The ear is comprised of the…. There are three bones located in the middle ear: the incus, the malleus and the stapes. Collectively, all three bones comprise the ossicles. The malleus is the outermost and largest of the three small bones in the middle ear, and reaches an average length of about eight millimeters in the….
The human ear consists of three regions called the outer ear, middle ear, and inner ear. The oval window, also known as the fenestra ovalis, is a…. The auricularis anterior muscle is located between the ear and the eye. It is in an area with few other points of insertion or origination, which is…. The posterior auricular vein is the name for a vein that is formed via the collection of several venous tributaries situated behind the ear.
The jejunum is one of three sections that make up the small intestine. Learn about its function and anatomy, as well as the conditions that can affect…. The vagus nerve is the longest of the 12 cranial nerves. Here, learn about its anatomy, functions, and the kinds of health problems that can occur. The main function of stapes is to amplify the sound vibrations which plays an important role in setting the fluids of the inner ear in motion.
This induces the neural electrical signals in auditory nerve fibres so that the information about the frequency component of the sound is coded and sent to the brain.
Once the Pinna or Auricle directs the sound waves to the auditory canal, eardrum which is sensitive enough to detect even the faintest sound replicates the sound vibrations and results in the vibration of Malleus too. The mechanical vibration gets transferred from eardrum to malleus and then to anvil. Stapes or Stirrup being the smallest bone amplifies the vibration transmitted by Anvil. Due to the amplification of this vibration, the fluid present in the cochlea starts vibrating like a wave, stimulating the small hair cells present in the cochlea.
Each hair cell is associated with a particular frequency. When the vibration passes through the hair cells, it makes the hair cells detect the frequency of the vibration and changes the mechanical vibration to electrical signals which are carried to the brain through the auditory nerve. The brain recognises the sound and identifies its source. This is how the pressure wave of the sound is converted to neural electrical signals and enable us to hear all the audible sound produced by different sources.
We know that the sound vibration received by Malleus from the eardrum needs to be amplified so it is important for the last bone of the ear ossicles i,e stapes to be the smallest in size. Smaller the bone more is the amplification of sound. Stapes acts a lever with a mechanical advantage that is used to transfer a large force here, sound signal over a small distance by applying a smaller force.
The force reaching the ear is said to be smaller because the sound produced by the source is usually from far and is feeble. Thus, the small size of the stapes enables the ear to generate the large force from small incoming force to aid in hearing.
Over the course of a day, the cartilage, particularly in your spine, is compressed by gravity. This means that you are shorter by the time you go to bed. Thankfully, after a period of lying horizontally, the cartilage is able to return to its original size. Scientists have shown that on impact when running, the tibia shin bone temporarily shortens by a millimetre. The one exception is the hyoid bone.
The U-shaped hyoid bone sits at the base of the tongue and is held in place by muscles and ligaments from the base of the skull and jaw bones above. This bone enables humans and our Neanderthal ancestors to talk , breathe and swallow. It is very rare to break the hyoid bone , and a finding of fracture in a post-mortem examination may indicate strangulation or hanging. Long bones, such as the thighbone, are filled with bone marrow made of fat cells, blood cells and immune cells. In children, the bone marrow is red reflecting its role in making blood cells.
It was long thought that bone marrow fat cells were nothing more than a space filler, but scientists are increasingly learning how the fat inside bones has important metabolic and endocrine functions , affecting the whole human body. The smallest bones in the human body are the malleus hammer , incus anvil and the stapes stirrup. Not only are these the smallest bones in the body, but they are also the only bones that do not remodel after the age of one.
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