Unit 7 Reflection

This unit was about the different types of muscle movement, narrowing down to the classification of muscles and how each muscle worked at a cellular level. The essential understands were how muscles work in opposing pairs to produce various movements, as well as muscle contraction. How lifestyle choices affect muscle health and performance enhancement drugs were also other focuses of the unit. One other theme of the unit was again to live  a healthy lifestyle in order to make sure that your muscles are in peak condition for as long as possible. I would like to learn more about how performance enhancement drugs affect your body. I also wonder whether there are nay performance enhancement drugs that have no side effects, simply because all the ones we went over in class had very bad side effects. As a student, I have grown in that I spend a lot more time on my cooking blog now thanks to it being incorporated into my 20 time project.In this unit. I also learned how to make an animation video with my group during our project showing muscle contraction. 

My favorite part was the chicken dissection; here are a few photos from the lab showing various muscles in the chicken: 

As for my new year's goals, I have been getting in a lot of yoga recently, and I have also been eating healthily. I am trying to improve on my sleeping time, but life is really really busy right now so it is difficult to sleep early. 

Performance Enhancement Advertisement

I think that massages are often overlooked as a performance enhancement technique to non-athletes. Although many professional athletes do get massages, I think that the general public would find self-massage techniques very effective. For example, a swimmer who has arm pain could greatly benefit from doing a self massage on the arm muscle groups to relieve future pain and to greatly speed up recovery. I think that massage is one of the safest techniques for recovery, if not the safest. People can easily overstretch their muscles and pull a muscle, but with massage, it is quite difficult to damage your muscle as you have full control over the pressure and there is less strain on the muscle. Also, massage does not involve putting any artificial chemicals into your body in contrast to steroids or other enhancement technique. Massage also does not cause damage to your organs and body systems and is generally not a concern for addiction. A lingering question I have is whether it is better to work on sore muscles with more pressure or not, and how big a difference the amount of pressure you use has on the effectiveness and speed of the recovery process.

Chicken Dissection Analysis

In this lab, we dissected an entire chicken. The first thing we did was pat it dry and remove all the skin from the breast part, and then we identified the various muscles, even cutting off a wing to take a look close up at the muscles in the "arm" of the chicken. The bones provide the structural frame of the chicken, and the tendons attach to the bones and muscles to keep everything stable. The muscles are responsible for controlling the movement of the chicken and supporting is structure. For example, when we flexed and extended the leg of our chicken, we could clearly feel the quadriceps tensing and relaxing, so we knew that it was responsible for that movement.

One major difference between the tendon where it attaches to the origin and insertion site is that at the site of insertion, all the tendon fibers are bundled together very tightly and compactly, whereas at the origin, it fans out a bit and becomes a thinner layer of visible tendon fibers where it attaches. At the site of insertion, there must be a very strong foundation, so the tendon is very compact to ensure that it can hold all the weight. The site of origin requires the tendon to support the bone, so it is required to be more spread out in order for nerve impulses and motion neurons to reach it more easily.
The chicken has much larger pectoralis major that humans do, which is because chickens are farmed for food, and humans prefer chicken breast, so they select the chickens to breed so that all the offspring have larger pectoralis major. Compared to humans, chickens have a relatively small trapezius muscle, probably because they have such a small head and stubby neck, so they don't need that much muscles to hold their head up. Compared to chickens, we have very large and heavy heads with a relatively long neck, so we need stronger trapezius muscles to support our head movements. Finally, chickens also have a very large tibialis major, which is located on their leg, the drumstick part. This is also because humans really like to eat drumsticks, so chickens are bred to have large drumsticks. At the same scale, humans have much smaller tibialis major. Below are the pictures that we took of the muscles and other parts:

Deltoid allows arm abduction along frontal plane.

Trapezius muscle moves scapula and supports arm movements. 

Latissimus Dorsi allows for extension, flexion, rotation of shoulder joint, and more.

Pectoralis minor abducts and depresses the scapula toward the ribs. 

Pectoralis major moves the shoulder joint.

Biceps Brachii controls the movement between the shoulder and elbow joints.

Triceps Humeralis are supportive of arm structure and have populations of slow fibers. 

The flexor carpi ulnaris adducts and flexes the hand.

Biceps femoris supports the knee extension.

brachioradialis flexes forearm at elbow. 

Quadriceps extend the knee joint and are used for walking and running.

semimembranosus allows leg to flex and rotate and serves as a thigh extensor. 

Tendons are dense collagenous fibers that connect muscles to bones. 

Semitendinosus works with other hamstring muscles to flex knee and extend hip.

Iliotibialis flexes the thigh. 

The longest muscle in the body, the sartorius flexes, adducts and rotates the hip. 

Gastrocnemius flexes the knee and foot. 

Peronius Longus everts and pronates the foot. 

The tibialis anterior dorsiflexes and inverts the foot. 

What Happens When You Stretch Notes

1. "The nerve endings that relay all the information about the musculoskeletal system to the central nervous system are called proprioceptors. Proprioceptors (also called mechanoreceptors) are the source of all proprioception: the perception of one's own body position and movement." 

I thought that this quote was interesting because it showed how many words that are used in science are actually very easily definable despite the fact that they look complicated. this in large is due to the fact that many words, such as propioception, is made of prefixes and other parts that all mean words that we know in everyday life. 


2. "When muscles contract it places tension on the tendons where the golgi tendon organ is located. The golgi tendon organ is sensitive to the change in tension and the rate of change of the tension."

This makes me wonder about whether the golgi tendon organ is in anyway related to the golgi apparatus in the cell. Since they share a name, I would guess that they either perform similar functions or have some other correlation. 

3. "Some sources suggest that with extensive training, the stretch reflex of certain muscles can be controlled so that there is little or no reflex contraction in response to a sudden stretch. While this type of control provides the opportunity for the greatest gains in flexibility, it also provides the greatest risk of injury if used improperly. Only consummate professional athletes and dancers at the top of their sport (or art) are believed to actually possess this level of muscular control." 

I am curious about the stretch reflex and its control. How long does it take for athletes and dancers to develop this control? Do they have to do certain types of exercise in particular that help with this? 

Relate and Review:

I thought that this article was very interesting because it connected well to what we learned in class. In particular, I found it interesting how the sacromeres are stretched to their fullest when you stretch. I thought that it was great because even though it was an in depth article, because I already had prior knowledge in this topic and especially in how the muscle works when it contracts and relaxes, I was able to clearly visualize how muscles behave when they are stretched.  I also thought it was interesting how the stretching reflex could be trained and be controlled, especially by athletes. I am curious to learn more about the process of how it is controlled, as well as what goes on at a cellular level when it is changed. Are the genes that are expressed and proteins that are produced permanently altered? What mechanism makes it change?

Unit 6 Reflection

This unit was all about the skeletal system and how bones all work together in harmony to support the functions of the human body. We first explored the structures of bones, including the different types and the cells, bone marrow, lacuna, etc. that make up all bones. We then learned about the different disorders that affect the skeletal system, which consisted of mainly spinal deformity diseases such as kyphosis. Here is a video explaining kyphosis:

I would like to learn more about how people get diseases in the skeletal system, particular the spine deformity diseases. In the lecture notes it was mentioned a lot that some of the diseases had unknown causes even though there was a vague correlation between the disease and certain groups of people. Some unanswered question I have are what causes these diseases, such as the balance between how environmental factors and genetic factors will causes these diseases. 

One activity that we did during this unit that I found to be quite interesting was the owl pellet lab; ow our group did not have a full set of bones to construct a full skeleton, here is an example of an owl pellet and a completed skeleton built from an owl pellet: 

I am very optimistic about my 20 time project and I think that it will be a manageable workload. I cannot wait to start cooking and resuming my blogging. I also have been semi-successful in my new year goals in that I have recently started a yoga shredding series that I do daily. I actually really like shreds because they are short, yet provide the same amount of hardcore exercise that usually takes hours. I think that it is especially convenient for students because we are often "too busy to exercise," but with shredding, there is really no excuse because it takes less than 15 minutes to do a full day's worth of working out. 

Owl Pellet Lab Analysis & Conclusion

In this lab, we dissected an owl pellet and tried to use the bones in the pellet to piece together skeletons of organisms that the owl may have eaten. WE also compared and contrasted the bones to human bones. To dissect the owl pellet, we used probes and forceps.

Based on the bones that we were able to find, we concluded that the organism was either a shrew or a vole. We believe this because the vertebrae in its our creature's tail matches both the shrew and the vole, and it has the correct number of ribs as well. There was also a femur that looked very similar to that of the vole and shrew. However, because we lacked a skull, we could not deduce exactly which organism it was. As seen below, we managed to piece together a skeleton that looked very similar to a vole or a shrew. In the diagram in the book, the shrew had 12 ribs on each side, which is what we managed to obtain. The tail vertebrae in our picture also supports the hypothesis that the organism is either a shrew or a vole.

Both humans and the shrew/vole skeleton have ribs, and we both have 24 ribs total, with 12 on each side. The shrew/vole also had floating ribs, much like we do. They also had a skull similar to us, with eye sockets, a hole for the nose, and mandibles for the jaw area. Their appendicular skeleton is also quite similar as they also have a femur tibia and fibula, much like we do. One key difference is that they have a full tail vertebrae column, whereas humans only have remnants of a tailbone. This is because we do not use our tails for balance and overtime it was not selected for so it reduced in size. See below for a comparison picture. Also, although we do have the same general bones, the shape of the vole/shrew's tibia and fibula was different; in humans, the bones are really two that are connected in the top and bottom, whereas in the rodent, it is one bone with a section that branches out and in again. Finally, a big difference was the entire pubic region. Since humans walk on two legs instead of four, there is a difference in the structure of our respective pelvises.

Unit 5 Reflection

Some of the essential themes from this unit were how the different systems worked together to provide energy for the body and regulate waste and hormone levels. I thought the lymphatic system was particularly interesting because I did not know that there were lymph vessels that circulated throughout the body just as blood vessels do. I also thought the "heart" of the lymphatic system was cool, because it was almost like there was a separate heart pumping the lymph throughout the body. One strength I had throughout this unit was being able to grasp the different systems well and know how each one worked in terms of all its components and its specific functions, as well as how all the parts united to serve its overall purpose. A weakness for me was understanding metabolism; I was confused on the different processes and the organs and steps that were involved and it took me a long time to understand it fully. One activity that I enjoyed this unit was the digestive system lab because through it I was able to understand how large our digestive organs really are when they are fully stretched out. here is a link to the lab questions, as well as a picture of my findings in a table:
http://alexandriatso17.blogspot.com/2016/01/digestive-system-lab-questions.html
Through this lab I was able to learn that the digestive system has evolved to efficiently maximize its space and use by folding up into a tiny structure that can fit within our abdominal cavity. I would like to learn more about the lymphatic system, specifically what the spleen does in general because I felt like we kind of glossed over it with just the big functions and not really how its related to the lymph system, or why its even in the same lecture if it is not considered a part of the lymphatic system.

Here are two videos that I enjoyed watching on the digestive system and lymphatic system to study:

As for my new year goals, I have been sleeping a lot earlier, but I still sleep past midnight quite often. Next steps will include continuing my progress in less procrastination and trying to sleep earlier. now that SATs are over, it should be much easier to catch up on sleep because I have one less thing to study for. My notebook is also more organized; I take more care to write neatly, although sometimes the lecture is a bit too fast and it is hard to keep up, or I am falling asleep. To improve this, I will try to be more awake by sleeping earlier as mentioned before, and also continue writing neatly in all my notebook assignments to maximize organization.