We're unable to sign you in at this time. Please try again in a few minutes.
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Article |


JAMA. 1915;LXIV(5):441-442. doi:10.1001/jama.1915.02570310061027.
Text Size: A A A
Published online


So long ago as 1859, Bidder and Kuyfer originated the conception that axis cylinders grow outward from the nerve cells, and that regeneration of nerve fibers is a result of proliferation of the distal end of the axis cylinders, each cylinder having at its end "an incremental cone of growth." This view, which long has held sway, is now being questioned. It has been found that undifferentiated cells from the early medullary tube or neural crest, after remaining undeveloped and dormant in the tissues, may take on activity and, it is asserted, develop into nerve fibers. As seen in neuromas, Weichselbaum interpreted such undifferentiated cells as cells of the sheath of Schwann. Kennedy,1 on examination of specimens from both ends of a nerve previous to its suture, found irregularly arranged groups of new nerve fibers both centrally and peripherally, and on the distal side were enormous numbers of spindle-shaped nuclei


Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

First Page Preview

View Large
First page PDF preview




Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.


Some tools below are only available to our subscribers or users with an online account.

0 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.