What is the function of the otolithic membrane?

What is the function of the otolithic membrane?

The otolithic membrane is a fibrous structure located in the vestibular system of the inner ear. It plays a critical role in the brain’s interpretation of equilibrium. The membrane serves to determine if the body or the head is tilted, in addition to the linear acceleration of the body.

What do utricle and Saccules detect?

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 the function of the Maculae?

Its function is to detect vertical linear acceleration. It is a 2 mm by 3mm patch of hair cells. Each hair cell of the macula contains 40 to 70 stereocilia and one true cilia, called a kinocilium. A gelatinous cover called the otolithic membrane envelops the tips of the stereocilia and kinocilium.

Which parts of the otolithic membrane in the utricle and saccule are affected the most by the pull of gravity or acceleration?

When the head is held erect, the macula in the utricles is oriented in the horizontal plane whereas the macula in the saccule is oriented vertically. Gravity pulls on the dense otoliths, which deform the gelatinous mass and subsequently press on the stereocilia and influence the firing rate of the hair cells.

What is otolith and macula?

Both of these organs contain a sensory epithelium, the macula, which consists of hair cells and associated supporting cells. The crystals give the otolith organs their name (otolith is Greek for “ear stones”).

How do otolith organs work?

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.

What are Cristae and maculae?

Crista is a ‘rotational’ sense organ. It’s found in the ‘ampullae’ of the inner ear’s semi-circular canals. The macula is a’sensory area’ in the saccule’s walls that is located in the saccule. The purpose of this sensor is to detect linear acceleration in a vertical plane.

Where specifically do you find the maculae What do they detect?

The macula of saccule lies in a nearly vertical position. Its function is to detect vertical linear acceleration. It is a 2 mm by 3mm patch of hair cells. Each hair cell of the macula contains 40 to 70 stereocilia and one true cilia, called a kinocilium.

What type of movement do the saccule and utricle respond to respectively?

They also are covered by a gelatinous cap in which are embedded small granular particles of calcium… … movements (angular acceleration); and the utricle and saccule within the vestibule, which respond to changes in the position of the head with respect to gravity (linear acceleration).

What is the name of the gelatinous glycoprotein layer when shifted pulls on hair cells to stimulate an action potential?

The numerous stereocilia and a single kinocilium project from the surface of the hair cells into a gelatinous matrix called the cupula; this projects into the endolymph.

Where can Maculae be found?

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.

What are graded membrane potentials and action potentials?

In excitable cells, the other possible states are graded membrane potentials (of variable amplitude), and action potentials, which are large, all-or-nothing rises in membrane potential that usually follow a fixed time course. Excitable cells include neurons, muscle cells, and some secretory cells in glands.

What is resting membrane potential?

Introduction The resting membrane potential is the result of the movement of several different ion species through various ion channels and transporters (uniporters, cotransporters, and pumps) in the plasma membrane. These movements result in different electrostatic charges across the cell membrane.

What is membrane potential (MV)?

Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. For the exterior of the cell, typical values of membrane potential, normally given in units of milli volts and denoted as mV, range from –40 mV to –80 mV.

What is the resting membrane potential at-70 mV?

[4] Since the ion with the greatest conductance across the membrane at rest is potassium, the potassium equilibrium potential is the major contributor to the resting membrane potential. However since some sodium and other ions leak out of the cell at rest, and so the resting membrane potential is a bit more positive at -70 mV.