Chapter 15:Gaseous Exchange In Humans

Question 1

Flashcard 1:
Q: What is breathing?

Answer 1

A: The physical process of inhaling oxygen-rich air from the atmosphere into the lungs and exhaling carbon dioxide-rich air from the lungs into the atmosphere.

Question 2

Flashcard 2:
Q: What is respiration?

Answer 2

A: The release of energy from breaking down food substances (glucose) in all living cells.

Question 3

Flashcard 3:
Q: What are the features of gas exchange surfaces in humans?

Answer 3

A: Large surface area, thin surface, good blood supply, and good ventilation with air.

Question 4

Flashcard 4:
Q: Where does gas exchange take place in humans?

Answer 4

A: In the alveoli (alveolus).

Question 5

Flashcard 5:
Q: What are the characteristics of alveoli that make them efficient for gas exchange?

Answer 5

A: Very large surface area, thin walls (one cell thick), moist surface, good blood supply, and good ventilation with air.

Question 6

Flashcard 6:
Q: What is the function of external intercostal muscles during breathing?

Answer 6

A: They contract to move the rib cage upwards and outwards to allow oxygen-rich air to flow into the lungs, and relax to move the rib cage inwards and downwards to allow carbon dioxide-rich air to flow out of the lungs.

Question 7

Flashcard 7:
Q: What is the function of internal intercostal muscles during breathing?

Answer 7

A: They relax to move the rib cage upwards and outwards to allow oxygen-rich air to flow into the lungs, and contract to move the rib cage inwards and downwards to allow carbon dioxide-rich air to flow out of the lungs.

Question 8

Flashcard 8:
Q: What is the function of the diaphragm during breathing?

Answer 8

A: It contracts and flattens to increase the volume of the chest cavity to allow oxygen-rich air to flow into the lungs, and relaxes to form a dome shape to decrease the volume of the chest cavity to allow carbon dioxide-rich air to flow out of the lungs.

Question 9

Flashcard 9:
Q: What is the role of cartilage in the trachea?

Answer 9

A: To keep the trachea (windpipe) open to prevent it from collapsing during breathing.

Question 10

Flashcard 10:
Q: What is the composition of nitrogen in inspired and expired air?

Answer 10

A: 78% in both inspired and expired air, because it is insoluble and not absorbed into the blood.

Question 11

Flashcard 11:
Q: What is the composition of oxygen in inspired and expired air?

Answer 11

A: 21% in inspired air and 16% in expired air, because it is absorbed into the blood and used in respiration.

Question 12

Flashcard 12:
Q: What is the composition of carbon dioxide in inspired and expired air?

Answer 12

A: 0.04% in inspired air and 4% in expired air, because it is a waste product of respiration expelled from the lungs.

Question 13

Flashcard 13:
Q: How does the temperature of inspired and expired air differ?

Answer 13

A: Inspired air has a variable temperature, while expired air is warmer as the body heats it up to body temperature.

Question 14

Flashcard 14:
Q: How does the water vapor content of inspired and expired air differ?

Answer 14

A: Inspired air has variable water vapor content, while expired air is saturated with water vapor as it evaporates from the surface of the alveoli.

Question 15

Flashcard 15:
Q: How is lime water used to test for the presence of carbon dioxide?

Answer 15

A: Clear lime water turns milky/cloudy in the presence of carbon dioxide.

Question 16

Flashcard 16:
Q: What is the practical procedure for testing the concentration of carbon dioxide in inspired and expired air?

Answer 16

A: Bubble room air through lime water in one beaker and exhaled air through lime water in another beaker, then observe and record the results.

Question 17

Flashcard 17:
Q: What happens to lime water when carbon dioxide is bubbled through it?

Answer 17

A: It produces calcium carbonate, making the lime water appear cloudy or milky.

Question 18

Flashcard 18:
Q: What happens to the breathing rate and depth during vigorous exercise?

Answer 18

A: Both increase to allow more oxygen to be supplied to active muscles and more carbon dioxide to be expelled from the body.

Question 19

Flashcard 19:
Q: How can you investigate the effects of exercise on breathing rate?

Answer 19

A: Measure the breathing rate at rest, perform physical activity (e.g., jumping up and down), and then measure the breathing rate again.

Question 20

Flashcard 20:
Q: What harmful substances are found in tobacco smoke?

Answer 20

A: Tar, nicotine, and carbon monoxide.

Question 21

Flashcard 21:
Q: How does tar affect the gas exchange system?

Answer 21

A: It stimulates extra mucus production, narrows air passages, restricts airflow, contains carcinogenic chemicals, and can cause lung cancer and emphysema.

Question 22

Flashcard 22:
Q: How does nicotine affect the gas exchange system?

Answer 22

A: It is addictive, causes narrowing of arteries, increases blood pressure, and makes platelets sticky, leading to blood clots.

Question 23

Flashcard 23:
Q: How does carbon monoxide affect the gas exchange system?

Answer 23

A: It combines with hemoglobin in red blood cells, preventing oxygen transport and causing shortness of breath.

Question 24

Flashcard 24:
Q: What is COPD and how is it related to smoking?

Answer 24

A: COPD is a lung disease that makes it difficult to breathe due to obstructed airflow, and smoking increases the risk of developing COPD, including lung cancer and emphysema.