Question 1

Where does the process of gaseous exchange take place in the body during respiration?
A) between the parietal and visceral pleura
B) in the right primary bronchus
C) in the tracheal passage
D) in the pulmonary capillaries
E) at the nasal conchae

Accepted Answer

The process of gaseous exchange takes place in the pulmonary capillaries, specifically in the alveoli of the lungs where oxygen is taken in and carbon dioxide is expelled.

Question 2

What is the function of the external intercostal muscles during inspiration?
A) They help decrease alveolar pressure.
B) They increase the pressure within the thoracic cavity.
C) They help increase the volume of the thoracic cavity.
D) They help promote elastic recoil of the chest walls.
E) They elevate the sternum and the upper two ribs.

Accepted Answer

The external intercostal muscles aid in the expansion of the thoracic cavity during inspiration by pulling the ribs upward and outward, which increases the volume of the thoracic cavity. This expansion of the thoracic cavity decreases the pressure within the lungs, allowing air to flow in.

Question 3

Surface tension accounts for
A) the increase in the size of alveoli
B) the maintenance of mucus volume
C) muscular contraction during expiration
D) the attachment of the lungs to the chest wall
E) elastic recoil of the lungs

Accepted Answer

Surface tension contributes to the elastic recoil of the lungs by creating a force that tends to collapse the alveoli, which is counteracted by surfactant to maintain lung stability.

Question 4

Identify structure A in the image. 
A) nostril
B) sinus
C) olfactory epithelium
D) nasal cavity
E) nasal conchae

Accepted Answer

The answer of Identify structure A in the image. 
A)...

Question 5

What is the function of the cilia in the nose?
A) They move mucus and trapped particles down toward the pharynx.
B) They lubricate the lining of the respiratory tract.
C) They cause the inhaled air to become turbulent.
D) They facilitate the movement of mucus along the respiratory tract.
E) They help increase the total surface area for gaseous exchange.

Accepted Answer

The cilia in the nose help move mucus and trapped particles down toward the pharynx, where they can be swallowed or coughed out. This is an important defense mechanism of the respiratory system to prevent particles from reaching the lungs.

Question 6

The nose helps make the incoming air warm and humid by
A) stimulating the lubrication of the respiratory tract lining
B) facilitating decreased mucus secretion
C) causing a turbulence of the inhaled air
D) secreting large amounts of periciliary fluid
E) promoting ciliary growth

Accepted Answer

The turbulence of inhaled air in the nasal passages helps warm and humidify the air by increasing its contact with the warm, moist surfaces of the nasal cavity.

Question 7

Flow of air into and out of the lungs can be attributed to
A) a pressure gradient between the atmosphere and the alveoli
B) a pulsating contraction and relaxation movement of the trachea
C) the air turbulence created in the nasal conchae
D) the rigidity of the diaphragm that maintains the pressure in the thorax
E) a change in the volume of the intrapleural fluid

Accepted Answer

The flow of air into and out of the lungs is due to a pressure gradient between the atmosphere and the alveoli. During inhalation, the diaphragm contracts and the intercostal muscles expand the ribcage, creating a larger volume in the thoracic cavity. This decrease in pressure allows air to rush into the lungs. During exhalation, the opposite occurs - the diaphragm relaxes and the ribcage contracts, decreasing the volume in the thoracic cavity and increasing the pressure, forcing air out of the lungs.

Question 8

What causes the alveoli to assume the smallest possible diameter in the lungs?
A) airway resistance
B) surface tension
C) gas pressure
D) capillary action
E) Poiseuille flow

Accepted Answer

The surface tension created by the thin layer of fluid that lines the alveoli pulls inward, causing the alveoli to assume the smallest possible diameter. This is known as the law of Laplace, which states that the pressure inside a sphere is directly proportional to the surface tension and inversely proportional to the radius of the sphere. Therefore, as the alveoli become smaller in diameter, the pressure inside them increases, which could lead to collapse without the presence of surfactant.

Question 9

What happens if the epiglottis fails to function?
A) air humidification and warming does not occur
B) food or liquid substances flow into the airways
C) cilia fail to trap and eliminate foreign particles
D) periciliary fluid volume reduces
E) the cough reflex for foreign material expulsion does not occur

Accepted Answer

The function of the epiglottis is to close off the trachea when we swallow, preventing food and liquid from entering the airways. If it fails to do this, it can lead to aspiration pneumonia, choking, and other serious respiratory complications.

Question 10

Identify the group of muscles indicated on the image by the double arrows. 
A) deltoideus muscles
B) scalene muscles
C) intercostal muscles
D) rectus abdominis
E) gluteus maximus

Accepted Answer

The answer of Identify the group of muscles indicated on...

Question 11

Which of the following occurs during expiration?
A) The external intercostals relax, and the ribs become depressed.
B) Alveolar pressure becomes equal to atmospheric pressure.
C) The diaphragm descends at least 1 cm.
D) Intrapleural pressure increases considerably.
E) The abdominal muscles expand and push the ribs upward.

Accepted Answer

During expiration, the external intercostals relax, making the ribs move downward and inward, which decreases the size of the thoracic cavity and forces air out of the lungs. The other choices are incorrect: B is describing the conditions at the end of exhalation, not during it; C is describing the movement of the diaphragm during inhalation; D is misleading since intrapleural pressure actually decreases during exhalation; and E is an incorrect statement.

Question 12

In the process of respiration, the step in which air flows into and out of the lungs is called
A) systemic circulation
B) inflation reflex
C) ventilation
D) bronchoconstriction
E) perfusion

Accepted Answer

Ventilation refers to the process of breathing in which air flows into the lungs (inhalation) and out of the lungs (exhalation). Systemic circulation refers to the part of the circulatory system that carries oxygenated blood from the heart to the rest of the body, while perfusion refers to the movement of blood through the capillaries to deliver oxygen and nutrients to tissues. The inflation reflex is a reflexive response to lung inflation, and bronchoconstriction refers to the narrowing of the airways in the lungs.

Question 13

The collapse of the air sacs shown in this image will have which of the following consequences? A) the mucus layer will disintegrate B) lung ventilation will increase C) ciliary movement will be impaired D) gas exchange will be impaired E) expiration of oxygenwilloccur

Accepted Answer

The collapse of air sacs, also known as alveoli, will impair gas exchange between the lungs and bloodstream. This can lead to a decrease in the amount of oxygen that can be taken up by the body and an increase in the amount of carbon dioxide that cannot be properly eliminated. The other options listed are not directly affected by the collapse of air sacs.

Question 14

Pleurisy is a condition characterized by
A) thinning of the parietal and visceral pleura
B) inflammation of the pleural membranes
C) diffusion of intrapleural fluid through visceral pleura into the lungs
D) thickening of the intrapleural fluid
E) bacterial infection of the intrapleural fluid

Accepted Answer

Pleurisy is characterized by inflammation of the pleural membranes, which are the thin linings that surround the lungs and chest cavity. This inflammation can cause sharp chest pain, coughing, and difficulty breathing. Thin or thick intrapleural fluid, and bacterial infections may be present, but they are not defining characteristics of pleurisy.

Question 15

Exposing the pleural cavity to the atmosphere results in
A) excessive inflation of the lungs
B) negative intrapleural pressure
C) uncoupling of the lung from the chest wall
D) contraction of the chest wall inward
E) elevation of oxygen levels in the blood

Accepted Answer

Exposing the pleural cavity to the atmosphere results in the uncoupling of the lung from the chest wall. Normally, the negative intrapleural pressure within the pleural cavity helps to keep the lung inflated and in contact with the chest wall. However, exposing the pleural cavity to the atmosphere equalizes the pressure, causing the lung to collapse and detach from the chest wall.

Question 16

Which of the following is a function of periciliary fluid?
A) It allows only air, but not food or liquid, into the respiratory tract.
B) It facilitates thickening of the mucus along the respiratory tract.
C) It acts as the site of gas exchange between the air and blood.
D) It causes turbulence in inhaled air in the nasal cavity.
E) It facilitates movement of mucus along the respiratory tract.

Accepted Answer

Periciliary fluid facilitates movement of mucus along the respiratory tract by creating a thin layer of fluid on top of the cilia, allowing them to beat more effectively and move the mucus out of the respiratory tract.

Question 17

The _____ is a funnel-shaped tube that extends from the nasal and oral cavities to the larynx and esophagus.

Accepted Answer

The answer of The _____ is a funnel-shaped tube that...

Question 18

The surfactant in alveolar fluid reduces surface tension by disrupting the cohesive forces between water molecules.

Accepted Answer

This is because the surfactant molecules have a hydrophobic (water-repelling) end and a hydrophilic (water-attracting) end, which allows them to spread out on the surface of the alveolar fluid and disrupt the cohesive forces between water molecules, effectively reducing surface tension. This is important for maintaining the elasticity of the lungs and ensuring efficient gas exchange.

Question 19

Identify the true statement about the resting phase in a respiratory cycle.
A) During this phase, alveolar pressure is greater than atmospheric pressure.
B) The resting phase is characterized by a flattened diaphragm.
C) Alveolar pressure is lower than atmospheric pressure in this phase.
D) Alveolar pressure is equal to atmospheric pressure during this phase.
E) The external intercostal muscles remain contracted during this phase.

Accepted Answer

During the resting phase, also known as the respiratory pause or the transition phase, there is no air movement and alveolar pressure is equal to atmospheric pressure. The diaphragm is relaxed and the external intercostal muscles are also relaxed.

Question 20

Explain why smokers cough to remove foreign particles from their airways.
A) Deposits of carbon in the epiglottis obstruct expectoration of trapped particles.
B) The cilia are paralyzed by nicotine and are unable to help in the expulsion of trapped particles.
C) The air turbulence created by the act of coughing prevents cilia from trapping the foreign particles.
D) An increase in the periciliary fluid by nicotine causes mucus to thicken.
E) The presence of nicotine causes cilia to entangle and inhibits their ability to trap foreign particles.

Accepted Answer

Nicotine from smoking can paralyze the cilia in the airways, which are responsible for trapping foreign particles and moving them out of the airways. Without the assistance of cilia, coughing becomes necessary to remove these trapped particles.

Quiz 18: The Respiratory System

Where does the process of gaseous exchange take place in the body during respiration?

What is the function of the external intercostal muscles during inspiration?

Surface tension accounts for

Identify structure A in the image.

What is the function of the cilia in the nose?

The nose helps make the incoming air warm and humid by

Flow of air into and out of the lungs can be attributed to

What causes the alveoli to assume the smallest possible diameter in the lungs?

What happens if the epiglottis fails to function?

Identify the group of muscles indicated on the image by the double arrows.

Which of the following occurs during expiration?

In the process of respiration, the step in which air flows into and out of the lungs is called

The collapse of the air sacs shown in this image will have which of the following consequences?

Pleurisy is a condition characterized by

Exposing the pleural cavity to the atmosphere results in

Which of the following is a function of periciliary fluid?

The _____ is a funnel-shaped tube that extends from the nasal and oral cavities to the larynx and esophagus.

The surfactant in alveolar fluid reduces surface tension by disrupting the cohesive forces between water molecules.

Identify the true statement about the resting phase in a respiratory cycle.

Explain why smokers cough to remove foreign particles from their airways.