In this post we are talking about the muscular system! Our muscles allow us to move, maintain our body temperature, and hold our posture. Muscles contain cells, also called fibers, connective tissue, blood vessels and nerves. The nerves meet the muscles at neuromuscular junctions. These axons are what deliver stimuli from the brain and tell muscles to relax and contract; this is vital for any sort of movement. The first thing that may come to mind when thinking of a muscle contraction could be weight lifting or working out. This is true, but lifting our arms, walking, chewing and every other movement of the limbs or the trunk require muscle contraction and relaxation. Just think of everything our bodies could not do without the electric signals from our brains to our muscles! When action potential, the electric signal, travels along the nerve axon through our muscle, it ends at the synaptic terminal and releases acetylcholine. The acetylcholine is released into the synaptic cleft and binds at the motor end plate, causing a change in the fiber. This can all be summed up by say that sensory input (sensation or brain signals) consciously or unconsciously motor output (muscle movement).
Overall, I found the muscular system extremely interesting and it is probably my favorite system that we have studied so far. I liked how we studied location of the muscles yet also learned about all their roles and functions. I always assumed that bones held out posture and normal body position, but as I said above it is actually our muscles role! I was really fascinated by the extreme detail, even at the biochemical level, of muscle contractions. There is so much detail and work that goes into every little movement our bodies make, including my fingers typing this post right now. We dissected a chicken leg in class and I was in complete awe of how clearly I could identify the muscles and tendons and even see the striations of the fibers, it really tied to together all that we had been studying.. Even if I don’t eat meat! But in all seriousness, this system is extremely fascinating and I would really love to learn about muscles even deeper and also become familiar with some of the many injuries and diseases that plague our muscles.
Bibliography:
"How the Nervous System Interacts with Other Body Systems." Washington Edu, n.d. Web. 9 Feb. 2015.
McMahon, Mary. "What Is a Neuromuscular Junction?" WiseGEEK. Conjecture Corporation, 08 Jan. 2015. Web. 09 Feb. 2015.
Knierim, James. "Motor Units and Muscle Receptors (Section 3, Chapter 1) Neuroscience Online: An Electronic Textbook for the Neurosciences | Department of Neurobiology and Anatomy - The University of Texas Medical School at Houston." Motor Units and Muscle Receptors. University of Texas: UT Health, n.d. Web. 09 Feb. 2015