<h2>(D) is the correct option </h2>
Explanation:
- Both the stapedius and tensor tympani are striated muscles
- The stapedius is about 6 mm in length, arises from the pyramidal process and the tendon attaches to the posterior neck of the stapes
- The stapedius is a muscle with a high oxidative capacity
- The tensor tympani is about 25 mm in length, the muscle is not as strong as the stapedius, and the tendon also contains more elastic tissue and fat
- The tensor tympani courses through a bony canal in the wall of the anterior middle ear, and attaches to the neck of the manubrium
- The tensor tympani and stapedius muscles are protective reflexes
- They reduce the amount of sound that gets into the inner ear
- They are somewhat similar to the blink reflex thus they can be triggered by loud noise, and when they go off, both ears can be involved
- If stapedius and tensor tympani muscles is not present then loud sounds would cause the ossicles to move too much, potentially causing damage to the inner ear
(A) a change in a developmental gene or in its regulation that altered that spatial organization
