PDFs are the instructions for the lab. The word documents are the ones that need to be worked on.

Your Name: Oniel Blair

INSTRUCTIONS:

• On your own and without assistance, complete this Lab 5A Answer Sheet electronically and submit it via the Assignments Folder by the date listed in the Course Schedule (under Syllabus).
• To conduct your laboratory exercises, use the Laboratory Manual located under Course Content. Read the introduction and the directions for each exercise/experiment carefully before completing the exercises/experiments and answering the questions.
• Save your Lab 5A Answer Sheet in the following format:  LastName_Lab5A (e.g., Smith_Lab5A).
• You should submit your document as a Word (.doc or .docx) or Rich Text Format (.rtf) file for best compatibility.

Pre-Lab Questions

1. Describe 2-3 ways that the musculoskeletal system supports the actions of other organ systems.

The musculoskeletal system provides structural support for the entire body. Individual bones and groups of bones provide a framework for the attachment of soft tissues and organs.

The musculoskeletal systems assist with movement and organic functioning by contracting and relaxing. Such contraction and relaxation of muscles allow various vital organs to function properly. For example, the contraction of the heart muscle allows the heart to pump blood to the rest of the body.

The musculoskeletal system protects body organs. Usually, soft tissues and organs are surrounded by the musculoskeletal system. For instance, the rib cage protects the heart and lungs, the pelvis protects the reproductive organs while the skull protects the brain, and the vertebrae protect the spinal cord

1. 2.      Use online resources to research a musculoskeletal disease not discussed in this lab. Be sure to include the causes of the disease (if known), symptoms, and treatments (if any).

There is a wide range of musculoskeletal diseases that have caused disabilities around the globe. Examples of musculoskeletal disorders include ankylosing spondylitis,osteoarthritis, rheumatoid arthritis, psoriatic arthritis, gout. I will discuss ankylosing spondylitis.

Ankylosing spondylitis (AS), also called Bechterew disease, is an uncommon and lifelong type of arthritis. It causes pain and stiffness in the spine. AS is an autoimmune disease of unknown cause belonging to the category of spondyloarthritides associated with HLA B27 (Wolf & Fasching, 2010). AS disorder affects the spine and sacroiliac joints. It comes with critical concern on peripheral joints and other different organs. Its symptoms include morning stiffness and dull low back pain, which are improved by exercise. More often, the pain is worse in the morning or after sitting for a long time. It is marked by the rigidity of the spine that curves forward, swelling of joints, difficulty in breathing, and fatigue. The main manifestation of AS is inflammatory spinal pain, which, as time progresses, some patients develop ankylosis and spinal immobility (Tam, Gu & Yu, 2010). More often, AS is managed with physiotherapy, physical exercise, and medication like nonsteroidal anti-inflammatory drugs.

1. 3.      How does an action potential in a muscle fiber differ from an action potential in a nerve cell?

One critical difference is in the duration of the action potentials. In a typical nerve, the action potential duration is about 1 ms, while in skeletal muscle cells, the action potential duration is approximately 2-5 ms (CV Physiology)

Experiment 1: Muscle Action

Data Sheet

Table 1: Temperature on Muscle Action

Post-Lab Questions

1. Record your hypotheses from Step 1 here.

The number of firsts is directly proportional to the temperature. As the temperature is increased, the amplitude of action potential is decreased, and its duration is reduced.

1. What effect did the temperature of the water have on your muscle action? Explain using data.

At lower temperatures, there is a lower muscle shortening velocity resulting in lower rates of force generation. Cold weather causes muscles to lose more heat and contract, causing tightness throughout the body and muscles to lose their range of motion. All aspects of neuromuscular function, e.g., mechanical, biochemical, and neural, tend to deteriorate with lowered muscle temperature. However, warming‐up the muscle would increase muscle performance. For example, from the experiment, warming the water up to 42  degrees celsius would increase the number of fists made (68)  the lower temperatures, i.e., 10 and 24 degrees Celcius are associated with lower muscle performance as shown by fists made, which are 45 and 60 respectively.

1. 3.      Did hand muscle fatigue play a role in this experiment? Explain why or why not.

Yes, muscle fatigue can reduce the number of fists made.

1. 4.      What does this experiment indicate about muscle performance?

Muscles perform better in optimal temperatures, which mean they should not be either too low or too high.

Experiment 2: Simulating the Effects of pH on Bone

Data Sheet

Table 2: pH of Mixtures

Post-Lab Questions

1. 1.      Record your hypotheses from Step 6 here.

Acid tends to have a net effect of decreasing bone strength, as evidenced by its impact on lime.

1. 2.      Describe the rock’s effect on the pH of the water. What caused the pH to change? How might this have related to the change in rock strength?

The PH increases due to the interaction of lime (CaCo₃) and directed acetic acid. The PH moves towards alkaline due to the dissociation of acid with a corresponding formation of calcium acetate salty. The strength of limestone or rock gradually decreases as it will be dissolved by the acid to form calcium acetate.

1. 3.      Did a solid form on the bottom of the beaker? If so, how do you think this solid was formed, and how did it affect the water? How did it affect the limestone?

The solid formed in the bottom of the beaker. There is a dissociation of acetic through its reaction with lime to form calcium acetate, water, and carbon dioxide. Thus, the PH of the water is creased towards the alkaline side, and the strength of limestone is gradually reduced.

1. 4.      Describe how this experiment relates to the musculoskeletal system. What did each material represent? Using online resources, find a musculoskeletal disease that mimics your observations of rock strength between days zero and ten. Describe the disease and relate it to your observations in the experiment.

The lime rock represents the bone. Acidity has been shown to ramp up the activity of osteoclasts, which are cells that promote bone loss and minimize the work of osteoblasts, which are cells actively engaged in bone formation.

Osteoporosis is an example of such disease result from suppression of osteoblast. Osteoporosis weakens bones, leading to increased susceptibility to unexpected fractures. It results from osteoclastic bone resorption not compensated by the osteoblastic bone formation, and this causes bones to become fragile, leading to an increased risk of fractures (Föger-Samwald et al., 2020)

Experiment 3: Design Your Own Experiment: Muscle Fatigue

Purpose: Demonstrate Muscle Fatigue

Resources Required:  Clothespin, Test tube clamp, and Timer

Procedure:

1. Create a chart for data collection.

2. Work with a partner.

 3. Hold the test tube clamp using the dominant hand.

 4. Squeeze the clamp with your thumb and first two fingers until your fingers meet.

5. Relax the grip until the clamp is back in its original position. This is one squeeze.

6. Using the timer, the partner will record the number of squeezes you can do every 30 seconds for a total of 150 continuous seconds (5 trials).

7. Count the number of squeezes out loud.

 8. At the end of the first 30 second period, the partner will record the number of squeezes made in the data chart. Continue to squeeze the clamp. Record the number of squeezes after 60, 90, 120, and 150 seconds.

Hypothesis: The more the trials through squeezing, the more the production of lactate acid, which makes the muscles get fatigued.

The independent variable in this experiment is the time, while the dependent variable is time.

It is expected from the data that the number of squeezes will reduce as the time increase.

References

CV Physiology ActionPotentials https://www.cvphysiology.com/Arrhythmias/A010#:~:text=One%20major%20difference%20is%20in,from%20200%20to%20400%20ms.

Föger-Samwald, U., Dovjak, P., Azizi-Semrad, U., Kerschan-Schindl, K., & Pietschmann, P. (2020). Osteoporosis: Pathophysiology and therapeutic options. EXCLI journal, 19, 1017–1037. https://doi.org/10.17179/excli2020-2591

Tam, L. S., Gu, J., & Yu, D. (2010). Pathogenesis of ankylosing spondylitis. Nature Reviews Rheumatology, 6(7), 399-405.

Wolf, J., & Fasching, P. (2010). Ankylosing spondylitis. Wiener Medizinische Wochenschrift, 160(9-10), 211-214.

When designing an experiment (last part on your answer sheet) to test temperature independent musculoskeletal fatigue (Experiment 3) please submit a summary statement and photos of your proposed experiment or photos if you do complete. Please include the following and any references such as webpage:

create a hypothesis

identify dependent and independent variables

identify controls

include calculations where useful

record appropriate data, and

report important data in an organized manner.

After completing your experiment, write a brief post-lab report in which you address your hypothesis, procedure, data, calculations, data analysis, potential sources of error, conclusion and additional questions or “next-steps”.

Example: Work out barefoot vs. with shoes

Next time you do Squats, Deadlifts, Lunges or other leg exercises, ditch your shoes. Your feet have over 100 muscles, tendons, and ligaments in them, and a typical pair of workout shoes limits their use in a workout. You may also notice an increased range of motion, because your shoe likely has a built-in heel lift, restricting your ankle from moving freely. Working out without the support of the shoe forces your body to use more muscles and create a bigger challenge. Because most of the muscles are underdeveloped, pay attention to how your balance is affected when you perform single-leg exercises like Lunges. Do not expect to be as strong without shoes either, because the support of the shoe boosts strength. Then complete a-g steps as listed above. Reference: https://www.stack.com/a/sports-science-experiments

For the pH level/bone experiment:

please do not inhale or swallow the contents of the solutions.

For experiment elimination of gases from the human digestive tract:

please do not inhale or swallow the contents of the beaker. If you become light-headed, stop, rest, and continue with the experiment once you do not feel light-headed.