What Happens When You Stretch

Title: What Happens When You Stretch
Relate & Review:
When we stretch, there are many things that we can't physically see but goes on within our muscles. The stretching of muscle fibers starts with myofibrils which are made of many sarcomeres. Every sarcomere has thick and thin myofilaments that overlap every time the muscle contracts. This is why the muscle shortens every time it contracts. Proprioceptors are the main nerve endings found in joints, muscles, and tendons that help send signals to the central nervous system. The stretch reflex is triggered when the muscle is stretched and the muscle spindle notes the change in length. This reflex resists the change in length by making the muscle contract and this action helps to maintain muscle tone and protect the body from potential injury. If you hold a stretch for a long period of time, the muscle spindle gets used to the new length and stop signaling so you can gradually lengthen your muscles. As the muscle contracts, it reaches a point when it has gone beyond a certain threshold and needs to relax which triggers the lengthening reaction. This stop the muscle from contracting and causes it to relax. In this unit, we also learned about how one muscle relaxes when one contracts and that is called the reciprocal inhibition. A great example would be the biceps and the triceps.
Quotes:
1. "Hence when you stretch, the muscle fiber is pulled out to its full-length sarcomere by sarcomere, and then the connective tissue takes up the remaining slack. When this occurs, it helps to realign any disorganized fibers in the direction of the tension". It really points out how important stretching really is no matter how simple the action may be. Stretching helps place the fibers back in place so our muscle can go back to function normally.
2. "One of the reasons for holding a stretch for a prolonged period of time is that as you hold the muscle in a stretched position, the muscle spindle habituates and reduces its signaling". Basically the longer we hold a stretch, our muscle can actually stop contracting and allow the muscle to lengthen. This might be why dancers are often more flexible due to the amount of time they spend stretching.
3. "The basic function of the golgi tendon organ helps t protect the muscles, tendons, and ligaments from injury. The lengthening reaction is possible only because the signaling of golgi tendon organ to the spinal cord is powerful enough to overcome the signaling of the muscle spindles telling the muscle to contract". As our body is able to contract as it stretches, it can help prevent from overdoing it and causing potential injuries. The Lengthening Reaction help over the signal that tells the muscle to contract.