Anatomically, the ear can be divided into three major sections called the outer ear, the middle ear and the inner ear. How many statements are correct for inner ear?
i. The organ of Corti is a structure located on the basilar membrane which contains hair cells that act as auditory receptors.
ii. A large number of processes called stereo cilia are projected from the apical part of each hair cells
iii. Above the rows of the hair cells is a thin elastic membrane called tectorial membrane
iv. The vestibular apparatus is composed of three semi-circular canals and the otolith organ consisting of the saccule and utricle.
v. Semi-circular canals contain a projecting ridge called macula
vi. The saccule and utricle contain a projecting ridge called cristae
vii. The cristae and macula responsible for maintenance of balance of the body and posture.

Options

A. Three
B. Four
C. Five
D. All of these

Answer

To determine how many statements are correct regarding the inner ear, we will evaluate each statement one by one.

### Step-by-Step Solution:

1. **Statement i**: "The organ of Corti is a structure located on the basilar membrane which contains hair cells that act as auditory receptors."
- **Evaluation**: This statement is correct. The organ of Corti is indeed located on the basilar membrane and contains hair cells that function as auditory receptors.

2. **Statement ii**: "A large number of processes called stereocilia are projected from the apical part of each hair cell."
- **Evaluation**: This statement is also correct. Each hair cell in the organ of Corti has stereocilia that project from its apical surface.

3. **Statement iii**: "Above the rows of the hair cells is a thin elastic membrane called tectorial membrane."
- **Evaluation**: This statement is correct. The tectorial membrane is situated above the hair cells in the organ of Corti.

4. **Statement iv**: "The vestibular apparatus is composed of three semi-circular canals and the otolith organ consisting of the saccule and utricle."
- **Evaluation**: This statement is correct. The vestibular apparatus includes three semi-circular canals and the otolith organs (saccule and utricle).

5. **Statement v**: "Semi-circular canals contain a projecting ridge called macula."
- **Evaluation**: This statement is incorrect. The semi-circular canals do not contain macula; they contain a structure called crista.

6. **Statement vi**: "The saccule and utricle contain a projecting ridge called cristae."
- **Evaluation**: This statement is incorrect. The saccule and utricle contain a structure called macula, not cristae.

7. **Statement vii**: "The cristae and macula are responsible for maintenance of balance of the body and posture."
- **Evaluation**: This statement is correct. Both the cristae (found in the semi-circular canals) and the macula (found in the saccule and utricle) play important roles in balance and posture.

### Summary of Correct Statements:
- Correct Statements: i, ii, iii, iv, and vii.
- Incorrect Statements: v and vi.

### Total Correct Statements:
There are **5 correct statements** regarding the inner ear.

### Final Answer:
**5 statements are correct for the inner ear.**

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