Need help running sub 53 second 400 Meter!?
So tomorrow is the County Track Fest where 50 schools participate in a huge meet and I'm running the 400 meter dash and the 4x400 meter relay. I'm nervous because I want to break my school's record which is 53.87. A little backstory: In 6th grade, my fastest time was a 61 seconds (which is extremely good for a 6th grader.) the following year, I didn't improve much and at the county meet I ran a 58.9. This year, my last year of middle school, I'm 14 years old and I'm running the 400 meter dash at the meet. My coach wants me to beat the record but I don't know if I can! This year, the first meet I ran a 57.1 and got second. The next meet, I was able to run a 55.7. And the recent meet on Wednesday, my coach thinks I ran a 54 on asphalt but he doesn't know because I ran the 4x400 meter to conserve energy for Saturday. Anyway, the meet's tomorrow and I really want to run a 52 second 400 meter, get a medal, and break the school's record. Can anybody help me with techniques to run the 400 and get a 52? Maybe I'm stressing out too much but I'm really nervous! Just in case you didn't understand my times through the years. 6th: 61(Asphalt) 7th: 60(Asphalt), 58(Rubber) 8th: 55(Asphalt) and hoping 52(Rubber)
What would happen to the nervous system functions if all neurons were myelinated?
The myelin sheath speeds up the process of charge exchange throughout the axon by preventing the electrical current from leaving the axon (by preventing the sodium to leak, and maintaining a big charge difference between in and out of the axon). I like to visualize it like the rubbery sheath wrapped around metal wire, that provides insulation to avoid the current from jumping to another metal wire that is in contact, promote efficiency of direct transmission, and prevents the wire from burning. Likewise, our nervous system is packed tightly with neurons, so without the sheath, an electrical signal can ‘exhaust’ away quickly, or jump from axon to a close axon, uncontrolled.But the very exchange of electrical charges in and out of the axon, occur where there is no insulation sheath, because as mentioned before, myelin ‘prevents’ charges from leaving. Beneath the myelin sheath, sodium diffuses out through the axon rapidly, and its concentration becomes lower- the signal eventually dissipates. So for the actual impulse to be transmitted, for depolarization to occur, we would still want some exposed vents in between the myelin sheath. As a result, we have neurons that are covered in separated Schwann cells that produce myelin sheath, like a chain of sausages. These ‘vents’ in between are the Nodes of Ranvier, where there are sodium channels that let the sodium flush into the axon, replenishing (regenerating) the action potential. And the current moves in a rather discontinuous, ‘hopping’ behavior. I think this animation really helps visualizing that.Without the sheath, it will take much longer for charges to pass through axons, signals will be harder to control, and neurons will be more prone to damaging. But without the vents in between the sheath here and there, the signal will weaken in the middle of the axon, not making all the way through. I think that metal wires do not involve the exchange of charges in and out of the conduct medium, which is why they don’t need the Nodes of Ranvier.
How long does it take for a nerve impulse to reach the brain? ** super important?
It depends on the type of tissue that is transferring the neural [nerve] impulse to the brain. See examples in the following excerpts. "Depending on the type of fiber, the neural impulse travels at speed ranging from a sluggish 2 miles per hour to, in some myelinated fibers, a breackneck 200 or more miles per hour. But even this top speed is 3 million times slower than the speed of electricity through a wire." Myers, David G. Psychology 4th Edition.New York:Worth Publishers Inc,1995: 43. "Some actions require split second responses--withdrawing a hand from a hot stove, for example. To relay the information necessary for such a reaction, there are large nerve fibers that can conduct impulses at speeds as high as 330 feet (100 meters) per second. Other kinds of activities, such as scholarly pursuits, may require a lifetime of thought. For these kinds of activities, other nerve fibers can be used to conduct signals more slowly--70 to 100 feet (20 to 30 meters) per second." Comptons Interactive Encyclopedia. Softkey Multimedia Inc, 1997. "For example if we touch something, impulses travel through the nerve network to the brain at a rate of 350 feet per second" Nervous System. ThinQuest. January 1, 1995. "The speed of the nerve impulse can be as high as one hundred meters (0.6 mile) per second." Kraus, David. Concepts in Modern Biology.New York:Globe Book Company, 1969: 170. "Some kinds of signals, like the ones for muscle position travel on extra-fast nerve impulses at speeds of up to 390 feet per second (119 meter/second). Close your eyes and wave your arms around: you can tell where they are at every moment because the muscle-position nerves are very fast.... But other messages, like some kinds of pain signals travel much more slowly. If you stub your toe, you feel the pressure right away because touch signals travel at 250 feet per second. But you won't feel the pain for another two or three seconds, because pain signals generally travel at only two feet per second." How fast do nerve impulses travel? May 27, 2000. http://www.painstudy.com/NonDrugRemedies... To get a clearer understanding of this process it would be helpful to read about action potential and the role it plays in impulse transmission and also look at the cell types and the structure or a Neuron. http://en.wikipedia.org/wiki/Action_pote...
How fast do Neurons travel?
What is the the Average speed of a Neuron? And does anybody know if Neurons travel faster in certain locations, for example: Do Neurons travel faster in the brain, spine, muscle tissues, etc. Any information would great, Thanks for your time!!
Does vision travel at the speed of light?
Vision consists of the photons that travel to your eye, your retina that detects them and encodes that for transport via the optic nerve to the visual cortex of your brain, where the perception or sense of vision actually happens for you.The photons travel at the speed of light, minus whatever slow down exists in the medium they are in. This is negligible in this context, because the human parts are much, much slower in comparison.Humans experience latency between a physical event happening and their perception of said event, and that latency is caused by the time it takes for the nerves to both respond to and generate signals that carry sensory data to the brain, and the additional time required for the brain to make sense of those signals in a way that actualizes those signals in the form of perception: seeing, hearing, etc...When considered in this way, "vision" really doesn't travel very far, and it doesn't happen anywhere near the speed of light either. Typical nerve propagation speed is something on the order of 50 meters / second. You can find out more on Nerve conduction velocity.Of course, the photons are much faster, meaning the world gets the information to us needed for us to see at the speed of light, basically.The result of all this is a human visual response time on the order of milliseconds to seconds, depending on the type of visual stimulus and other factors, such as the state of the person: distraction, illness, age, etc...We quite literally live in the past, just behind reality. Things happen, then we become aware of that, and then we can respond.When you open your eyes, you see data that has already traveled to you at speed of light, and the remaining time is the time it takes for you to translate that data into the perception of sight.
Can you die with a resting heart beat of 265 beats per minute?
Sounds like what you experienced was super ventricular tachycardia, which in layman's terms means super fast heart beat, Tachycardia, or rapid heart beat, is a condition affecting the heart. It's actual cause is sometimes unknown and can strike anyone at any age at any level of weight of health condition. It just...happens. Sometimes when it occurs, it's because of some other underlying issue or illness, but it can simply occur by itself. Typically this condition can be controlled with medication. But in cases where medication doesn't work, there is a minor surgical procedure drs can do called ablation that is a final resort. All over the heart there are nerves. These nerves carry electrical signs to different parts of the heart from the brain stem telling it to beat and how fast. When we are using muscles to exercise or work out or otherwise exert ourself , our muscles need fuel, like oxygen and glucose etc. The more we exert, thr more oxygen and glucose our muscles need. The brain stem monitors this and determines how much more of those things our muscles need and speeds our heart up to the right speed to accommodate the body's needs. Sometimes these nerves can become touchy or too sensitive. They may short circuit or send more signals than is necessary, resulting in tachycardia. Meds for tachycardia tend to numb these nerves a bit and this makes them less touchy and less sensitive, resulting in a slower and more normal heart rate. Ablation is a surgical procedure where some of these over/active nerves on the heart are cut, so their signal no longer gets to the heart. The doctors are careful to leave enough nerves in tact that the brain stem can still get a regular heattbeat signal to the heart. 265 bpm, while not unheard of, is very rare and very fast. I can certainly see why u were in the ER getting drugs pumped into you. A heart rate that high for very long can cause severe damage to your heart, snd yes can even kill you. Luckily it sounds like yours was caught in time and I'm guessing u are now on meds for it. Meds are the usual treatment for tachycardia but don't be surprised if your cardiologist suggests ablation to solve your problem. Good luck to you. I wish u well wish your heart health.