Question

The given diagram is of the membranous labyrinth found in the inner ear. Study the diagram and answer the questions that follow:

1. Name the sensory cells that help in hearing.
2. The part that is responsible for the static balance of the body.
3. The membrane-covered opening connects the middle ear to the inner ear.
4. The fluid is present in the middle chamber of the cochlea.
5. The structure maintains the dynamic equilibrium of the body.

Answer 1

1. Sensory cells that help in hearing:

1. The coiled portion of the membranous labyrinth is called the cochlea.
2. A structure called the organ of Corti is found on the basilar membrane of the cochlea. The hair cells present in it act as auditory receptors.
3. Hair cells are the sensory cells that help in hearing.

2. Static balance of the body:

1. The inner ear comprises a complex system called the vestibular apparatus. This apparatus has three semi-circular canals and two otolith organs called saccule and utricle.
2. Saccule and utricle are responsible for maintaining the static balance of the body.

3. The membrane-covered opening that connects the middle ear to the inner ear:

1. The middle ear contains three ossicles- malleus, incus, and stapes. Among these, stapes are attached to the oval window of the cochlea.
2. The oval window is a membrane-covered opening that connects the middle ear to the inner ear.

4. The fluid present in the middle chamber of the cochlea

1. The fluid present in the middle chamber of the cochlea is called endolymph.
2. The endolymph helps in the transmission of sound waves to the hair cells.

5. Dynamic equilibrium of the body:

1. The maintenance of balance and the position of the head during rotational movements like turning is called dynamic equilibrium.
2. The vestibular apparatus of the inner ear contains three semi-circular canals.
3. The base of the canals is known as the ampulla, which comprises a projecting ridge called crista ampullaris.
4. Crista ampullaris maintains the dynamic equilibrium of the body.