Unit 7 Blog Reflection

• Reflect on your learning and growth as a student.  Consider experiences during labs, 20 Time, homework etc.  Check in on your New Year's goals, and modify them if needed.

This unit, we learned in depth about muscles and it was really interesting to learn about the different types of muscles and their corresponding movements, the effects of various drugs and steroids on the muscles, and the various types of oxidative fibers. I felt that this unit corresponded a lot with the previous unit, since a lot of the muscles that we learned a lot about in either lectures or labs seemed to be closely related to the bones from the previous unit.

 In the beginning of the unit, we started with Synoial Movement Dances, in which we had to use the various types of muscle movements (e.g. flexion, adduction, abduction, etc.) three times in a dance to help ingrain the types of muscle movements for the quiz and test. I really enjoyed this activity since I found that repeatedly seeing and doing the movements enabled me to permanently remember the muscles.  

 Another interesting thing that we completed this unit was the chicken dissection, in which we dissected a chicken carcass to compare and contrast the physical and functional differences between chickens and humans. It was really shocking to see how unbalanced the chickens were since they often toppled over with parts of their bodies (e.g. the pectoralis major) far larger in proportion compared to the rest of their bodies. On the other hand, humans generally seem far more proportional. 

Deltoid/Biceps/Triceps from the Chicken Dissection

Whole Chicken before dissection

 Furthermore, we also completed a muscle contraction skit, in which our group incorporated a white board and various markers to demonstrate the muscle movements. Although the process was quite difficult, watching the end result enabled me to learn more in depth of the steps of muscle movement. 

One thing that surprised me a lot about this unit was the effect of steroids and life choices on the body. For instance, stimulants, which are able to help increase heart rate and blood pressure are effective in stimulating the central nervous system has many negative side effects, including dehydration, heat stroke, and insomnia. Even massages, which are responsible for helping muscles relax and stimulating the nervous system can cause an increased blood pressure and even heart problems. 

 In general, I really enjoyed this unit and I felt that I was able to learn a lot about the various types of muscles with the help of labs, lectures, and various activities. With my 20 time project, I've had a couple setbacks in the past few weeks; however, I think that I've learned about the accumulation of trash and have effectively made a few successful art projects. I also feel like I've done well on my New Year Goals, in which I've spending a lot more time getting sleep and getting my homework done ahead of time. 

Caffeine Post

 Today in class, we created an ad demonstrating the effects of caffeine. Even though caffeine may be viewed as a relatively safe substance since it's not only legal but can also be purchased at a coffee shop located on nearly every street corner by even young children, the reality is that caffeine can easily become addictive and has rather negative side effects. Even though caffeine has the ability to stimulate one's mind to allow one to cram for a test or finish a homework assignment, the drug has a tendency to cause insomnia, nervousness, dehydration, and irritability.
 One thing that concerns me with caffeinated beverages, specifically energy drinks, is the amount of caffeine each one has. After doing some research, I found a website stating that a 16 oz. can of Monster has about 160 mg. of caffeine, which is "more caffeine than a double espresso". It was really surprising to see that a 16 ounce can of an energy drink has over half of the maximum recommended dose of caffeine daily. Since most consumers are probably not aware of the possible side effects that caffeine has, I feel that all bottled and canned drinks should have a small label warning consumers of the possible side effects that may occur with caffeine consumption.

Chicken Dissection

 On Thursday, we spent the class period dissecting a chicken carcass using a scalpel, a probe, and tweezers while labeling the various muscle structures and comparing the chicken's physical and functional differences to the human's. Because we went over the majority of the muscles previously in the lecture, it was easy to locate the general area of each muscle on the chicken's body.
 Muscles, bones, and tissues all play important functions in our bodies; for instance, our bones, which are composed of dense connective tissue, are responsible for supporting the body, protecting the body's soft organs, and forming blood cells. Tendons are flexible chords of fibrous tissue that is responsible for attaching a muscle to a bone.  For instance, the biceps are joined together by a tendon at the radius and ulna. Muscles are responsible for stabilizing joints, heat generation, maintaining the body's posture, and moving the body's bones and fluids.

 Overall, we noticed that the chicken had many functional similarities but had vastly different physical similarities. Because the chicken that we dissected was bred primarily for meat, we noticed that its body was extremely unbalanced and often toppled over, with parts of their bodies (e.g. the pectoralis minor and major) much larger in proportion than other parts of their body. On the other hand, most humans seem to have relatively proportional bodies. Another difference that we found was that the upper limbs of humans are arms while chickens possess wings as their upper limbs. While chickens and humans possess structural differences, both use their upper limbs for the same function. One similarity that we found between humans and chickens is that both possess epithelial, muscle, and connective tissue.

The pectoralis major is the breast muscle that runs from the shoulder to the humerus

The pectoralis minor lifts the wings dorsally which allows the chicken to recover when flying.

In chickens, the trapezius runs perpendicular 

from the backbone to the shoulder of the bird 

and is responsible for pulling the shoulders back.

In humans, the trapezius is split in 2 parts. 

The deltoid helps the raise the upper arm/wing.
The biceps is responsible for bending the arm/wing.
The triceps are responsible for straightening the arm/wing.

This is the chicken's largest muscle on the posterior side of the chicken's lower wing.
In humans, this muscle is responsible for flexing the hand.

This is the chicken's largest muscle on the superior side of the lower wing.
In humans,this muscle is responsible for pulling the hand back.

The sartorius is responsible for flexing the thighs and crossing the legs.

The iliubialis covers the lateral side of the chicken's thigh. In humans, it runs from the dorsal and lateral sides of the pelvis to the lateral side of the knee.

The biceps femoris lies medial to the inferior section of the iliotibialis and is responsible for flexing the leg.

The semimembranosus is inferior and medial to the biceps femoris and is responsible for extending the thigh.

The semitendinosus is anterior and medial to the semimembranosus and extends the thigh.

The quadriceps femoris lies on the inside of the thigh medial to the sartorius and is responsible for flexing the thigh and extending the lower leg. 

The gastrocnemius is the primary muscle of the drumstick. In both humans and chickens, the gastrocnemius is attached to the Achilles tendon/

Whole chicken before the dissection

An example of some of the chicken's tendons

What Happens When You Stretch

  In this reading involving stretching, I was able to learn more in depth about proprioceptors, the lengthening reaction, reciprocal inhibition, the stretch reflex, and components of the stretch reflex. When stretching, the sacromere, the basic unit of contraction in the muscle fiber, contracts which causes an increase of the area of overlap between the thick and thin myofilaments. When stretching, the overlapping area decreases which causes an increased length of the muscle fiber and more force to be placed on the surrounding connective tissue. An interesting thing that I learned about in the reading was that overstretching of muscles can exhibit either a positive or negative result on the body; while overstretching may lead to an increase in flexibility, it can also cause an increased risk of injury.



Some quotes that I found interesting in the reading include:

"When you stretch...it helps to realign any disorganized fibers in the direction of the tension. The realignment is what helps to rehabilitate scarred tissue back to health," (1).
In the past, I perceived that people stretched primarily to reduce the chance of injury; however, this quote made me realize that many individuals who have already injured themselves often undergo physical therapy or incorporate various stretches in our for their bodies to heal more quickly.

"Some sources suggest that with extensive training, the stretch reflex of certain muscles can be controlled so that there is little or no reflect 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," (2).
I thought it was interesting to see that too much stretching can exhibit both a positive and negative effect. While excessive stretching may be beneficial in allowing the muscles to relax and become more flexible, it can also cause further damage.


"When stretching, it is easier to stretch a muscle that is relaxed than to stretch a muscle that is contracting. By taking advantage of the situations when reciprocal inhibition does occur, you can get a more effective stretch by inducing the antagonists to relax during the stretch due to the contraction of the agonists" (3).
This quote was interesting since I originally thought that all types of stretching would inhibit the same result; however, after reading the article, I was able to learn that stretching is far easier what the muscle is relaxed and can also yield more effective results.