![]() ![]() Thus, the left brain controls movement of the right side of the body, and the right brain controls movement of the left side. Through the medulla, at the lower end of the brainstem, pass all the nerves running between the spinal cord and the brain in the pyramids of the medulla, many of these nerve tracts for motor signals cross over from one side of the body to the other. This region is also an important junction for the control of deliberate movement. The brainstem, at the top of the spinal cord, controls breathing, the beating of the heart, and the diameter of blood vessels. The hindbrain contains several structures that regulate autonomic functions, which are essential to survival and not under our conscious control. The human brain actually has its beginnings, in the four-week-old embryo, as a simple series of bulges at one end of the neural tube. In the growth of the individual embryo, as well as in evolutionary history, the brain develops roughly from the base of the skull up and outward. Indeed, in strictly biological terms, these structures can claim priority over the cerebral cortex. But underneath this layer reside many other specialized structures that are essential for movement, consciousness, sexuality, the action of our five senses, and more-all equally valuable to human existence. The cortex contains the physical structures responsible for most of what we call ''brainwork": cognition, mental imagery, the highly sophisticated processing of visual information, and the ability to produce and understand language. The preponderance of the cerebral cortex (which, with its supporting structures, makes up approximately 80 percent of the brain's total volume) is actually a recent development in the course of evolution. This schematic image refers mainly to the cerebral cortex, the outermost layer that overlies most of the other brain structures like a fantastically wrinkled tissue wrapped around an orange. We do not experience our brain as an assembly of physical structures (nor would we wish to, perhaps) if we envision it at all, we are likely to see it as a large, rounded walnut, grayish in color. Thalamus: A major relay station between the senses and the cortex (the outer layer of the brain consisting of the parietal, occipital, frontal and temporal lobes).Outside the specialized world of neuroanatomy and for most of the uses of daily life, the brain is more or less an abstract entity. Temporal Lobe: Processes hearing, memory and language functions. It also is involved in the coordination of eye movements and balance. ![]() Pons: Contains centers for the control of vital processes, including respiration and cardiovascular functions. ![]() Reading and arithmetic are also processed in this region. Parietal Lobe: Receives and processes information about temperature, taste, touch, and movement coming from the rest of the body. ![]() Parahippocampal Gyrus: An important connecting pathway of the limbic system. Occipital Lobe: Helps process visual information. Limbic System: A group of interconnected structures that mediate emotions, learning and memory. Medulla Oblongata: Contains centers for the control of vital processes such as heart rate, respiration, blood pressure, and swallowing. Hippocampus: Plays a significant role in the formation of long-term memories. It is part of a system that processes "reflexive" emotions like fear and anxiety.Ĭingulate Gyrus: Plays a role in processing conscious emotional experience.įornix: An arch-like structure that connects the hippocampus to other parts of the limbic system.įrontal Lobe: Helps control skilled muscle movements, mood, planning for the future, setting goals, and judging priorities. Glossary of TermsĪmygdala: Limbic structure involved in many brain functions, including emotion, learning and memory. The hippocampus is one of the first areas affected by Alzheimer's disease. As the disease progresses, damage extends throughout the lobes. The limbic system consists of a number of structures, including the fornix, hippocampus, cingulate gyrus, amygdala, the parahippocampal gyrus, and parts of the thalamus. The image on the right is a side view showing the location of the limbic system inside the brain. The image on the left is a side view of the outside of the brain, showing the major lobes (frontal, parietal, temporal and occipital) and the brain stem structures (pons, medulla oblongata, and cerebellum). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |