The human ear has two different functions--to hear and to keep the body balanced. The ear is made up of three different sections including the inner ear, middle ear and outer ear. The middle ear section, located in an opening in the temporal bone of the skull, houses three bones, collectively called ossicles. These three bones--linked together--connect to the tympanic membrane (also called the eardrum). The function of the bones is to convert the sound waves that hit the tympanic membrane into mechanical vibrations for the brain to interpret as sound.
Malleus
The malleus, also called the hammer, attaches to the eardrum. The malleus gets its name from the shape of the bone. The shape includes a head, neck and handle. The handle portion of the bone is attached to the tympanic membrane, and the head end attaches to the next bone in the chain--the incus. The malleus is the largest of the three bones found in the middle ear. A muscle called the tensor tympani connects to the malleus. The function of this small muscle is to help protect and tune the ear, according to the Merck Manual of Health Information.
Incus
The second bone of the middle ear is the incus, also called the anvil. The incus bone has three distinct parts. The body and two extensions--one long and one short--make up the shape of the bone. The body portion of the incus connects to the malleus. The short extension connects a ligament on the wall of the ear. The long process attaches to the head of the stapes bone.
Stapes
The stapes bone resembles a stirrup, which is how it earns its nickname. The top portion is the head, and two sections extend down from the head and meet at the base. The stapes is the innermost bone in the middle ear. The head of the stapes connects with the incus, and the base covers the opening into the inner ear. The area just before the inner ear canal begins is the oval window, according to Merck. The stapedius muscle helps connect the stapes to the oval window. As this muscle contracts, the connection between the ossicles tightens and the bones become rigid. This helps block sound from transmitting and protects the inner ear from damage to loud noises.
