Muscular System Reflection Unit 7

To start off with in this Unit, we learned about directional terms and joint movements. We learned a little bit about this in the last unit when talking about synovial joints, such as elevation/depression, plantar flexion, supination/pronation, and retraction/protraction. The next section we learned about was properties of muscle tissue such as contractibilty, excitability, extensibility, and elasticity. We then learned about different components of a muscle. There is the fascia, which is the thin sheet of fibrous connective tissue that hold the muscle fibers together; then there is epimysium, perimysium, and endomysium, which are the smaller building blocks that make up muscle fibers (a lot like the layers of skin and also similar root words found in the heart); and also tendons, which attaches the muscle periosteum to bone.


After learning about this section, we did a Chicken Dissection, and then did a blog post of the Chicken Dissection Lab Analysis. To sum that experience up, we cut into the chickens breast, back, wings and legs to find a whole list of certain muscles. 


Muscle Contractions are when a muscle contracts and the myosin and actin filaments slide past each other. This causes the muscles to shorten. There is a whole lot more to this process and we were told to make a stop motion video depicting how a muscle contraction worked: Stop Motion Video. This was pretty fun to make but it was a little difficult as well. None of the people in my group were great artists as you can probably tell so it didn't turn out as pretty as I had hoped. In part of it we were trying to have the picture to the left be out guide, and then we had to repeat that process three times. This was where the ATP attaches to the ATP binding site on the myosin crossbridge to move the muscle. The ATP turns into ADP+P and then the P flies off and the myosin head binds to binding site on actin. The ADP is then pushed off as well causing the myosin to swivel back to its resting state. 

The last thing we learned about was muscle enhancers. Commonly known ones are steroids, and athletes usually take them to boost heart rate and blood pressure to perform better. Different types of performance enhancers do different things, but they all have bad side effects. While some enhancers such as caffeine only make you jittery and dehydrated, other such as Erythropoietin can cause heart attack, stroke, or pulmonary edema. For Anatomy homework, a partner and I had to make a Satirical Ad on Performance Enhancers.

Even though this Unit was about muscle, we didn't really hit on the disease aspect of it. Since my sister has muscular sclerosis, I was hoping to learn a little bit more about that. Butt, throughout this unit, I learned a lot of others things. It was a lot of information to take in, but it was interesting.