1. Which of the following is the primary site of gaseous exchange in humans?
Answer:
Explanation:
Alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place.
2. Which muscle plays a crucial role in the process of inhalation?
Answer:
Explanation:
The diaphragm contracts during inhalation, increasing the volume of the thoracic cavity and allowing air to be drawn into the lungs.
3. Which gas has the highest solubility in blood plasma?
Answer:
Explanation:
Carbon dioxide is approximately 20 times more soluble in blood plasma than oxygen.
4. The binding of oxygen to hemoglobin is primarily influenced by:
Answer:
Explanation:
The binding affinity of oxygen to hemoglobin decreases as the pH decreases, leading to the release of oxygen in tissues.
5. Which part of the human brain regulates the respiratory rhythm?
Answer:
Explanation:
The medulla oblongata contains the respiratory center and controls the rate and depth of respiration.
6. What is the primary form in which carbon dioxide is transported in the blood?
Answer:
Explanation:
Around 70% of carbon dioxide is transported in the blood as bicarbonate ions.
7. During an asthma attack, which part of the respiratory system narrows or constricts?
Answer:
Explanation:
Asthma attacks involve the constriction of bronchioles, making it difficult for air to flow in and out of the lungs.
8. Which of the following increases during vigorous exercise?
Answer:
Explanation:
Tidal volume, or the volume of air inhaled or exhaled during a normal breath, increases during vigorous exercise to meet the increased oxygen demand.
9. Which protein in RBCs carries oxygen?
Answer:
Explanation:
Hemoglobin is an iron-containing protein in red blood cells that binds to oxygen and transports it to tissues.
10. What percentage of air is composed of oxygen?
Answer:
Explanation:
Approximately 21% of air is composed of oxygen, with nitrogen making up the majority at around 78%.
11. The process by which gasses move from areas of high concentration to low concentration is called:
Answer:
Explanation:
Gasses move down their concentration gradient via the process of diffusion.
12. Which of the following conditions leads to an increased affinity of hemoglobin for oxygen?
Answer:
Explanation:
An increase in pH (alkaline condition) enhances the binding affinity of hemoglobin for oxygen.
13. Emphysema, a lung condition, primarily affects which of the following structures?
Answer:
Explanation:
Emphysema involves damage to the alveoli, reducing the surface area available for gaseous exchange.
14. The amount of air that can be forcefully inhaled after a normal inhalation is called:
Answer:
Explanation:
Inspiratory reserve volume represents the additional volume of air that can be inhaled with effort after a normal inhalation.
15. Which of the following is NOT involved in gaseous exchange in amphibians?
Answer:
Explanation:
Amphibians like frogs respire through their skin, lungs, and buccal cavity, but not through a trachea.
16. Which gas primarily regulates the respiratory rate?
Answer:
Explanation:
An increase in carbon dioxide levels in the blood stimulates an increase in the respiratory rate to expel it.
17. What is the total lung capacity in a healthy adult male?
Answer:
Explanation:
The total lung capacity in a healthy adult male typically ranges between 6 to 8 liters.
18. Which part of the respiratory system helps in warming, moistening, and filtering the inhaled air?
Answer:
Explanation:
The nasal cavity has a mucous lining that helps in warming, moistening, and filtering the air before it reaches the lungs.
19. Which of the following animals respire through their skin?
Answer:
Explanation:
Earthworms respire through their skin as they lack specialized respiratory organs.
20. Which of the following terms refers to a reduced rate and depth of breathing?
Answer:
Explanation:
Bradypnea refers to an abnormally slow breathing rate.