The human body is a complex system. It is not in vain that medical universities devote much time to the study of anatomy. The design of the auditory system is one of the most difficult topics. Therefore, some students are lost when they hear on the exam the question "What is a tympanic cavity?". It will be interesting to learn about this for people who do not have a medical education. Let's look at this topic later in the article.
Middle ear anatomy
The human auditory system consists of several parts:
- outer ear;
- middle ear;
- inner ear.
Each plot has a special structure. So, the middle ear performs a sound-conducting function. It is located in the temporal bone. Includes three air cavities.
The nasopharynx and tympanic cavity are connected using the Eustachian tube. Behind - the airways of the mastoid process, including the largest - the mastoid cave.
The tympanic cavity of the middle ear has a parallelepiped shape and has six walls. This cavity is located in the thickness of the pyramid of the temporal bone. The upper wall is formed by a thin bone plate, its function is to separate from the skull, and the thickness reaches a maximum of 6 mm. On it you can find small cells. The plate separates the cavity of the middle ear from the dura mater and temporal lobe of the brain. At the bottom of the tympanic cavity is adjacent to the bulb of the jugular vein.
The middle part of the inner ear is formed by a bone labyrinth, inside of which there is a snail. Below - a stirrup, a malleus, an anvil and an eardrum. Across the tympanic cavity passes the channel of the facial nerve. The lateral walls of the tympanum consist of bone and membranous tissue.
An important part of the middle ear is the auditory tube. Its main function is to maintain optimal pressure. It connects the nasopharynx and the tympanic cavity. With each sip, a passage in the auditory tube opens.
Eardrum
A kind of role of the dividing septum between the outer and inner ear is played by the eardrum. This is a membrane consisting of three layers. Its first layer is formed by epithelial cells, the second by fibrous fibers, the third by the mucous membrane. It protects the structures of the middle ear from external influences.
In the middle, the eardrum is pulled inward in the form of a funnel. Its main function is the transmission of sound vibrations. An important feature of the auditory system allows not only to perceive sound, but also to determine its direction.
Accessory spaces
The drum cavity is adjacent to the cavity of the mastoid process. From it in different directions the air cells disperse. They reach the dura mater and cranial fossa. They also penetrate deep into the pyramid of the temporal bone.
Physiology of hearing
Initially, sound travels through the external auditory canal and enters the eardrum. Under its influence, it begins to fluctuate. It is the tympanic cavity that turns sound into a mechanical wave, and all thanks to the small bones: anvil, stapes and a hammer. It is with their help that sound is transmitted to the inner ear. Already there, in the cochlea, there are special receptors that turn mechanical waves into electric ones, allowing nerve cells to perceive information.
Inflammation of the tympanic cavity: features
Every mother is familiar with such a disease as otitis media, as it often affects young children. In the absence of timely treatment, this ailment can lead to a permanent decrease in hearing or its complete loss.
The drum cavity is reliably protected from external influences, and therefore the inflammatory processes in it are secondary. Bacteria come from neighboring spaces. And most often this happens due to hypothermia, decreased immunity, infection of the nose and poor nutrition.
The main symptom of otitis media is acute pain in the ear. Secondarily, migraine, fever, etc. may occur. But to establish an accurate diagnosis, a full-time consultation with a doctor is required.
Particular inflammations of the tympanic cavity include eustachitis. This disease affects the auditory tube, where bacteria most often enter from the oral cavity, since at one end the tube opens next to the tonsils. Therefore, for example, sinusitis and rhinitis can become causes of diseases of the hearing organs.
The drum cavity may also be affected due to inflammation in the mastoid cave. Such a disease is called mastoiditis. Most often, the infection enters this area from the lymphatic or circulatory system, as the vessels pass densely in this place. Inflammation often occurs against a sluggish infection such as pyelonephritis. At the same time, bacteria spread with blood flow and affect the mastoid cells.
The drum cavity is part of the middle ear, including important bones: stirrup, hammer, and anvil. An important function of this area is the conversion of a sound wave into a mechanical one and its delivery to recipes inside the cochlea. Therefore, inflammatory processes in this place threaten a temporary or permanent hearing loss.