Articles - Detailed Questions en-us http://www.thescizone.com/info N/A http://www.thescizone.com/info webmaster@thescizone.com 20 http://www.thescizone.com/info/articles/300/1/When-the-cord-is-bruised-are-the-A--cells-killed-B--cells-demylinated-C--axons-destroyed-D--combinations-all-three-or-does-it-depend-on-the-injury.html  All three can occur. Cells and axons are stretched and sheared when compression displaces the spinal cord. At the compression site, there are axons, neurons, astrocytes, and oligodendroglial cells. Depending on the velocity and extent of the stretching and shearing, cellular damage occurs to these cells. If the injury causes bleeding, the blood is toxic to cells and contributes to the injury. Finally, the injured tissues release a variety of chemicals that causes further tissue damage. These include free radicals, inflammatory cytokines, neurotoxic neurotransmitters, and other chemicals. webmaster@thescizone.com (Super Admin) Fri, 23 Sep 2005 00:00:00 -0400 http://www.thescizone.com/info/articles/296/1/What-is-the-phrenic-nerve-and-where-is-it-situated.html  The phrenic nerve goes from the spinal cord to the diaphragm, a large muscle at the bottom of your chest that mediates breathing activity. Axons of the phrenic nerve come from the phrenic nucleus situated at spinal cervical segments C3, C4, and C5. Most of the axons About 75% of people have an accessory phrenic branch that comes from C5 and even C6. The sternocleidomastoid muscle is the long muscle that goes from the angle of your jaw to the head of clavicle, the long horizontal bone that goes from your shoulder to the front base of your neck. Various branches of the phrenic nerve head down behind the sternocleidomastoid, joining together at the subclavian vein (a vein that is under the clavicle) and descending downward into the chest. webmaster@thescizone.com (Super Admin) Fri, 23 Sep 2005 00:00:00 -0400 http://www.thescizone.com/info/articles/318/1/Where-should-spinal-cord-injured-persons-go-for-rehabilitation.html  The National Spinal Cord Injury Association (NSCIA at 1-800-962-9629) maintains a current list of all accredited programs... over 50 in all. Some factors to consider in choosing a facility:1. Reputation/word of mouth.2. Proximity to home, family, friends.3. Availability of facilities needed/wanted for one's specific rehab objectives. For example, FES, occupational therapy, attitudes of staff, etc. webmaster@thescizone.com (Super Admin) Thu, 23 Sep 2004 00:00:00 -0400 http://www.thescizone.com/info/articles/308/1/Is-the-only-difference-between-acute-and-chronic-the-scar-What-else-happens-to-the-cord-after-the-acute-stage-Also-how-long-does-the-quotacutequot-stage-last-2-weeks-couple-days-1-month.html  I define the \"acute\" phase of spinal cord injury as the period during which damage may be continuing. \"Subacute\" is when the spinal cord is beginning to resolve the damage and starting repair. There is then a period of recovery that may take years. At the end of that period, when recovery has stabilized and the condition is stable, I would use the descriptor \"chronic\" spinal cord injury.Thanks to: http://carecure.rutgers.edu webmaster@thescizone.com (Super Admin) Thu, 23 Sep 2004 00:00:00 -0400 http://www.thescizone.com/info/articles/307/1/I-understand-that-10-repair-will-make-functional-recovery-at-what--would-the-person-appear-as-if-the-injury-never-happened-in-your-opinion/Page-1.html  Let me rephrase your question. Only 10% of the axons in the spinal cord are necessary and sufficient for recovery of functions such as locomotion. That is probably why a majority of people with so-called "incomplete" spinal cord injury recover walking. As many as 50% of people with incomplete spinal cord injuries will recover walking. webmaster@thescizone.com (Super Admin) Thu, 23 Sep 2004 00:00:00 -0400 http://www.thescizone.com/info/articles/306/1/What-is-the-nerve-center-at-L1-Why-cant-anyone-with-an-injury-below-that-have-function-below-injury-or-respond-to-FES.html  The part of the spinal cord that is situated at the bony segmental level of L1 contains most of the spinal cord that represent the L1-S4 spinal segments. These segments innervate the pelvic area and the legs. Collections of neurons in these segments control a variety of functions. These include walking (locomotion), the series of reflexes leading to urination (micturation), sexual function, etc. The neurons of course also mediate the reflexes that control and coordinate movements in the legs. Finally, many of the neurons that innervate the muscles of the pelvic area and legs are situated in these segments. If these motoneurons are killed, the muscles that they innervate will undergo atrophy. Electrical stimulation may not be able to activate atrophied muscles. webmaster@thescizone.com (Super Admin) Thu, 23 Sep 2004 00:00:00 -0400 http://www.thescizone.com/info/articles/305/1/Does-demylination-STOP-conduction-or-SLOW-DOWN-conduction.html  Axons that are demyelinated cannot conduct as well. Cells called oligodendroglial cells form myelin around segments of axons. Each segment may be as long as several millimeters in length. Also, the axons are usually partially remyelinated after injury. The conduction deficit depends on the extent of demyelination and remyelination. Demyelination may stop or slow down conduction. More important, it may prevent the conduction of a train of impulses. Axonal information is often coded in bursts of action potentials. Demyelinated axons may be able to support one impulse but not a rapid train of impulses. Demyelination can also reduce the safety factor of conduction. In other words, an impulse has a smaller chance of getting through a demyelinated zone. Demyelination or abnormal myelination reduces the amount of information that an axon can pass through. webmaster@thescizone.com (Super Admin) Thu, 23 Sep 2004 00:00:00 -0400 http://www.thescizone.com/info/articles/304/1/Why-cant-the-nerves-above-the-injury-reconnect-w-nerves-below-the-injury-Why-do-they-have-to-grow-all-the-way-down-Especially-in-the-case-of-demylination-if-they-are-connected-just-demylinated-then-wouldnt-remylination-solve-everything-th/Page-1.html  Axons that have been disconnected form the injury site must grow all the way back to their original cells to reconnect with them. Axons that have been damaged will sprout short distances but they often stop at the injury site. There is much debate concerning why the axons do not continue growing. Several theories have been popular. webmaster@thescizone.com (Super Admin) Thu, 23 Sep 2004 00:00:00 -0400 http://www.thescizone.com/info/articles/303/1/If-the-scar-forms-around-the-outside-from-a-bruise-why-do-the-nerves-and-axons-have-to-grow-throught-it-I-could-see-if-the-bruise-went-across-the-cord-but-what-about-in-a-bruise.html  Adhesion of the spinal cord to the surrounding dura and tethering of the cord has several potential deleterious effects on the spinal cord. First, cerebrospinal fluid normally flow in the space between the spinal cord and dura. Adhesions between the spinal cord and dura may obstruct the fluid flow. The fluid then may be forced to flow in the central canal or through any channel that it can find. Over time, this abnormal flow causes an enlarged cyst in the spinal cord called a syringomyelia or syrinx. Second, the spinal cord normally slide smoothly within its dural enclosure. When it does not, every movement of the spinal cord imposes additional tension on the spinal cord, stretching or pulling the cord. This may cause progressive damage and loss of function over time. Removal of such adhesions or untethering the spinal cord may be useful. webmaster@thescizone.com (Super Admin) Thu, 23 Sep 2004 00:00:00 -0400 http://www.thescizone.com/info/articles/301/1/What-happens-below-the-injury-DO-the-nerve-cells-stay-alive-do-they-die-over-time-or-are-they-still-connected-with-each-other-just-not-with-the-brain.html  The axons that have been disconnected from their cell bodies will die. This takes place over a period of days or even weeks. However, the cells that the axons contact usually are not killed, unless they have been directly injured by the mechanical trauma. Likewise, the cells that the axons come from also usually survive the axonal injury unless they are close to the injury site. The cells above and below the injury site are still connected with each other. In fact, after any injury, many of these cells develop new connections to each other, possibly accounting for spasticity. Likewise, some of the cells above the injury site develop new connections to each other, possibly account for neuropathic pain. webmaster@thescizone.com (Super Admin) Thu, 23 Sep 2004 00:00:00 -0400