Unit 7 Reflection

In this unit we learned about the different movements of the body and specific vocabulary to describe them. These movements happen at synovial joints. There are angular movements such as flexion and extension and special movements such as elevation and depression. We also learned about how muscles are organized and classified. Muscles are in charge of the movements of bones or fluids and help maintain posture and body posture. They have certain properties that help them with these functions i.e. contractility, extensibility, and elasticity. There are many terms that classify the size, shape, number of origins, and location of the muscles. These are used to identify specific types of muscles. To deepen our understanding we dissected a chicken carcass and identified the different muscles and tendons while relating them to human muscles. In this unit we also discussed how how muscles contract and how an impulse translates though to movement that is driven by the release of calcium and ATP. To illustrate this process, we made a muscle contraction video. To end the unit we went over how muscles develop ,and how specific types of exercises can help muscle health and growth. Muscles have slow twitch and fast twitch fibers. Long duration uses slow twitch while shorter duration exercises use fast twitch. Exercises such as weight lifting can benefit muscles while certain shortcuts can actually cause more harm such as steroids as shown by our satirical advertisement.

Chicken dissection 

Advertisement that shows how the benefits of steroids do not outweigh the health problems that come with it

I enjoyed the different activities and labs in this unit because they helped simplify the complex system of muscles and how they worked. This unit made me more curious about how muscles develop ,and I want to learn more about how muscles are able to carry such large amounts of weight.

My New Year's goals are still in progress and I am currently doing well in staying more organized and being healthy. I feel that my lifestyle has changed ,and I am still working to make it better.

Performance Enhancements Advertisement

Steroids seem to appeal to people because they think that whatever they are currently doing is not enough for them to get the ideal body or meet their own standards. Anabolic steroids may increase muscle gain, but its costs are not worth it. It can cause an increase in blood pressure, heart disease, liver damage, stroke, and many other health problems. It can also affect gender specific qualities such as sperm count and breast size. Steroids are definitely not a safe performance enhancement.  
Other enhancements such as high protein diets (if paired with the proper amount of exercise and done properly) and strength training are safe ways to increase performance and gain muscle. They might require more time the other ways, but have little to no risk if done properly as apposed to steroids and androstenedione which can cause an imbalance in hormones.

Chicken Muscle Dissection Analysis

1. In this lab we first obtained a chicken carcass and began identifying any muscles that we saw. To see more of the chest, we cut through the mid line and got a better look at the pectoralis major and pectoralis minor. After looking for any tendons and clumps of fat, we then opened up the back to locate the trapezius and latissmus dorsi. We then opened up the two different segments of the chicken wing to reveal the deltoid, biceps brachii, tricpes humeralis, flexor carpi ulnaris, and brachioradialis. In the last parts of the dissection we opened up the chicken's thigh and calf and located the various muscles in each part.
In relation to motion muscles play the role of producing motion by contracting and stabilizing body positions. Tendons attach muscle to bone and helps to move bone. The bone stabilizes the movement, so the limb stays in place. The biceps brachii contracts and bends the arm/ wing, causing movement. The humerus stabilizes the arm/wing and gives a platform for the muscle to move on.
The tendon at the origin stabilize the muscle and do not let it move while the tendon at the insertion allow the muscle to contract and move. At the origin it is broader while at the insertion it is narrower.
Muscles in chickens are similar in humans in that they both have similar functions. For example, they both have biceps brachii and triceps humeralis that help move the limb in a similar fashion. The bones also have similar structure with the chicken wing having a humerus, ulna, and radius. There also differences in that the muscles have different proportions than the human's muscles because the chicken's bodily structure is different.

2.

Sartorius-flexes thigh and runs across front of the thigh

Latissimus dorsi- extend or pull wing/arm

Trapezius- run perpendicular from backbone to shoulders

Iliotibialis- extends the thigh and flexes the leg

Deltoid- helps raise arm/wing

Biceps brachii-flexes arm/wing

Quadriceps- group of four muscles,extends lower leg

Gastrocnemius-primary muscle of the dorsal and medial sides of drumstick

Brachioradialis- largest muscle on the superior side of the lower wing

Pectoralis major- pull wings ventrally

Latissimus dorsi- extend or pull wing/arm

Peroneus longus-

Triceps humeralis- extends and straightens wing/arm

Peroneus longus- extends foot

Flexor carpi ulnaris- flexes hand, runs from back to elbow to side of hand

Pectoralis minor- pulls shoulder down and forward

Tibialis anterior- flexes the foot

What happens when you stretch?

Relate and Review
When you stretch, you stretch certain fibers in your muscles. Proprioceptors perceive the movements of the muscles fibers  and relay that information to the central nervous system. Muscle spindles record how far a muscle stretches, which results in stretch reflex that causes muscles to contract. There is an initial response called the static component and the dynamic component that only occurs moments after the stretch begins. Holding a stretch longer helps with muscle lengthening which occurs after the muscle relaxes after initially contracting. Reciprocal inhibition is when a muscle contracts and antagonist muscle is forced to relax. These factors that go into how muscles relax and contract when stretching can be applied to different exercises and gives me a new perspective as to why it is important to stretch for longer periods of time before working out.


"The dynamic component of the stretch reflex (which can be very powerful) lasts for only a moment and is in response to the initial sudden increase in muscle length."
This response is something I felt in class when I was first doing the stretch with my leg. At first I did not think my leg could go any further because of this response, but it was only the initial response

"Another reason for holding a stretch for a prolonged period of time is to allow this lengthening reaction to occur, thus helping the stretched muscles to relax. It is easier to stretch, or lengthen, a muscle when it is not trying to contract."
After multiple times contracting and relaxing my leg when it was being stretched I could feel it begin to relax more and more. It also became easier to stretch because the initial contraction faded away. 

"You also want to relax any muscles used as synergists by the muscle you are trying to stretch. For example, when you stretch your calf, you want to contract the shin muscles (the antagonists of the calf) by flexing your foot."
This is an interesting idea that I never thought of before. By contracting certain muscles, other muscles relax and actually help you while stretching.  I wonder what synergists are in play in different types of stretches.