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굴근반사의 중추반사궁에 관한 실험적 연구

Other Titles
 Experimental study for the central reflex arc of the flexion reflex 
Authors
 한용표 
Issue Date
1980
Description
의학과/박사
Abstract
[한글]

Sherrington(1910)은 굴근반사가 동물의 외부에 동통자극을 가할때 자신을 보호하려는 동통에 대한 도피반사(withdrawal reflex)로 나타나는 일종의 중추반사라고 결론지었다.

굴근반사에 대한 연구는 이후 정상인체나 실험동물을 통하여 점차 자세히 밝혀지게 되었다. 특히 Price(1972)나 Willer(1977)의 실험에서 굴근반사는 빠른성분(early component)과 느린성분(late component)의 두가지 성분이 있음을 밝혀냈는데 이는 Sinclair 및 St

okes(1964)가 발표한 동통자극은 빠르고 느린 두개의 통각을 수반한다는 설명과 부합된다.

본 실험은 현재까지 잘 알려지지 않은 굴근반사의 두가지 성분에 대한 중추반사궁과 구심성 신경을 찾으려는 시도를 했다.

실험재료 및 방법

16마리의 성숙한 고양이를 두군으로 나누어 대조군은 제뇌(decerebration)만 시킨다음 굴근반사를 유발-기록하였으며 척수고양이군은 하부흉(lower thoracic spinal cord)를 절단하고 제뇌시켜 굴근반사를 유발-기록하였다. 이 두군에서 나타난 굴근반사의 양상을 비교함으로써 굴근반사의 중추반사궁이 척수인지 척수보다 상부인지 판단하였다. 또한 본 실험에서 굴근반사를 유발시킨 구심성 신경인 sural nerve를 전기자극할 때 Aβ, Aδ 및

C섬유가 활성화되도록 전기강도를 점차 높여 이때 나오는 afferent volley와 굴근에 분포하는 운동신경에서 compound action potential(이하 굴근반사라 칭함)을 기록하여 비교 관찰함으로써 굴근반사를 유발시키는 구심성 신경의 종류를 식별하였다.

연구결과 및 결론

1. 대조군과 척수고양이군에서 굴근반사가 나타나는 양상은 비슷하였다. 다만 척수고양이군에서 빠른성분의 지속시간은 좀 더 길게 나왔고 느린성분의 지속시간은 좀 더 짧게 나왔다. 즉 굴근반사의 빠른성분과 대부분의 느린성분의 중추반사궁은 척수이며 느린성분의 일부는 뇌간 혹은 상부척수까지 올라가는 반사궁을 가지는 것 같다.

2. 굴근반사의 빠른성분에 대한 구심성 신경섬유는 Aβ와 Aδ섬유이며 느린성분에 대한 구심성 신경섬유는 C섬유이다. 대개 느린성분은 C섬유가 활성화되는 강도의 전기자극을 여러개 연속적으로 가하였을때 더욱 잘 나타났다. 즉 굴근반사의 느린성분은 C섬유로부터의 temporal summation이 필요했다.





Experimental Study for the Central Reflex Arc of the Flexion Reflex



Yong Pyo Han

Department of Medical Science, The Graduate School, Yonsei University

(Directed by Professor Hun Jae Lee, M.D.)



The flexion reflex is generally known as a withdrawal reflex in response to a

painful stimulus. Since Sherrington's first detail report in 1910, it has teen

established that the flexion reflex is a central reflex evoked by a painful

stimulus applied to the skin or afferent nerves. Recent studios indicate that the

reflex is not a single component but has two components, the early and the late.

Although many aspects of the reflex is known, it is still obscure as to the

pathways for the two components of the reflex.

The central reflex arc of the each component has not been localized

systematically. Furthermore, there are considerable discrepancies in literatures

regarding to the type of afferent nerve fiber responsible for the flexion reflex.

The present study was, therefore, conducted to find out the pathways for the

flexion reflex including the location of the central reflex arc and the afferent

nerve fiber types in an experimental animal.

Sixteen healthy adult cats(2∼3.5 kg) were preanesthetized with ketamine

hydrochloride(20mg/kg, im.) and decerebrated anemically by ligating the basilar

artery and the bilateral common carotid arteries. Animals were paralized with

gallamine triethiodide and kept under artificial respiration. The flexion reflex

was elicited by stimulating the sural nerve and recorded as a form of compound

action potential from the nerve supplying to the semitendinous muscle. The central

reflex arc of the flexion reflex was localized by comparing the reflex components

of decerebrate cats with those of decerebrated and spinalized cats. The type of

afferent nerve fiber responsible for each component of the flexion reflex was

identified by recording afferent volleys from tje sural nerve at 40∼50mm proximal

to the stimulating site.

The results are summarized as follows:

1. The flexion reflex is composed of two components, the early and the late. The

early and the late components have a latency of 7.8 and 173.8msec, and a duration

of 7.3 and 906.3 msec, respectively.

2. The central reflex arc of the early component and most of the late component

is in the spinal cord while some of the late component is mediated by either

rostral part of the spinal cord or the brain stem, most likely medulla oblongata.

3. The afferent nerve fibers responsible for the early component are Aβ and Aδ

fibers and that of the late component is C fibers. In general, temporal summation

from C fibers is necessary to elicit the late component.

These results indicate that the two components of the flexion reflex have

different pathways. This may imply that the two components have different

functional roles.

[영문]

The flexion reflex is generally known as a withdrawal reflex in response to a painful stimulus. Since Sherrington's first detail report in 1910, it has teen established that the flexion reflex is a central reflex evoked by a painful stimulus applied to the skin or afferent nerves. Recent studios indicate that the reflex is not a single component but has two components, the early and the late.

Although many aspects of the reflex is known, it is still obscure as to the pathways for the two components of the reflex.

The central reflex arc of the each component has not been localized systematically. Furthermore, there are considerable discrepancies in literatures regarding to the type of afferent nerve fiber responsible for the flexion reflex.

The present study was, therefore, conducted to find out the pathways for the flexion reflex including the location of the central reflex arc and the afferent nerve fiber types in an experimental animal.

Sixteen healthy adult cats(2∼3.5 kg) were preanesthetized with ketamine hydrochloride(20mg/kg, im.) and decerebrated anemically by ligating the basilar artery and the bilateral common carotid arteries. Animals were paralized with gallamine triethiodide and kept under artificial respiration. The flexion reflex was elicited by stimulating the sural nerve and recorded as a form of compound action potential from the nerve supplying to the semitendinous muscle. The central reflex arc of the flexion reflex was localized by comparing the reflex components of decerebrate cats with those of decerebrated and spinalized cats. The type of afferent nerve fiber responsible for each component of the flexion reflex was identified by recording afferent volleys from tje sural nerve at 40∼50mm proximal to the stimulating site.

The results are summarized as follows:

1. The flexion reflex is composed of two components, the early and the late. The early and the late components have a latency of 7.8 and 173.8msec, and a duration of 7.3 and 906.3 msec, respectively.

2. The central reflex arc of the early component and most of the late component is in the spinal cord while some of the late component is mediated by either rostral part of the spinal cord or the brain stem, most likely medulla oblongata.

3. The afferent nerve fibers responsible for the early component are Aβ and Aδ fibers and that of the late component is C fibers. In general, temporal summation from C fibers is necessary to elicit the late component.

These results indicate that the two components of the flexion reflex have different pathways. This may imply that the two components have different functional roles.
Full Text
https://ymlib.yonsei.ac.kr/catalog/search/book-detail/?cid=CAT000000004462
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URI
https://ir.ymlib.yonsei.ac.kr/handle/22282913/117324
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