Question 1

In the bell jar model of the lungs, what happens to the balloons (representing lungs) when the diaphragm (the rubber sheet at the base) is pulled downward?

Accepted Answer

The balloons inflate because air is drawn in due to decreased pressure.

Question 2

If the seal at the base of the bell jar model is broken, what would be the most immediate effect on the balloons inside?

Accepted Answer

The balloons would collapse because negative pressure cannot be maintained.

Question 3

Which of the following best explains why a collapsed lung (pneumothorax) is non-functional?

Accepted Answer

Because the lung cannot expand due to loss of negative pressure in the pleural cavity.

Question 4

During inhalation, what is the primary cause of chest enlargement?

Accepted Answer

Contraction of the diaphragm and external intercostal muscles, increasing thoracic volume.

Question 5

Why is it not possible to take a deep breath without expanding your chest?

Accepted Answer

Because chest expansion is necessary to increase lung volume and decrease intrapulmonary pressure.

Question 6

What happens to your abdominal muscles when you exhale forcefully?

Accepted Answer

They contract to help push air out of the lungs.

Question 7

Which of the following best describes the relationship between a person's height and their vital capacity?

Accepted Answer

Vital capacity generally increases with height due to larger thoracic cavity size.

Question 8

After hyperventilating, why are you able to hold your breath longer than usual?

Accepted Answer

Because hyperventilation decreases the carbon dioxide levels in your blood, delaying the urge to breathe.

Question 9

After vigorous exercise, why does your breathing rate increase?

Accepted Answer

Because increased carbon dioxide ($$CO_2) in $$the blood stimulates chemoreceptors to increase respiratory rate.

Question 10

Which disease would most significantly reduce the alveolar surface area for gas exchange?

Accepted Answer

Emphysema

Question 11

What is the clinical significance of measuring a person's vital capacity?

Accepted Answer

It helps diagnose and monitor respiratory diseases by assessing the maximum amount of air a person can exhale after a maximal inhalation.

Question 12

How does smoking most directly affect lung capacity?

Accepted Answer

It damages alveolar walls, reducing surface area and vital capacity.

Question 13

Which formula correctly represents vital capacity ($$VC) in $$terms of tidal volume ($$TV$$), inspiratory reserve volume ($$IRV$$), and expiratory reserve volume ($$ERV$$)?

Accepted Answer

$$ VC = TV + IRV + ERV $$

Question 14

A patient has a tidal volume ($$TV) of 500 mL$$, an inspiratory reserve volume ($$IRV) of 3000 mL$$, and an expiratory reserve volume ($$ERV) of 1200 mL. $$What is their vital capacity ($$VC$$)?

Accepted Answer

$$ VC = 500 + 3000 + 1200 = 4700 	ext{ mL} $$

Question 15

Which of the following would be the best experimental design to measure the effects of exercise on vital capacity?

Accepted Answer

Measure vital capacity before and after a period of regular exercise in the same individuals.

Question 16

Which of the following best explains why a large alveolar surface area is critical for efficient breathing?

Accepted Answer

It maximizes the area available for gas exchange, enhancing oxygen uptake and carbon dioxide removal.

Question 17

Which muscles are primarily responsible for increasing thoracic volume during inhalation?

Accepted Answer

Diaphragm and external intercostal muscles

Question 18

A person with emphysema has a reduced vital capacity. Which physiological change best explains this?

Accepted Answer

Destruction of alveolar walls, reducing surface area for gas exchange

Question 19

Which of the following would most likely cause a decrease in a person's vital capacity?

Accepted Answer

Chronic smoking

Question 20

Which of the following best describes the effect of increased $$CO_2 in $$the blood on the respiratory rate?

Accepted Answer

It increases respiratory rate by stimulating chemoreceptors in the medulla and carotid bodies.

Guided Study: Animal Kingdom Lab – Respiratory System and Lung Function

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