A gymnast is able to balance his body upside down even in the total darkness because of

Options

A. Organ of corti
B. Cochlea
C. Vestibular apparatus
D. Tectorial membrane

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks why a gymnast can balance his body upside down in total darkness. This implies that the answer relates to a sensory system that helps maintain balance, independent of visual cues.

2. **Identifying the Relevant Body System:**
The human body has various systems that contribute to balance, but the primary system responsible for maintaining balance is the vestibular system, which is located in the inner ear.

3. **Exploring the Structures of the Inner Ear:**
The inner ear contains several structures, but the key components involved in balance are:
- Semicircular canals
- Utricle (or sacculus)
- Saccule (or utricle)

4. **Function of the Vestibular Apparatus:**
The vestibular apparatus, which includes the semicircular canals and otolith organs (utricle and saccule), detects changes in head position and motion. It helps the gymnast maintain balance by providing information about the orientation of the head in space.

5. **Role of Hair Cells:**
Within the semicircular canals, there are specialized cells called hair cells that have hair-like projections (stereocilia and kinocilia). These hair cells respond to fluid movement within the canals when the head moves, sending signals to the brain about the body's position.

6. **Conclusion:**
Therefore, the gymnast is able to balance his body upside down in total darkness due to the functioning of the vestibular apparatus in the inner ear, which detects changes in position and motion.

**Final Answer:**
A gymnast is able to balance his body upside down even in total darkness because of the vestibular apparatus in the inner ear.

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