Question

The smallest muscle in rabbit and man is:
a. Gluteus maximus
b. Stapedius
c. Sartorius
d. Masseter

Answer 1

Muscles are classified into groups such as skeletal muscles, smooth muscles and cardiac muscles. These are responsible for locomotion; maintaining posture and the movement of internal organs. The muscles function to produce motion either voluntarily or involuntary. These are generally derived from the mesodermal layer of the embryonic germ layers.

Complete answer:

Option A- Gluteus maximus:
It is the muscle present in the hips and is reported to be the largest muscle present in the human body. It is the outermost muscle of the three gluteal muscles and forms the large part of shape and appearance of both sides of the hips. The other two gluteal muscles are medius and minimus. The main function of these muscles is to maintain and support the posture.

Option B- Stapedius:
This muscle is present in part of the ear, specifically attached to the stapes. It is the smallest muscle in the body which is only one millimeter in length. Its main function is to support the smallest bone stapes. This muscle dampens the vibrations of the stapes by pulling on the neck of the bone. Also, it controls the excess movement of stapes and controls the amplitude of the sound waves from the external ear.

Option C- Sartorius:
The Sartorius muscle is the longest muscle in the human body. It is a long, thin and superficial muscle that is present along the length of the thigh in the anterior region; it runs obliquely across the upper and anterior part. The name Sartorius is derived from the Latin word Sartor which means tailor, thus this muscle is also called the tailor’s muscle. It is used to move the hip joint and the knee joint, despite the fact that it has weak actions.

Option D- Masseter:
It is the muscle of mastication which is found only in mammals. The main function of this muscle is to elevate the mandible and rising of the lower jaw. This muscle is stronger and its superficial fibers can cause protrusion.

Therefore, from here we can conclude that the smallest muscle present in man and rabbit is Stapedius.
Hence, the correct answer is option (B).

Note: The muscles are made up of protein fibers which are composed of actin and myosin which produce contractions. The muscular function is aided by the oxidation of fats and carbohydrates, these produce ATP as energy. Also, anaerobic chemical reactions are used to produce energy by fast twitch fibers. The energy is produced in the form of ATP which is used to power the movement of myosin heads of the muscle.