Question

The smallest muscle in the human body is
a. Sartorius
b. Spinal muscle
c. Stapes
d. Stapedius

Answer 1

The smallest muscle is present in the middle ear. This muscle provides protection to the inner ear against the louder noises. Also, the vibration of the stirrup bone that is the smallest bone of the body is controlled by this muscle only.

Complete answer:
In the middle ear, the wall of the tympanic cavity consists of a skeletal muscle known as stapedius. This is the smallest known skeletal muscle present in the body of humans. It protects the inner ear against excessive vibrations by providing a swift reflex action against the loud noises. It helps in stabilizing stapes, which is the smallest bone present in the body.

In the posterior of the tympanic cavity, pyramidal eminence is present which is hollow and cone shaped structure. The stapedius muscle arises from the apex of this pyramidal eminence and it extends into the stapes bone. A branch of the facial nerve known as the nerve to stapedius is supplied to this muscle.

On the other hand, the sartorius is referred to as the longest muscle that is present in the human body. Spinal muscles are tiny muscles linked to the spinous and transverse courses of the vertebral column while stapes is a smallest bone occurring in the middle ear of the human body. It is also known as stirrup bone based on its shape and it helps in the vibration transmittance from the incus towards the inner ear.

Hence, the correct answer is option (D).

Note: The vibration of the stapes bone is reduced by the stapedius muscles. Also, the stapes is prevented from the excess movement through the acoustic reflex provided by stapedius muscle. This helps in controlling the heft of the sound waves reaching the inner ear from the external environment.