![somatic nervous system definition psychology somatic nervous system definition psychology](https://img.haikudeck.com/mg/59E0A821-0BF7-4C6A-B5D0-530250F9EF43.jpg)
It is involved in the coordination of different muscle groups to produce smooth movement, controlling posture and balance. The cerebellum is smaller than the cerebrum, is made of two lobes, and is located behind the brain stem. These demarcations of the cerebral cortex are usually represented bilaterally in both hemispheres as seen in the image below. Brain Motor and Sensory of the Cerebral Cortex Association areas are necessary for perception, abstract thinking, and associating new sensory input with memory. The motor areas are involved in the control and execution of voluntary motor activities. For instance, the primary sensory cortex receives sensory input from the body as well as from specialized sense organs. It can be divided on the basis of function into sensory, motor and association areas as shown in the image below. The outer layer of the cerebrum is called the cerebral cortex and this is usually pinkish grey in color and contains neural cell bodies. Further study has indicated a high level of plasticity as well as communication and integration between neurons in different lobes. The localization of function to different lobes was initially discovered in patients with brain damage. These are named the frontal, parietal, temporal and occipital lobes.Įach of these lobes is relatively distinct in function, relating to higher levels of cognition (frontal lobe), somatosensory input ( parietal lobe), auditory stimuli ( temporal lobe), or visual stimuli ( occipital lobe). Each of the hemispheres can be divided into four lobes. The cerebrum consists of two large hemispheres demarcated by a thick band of nerve fibers called the corpus callosum. The brain is made of the cerebrum, cerebellum, and brain stem. Special glial cells called ependymal cells produce CSF. Pia mater is the layer closest to the nervous tissue and dura mater lies next to the bone.Īdditionally, cerebrospinal fluid (CSF), produced in the four ventricular cavities of the brain, flows between the pia mater and arachnoid mater, providing protection from pathogens and mechanical support to the entire central nervous system. These meninges are called pia mater, arachnoid mater and dura mater. Three membranous coverings, called the meninges, provide mechanical support and protection to the central nervous system. In vertebrates, the brain and spinal cord are encased in bony cavities, with the brain residing within the skull, and the vertebral column protecting the spinal cord. The CNS directly or indirectly influences nearly every internal organ system, whether related to respiration, digestion, excretion, circulation or reproduction. In addition, involuntary reflexes are mediated by the spinal cord, providing protection and quickly preventing injury. Motivation, ambition, reward, and satisfaction are also mediated through neuronal connections in the CNS.Īt the same time, the limbic system of the brain also controls the most basic emotions and drives, such as pleasure, fear, anger, hunger, thirst, sleepiness and sexual desire. These tasks involve an association of abstract symbols and sounds with concrete objects and emotions. The brain plays an important role in the development of speech, language, and communication. Neuronal connections form the basis for thought and retention of memory. The CNS, especially the brain, is considered the physical seat for most higher-order mental functions. A similar process of receiving complex stimuli and generating a coordinated response is required for vastly varied activities – whether it is balancing a bicycle, maintaining a conversation or mounting an immune response. Once infants learn to walk, this happens involuntarily, no longer requiring conscious thought or concentration. For instance, in order to walk the CNS needs visual and integumentary cues – the texture of the surface, its incline, the presence of obstacles, and so forth.īased on these stimuli, the CNS alters skeletal muscle contraction. The CNS receives input from a variety of different sources, and implements an appropriate response to the stimuli, in a cohesive manner. The primary function of the central nervous system is integration and coordination. Central Nervous System Diagram Central Nervous System Function Coordination and Movement As such, the central nervous system is the coordinated processing center of the body. All other nerves are part of the peripheral nervous system, but they still connect to the CNS. Some cranial nerves, like the optic and olfactory nerves, are also considered to be a part of the central nervous system. While the CNS is functionally made of neurons, other cell types such as glial cells play important supporting roles.