Respiratory System Worksheet Fill-In | PDF - Free Printable

Problem Overview:

The task involves matching respiratory system vocabulary terms to their definitions and filling in blanks related to the process of respiration. The provided word bank includes:

- lungs
- diaphragm
- nasal passages
- trachea
- bronchi
- alveoli

Step-by-Step Solution:

#### Matching Definitions:
1. These little sacs are where carbon dioxide leaves the blood and oxygen enters it.
- Answer: alveoli
- Explanation: Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen diffuses into the bloodstream, and carbon dioxide diffuses out.

2. This large muscle helps you fill and empty your lungs.
- Answer: diaphragm
- Explanation: The diaphragm is a dome-shaped muscle located below the lungs. It contracts to expand the chest cavity, allowing air to enter the lungs (inhalation), and relaxes to push air out (exhalation).

3. You inhale air through these about 20 times a minute.
- Answer: nasal passages
- Explanation: Air enters the body through the nasal passages, which filter, warm, and humidify the air before it reaches the lungs.

4. Two large, and very important, organs inside your chest cavity.
- Answer: lungs
- Explanation: The lungs are the primary organs of the respiratory system, responsible for gas exchange.

5. This tube that carries air to the lungs.
- Answer: trachea
- Explanation: The trachea, also known as the windpipe, is a tube that connects the larynx (voice box) to the bronchi, carrying air to and from the lungs.

6. The tubes inside the lungs that lead to the alveoli.
- Answer: bronchi
- Explanation: Bronchi are the main airways that branch off from the trachea into each lung. They further divide into smaller bronchioles, which eventually lead to the alveoli.

#### Filling in the Blanks:
The passage describes the process of respiration. Let's fill in the blanks step by step:

Respiration begins in the ________, where air comes into the body.
- Answer: nasal passages
- Explanation: Air enters the body through the nasal passages.

Air travels through the ________ to the ________.
- Answer: trachea, lungs
- Explanation: After entering through the nasal passages, air travels down the trachea and into the lungs.

The ________ pushes up and down to fill and empty the lungs.
- Answer: diaphragm
- Explanation: The diaphragm's contraction and relaxation control the movement of air in and out of the lungs.

Inside the lungs, air in the ________ travels to the small sacs called ________.
- Answer: bronchi, alveoli
- Explanation: Inside the lungs, air travels through the bronchi and bronchioles to reach the alveoli, where gas exchange occurs.

Final Answer:

#### Matching Definitions:
1. alveoli
2. diaphragm
3. nasal passages
4. lungs
5. trachea
6. bronchi

#### Filling in the Blanks:
Respiration begins in the nasal passages, where air comes into the body.
Air travels through the trachea to the lungs.
The diaphragm pushes up and down to fill and empty the lungs.
Inside the lungs, air in the bronchi travels to the small sacs called alveoli.
Inside those small sacs is where the important gas exchange occurs.

Final Answer:
\boxed{
\text{1. alveoli, 2. diaphragm, 3. nasal passages, 4. lungs, 5. trachea, 6. bronchi, nasal passages, trachea, lungs, diaphragm, bronchi, alveoli}
}