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Question 1:

Which of the following is the correct order of structures involved in the process of respiration?

A) Lungs, trachea, bronchi, alveoli
B) Trachea, bronchi, lungs, alveoli
C) Trachea, bronchi, alveoli, lungs
D) Alveoli, bronchi, trachea, lungs

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Explanation: The correct answer is B) Trachea, bronchi, lungs, alveoli. The process of respiration begins with the trachea (windpipe), which branches into the bronchi, leading to the lungs. Within the lungs, oxygen is exchanged with carbon dioxide in the tiny air sacs called alveoli.

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Question 2:

What is the role of cilia in the respiratory system?

A) Producing mucus to trap foreign particles
B) Filtering out oxygen from inhaled air
C) Expanding and contracting the lungs
D) Facilitating the exchange of gases in the alveoli

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Explanation: The correct answer is A) Producing mucus to trap foreign particles. Cilia are small hair-like structures found in the respiratory tract. They help move mucus, which is produced by goblet cells, upward and out of the airways. This process helps to remove foreign particles, such as dust and pathogens, from the respiratory system.

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Question 3:

What is the primary function of the diaphragm in the respiratory system?

A) Contracting and relaxing to control breathing
B) Filtering out harmful gases from inhaled air
C) Producing mucus to lubricate the airways
D) Assisting in the exchange of gases in the alveoli

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Explanation: The correct answer is A) Contracting and relaxing to control breathing. The diaphragm is a dome-shaped muscle located beneath the lungs. When it contracts, it flattens, causing the volume of the thoracic cavity to increase. This expansion creates a negative pressure, allowing air to be drawn into the lungs. When the diaphragm relaxes, it returns to its dome shape, compressing the lungs and expelling air during exhalation.

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Question 4:

Which of the following is responsible for the production of surfactant in the lungs?

A) Alveoli
B) Trachea
C) Bronchi
D) Epiglottis

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Explanation: The correct answer is A) Alveoli. Surfactant is a substance produced by the alveoli (air sacs) in the lungs. It reduces surface tension within the alveoli, preventing their collapse during exhalation and promoting efficient gas exchange. Without surfactant, the alveoli would have a tendency to stick together, making it difficult to breathe.

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Question 5:

What is the main function of the capillaries in the respiratory system?

A) Transporting oxygen to the body cells
B) Filtering out carbon dioxide from the blood
C) Producing mucus to humidify inhaled air
D) Expanding and contracting to control breathing

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Explanation: The correct answer is A) Transporting oxygen to the body cells. Capillaries are tiny blood vessels that connect arteries and veins. In the respiratory system, the capillaries surround the alveoli in the lungs. Oxygen from the inhaled air diffuses across the thin walls of the alveoli and enters the capillaries, where it binds to red blood cells for transport to the body's cells and tissues.