THE CEREBRAL CORTEX (PROJECTION AREAS) PREPARE BY KARIN BABIJANTZ
PROJECTION AREAS Among the first discoveries in the study of cortical function was the existence of the so-called projection areas. I want to make it clear that these serve as receiving stations for sensory information or as dispatching for motor commands. I want to underline the fact that Sensory projection areas are those regions of the cortex where the messages that come from the various senses (usually through some other relay stations) are first received Motor projection areas are those from which directives that ultimately go to the muscles are issued.
Everyone should know by now that the term projection here used in a geometrical sense: motor and sensory areas of the body are projected (mapped) onto particular regions of the cortex, resulting in a rough topographical correspondence between the location in the body and the location of the receiving or dispatching center in the cortex.
MOTOR AREAS the location of the motor projection area in a side view of the brain
I must emphasis that the study of motor areas were conducted on human subjects by the Canadian neurosurgeon Wilder Penfield. The stimulation was administered in the course of a brain operation. I want to remember such operations are usually administered under local rather than general anesthesia and patients are therefore able to report their experiences. Electrical stimulation applied to the open brain produces no pain. While pain receptors are located throughout the body and send their messages upward to the brain, the brain itself contains no such receptors. I’d like to dwell upon on the results of Penfield’s studies. They are showed that the cortical motor area in humans is in a region of the frontal lobe. Stimulation there led to movement of some parts of the body, much to the surprise of patients who had no sense of “willing” the action, or “performing it themselves”.
Systematic exploration showed that for each portion of the motor cortex, there was a corresponding part of the body that moved its cortical counterpart was stimulated, with each hemisphere controlling the side of the body opposite to it. The results of Penfield’s discover are sometimes expressed graphically by drawing a “motor homunculus”, a schema of the body as it is represented in the motor projection area
The motor projection area of one hemisphere shown in a cross-section of the brain.
The head shows the plane of the cross-section of the Penfield’s “motor homunculus”
Our lecture is over. Thank you for attention. And now answered the questions: 1. What is the projection areas? 2. What kind of projection areas do you now? 3. What kind of function doing the sensory projection areas? 4. What kind of function doing the motor projection areas? 5. Ho was opened the function of projection areas ? 6. What the Penfield’s “motor homunculus” representation? 7. Why electrical stimulation applied to the open brain produces no pain?
VOCABULARY Cerebral cortex - мозговая кора Cortical - мозговой Projection areas – проекционные зоны Sensory projection areas – сенсорная проекционная зона Motor projection areas – моторная проекционная зона Forelimb – передняя часть (тела) Exciting the left hemisphere – возбуждение левого полушария Stimulation - поощрение Administer - управлять Existence - существование Rough topographical – грубая топография Receiving stations for sensory – принимающие пункты сенсорной информации Dispatching centers for motor commands – распределяющие центры моторных команд Relay stations – передающие пункты Ultimately – в конечном счете, в конце концов muscles – мускулы, мышцы Issued – истечение, выход neurosurgeon – нейрохирург rather than – скорее… чем… therefore - поэтому experiences - ощущение applied – наложенные (электроды) produces no pain – не вызывали боли while – в то время как throughout – по всему (телу) upward – по направлению вверх the led – зона (мозга) counterpart – противоположный
Скачать презентацию THE CEREBRAL CORTEX PROJECTION AREAS PREPARE BY KARIN
Презентация К лекции_5_THE CEREBRAL CORTEX.pptx