Answers to… Shark Attack!

1. Answers to…Shark Attack!

2. 1.  Identify at least five organ systems located in this region of the arm that the surgeon would have marked for reattachment. • Circulatory, skeletal, lymphatic, nervous, integumentary, and muscular.

3. 2.  List the names of the specific structures that had to be reattached • Specific bone:Humerus

4. 2.  List the names of the specific structures that had to be reattached • Specific muscles:  Biceps brachii, brachialis, triceps, tendon of the coracobrachialis and/or part of the brachioradialis (depending on exact location of bite).

5. 2.  List the names of the specific structures that had to be reattached • Specific nerves:  Median nerve, ulnar nerve, radial nerve, musculocutaneous nerve, antebrachialcutaneous nerves.

6. 2.  List the names of the specific structures that had to be reattached • Specific blood vessels:  Brachial artery, superior and inferior collateral artery, profundabrachii artery and veins, cephalic vein, basilic vein, other venous tributaries.

7. 3.  What organ system was most likely not reattached?  Explain. • Lymphatic, since the vessels are very small and hard to find.  Also the surgeons need to get the blood flowing as quickly as possible and not take the time to reattach the lymphatic vessels, which are not as critical.

8. 4.  Why was a clean bite so important? • Ragged edges would make ends of blood vessels and nerves difficult to identify and put together, while clean edges would facilitate identification and reattachment.

9. 5.  Why was the bone shortened? • To cut off the damaged area and to avoid stretching the severed blood vessels and nerves.

10. 6.  Identify the movements associated with the arm, forearm, wrist, and fingers. • Flexion, extension, abduction, adduction, grasping, and mobility of individual fingers. 

11. 7.  Explain how the movements of the reattached arm might be altered after the reattachment. • Decreased, because not all nerve fibers are reconnected or can regenerate.

12. 8.  Identify specific types of activities that might cause Jim problems after recovery. • Grasping and moving individual fingers. 

13. 9.  Why would full use of his forearm and hand be unlikely? • Jim would not likely regain full use of his forearm and hand because not all of the nerve fibers would regenerate.

14. 10.  Assume the role of the surgeons as they explain the procedure to Jim's parents.  Write a one- to two-page explanation about the surgery, paying particular attention to what you would say about regaining use of his arm, forearm, and hand. • This is a summary of what students have learned from the previous questions but put into their own words.

15. 11.  Assume the surgery to reconnect blood vessels was successful and blood flow was re-established immediately throughout the arm.  Would the nerves of the arm recover as quickly and completely as the muscles?  Explain why or why not.

16. (11) If the surgery were successful, the nerves would not recover as quickly and completely as the muscles because nerves do not grow or regenerate as well.  [Students may discuss the role of the myelin sheath when explaining the problems associated with getting all the fibers to reconnect.]

17. 12.  How might this situation have been different if Jim had been 80 instead of 8 years old?

18. (12) An 80-year-old person might have underlying medical conditions that would make reattachment difficult (e.g., congestive heart failure, diabetes, arteriosclerosis, a weakened immune system, or other age-related problems).  A person that old would also have more difficulty regenerating nerves and having the brain understand any "rewiring."

19. The End of Shark Attack!