Unit 7 Reflection

 This Unit was about muscles and how they move, contract, function, and help the body. First, we leafed about directional terms and joint movements such as abduction (away from the body), and adduction (towards the body). After learning movements, our teacher Mr. Orre assigned us a project where we had to come up with out own dance that involved all of the movement we were taught prior.  The next lecture taught us about the muscular system. Here we learned about the different tissues used to make up muscles, the properties of muscles, muscle classification, and muscle names. For example we learned muscle names are named according to any of the following criteria; directions, size, shape, action, location and number of attachments. Piriformis means pear shaped; Gracilis means slender; Brachii means arm; and tensor means to make a body part more rigid. These are just examples of some of the terms we learned.

The next thing we learned about was muscle contractions. In this lecture we learned that each muscle is composed of many bundles of fibers, and that in each little fiber, it is an individual cell, it contains myofibrils and has a sarcolemma. Muscle contractions are when a muscle contracts and the myosin and actin filaments slide past each other causing the muscle to shorten. To help us learn it better, me and three other teammates created a Stop Motion Video presentation on a white board. The step of a contraction are 
1) Nerve sends impulse to muscle fiber 
2) Ca2+ ions are released from sarcoplasmic reticulum into the cytoplasm
3) Ca2+ ions bind to proteins wrapped around actin filaments 
4) Binding of Ca2+ ions causes myosin filaments to bind to and pull on actin filaments (like tugging a rope) 
5) Sarcomere shortens 

Then we learned about the different types of muscles such as Biceps, triceps, deltoids, external obliques, gluteus maximus, Hamstrings, quadriceps, gracilis, and tibialis anterior. 

Finally we learned about muscle twitches and the effects of steroids. For muscle twitches, there are slow and fast. Slow tend to be more dependent on oxygen, high amounts of myoglobin, mitochondria and capillaries, and are slow to fatigue. Then theres fast. Fast Oxidative ( moderately high oxygen capacity, fatigue resistant, high blood flow, capillary density, and mitochondrial content). Fast Glycolytic is basically the opposite in fast oxidative. Then in the same lecture, it talked about types of muscle contractions. 
Eccentric contraction: Muscle actively lengthening (walking, quads lengthen when knee flexes after taking a step)
Concentric Contraction: Muscle actively shortening (bicep curl)

Isometric Contraction: Muscle actively held at fixed length. (holding weight in front of you)

Passive Stretch: Muscle passively lengthening (touching your toes)

To end the unit, we learned about how bad steroids are for teenagers and adults as they do many things to your body such as baldness, joint pain, stroke, heart attack, stress on organs and so much more. 

I want to learn more about muscles in direct relativity to sports. Such as what sports affect what muscles and how can you take care of those muscle better. As a second semester senior this year, I am beginning to learn that planning/scheduling is very important in life. I feel as if I've gotten a little better this semester too.