We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
from Section 2 - Regional Paediatric Orthopaedics
Published online by Cambridge University Press: 30 January 2024
The development of the upper limb begins during the fourth week of in utero life, when a limb bud consisting of undifferentiated mesenchymal cells encased in ectoderm develops. By 9 weeks, the bud has developed into an arm and hand with identifiable digits, and by 12 weeks, the digits have differentiated. Growth and differentiation are under the control of signal regions at the tip of the developing limb, with complicated interactions and feedback systems (Figure 16.1). Induction of mesenchymal cells in the ‘progress zone’ at the tip of the developing limb occurs under the influence of specific zones. The apical ectodermal ridge (AER) is the director of growth in the proximo-distal axis (excision of the AER results in a limb stump only, and transplantation may result in a duplicate limb).
To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.
