Question

Ear ossicle, incus is modified
a. Jugal bone
b. Articular bone
c. Quadrate bone
d. Hyomandibular bone

Answer 1

Hint: Ear ossicles are of 3 in number and their names are, Malleus, Incus, and Stapes, where Malleus is attached to the tympanic membrane and stapes is attached to the circumference of the fenestra vestibular, and this both are connected together by middle Incus by the structure Called delicate articulate.

Complete answer:
- The major function of the ear ossicles is to transmit the sounds from outside or from the tympanic membrane to the fluid-filled cochlea.
- The absence of this ear ossicle or auditory ossicles may cause hearing loss.
- When coming to the development of the ear ossicles, which are in the embryonic stage these bones are generally attached to the dentary, which is nothing but a part of the jaw.
- This ear ossicles are considered as modified portions of the cartilage called Meckel's cartilage.
- As the embryos develop, this cartilage becomes hard and forms the bone structures.
- As the period is going on, in the later stages of the embryonic development, these bones start breaking, and they lose from the jaw and migrate to the inner ear.
- These ear ossicles such as Malleus, Incus, stapes are the modified bones of columella, quadrate, articulate, and angular structures respectively.
- Among all the ear ossicles, the smallest one is the stapes, along with it is the smallest bone of the human body.

Hence, the correct answer is option (C).

Note: When the sound vibrations touch the tympanic membrane, it transmits to the nearby ear ossicles, Malleus, and later it is transmitted to the incus and to stapes from which it is transmitted to the vestibule of the inner ear through fenestra ovalis.