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What is the eardrum in anatomy?

In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear.

What are the two structures that vibrate inside the ear?

The tympanic membrane (eardrum) and auditory ossicles vibrating inside a human ear. Encyclopædia Britannica, Inc. See all videos for this article The thin semitransparent tympanic membrane, or eardrum, which forms the boundary between the outer ear and the middle ear, is stretched obliquely across the end of the external canal.

What is the structure of the middle ear?

The middle ear itself (the tympanum) lies deep to the eardrum and is an air-filled space that holds three small bones (ossicles), which connect the eardrum to the inner ear. These bones are called the hammer (malleus), anvil (incus) and stirrup (stapes) because of their resemblance to these objects.

What are the structures of the outer ear and auditory tube?

Overview of the structures of the outer ear and auditory tube. The outer ear consists of the auricle, which is a cartilaginous structure that is covered with skin and which is lightly vascularized.

What structure is the eardrum?

tympanic membrane, also called eardrum, thin layer of tissue in the human ear that receives sound vibrations from the outer air and transmits them to the auditory ossicles, which are tiny bones in the tympanic (middle-ear) cavity.

What is the structure and function of the eardrum?

The eardrum is a thin flap of skin that is stretched tight like a drum and vibrates when sound hits it. These vibrations move the tiny bones of the middle ear, which send vibrations to the inner ear. From the inner ear, the message is sent to the brain, which says, “Hey!

What is the functional unit of the ear?

The inner ear consists of two functional units: the vestibular apparatus, consisting of the vestibule and semicircular canals, which contains the sensory organs of postural equilibrium; and the snail-shell-like cochlea, which contains the sensory organ of hearing.

How is eardrum adapted to its function?

(e) The mammalian ear has an eardrum which is stretched accors the inner end of external auditory canal to increase surface area for sound reception, the eardrum is thin and membranous hence has the ability to vibrate when it is struck by sound waves by converting them to vibration and then transmitting them to the ear …

How is the structure of the ear similar to the eye?

Just as the curved cornea of the eye angles light onto the pupil, so too the ear cartilage and ear canal concentrate sound onto the eardrum. In the eye, further focus is achieved by the lens, which concentrates light-rays onto the photosensitive retina lining the back of the eye.

Where is the eardrum located quizlet?

commonly called the eardrum. it is the paper thin connective tissue membrane that’s tightly stretched across the opening between the external auditory canal and the middle ear canal.

Where is your eardrum?

At the end of the ear canal is the ear drum. The ear drum is a thin membrane which separates the ear canal from the middle ear. The ear drum is fixed to part of the first hearing bone which is called the malleus. The ear canal and the ear drum are covered with skin just like the skin on the outside of the body.

What is the function of the ear auricle quizlet?

AURICLE/PINNA FUNCTION HELPS TO COLLECT SOUNDWAVES NEAR THE OPENING OF THE EAR; DIRECTS (RATHER POORLY) SOUNDWAVES INTO THE EXTERNAL AUDITORY CANAL.

What are the structures of the ear?

The parts of the ear include:External or outer ear, consisting of: Pinna or auricle. This is the outside part of the ear. … Tympanic membrane (eardrum). The tympanic membrane divides the external ear from the middle ear.Middle ear (tympanic cavity), consisting of: Ossicles. … Inner ear, consisting of: Cochlea.

Can you hear without an eardrum?

Can you hear without an intact eardrum? A. “When the eardrum is not intact, there is usually some degree of hearing loss until it heals,” said Dr.

How is cochlea adapted to its function?

Cochlear adaptation is postulated to arise in the haircell-first auditory neuron junction due to steady-state reactions between transmitter quanta and receptor sites, thus forming transmitter-receptor complexes which are destroyed enzymatically.

Is the eardrum a muscle?

The tensor tympani is a muscle within the middle ear, located in the bony canal above the bony part of the auditory tube, and connects to the malleus bone….Tensor tympani muscleArterySuperior tympanic arteryNerveMedial pterygoid nerve from the mandibular nerve (V3)ActionsTensing the tympanic membraneIdentifiers10 more rows

What is the structure of the eardrum Brainly?

The tympanic membrane, also called the eardrum (or just the drum), is a stiff (but flexible), translucent, diaphragmlike structure. The eardrum moves synchronously in response to variations in air pressures, which constitute sound waves. The drum’s vibrations are transmitted through the ossicular chain to the cochlea.

What is the purpose of the eardrum quizlet?

Function of the eardrum is to carry sound waves to bones that are located in the middle ear. These bones are called ossicles.

What are the structures of the inner ear?

The inner ear has 3 main parts:Cochlea. The cochlea is the auditory area of the inner ear that changes sound waves into nerve signals.Semicircular canals. The semicircular canals sense balance and posture to assist in equilibrium.Vestibule.

What are the major structures of the ear?

The parts of the ear include:External or outer ear, consisting of: Pinna or auricle. This is the outside part of the ear. … Tympanic membrane (eardrum). The tympanic membrane divides the external ear from the middle ear.Middle ear (tympanic cavity), consisting of: Ossicles. … Inner ear, consisting of: Cochlea.

What is the shape of the eardrum?

Conical shape. The mammalian eardrum is approximately conical, with the apex pointing medially. {Fumagalli (1949)} found that the eardrum shapes of all of the nine species he observed could be represented approximately by a cone with an apex angle of 120o, cut at various angles by the plane of the tympanic ring.

What is the eardrum made of?

The typical mammalian eardrum consists basically of a very thin sheet of connective tissue (pars tensa). The annular ligament firmly anchors it to bone around most of its circumference, and the manubrium of the malleus is tightly coupled to it. The outline of the pars tensa varies in different species from more or less circular to a somewhat elongated ellipse. The manubrium may be placed symmetrically, or it may be somewhat closer to the anterosuperior edge of the pars tensa. The significance of these variations is unclear.

What are the factors that affect the operation of the middle ear?

The operation of the middle ear is affected by a number of factors (such as external ear-canal shape, eardrum curvature, the mode of vibration of the eardrum, the nature of the ossicular suspension and muscles, and the ossicular load) about which little or nothing is known in most species.

Why did Békésy and Kirikae’s experiments not detect eardrum tension?

The fact that Békésy’s and Kirikae’s experiments were done on cadaver ears obviously means that they could not detect any component of eardrum tension due to tonus in the tensor tympani. Also, any tension maintained passively by the ossicular ligaments might be sensitive to post-mortem tissue changes.

How does the size of the eardrum vary?

The size of the eardrum tends to vary less from species to species than does overall body size . {Khanna & Tonndorf (1969)} demonstrated that a linear dimension of the eardrum (square root of the area) is approximately proportional to the square root of a linear dimension of the whole body (i.e., of the cube root of weight) among seven diverse mammalian species. Hunt & Korth (1980)} calculated a regression line with a slope of 0.26 relating the logarithm of eardrum area to the logarithm of body weight among 40 mammalian species; this corresponds to an exponent of about 0.4 when comparing linear dimensions, close to the value of 0.5 of Khanna & Tonndorf. The size of the rest of the middle ear is generally comparable to that of the eardrum. {Webster & Webster (1975)}, for example, have shown that among one group of rodents a linear dimension of the eardrum is approximately proportional to a linear dimension (cube root of the volume) of the middle-ear cavity. In fact, the values for the cat and guinea pig fall quite close to the same straight line.

Where are the eardrums not directly inserted?

As noted above, the fibres of the eardrum are not directly inserted into the middle third of the manubrium, at least in the human. {Tonndorf & Khanna (1972)} noted that the drum and manubrium did not seem to be so tightly coupled in this region, although the effect was quite small.

How thick is the eardrum?

{Kojo (1954)} measured the thickness at seven locations on each of seven human eardrums: the total range was from 30 to 120 um, with the average values for the seven locations ranging from 55 to 90 um, the smallest values being in between the periphery and the manubrium. By comparison, {Lim (1970)} reported that the human eardrum varies in thickness from 30 to 90 um. The cat drum is 30 to 50 um thick, and the guinea-pig drum is about 10 um thick ({Lim, 1968a)}. More detailed measurements are required on variations of over-all thickness across the surface of the drum, and also on the thicknesses of the constituent layers discussed below.

What is the eardrum called?

v. t. e. In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear.

What is the eardrum?

The eardrum is divided into two general regions: the pars flaccida and the pars tensa. The relatively fragile pars flaccida lies above the lateral process of the malleus between the notch of Rivinus and the anterior and posterior malleal folds. Consisting of two layers and appearing slightly pinkish in hue, it is associated with Eustachian tube dysfunction and cholesteatomas.

What bone bridges the gap between the eardrum and the other ossicles?

The malleus bone bridges the gap between the eardrum and the other ossicles. Rupture or perforation of the eardrum can lead to conductive hearing loss. Collapse or retraction of the eardrum can cause conductive hearing loss or cholesteatoma .

How to treat a ruptured eardrum?

The pressure of fluid in an infected middle ear onto the eardrum may cause it to rupture. Usually, this consists of a small hole (perforation), which allows fluid to drain out. If this does not occur naturally, a myringotomy (tympanotomy, tympanostomy) can be performed. A myringotomy is a surgical procedure in which a tiny incision is created in the eardrum to relieve pressure caused by excessive buildup of fluid, or to drain pus from the middle ear. The fluid or pus comes from a middle ear infection ( otitis media ), which is a common problem in children. A tympanostomy tube is inserted into the eardrum to keep the middle ear aerated for a prolonged time and to prevent reaccumulation of fluid. Without the insertion of a tube, the incision usually heals spontaneously in two to three weeks. Depending on the type, the tube is either naturally extruded in 6 to 12 months or removed during a minor procedure.

What is the manubrium of the malleus?

The manubrium ( Latin: handle) of the malleus is firmly attached to the medial surface of the membrane as far as its center, drawing it toward the tympanic cavity. The lateral surface of the membrane is thus concave. The most depressed aspect of this concavity is termed the umbo ( Latin: shield boss ).

Why do children have tympanostomy tubes?

The fluid or pus comes from a middle ear infection ( otitis media ), which is a common problem in children. A tympanostomy tube is inserted into the eardrum to keep the middle ear aerated for a prolonged time and to prevent reaccumulation of fluid.

What are the layers of the pars tensa?

The larger pars tensa consists of three layers: skin, fibrous tissue, and mucosa. Its thick periphery forms a fibrocartilaginous ring called the annulus tympanicus or Gerlach’s ligament. while the central umbo tents inward at the level of the tip of malleus.

What are the structures of the middle ear?

structures of the middle ear. The auditory ossicles of the middle ear and the structures surrounding them. Encyclopædia Britannica, Inc. The malleus consists of a handle and a head. The handle is firmly attached to the tympanic membrane from the centre (umbo) to the upper margin.

What is the outer wall of the middle ear?

The outer (lateral) wall of the middle-ear space is formed by the tympanic membrane. The ceiling (superior wall) is a thin plate of bone that separates the middle-ear cavity from the cranial cavity and brain above. The floor (inferior wall) is also a thin bony plate, in this case separating the middle-ear cavity from the jugular vein and …

What is the inner layer of the mucous membrane?

The inner layer of mucous membrane is continuous with the lining of the tympanic cavity of the middle ear. Between these layers is a layer of fibrous tissue made up of circular and radial fibres that give the membrane its stiffness and tension. The membrane is well supplied with blood vessels and sensory nerve fibres that make it acutely sensitive …

What is the tympanic membrane?

The tympanic membrane (eardrum) and auditory ossicles vibrating inside a human ear. Encyclopædia Britannica, Inc. See all videos for this article. The thin semitransparent tympanic membrane, or eardrum, which forms the boundary between the outer ear and the middle ear, is stretched obliquely across the end of the external canal.

Why is the eustachian tube closed?

The tube is closed at rest and opens during swallowing so that minor pressure differences are adjusted without conscious effort.

What is the back of the ear?

The back (posterior) wall partly separates the middle-ear cavity from another cavity, the mastoid antrum, but an opening in this wall leads to the antrum and to the small air cells of the mastoid process, which is the roughened, slightly bulging portion of the temporal bone just behind the external auditory canal and the auricle.

What is the middle ear space?

The middle-ear space roughly resembles a rectangular room with four walls, a floor, and a ceiling.

What are the components of the ear?

However in terms of function, the ear has four components, the three stated above and the brain. It is a thin, circular, tough and flexible layer of tissue which separates the middle and external ear. The tympanic membrane is composed of three layers of tissue (outer cutaneous layer, fibrous middle layer, mucous membrane layer).

Which part of the ossicular chain transmits vibrations to the inner ear?

It is a small bone which receives vibrations from the tympanic membrane and transmits the vibrations to the inner ear – through the other two parts of the ossicular chain (incus & stapes). Incus (anvil) The ‘incus’, is the second section of the middle ear ossicular chain. It is also (like the maleus) a small bone.

Which part of the ear is responsible for hearing?

The middle ear communicates with the pharynx, equilibrates with external pressure, and transmits the eardrum vibrations to the inner ear. Inner ear. The inner, liquid-filled, membranous portion of the ear, involved in hearing and balance. Oval window.

Which part of the ossicular chain receives vibrations from the tympanic membrane?

The ‘maleus’ is the first section of the middle ear ossicular chain. It is a small bone which receives vibrations from the tympanic membrane and transmits the vibrations to the inner ear – through the other two parts of the ossicular chain (incus & stapes).

Which organ of the ear produces nerve impulses in response to sound vibrations?

Organ of corti . A structure in the cochlea of the inner ear which produces nerve impulses in response to sound vibrations. Basilar membrane. A supporting membrane, especially the membrane that supports the organ of Corti in the ear and aids in translating sound vibrations into electrical signals. Upgrade to remove ads.

What is the outer ear?

Outer ear. The part of the ear that is visible along the side of the head. The outer ear consists of the pinna, or auricle (the visible projecting portion of the ear), the external acoustic meatus (the outside opening to the ear canal), and the external ear canal, which leads to the eardrum. Middle ear.

What is the function of the Eustachian tube?

Eustachian tube. The tube which runs from the middle ear to the pharynx. It’ function is to areate, protect and drain the middle ear and mastoid. It also allows air pressure in the middle ear cavity to adjust to the external air pressure thus equalizing the air pressure.

Which structure vibrates sound from the tympanic membrane to the inner ear?

air-filled cavity within the temporal bone; structures of the ear that vibrate sound from the tympanic membrane to the inner ear

What part of the ear contains the saccule?

middle part of the inner ear, in front of the semicircular canals and behind the cochlea, that contains the utricle and the saccule; functions to provide body balance and equilibrium

What is the first of the three auditory ossicles of the middle ear?

hammer; first of the three auditory ossicles of the middle ear

What is the eardrum?

At the far end of the ear canal and stretched across it is the eardrum (tympanic membrane), which forms the boundary between the outer and middle ears.

What is the structure of the ear?

The Structure of the ear. The human ear is one of the more remarkable parts of the human body, not only because of the beauty and unlikelihood of its structure, but also because of its remarkable sensitivity to sounds. From an anatomical point of view, the ear is conventionally and conven­iently divided into three parts: the outer, …

How are hair cells arranged?

These hair cells are arranged in two groups that follow the coils of the cochlear duct and spiral upwards from base to apex. There is a single row of inner hair cells (IHCs), which lie closer to the core of the cochlea (modiolus), and three or four rows of outer hair cells (OHCs), which are further away.

How are hammer and anvil supported?

The hammer and anvil are supported in the middle ear by several membranes and ligaments, which minimise their weight, allow them to move easily and bring them a blood supply. Unfortunately, this leaves only a small space for the passage of air from the middle ear to the attic.

What is the outer ear made of?

THE OUTER EAR. The outer ear comprises the pinna (auricle), which is made of a convoluted plate of flexible cartilage that extends as a nearly closed tube one-third of the way down the ear canal.

Why does the middle ear not work?

Unfortunately, in humans, the mechanism is rather fragile and often fails to work adequately, possibly because of the shape of the skull that is needed to accommodate the large brain. There is also an extension of the air-filled spaces of the middle ear backwards into the mastoid bone.

How many layers does the eardrum have?

Despite its name, it is not flat like the skin of a drum, but is slightly conical with the curved sides sloping inwards. The eardrum has three layers.

What is the external ear?

External ear. The external ear, like the middle ear, serves only to conduct sound to the inner ear. It consists of the auricle and external acoustic meatus (or ear canal). Key facts about the external ear. Parts. Auricle, external acoustic meatus. Blood supply.

What are the parts of the middle ear?

Middle ear. Parts: tympanic cavity, auditory ossicles, muscles of the ossicles. Function: transforming a high-amplitude low-force sound wave into a low-amplitude high-force vibration and transmitting it to the internal ear. Internal ear.

Why do you pull the helix of the auricle posterosuperiorly?

This procedure provides an examination of the external ear and the tympanic membrane. Because of the natural curvature of the external acoustic meatus, the physician needs to pull the helix of the auricle posterosuperiorly, in order to align the meatus in a straight direction.

What nerve is at the bottom of the ear canal?

Function. Conducts sound to the inner ear. At the bottom of the ear canal is the tympanic membrane which establishes the border between the external and middle ear.

Where is the tympanic membrane located?

The tympanic membrane, or simply the eardrum, is found at the bottom of the bony external acoustic meatus and it is the border between the external and middle ear. It is attached with a fibrocartilaginous ring to the tympanic part of the temporal bone.

What is the function of the smallest bones?

Their main function is to transmit sounds to the internal ear, precisely to the labyrinth within the internal ear. They articulate with each other with synovial joints, and transmit vibrations by being moved by the muscles of the middle ear. In order from the tympanic membrane to the internal ear (lateral to medial), these bones are:

What is the auricle?

Auricle. The auricle, also known as pinna, is a wrinkly musculocutaneous tissue that is attached to the skull and it functions to capture sound. The auricle is mostly made up of cartilage that is covered with skin. There are two aspects of the auricle: and medial (inner) and lateral (outer).

Principle of Operation

• The eardrum serves so that the acoustic wave captured by the auricle can reach the organs of sound perception, which are located deep in the temporal bone. Under the influence of sound, the eardrum vibrates in the ear, but the human brain is able to perceive only weak electrical impulse…

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Causes and Prevention of Rupture

Tympanic Membrane Treatment

Introduction

• The eardrum has three layers: the outer layer, inner layer, and middle layer. The middle layer is made of fibers that give the eardrum elasticity and stiffness. Cartilageholds the eardrum in place. The eardrum covers the end of the external ear canal and looks like a flattened cone with its tip pointed inward toward the middle ear. It is transparen…

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Structure of The Eardrum

Mechanical Properties of The Eardrum

Properties of Structures Surrounding The Eardrum

Experimental Observations of Eardrum Vibrations

• 2.1 Gross Anatomy
  Tympanic ring and manubrium. The comparative gross anatomy of the middle ear has been described by a great many authors. {Fumagalli (1949)} and {Fleischer (1973)} have published particularly extensive accounts. The typical mammalian eardrum consists basically of a very thi…
• 2.2 Microscopic Structure
  Introduction. The pars tensa is composed of three layers: an outer epidermal layer; the lamina propria, consisting of two connective-tissue layers and a fibrous layer; and an inner mucosal layer. The pars flaccida is much the same as the pars tensa except that it lacks the highly organized la…

See more on audilab.bmed.mcgill.ca

Discussion

Acknowledgements

Overview

Structure

Clinical significance

Society and culture

In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit sound from the air to the ossicles inside the middle ear, and then to the oval window in the fluid-filled cochlea. Hence, it ultimately converts and amplifies vibration in air to vibration in cochlear fluid. The malleus bone bridges the gap between the eardr…

See also

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