The human ear can be divided into three important parts; the external ear, middle ear, and inner ear. In this article, students will get to learn about the middle ear. The middle ear lies close to the temporal bone. The extension of the middle ear occurs from the ear’s tympanic membrane and it moves to the lateral wall that is present in the inner ear.
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One of the primary functions that the middle ear has is the transmission of vibrations that are sent from the tympanic membrane to the inner ear. Students can learn what is middle ear is from this article.
The middle ear cavity or more commonly known as just the middle term is also called the tympanum or the tympanic cavity. It is a chamber in the ear that is filled with air. The location of the middle ear is on the petrous section that the temporal bone has. The tympanic membrane separates the inner ear from the external section of the ear.
Also, the medial wall situated in the tympanic cavity is responsible for the separation of the inner ear and the middle ear. There are three auditory ossicles are one of the primary middle ear structures that are present in the inner ear. These ossicles help in the amplification and transmission of sound.
The anatomy of the middle ear in human beings consists of different parts such as the tympanic membrane, the ossicles, the tympanic cavity, etc. This diagram of the middle ear will help the students understand the anatomy of the middle ear better.
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Tympanic Membrane- A very important part of the middle ear structure is the tympanic membrane. It is commonly known as the eardrum. The external ear and the middle ear are completely separated by the presence of this structure. It is semi-transparent in its appearance and has air surrounding it on both sides when the circumstances are normal. The tympanic membrane is about one mm thick and has a diameter of approximately 10 mm. The shape of the tympanic membrane happens to be slightly concave. There is a tense portion situated in the tympanic membrane and it is known as pars tensa. The membrane also has a flaccid and loose portion that is known as the pars flaccida. Mostly collagen fibers and epithelial cells are used in the creation of the tympanic membrane.
The Tympanic Cavity- Another one of the middle ear parts is the tympanic cavity which is situated medially to the entire tympanic membrane. This is the main constituent of the middle ear. The shape of the cavity is rectangular and there are four walls, a floor, and a ceiling. There is the lateral wall that is created with the tympanic membrane. The roof of the cavity separates the middle cranial fossa and the middle ear. The cavity’s floor separates the jugular vein and the middle ear. The tympanic cavity anatomy suggests that there is a particularly distinct budge present in the medial wall and it is created using the facial nerve.
The Ossicles- The 3 middle ear bones are known as ossicles. These structures mainly focus on the conduction of sound in the middle ear. The main bones are named malleus or the hammer, stapes or the stirrup, and incus or the anvil. Several ligaments as well as the synovial joints tend to connect the ossicles together. The three bones are combined in order to create the ossicular chain. The oval window receives certain vibrations through the tympanic membrane with the help of this chain. A very important thing to note about the bones in the middle ear is that the bone ‘stapes’ is considered to be the smallest bone to exist in the human bone.
The Eustachian or Auditory Tube- This tube runs from the middle ear’s anterior wall to the back of the throat where the nasopharynx is located. The tube’s inside is consistent with cilia or the small hairs that sweep the mucus particles out. The length of the auditory tube goes up to about 31-38 mm.
The sound that enters the human ear through the outer ear section is transported to the section of the inner ear through the middle ear. It is a primary middle ear function. It is in the inner ear’s cochlea where the sound inputs are further provided to the brain. The sound waves that are funneled into the section of the outer ear tend to hit the tympanic membrane which results in the vibration of sound which is then carried through the ossicles.
The middle ear is an essential component of the human ear as it helps us listen to the sounds that are produced. The human ear helps in providing sound inputs to the brain and the middle ear acts as the transportation channel between the outer section and the inner section of the ear.
1. Describe the Medical Condition of Ruptured Eardrums?
There is another term used to describe this medical condition of the ruptured eardrum and it is known as tympanic membrane perforation. In this condition, the tympanic membrane is compromised or torn due to certain problems. The main cause for a ruptured eardrum is the loud noises that can happen due to explosions, gunshots. Injury is also a very common cause of having a ruptured eardrum. Some of the common symptoms that are seen in the case of a perforated tympanic membrane or the ruptured eardrum are tinnitus or a loss of hearing, pain in the ear, and ear drainage. If the perforation is small, then the healing process will be quick. But in case the damage is severe, surgical processes can help in the repairing process.
2. What Muscles Function in the Middle Ear?
In the middle ear, there are two primary muscles that tend to serve the function of protection for the structure. These muscles are known as the stapedius and the tensor tympani. These muscles happen to contract when there is a loud noise. As a response to that, the vibrations traveling the ossicles are inhibited. Hence, the effect of the sound transmission into the inner ear is pretty much reduced. This particular action is called an acoustic reflex. The muscle of the tensor tympani actually originates from the middle ear’s auditory tube and it attaches itself to the handle of the malleus. This muscle then pulls the malleus handle medially during the contracting process. The nerve supply of the muscle is provided by the tensor tympani nerve. The facial nerve is responsible for the innervation of the stapedius.