What Happens When You Stretch: Reading

Title: What Happens When You Stretch
Author: ---
Publication: people.bath.ac.uk
Date: March 12, 2016

Relate and Review: The main subject of this reading is what happens to your muscles when you stretch, and the processes and anatomical structures involved with stretching. The stretching of a muscle fiber starts with the sarcomere, and is basically the elongation of the sarcomere. Then, the connective tissue around the muscle align themselves with the sarcomeres, which helps to rehabilitate scarred tissue back to health. Next, the nerve endings that relay all the information from the musculoskeletal system to the central nervous system are the proprioceptors, which detect any changes within the body; muscle spindles are the main proprioceptors of the body. Then, there is also a stretch reflex, which causes the muscles to contract when they are stretched. This function protects the muscle from injury, but the stretch reflex can be suppressed. The stretch reflex has a static and dynamic component, which both help to contract the muscle from the very beginning of the stretch. However, theres is also a lengthening reaction that occurs when muscles contract and the tension becomes too high. Lastly, the process of reciprocal inhibition is when an antagonist contracts as a reaction to an agonist contraction.

1. "This triggers the stretch reflex, which attempts to resist the change in muscle length by causing the stretched muscle to contract."
- I chose this quote because it surprised me that there is an entire stretch reflex in reaction to simple stretching. When I stretched, I never realized that my muscles were also contracting; it amazed me to think how complicated stretching actually was.

2. "When an agonist contracts, in order to cause the desired motion, it usually forces the antagonists to relax."
- I chose this quote because I have never physically realized this process. Whenever I flex a certain muscle, it feels like the entire area is being flexed and is tight. However, after reading this and flexing my bicep, I noticed that my tricep was not actually tight at all.

3. "There are actually two kinds of intrafusal muscle fibers: nuclear chain fibers, which are responsible for the static component; and nuclear bag fibers, which are responsible for the dynamic component."
- I chose this quote because it really demonstrates how complicated muscle fibers are; there are so many different types of muscle fibers, like the intrafusal muscle fibers. Then, there are also different types of intrafusal muscle fibers, the nuclear chain nuclear bag fibers.