This is a link to an online version of what Carol has described here: They include a cutesy picture. http://www.msnbc.com/news/247963.asp
Bill Goss College of the Rockies Box 8500, Cranbrook, BC V1C 5L7 1-877-489-2687, ext.324 (toll free) -----Original Message----- From: DeVolder Carol L [mailto:[EMAIL PROTECTED] Sent: Friday, September 26, 2003 10:08 AM To: Teaching in the Psychological Sciences Subject: RE: Student Question It's actually because the blood supply to a nerve has been cut off (from compression). The numbness and tingling are referred to as parasthesia. As the nerve is deprived of blood (and therefore oxygen and glucose), the excitability of the composite fibers changes. At first, it might feel like pins and needles as fibers briefly become hyperexcitable, but as the lack of oxygen and glucose continues, the nerve fibers diminish their activity. This happens in a systematic way, with the fibers that depend most on oxygen and glucose diminishing first. It turns out that pain is the last sensation to go and the first to return when the compression is lifted. This is important as a signalling function to help prevent things like compression sores (bed sores), and other serious situations. Hope this helps, Carol -----Original Message----- From: Jean-Marc Perreault [mailto:[EMAIL PROTECTED] Sent: Friday, September 26, 2003 10:35 AM To: Teaching in the Psychological Sciences Subject: Student Question Hi Everyone, I asked this question a while back and did not get any answers. Perhaps it fell through the cracks. So here it is again: (my students REALLY want to know, and I can't seem to find the answer anywhere). Q. What is the cause of the pins and needles sensation that occurs when one has sat too long on one's leg, or slept on one's arm? The sensation occurs after one removes the weight from the appendage. Is it related to the blood flow being re-established? Is it a compression of nerve bundles? I'd greatly appreciate if someone has that answer... Cheers! JM --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED] --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED] --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED]
