Respiratory System Unit 3

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What is the primary function of the surfactant produced by type II alveolar cells?

To facilitate gas exchange by increasing the surface area of the alveoli
To stimulate the contraction of diaphragmatic muscles during inspiration
To reduce the surface tension of water in the alveoli, preventing collapse (correct)
To regulate the pH of the alveolar airspaces

Which of the following respiratory muscles is responsible for approximately 70% of the inspiratory effort?

Diaphragm (correct)
Internal intercostal muscles
Accessory muscles, including the scalene and sternocleidomastoid muscles
External intercostal muscles

What is the term for the movement of air into the lungs during inspiration?

Pressure
Flow
Ventilation (correct)
Volume

What is the term for the amount of air that remains in the lungs after forceful exhalation?

Residual volume (D) Signup and view all the answers

What is the term for the volume of air that can be exhaled from the lungs after normal exhalation?

Expiratory reserve volume (D) Signup and view all the answers

What is the primary mechanism by which the diaphragm contracts during inspiration?

Stimulation of the phrenic nerve by the inspiratory center in the medulla oblongata (B) Signup and view all the answers

Which of the following factors contributes to the decrease in lung compliance during pulmonary edema?

Increased surface tension of the alveolar fluid (A) Signup and view all the answers

During forced expiration, which of the following muscles is responsible for compressing the thoracic cavity?

Internal intercostal muscles (A) Signup and view all the answers

What is the result of the shift of the oxygen-hemoglobin dissociation curve to the right?

Increased release of oxygen to the tissues (A) Signup and view all the answers

What is the purpose of the Hering-Breuer reflex?

To prevent over-inflation of the lungs (D) Signup and view all the answers

What is the primary effect of increased intra-alveolar pressure on the alveolar-capillary membrane?

Increased thickness of the membrane (B) Signup and view all the answers

What is the primary mechanism by which the parasympathetic nervous system regulates respiration?

Inhibition of the dorsal respiratory group (C) Signup and view all the answers

What is the effect of a shift of the oxygen-hemoglobin dissociation curve to the left on oxygen delivery to tissues?

Decreased oxygen delivery (A) Signup and view all the answers

What is the primary function of the apneustic center in the brainstem?

Stimulation of inspiration (D) Signup and view all the answers

What is the effect of an increase in pulmonary vascular resistance on the perfusion of the lungs?

Decreased perfusion (B) Signup and view all the answers

What is the primary mechanism that allows the diaphragm to generate a greater pressure difference during inspiration?

Increased radial tension of the diaphragm (D) Signup and view all the answers

Which of the following factors would increase the work of breathing?

Increased surface tension of the alveoli (B) Signup and view all the answers

What is the primary effect of a decrease in respiratory rate on the partial pressure of CO2 in the arterial blood?

Increased PaCO2 (A) Signup and view all the answers

What is the primary role of the dorsal respiratory group in the regulation of respiration?

Integration of sensory information from the lungs and airways (B) Signup and view all the answers

Which of the following would result in a decrease in the partial pressure of O2 in the alveoli?

Decreased diffusion capacity of the alveolar-capillary membrane (B) Signup and view all the answers

What is the primary effect of a decrease in the diameter of the airways on the lungs?

An increase in airway resistance and a decrease in the tidal volume (C) Signup and view all the answers

What is the result of the stimulation of the apneustic center?

A decrease in the respiratory rate and an increase in the tidal volume (C) Signup and view all the answers

What is the primary effect of a decrease in the partial pressure of CO2 in the arterial blood on the respiratory rate?

A decrease in the respiratory rate due to the inhibition of the ventral respiratory group (B) Signup and view all the answers

What is the primary effect of an increase in the surface tension of the alveolar fluid on the lungs?

A decrease in the lung compliance and an increase in the work of breathing (D) Signup and view all the answers

What is the primary effect of a decrease in the phrenic nerve activity on the diaphragm?

A decrease in the contraction force of the diaphragm and a decrease in the tidal volume (C) Signup and view all the answers