the central nervous system, and how does this impact overall function?
  • Neurotransmitters are chemical messengers that transmit signals across synapses between neurons in the central nervous system. When a neuron is activated, it releases neurotransmitters into the synaptic cleft, binding to receptors on adjacent neurons. This process can either excite or inhibit further neuronal firing, directly influencing cognitive processes, mood regulation, and muscle control. An imbalance in neurotransmitter levels can lead to neurological disorders, demonstrating their critical impact on CNS function.
• Evaluate how injuries to the central nervous system can affect daily life activities and overall well-being.
  • Injuries to the central nervous system can have profound effects on daily life activities and overall well-being. For example, spinal cord injuries can result in paralysis or loss of sensation below the injury site, drastically limiting mobility and independence. Brain injuries may impair cognitive functions such as memory or decision-making skills, affecting personal relationships and job performance. These injuries not only impact physical abilities but also contribute to psychological challenges like depression or anxiety due to changes in lifestyle and identity.

Related terms

Peripheral Nervous System:

The part of the nervous system that lies outside the central nervous system, consisting of nerves and ganglia that connect the CNS to limbs and organs.

Neurons: Specialized cells that transmit nerve impulses throughout the body, forming the basic building blocks of both the central and peripheral nervous systems.

Synapse: The junction between two neurons where communication occurs through neurotransmitters, enabling the transmission of signals within the nervous system.