Air is breathed through

Options

A. Trachea - lungs - larynx - pharynx - alveoli
B. Nose - larynx - pharynx - bronchus - alveoli - bronchioles
C. Nostrils - pharynx - larynx - trachea - bronchi - bronchioles - alveoli
D. Nose - mouth - lungs

Answer

To solve the question "Air is breathed through," we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Entry Point**: The first point of entry for air is through the **nose** (or nostrils). This is where air enters the respiratory system.

2. **Passage to Pharynx**: After entering through the nose, the air moves into the **pharynx**. The pharynx serves as a passageway for air.

3. **Movement to Larynx**: From the pharynx, the air then travels to the **larynx**. The larynx is also known as the voice box and plays a role in sound production.

4. **Trachea**: Next, the air passes into the **trachea** (windpipe), which is a tube that connects the larynx to the bronchi.

5. **Bronchi**: The trachea divides into two primary bronchi (right and left), leading the air into the **bronchi**.

6. **Bronchioles**: The primary bronchi further divide into **secondary bronchi** and then into **tertiary bronchi**, eventually leading to smaller branches known as **bronchioles**.

7. **Alveoli**: Finally, the air reaches the **alveoli**, which are tiny air sacs where gas exchange occurs. This is where oxygen is absorbed into the blood, and carbon dioxide is released.

### Conclusion:
The correct sequence of air passage is: **Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli**.

Thus, the answer to the question "Air is breathed through" is primarily through the **nose**.