encephalon(redirected from encephalons)
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Related to encephalons: encephala
The brain is made up of billions of nerve cells, intricately connected with each other. It contains nerve centers (groups of neurons and their connections) which control many involuntary functions, such as circulation, temperature regulation, and respiration, and interpret sensory impressions received from the eyes, ears, and other sense organs. Consciousness, emotion, thought, and reasoning are functions of the brain. It also contains centers or areas for associative memory which allow for recording, recalling, and making use of past experiences.
In appearance the cortex is rather like a relief map, with one very deep valley (longitudinal fissure) dividing it lengthwise into symmetrical halves, and each of the halves again divided by two major valleys and many shallower folds. The longitudinal fissure runs from the brow to the back of the head, and deep within it is a bed of matted white fibers, the corpus callosum, which connects the left and right cerebral hemispheres.
The major folds of the cortex divide each hemisphere into four sections or lobes: the occipital lobe at the back of the skull, the parietal lobe at the side, the frontal lobe at the forehead, and the temporal lobe at the temple.
It is in the sensory areas of the brain that all perception takes place. Here sweet and sour, hot and cold, and the form of an object held in the hand are recognized. Here are sorted out the sizes, colors, depth, and space relationships of what the eye sees, and the timbre, pitch, intensity, and harmony of what the ear hears. The significance of these perceptions is interpreted in the cortex and other parts of the brain. A face is not merely seen; it is recognized as familiar or interesting or attractive. Remembering takes place at the same time as perception, so that other faces seen in the past, or experiences linked to that face are called up. Emotions may also be stirred. For this type of association the cortex draws on other parts of the brain by way of the communicating network of nerves.
The symptoms of brain tumor vary and depend on the location and size of the tumor. Headache together with nausea is sometimes the first sign. The headache can be generalized or localized in one part of the head, and the pain is usually intense. Vomiting can be significant if it is sudden and without nausea. Disturbances of vision, loss of coordination in movement, weakness, and stiffness on one side of the body are also possible symptoms. Loss of sight, hearing, taste, or smell may result from brain tumor. A tumor can also cause a distortion of any of these senses, such as seeing flashes at the sides of the field of vision, or smelling odors or hearing sounds that do not exist. It can affect the ability to speak clearly or to understand the speech of others. Varying degrees of weakness or paralysis in the arms or legs may appear. A tumor may cause convulsions. Changes in personality or mental ability are rare in cases of brain tumor. When such changes occur they may take the form of lapses of memory or absentmindedness, mental sluggishness, or loss of initiative.
en·ceph·a·la(en-sef'ă-lon, lă), [TA]
encephalon/en·ceph·a·lon/ (en-sef´ah-lon) the brain.
en·ceph·a·lon, pl. encephala (en-sef'ă-lon, -lă) [TA]
encephalonbrain (i.e. that part of the cerebrospinal axis contained within the skull), formed of proencephalon, mesencephalon and rhombencephalon
Patient discussion about encephalon
Q. What effect it will have in his brain………. hi all…………..whenever my bipolar son gets in to different episodes it makes me to think what effect it will have in his brain……….does it got anything to do with brain? But It didn’t strike me to discuss about this with my doctor….
Q. Does the brain recognize pain? How does the brain recognize pain.
Q. Is surfing the internet good for your brain? I am 72 and I just discovered computers and the internet at our library. I find myself fascinated by it and I spend hours in front of the computer. Is surfing the internet good for your brain?