Problem
A. Choose ONE of the following chemicals / proteins and explain its role in the contraction cycle, where it originates and what happens to it at the end of contraction.
a. calcium
b. troponin
c. tropomyosin
d. adenosine triphosphate
e. actin
f. In question 1 , Cite and reference 2 or more sources to support your answers.
B. Meyer, V. E. (2003). Upper Extremity Replantation--A ReviewLinks to an external site.. European Surgery, 35(4), 167-173.
Scenario
A 19-year-old male patient's arm was severed at the distal forearm while working with a machine in his workplace. Both the limb and the patient was brought to the ER. When the severed limb was examined, it was noted that the tissue only received minor crush injuries at the site of amputation (see figure 1). After a long and arduous surgery reconnecting the muscles, nerves and blood supply the arm was replanted.
After years of therapy, the patient's limb was salvaged with most functionality and sensitivity returned. Although very satisfied that the limb wasn't lost, the patient notes that the functionality hasn't been the same. The deformities to the limb at the site of amputation are also notable (see figure 2).
Task
Answer the following questions based on the scenario and article above
A. Name the muscles severed during the amputation event.
B. If the patient were no longer to properly pronate his arm, which muscle do you think has been compromised?
C. In general, a patient with a severed limb has a smaller window of time for successful replantation when compared with finger replantation surgery. This is in part due to the difference in tissue composition of the two anatomical structures. What does this say about the metabolic demands for muscles, cartilage and bone? Why do you suppose that is?
D. What tissue type can be found bridging the two halves of the once severed muscle bellies? Why? (Hint: How do muscles grow, hyperplasia or hypertrophy?)