Skill Practice 2.1: Identify respiratory system organs and evaluate statements about breathing mechanisms.

Let's solve both questions step by step.

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Question 1: Identify the organs in the respiratory system (Drag and Drop)

We are given a diagram of the human respiratory system with labeled parts, and we need to match each label to the correct structure using the provided list:

List of Organs:
- Nasal cavity
- Bronchiole
- Nostril
- Rib
- Lung
- Larynx
- Pharynx
- Trachea
- Intercostal muscles
- Alveolus
- Bronchus
- Diaphragm

Now let’s identify each part based on the diagram:

#### Top Left (from top to bottom):
1. Nostril – The external opening of the nose.
2. Nasal cavity – The space inside the nose where air enters.
3. Pharynx – The throat area behind the nasal cavity and mouth.
4. Larynx – The voice box, below the pharynx.
5. Trachea – The windpipe connecting larynx to lungs.
6. Bronchus – Main branches from trachea into lungs.
7. Bronchiole – Smaller branches within the lungs.
8. Alveolus – Tiny air sacs in the lungs where gas exchange occurs.

#### Right Side (from top to bottom):
1. Lung – The large organ where gas exchange happens (left and right).
2. Rib – Bones forming the rib cage protecting the lungs.
3. Intercostal muscles – Muscles between the ribs that help breathing.
4. Diaphragm – The dome-shaped muscle below the lungs.

Now assign them correctly:

Left Side (from top to bottom):
1. Nostril
2. Nasal cavity
3. Pharynx
4. Larynx
5. Trachea
6. Bronchus
7. Bronchiole
8. Alveolus

Right Side (from top to bottom):
1. Lung
2. Rib
3. Intercostal muscles
4. Diaphragm

> ✔ Correct labels assigned based on anatomical positions.

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Question 2: Mark (√) for correct and (×) for incorrect statements about breathing mechanisms

Let’s evaluate each statement:

#### 1. The rib cage moves downwards and inwards during inhalation.
- ✘ Incorrect
During inhalation, the rib cage moves upwards and outwards due to contraction of intercostal muscles. This increases thoracic volume.
→ So, this statement is false → (x)

#### 2. Volume of the thoracic cavity increases during exhalation
- ✘ Incorrect
During exhalation, the thoracic cavity decreases in volume as the diaphragm relaxes and ribs move down and in.
→ So, this statement is false → (x)

#### 3. Diaphragm contracts and flattens during inhalation.
- ✔ Correct
During inhalation, the diaphragm contracts and moves downward (flattens), increasing the volume of the thoracic cavity and allowing air to enter.
→ So, this statement is true → (√)

#### 4. Air pressure inside the thoracic cavity increases during exhalation.
- ✔ Correct
During exhalation, the thoracic volume decreases, which causes increased pressure inside the thoracic cavity, pushing air out.
→ So, this statement is true → (√)

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✔ Final Answers:

#### Question 1: Labeling (from diagram)

Left Side (top to bottom):
1. Nostril
2. Nasal cavity
3. Pharynx
4. Larynx
5. Trachea
6. Bronchus
7. Bronchiole
8. Alveolus

Right Side (top to bottom):
1. Lung
2. Rib
3. Intercostal muscles
4. Diaphragm

#### Question 2: True/False

| Statement | Answer |
|--------|--------|
| 1. The rib cage moves downwards and inwards during inhalation. | (x) |
| 2. Volume of the thoracic cavity increases during exhalation | (x) |
| 3. Diaphragm contracts and flattens during inhalation. | (√) |
| 4. Air pressure inside the thoracic cavity increases during exhalation. | (√) |

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