The crus or crura are the two side parts of the stapes bone of the middle ear. They are named after the Latin word for “legs” because they resemble the legs of a crab.
What are the Three Muscles of the Ear?
The three muscles of the ear are:
- Tensor tympani – This muscle tenses the tympanic membrane (eardrum).
- Stapedius – This muscle dampens the movement of the stapes bone.
- Posterior stapedius muscle – This muscle is located behind the stapedius muscle and helps to dampen the movement of the stapes bone.
What are the Three Ossicles?
The three ossicles are the smallest bones in the human body. They are located in the middle ear and help to transmit sound waves from the eardrum to the inner ear. The three ossicles are:
- Malleus – This bone is also known as the hammer. It is attached to the eardrum and transmits sound waves to the incus.
- Incus – This bone is also known as the anvil. It receives sound waves from the malleus and transmits them to the stapes.
- Stapes – This bone is also known as the stirrup. It receives sound waves from the incus and transmits them to the inner ear.
What is the Smallest Bone in the Ear?
The smallest bone in the ear is the stapes. It is about 2.5 millimeters long and resembles a stirrup.
What is the Longest Bone in the Ear?
The longest bone in the ear is the malleus. It is about 9 millimeters long and resembles a hammer.