What is otolith and macula?

The macula in the utricle and saccule contains an array of hair cells whose stereocilia project into the otolithic membrane, a gelatinous mass that contains tiny crystals of calcium carbonate, called otoliths (literally, “ear stones”).

What is the otolith?

The otoliths (statoconia) are small calcium carbonate crystals which put pressure on the cilia, inclining them, thereby stimulating the sensory hair cells.

What is otolith in human ear?

An otolith (Greek: ὠτο-, ōto- ear + λῐ́θος, líthos, a stone), also called statoconium or otoconium or statolith, is a calcium carbonate structure in the saccule or utricle of the inner ear, specifically in the vestibular system of vertebrates. The saccule and utricle, in turn, together make the otolith organs.

What are otoliths What is its function?

Function: The otolith organs sense gravity and linear acceleration such as from due to initiation of movement in a straight line. Persons or animals without otolith organs or defective otoliths have poorer abilities to sense motion as well as orientation to gravity.

Does the macula contain otoliths?

The macula is composed of the otolithic membrane and macular epithelium. The otolithic membrane consists of a gelatinous membrane and some otoliths. The macular epithelium comprises sensory hair cells and supporting cells.

Anatomy | Physiology of the Utricle

Where is the macula?

The macula is part of the retina at the back of the eye. It is only about 5mm across, but is responsible for our central vision, most of our colour vision and the fine detail of what we see. The macula has a very high concentration of photoreceptor cells – the cells that detect light.

Where are otoliths found?

The otoliths (ear-stones) are small structures in the inner ear used to register gravity and linear acceleration. Quail otoconia from Dickman et al (2004). Most creatures have otoconia.

Are otoliths bones?

Ear Stones

Photo: Sandy Sutherland, NOAA Fisheries. The otolith (ear stone or ear bone) is the most commonly used structure for determining the age of fish. Otoliths are calcium carbonate structures found inside the heads of bony fish; sharks and rays lack otoliths.

What are the two otolith organs?

Displacements and linear accelerations of the head, such as those induced by tilting or translational movements (see Box A), are detected by the two otolith organs: the sacculus and the utricle. Both of these organs contain a sensory epithelium, the macula, which consists of hair cells and associated supporting cells.

Why are otoliths important for humans?

The otoliths may be important in spatial cognition because of their evolutionary age as a sensory detector of orientation and the fact that velocity storage is important to the way that the brain encodes its place in space.

What are ear stones called?

Ear rocks are small crystals of calcium carbonate called otoconia, which collect in the inner ear.

Is otolith a mineral?

Otoliths are bioinorganic minerals within the inner ear of all bony fishes. They grow incrementally, laying down alternating protein-rich and mineral-rich bands daily.

Where is the cochlear?

Location. The cochlea is one of two main structures that make up the inner ear. The inner ear is located behind the eardrum and next to the middle ear. The other structures are called the semicircular canals which are responsible for balance while the cochlea is involved in hearing.

What is saccule and utricle?

The utricle and saccule are the two otolith organs in the vertebrate inner ear. They are part of the balancing system (membranous labyrinth) in the vestibule of the bony labyrinth (small oval chamber). They use small stones and a viscous fluid to stimulate hair cells to detect motion and orientation.

What is a Endolymph?

Endolymph, also known as Scarpa fluid, is a clear fluid that can found in the membranous labyrinth of the inner ear. It is unique in composition compared to other extracellular fluids in the body due to its high potassium ion concentration (140 mEq/L) and low sodium ion concentration (15 mEq/L).

What are semicircular ducts?

Your semicircular canals are three tiny, fluid-filled tubes in your inner ear that help you keep your balance. When your head moves around, the liquid inside the semicircular canals sloshes around and moves the tiny hairs that line each canal.

What is vestibule of ear?

The vestibule is the central part of the bony labyrinth in the inner ear, and is situated medial to the eardrum (tympanic membrane), behind the cochlea, and in front of the three semicircular canals.

What is fovea and macula?

The fovea centralis, or fovea, is a small depression within the neurosensory retina where visual acuity is the highest. The fovea itself is the central portion of the macula, which is responsible for central vision.[1][2][3][4]

Why is the macula important?

The macula provides us with the ability to read and see in great detail whereas the rest of the retina provides peripheral vision. Of all the different parts of the eye, the macula is where the most important images are created before being sent along the optic nerve to the brain, where vision is completed.

Is retina and macula the same?

The retina is a layer of tissue in the back of your eye that senses light and sends images to your brain. In the center of this nerve tissue is the macula. It provides the sharp, central vision needed for reading, driving and seeing fine detail.

What is the main nerve of hearing?

Each nerve has distinct nuclei within the brainstem. The vestibular nerve is primarily responsible for maintaining body balance and eye movements, while the cochlear nerve is responsible for hearing.

What are the 3 parts of the inner ear?

What is the nerve in the ear called?

vestibulocochlear nerve, also called Auditory Nerve, Acoustic Nerve, or Eighth Cranial Nerve, nerve in the human ear, serving the organs of equilibrium and of hearing.

Does macula have hair cells?

The macula in the utricle and saccule contains an array of hair cells whose stereocilia project into the otolithic membrane, a gelatinous mass that contains tiny crystals of calcium carbonate, called otoliths (literally, “ear stones”).