WITH CORRECT WELL VERIFIED ANSWERS GRADED A+
Which nervous system promotes bronchodilation?
A) Parasympathetic
B) Sympathetic
C) Enteric
D) Somatic - ✅✅B) Sympathetic
Rationale: The sympathetic nervous system releases epinephrine, activating beta-2
receptors to cause bronchodilation.
Which mediator causes bronchoconstriction in asthma?
A) Epinephrine
B) Acetylcholine
C) Leukotrienes
D) Dopamine - ✅✅C) Leukotrienes
Rationale: Leukotrienes are inflammatory mediators that promote
bronchoconstriction in asthma.
,What effect does histamine have on bronchioles?
A) Bronchodilation
B) Increased mucus production
C) Bronchoconstriction
D) Decreased airway resistance - ✅✅C) Bronchoconstriction
Rationale: Histamine binds to H1 receptors, leading to bronchoconstriction and
increased airway resistance.
During inspiration, pleural pressure becomes:
A) More positive
B) More negative
C) Equal to alveolar pressure
D) Greater than atmospheric pressure - ✅✅B) More negative
Rationale: Pleural pressure becomes more negative to allow lung expansion during
inspiration.
What happens to alveolar pressure during expiration?
A) It becomes negative
B) It remains the same as atmospheric pressure
,C) It becomes positive
D) It decreases below pleural pressure - ✅✅C) It becomes positive
Rationale: Alveolar pressure rises above atmospheric pressure, forcing air out of
the lungs.
Which factor primarily prevents alveolar collapse?
A) Carbonic anhydrase
B) Surfactant
C) Hemoglobin
D) Alveolar macrophages - ✅✅B) Surfactant
Rationale: Surfactant reduces surface tension, preventing alveolar collapse.
Which of the following best describes the changes in alveolar structure due to
aging?
A. Increase in alveolar size with loss of elastic fibers
B. Thickening of alveolar walls with increased gas exchange efficiency
C. Increase in the number of alveoli with improved oxygen diffusion
D. Enhanced elastic recoil of the alveoli - ✅✅A. Increase in alveolar size with
loss of elastic fibers
, Rationale: Aging leads to alveolar enlargement due to loss of elastic fibers,
reducing surface area for gas exchange.
What is a major consequence of decreased elastic recoil in aging lungs?
A. Increased ability to exhale efficiently
B. Air trapping and difficulty expelling air
C. Decreased airway resistance
D. Increased surface area for gas exchange - ✅✅B. Air trapping and difficulty
expelling air
Rationale: Reduced elastic recoil results in air trapping, making expiration more
difficult and reducing lung efficiency.
How does aging affect pulmonary capillaries?
A. Increased number and complexity
B. Decreased number and complexity
C. No significant changes
D. Capillaries thicken to enhance gas exchange - ✅✅B. Decreased number and
complexity