Human`s brain is regarded as the most astonishing organ which comprises billions of cells that enable a human being to sense the outside world as well as move, talk and think. Together with peripheral nerves and spinal cord, it forms the nervous system. The nervous system works with the help of nerve and supportive cells that are called neurons and glial cells respectively. All the neurons are further divided into three types: Sensory neurons, Motor neurons, and Interneurons. Although Glial cells are aimed to carry out an auxiliary function to the neurons, they largely contribute to the development of nervous system in the adulthood. Neurons comprise a cell body and two additional processes called axons and dendrites. Axons carry out a function of transmitting data between two connected neurons whereas dendrites receive the data sent by neuron axons. Both axons and dendrites are involved into synapses. Neurons form a complex system of chains through which the data is transmitted in the nervous system (Shea 3). Long axons that form peripheral nerves connect spinal cord and brain to muscles and sensory receptors.
The spinal cord carries out two important functions: it is a center of simple and complex reflexes and it a connector between human`s brain and body which is aimed to transmit information. The human`s brain consists of two cerebral hemispheres and the brain stem. The stem is further divided into diencephalon, midbrain, and hindbrain. Hind-brain possesses two centers that control blood pressure and breathing. Human`s movements are controlled by cerebellum, which arises from hindbrain roof. The cerebral hemispheres are divisible into basal ganglia, core, and cerebral cortex. The basal ganglia control and initiate human`s movements. The cerebral hemispheres comprise a considerable number of areas, including auditory, sensory, motor, visual areas (Johnson 2). Due to the fact that paths from sensory receptors to the cortex and then muscles are crossed, the left part of the cortex provides control over the movements of the right part of the body. Nevertheless, two hemispheres cannot work separately and, therefore, they are connected by corpus callosum (“Neuroscience: the Science of the Brain” 3). The cortex establishes control over human`s language and speech, voluntary actions as well as memory and thinking.
These functions are customarily carried out by two hemispheres; nonetheless, some actions require activating only one hemisphere. The work of brain is considered to be one of the most complicated processes that take place in human`s organism. Although it has been investigated for decades, there are still highly debatable points that generate interest of researchers. The closer research on these points has resulted in the appearance of multiple theories. For example, the Dual Brain Theory states that human`s cerebral hemispheres may feel and respond to surroundings independently. Moreover, according to this theory, if one hemisphere has experienced emotional trauma, the second one will dominate it in order to diminish this exposure (“Neuroscience: the Science of the Brain” 4).
Evidently, this theory contradicts the generally accepted approach towards brain functioning. In-depth knowledge on human`s brains …