What Happens When You Stretch?

Article: What Happens When You Stretch?

In this article it talks about what physiologically is occurring within your muscles that allows you (and does not allow you) to stretch. As the muscle stretches the area of overlap of myofilament decreases. Once the sarcomere is at its most elongated position the connective tissue does the rest of the stretching. Not all fibers are stretched, some are just relaxed. Muscoskeletal receptors are called proprioceptors. The one's that take part in stretching are located in tendons and muscle fibers. Intrafusal fibers are the primary proprioceptors in the muscle. They receive a message from the muscle and send it to the spinal receptors. In order for a muscle to stretch it must have a counterpart that is contracting. This is called reciprocal inhibition.

Quotes: "The basic function of the golgi tendon organ helps to protect the muscles, tendons, and ligaments from injury."

The golgi tendon essentially prevents us from over-stretching and that is why we feel pain when we push ourselves to far in a stretch because the golgi is telling our nervous system that we need to stop stretching.

"You also want to relax any muscle synergists by the muscle you are trying to stretch."

On top of there being counter contracting and relaxing of muscles, there also needs to be a coesive stretching among synergists muscles.

"One reason for holding a stretch for a prolonged period of time is that...the muscle spindles habituates"

By holding the stretch for a longer period of time you are essentially training your receptors to allow greater lengthening of muscle. The longer you hold, the more the signal is reduced. This is also why in dance class we hold stretches for minutes at a time.

  

Unit 6 Reflection

First off, I'd like to say that is one of my favorite units. Now that that is out of the way let's get back to reflecting. Unit 6 was the bones unit. We started off simple, learning about the basics of bones. The anatomy of the human skeleton (not all of it because we don't have time to memorize 206 different bones), the functions of bones, types of bone cells, types of bones, etc. Then we dove a little deeper, into something a little more applicable, disorders. Things like arthritis, scoliosis, and kyphosis which are painful deformities caused by things like genetics, age, or even poor posture. The process of bone remodeling came into play, because when a bone breaks a hematoma forms, then fibrocartilage and spongy bone form around and in the area, then a bone callus replaces fibrocartilage, and lastly osteoclasts remove excess bony tissue restoring the new structure. And thats only touching on the basics  of bone remodeling. The last thing we learned about was joints, they are classified by 2 categories, which are then broken down into 3 types per category. First is structural the types are: fibrous, cartilagenous, and synovial. Second is functional: Synathroses (immovable), Ampiathroses (some movement), and Diathroses (freely moveable). This is the general classification of joints. We also did a owl pellet lab, which really helped me understand the human skeleton.(link below) Well that just about covers everything we went over in this unit. 

As for personal experiences, I'm doing much better with my  goals. I've been sleeping better, instead of staying up late, I've been going to bed earlier and doing my hw in the morning. Seems to be efficient,and I'm more awake at school since my brain has already been functioning fully a couple hours prior. I need to time manage better, and even when I have 10 or 15 minutes of time before dance or some other activity, I should be doing hw instead of being on my phone.Because every minute counts.

Owl pellet Lab link

Owl Pellet Lab

In this lab I dissected an owl pellet, which is the remains that are not digestible enough to even pass through the whole owl. To tart off the lab I read a large packet on general information about owls, such as what kinds of animals they eat, what an owl pellet is, etc. Then I did a small hypothesis, based on prior knowledge, what I expected the differences to be with the human skeleton. I measured the mass , length, and width of the pellet. Then I started breaking up the pellet, separating the hair from the bones. I had a great array of bones which you can see in the photos below, I had the skull, ribs, scapula, some vertebrae, and majority of the lower extremities. I then measured the dimensions of the skull and lower jaw.

From my observations I concluded that the animal was a vole. Firstly, the molars were pointed, the skull length was 25mm, and the lower jaw was 20mm, which all the directly correspond with the standards of a vole. There is also striking similarity between the scapula, hip bone, tibia, fibula, and femur. (Shown in pictures below)

As for the comparison of the human skeleton to the rodent skeleton, the rodent's skeleton includes the 4 types of vertebrae much like a human, but also has an extra, the caudal vertebrae (tail bones). Human's have the coccyx which is a variation of that. Both have a scapula,which presume the same function, but the rodent's sticks out more instead of mainly being spread across the back like that of a human. The final similarity/ difference that I noticed was, while both have pelvises that attach to the femur, the pelvis of a rodent is much longer. A human's seems a lot wider and shorter by comparison, considering the rodent's is actually longer than its femur. 

Unit 5 Reflection

This unit was the "Diabesity" unit, which included the digestive system, metabolism, endocrine system, and Lymphatic system. The main take away from this unit was that what you put in your body is not as simple as going through a tube. Many different systems work together to absorb nutrients, process waste, produce and store energy, monitor sugar content, respond to foreign invaders and more. It is way more complex than just one system that causes or does not cause obesity and diabetes. 

The main setback of this unit was its complexity. Especially the metabolism portion. There are so many new concepts that it was difficult to wrap my brain around them. For example : metabolism starts with extraction of energy from food, but there are already three different steps to this process and each step is completely different from the last.

We did activities such as the digestive system string model, where we make a to scale model (in length) of our digestive system. We made posters of the three states of metabolism, which was personally my favorite and really helped to better my understanding of the states. We also did multiple reading one called " Why Zebras don't get ulcers" which expanded on what we were learning about.

I want to learn more about the diseases and defects of these different systems, how they occur, why they occur, the cure, etc. 

So far I'm doing pretty well with my New year's goals. I;m doing pretty good with my dance goals, and almost good with my school goals. I said I would not procrastinate so much as to leave my homework to do in another class or during lunch, which I have so far not done any homework in school. But I also said I would not stay up past 11 doing hw, studying, etc and here I am 12:46 am doing homework and studying for my test.

Digestive System Lab

    In this lab we made a to scale model  of the length of our digestive system. The point of the lab was to show how truly massive your internal organs are.

    I am 1.7018 meters tall and my digestive tract is about 9.23 meters long. It baffling how this system is more than 8 times the size of me. But theses lengthy organs fit inside of me due to their ability to fold and scrunch together like a spring, more specifically the large and small intestines. 

     My guess is that it takes around 15 hours for food to go through the entire digestive system. But according to Health and Support, it can take anywhere between 12-72 hours depending on what kind of food is ingested. Fruits and vegetables take around 12-24 hours to pass through while red meat takes 72 hours.

      Digestion is the break down of food into smaller pieces and absorption is intake of nutrients from that food. The mouth, esophagus, and stomach are involved in digestion and the small intestine and large intestine are involved in absorption. 

  I want to learn more about metabolism and how digestion, absorption, etc have to do with it. I also want to understand what makes a "fast" or "high" metabolism. What (scientifically speaking) is going on?

New Year's Goals

I will manage my work time better. Managing my time includes, doing homework right after school instead of half an hour before I go to dance, staying up no later than 11:00 to do homework, never leaving homework that is due the next day to do in another class or during lunch.

I will work on dance skills outside of the studio. This includes practicing my solo at least once a week outside of class. Stretching before class on Saturdays, since we don't have warm ups that day. Doing acro (such as aerials, backbends, etc) at home, to work on more difficult skills.

I will focus on myself instead of other people. I will not be rude or selfish, but I will not care about what other people are doing that I am not doing. I will not let people determine my actions, simply because I admire their opinion. I will do what I want to do and not worry about what other people think of me. I will have achieved this goal when I no longer care about what specific people are doing.

Sheep dissection video

https://youtu.be/F10sQcK_vEw