a&p 2 chapter 21

What part of the following description is INCORRECT? Contraction of the diaphragm and external intercostal muscles leads to increased volume in the thoracic cavity and the lungs. The increase in volume leads to an increase in intrapulmonary pressure causing air to move into the lungs.

Increases in volume lead to a decrease in pressure, not an increase in pressure.

Central chemoreceptors are most sensitive to changes in __________.

PCO2

If the atmospheric pressure is 770 mm Hg and oxygen represents 13% of the total, then the partial pressure of oxygen is __________.

PO2 = 0.13 x 770 = 100 mm Hg

What is the advantage of breathing through the nose rather than the mouth?

The nose warms, humidifies, and filters inhaled air.

Respiratory acidosis results from:

hypoventilation

Which pressure is the result of the natural tendency of the lungs to decrease their size (because of elasticity) and the opposing tendency of the thoracic wall to pull outward and enlarge the lungs?

intrapleural pressure

Each secondary bronchus supplies air to a:

lobe of the lung.

Carina is the last ring of this organ

trachea

During inspiration, after leaving the larynx, air enters the __________.

trachea

Transports air from the larynx into the lower respiratory tract

trachea

Calculate the inspiratory reserve volume (IRV) If the vital capacity (VC) is 4500 ml, the tidal volume (TV) is 500 ml and the expiratory reserve volume (ERV) is 1000 ml.

3000 ml

One hemoglobin can bind a maximum of ___ oxygen(s).

4

The partial pressure of carbon dioxide (PCO2) in the blood of pulmonary capillaries is approximately:

45 mm Hg.

Under normal conditions, the forced expiratory volume is normally _______.

75 - 85% of the vital capacity

Which of the following structures is a component of the respiratory membrane?

Basal lamina

Which of the following chemical equations shows what happens to part of the CO2 picked up by blood in tissues?

CO2 + H2O → H2CO3 → H+ + HCO3-

_______ has a greater partial pressure in the pulmonary capillaries than in the alveoli, so it diffuses into the _______.

CO2; alveoli

Despite the fact that the partial pressure difference is so much smaller for CO2CO2, why is there as much CO2CO2 exchanged between the alveoli and blood as there is O2O2, ?

CO2CO2 is much more soluble in blood than O2O2.

Which way would O2O2 and CO2CO2 diffuse during internal respiration?

O2O2 would diffuse into the cells, and CO2CO2 would diffuse into the systemic capillaries.

Microvascular complications in diabetes lead to the walls of capillaries becoming abnormally thick. How will this affect tissue gas exchange?

The greater distance for diffusion will decrease the efficiency of diffusion.

How would the partial pressures of O2O2 and CO2CO2 change in an exercising muscle?

The partial pressure of O2O2 would decrease, and the partial pressure of CO2CO2 would increase.

Which of the following descriptions accurately describes Boyle's law?

The pressure of gas in your lungs is inversely proportional to the volume in your lungs.

Hyperventilation leads to __________.

a decrease in hydrogen ion concentration

What cells clean and digest debris entering the alveoli?

alveolar macrophages

Simple squamous epithelium creates these air sacs

alveoli

Hypoventilation causes __________.

an increase in blood PCO2

The majority of carbon dioxide is transported:

as the bicarbonate ion.

Through what openings of the nose does inhaled air enter the upper respiratory tract?

anterior nares

Which of the following is not one of the functions of the respiratory system?

assist with the flow of arterial blood

A patient presents with bronchoconstriction, inflamed airways and excessive mucus production triggered by aspirin. This patient most likely suffers from __________.

asthma

Most of the oxygen transported by blood is __________.

bound to hemoglobin

How is most oxygen transported in the blood?

bound to hemoglobin as oxyhemoglobin

The first branches of the trachea

bronchi

The smallest airways of the bronchial tree

bronchioles

The minute ventilation is _______.

calculated by multiplying the rate of respiration times TV

What would increase the amount of oxygen unloaded by hemoglobin into peripheral tissues?

decreased pH

Each of the following factors affects the efficiency of pulmonary gas exchange EXCEPT:

diameter of an alveolus.

What primarily determines airway resistance in the respiratory passageways?

diameter of the conducting zone passageways

Which muscles, when contracted, would increase the volume of air in the thoracic cavity?

diaphragm and external intercostals

Which of the following diseases is characterized by loss of alveolar surface area __________.

emphysema

During an allergic reaction, which of the following would aid respiration?

epinephrine

When the radius of the airway was decreased, _______.

expiratory reserve volume decreased

The amount of air that can be forcibly expired after a normal tidal expiration is known as the:

expiratory reserve volume.

Which of the following muscles is involved in normal quiet inspiration?

external intercostal muscles

Surfactant helps prevent atelectasis by humidifying air before it enters the alveoli.

false

The pharynx is known as the voice box due to the presence of vocal ligaments that vibrate to produce sound.

false

If peripheral chemoreceptors detect low PO2, the effect or response will be __________.

hyperventilation

Prevents food and liquid from entering the rest of the respiratory tract

larynx

If the transpulmonary pressure equals zero, what will happen to the lung?

lungs will collapse

There will be __________ carbon dioxide dissolved in water at a partial pressure of 45 mm Hg than at a partial pressure of 40 mm Hg.

more

As hemoglobin saturation decreases:

more oxygen is released from hemoglobin.

Compared to bronchi, bronchioles have __________.

more smooth muscle

Houses nasal conchae to enhance turbulence for filtering air

nasal cavity

Which of the following determines the direction of respiratory gas movement?

partial pressure gradient

Three regions are the naso-, oro-, and laryngo-

pharynx

Each lung is situated within a subcavity of the thoracic cavity known as the:

pleural cavity.

What reduces friction around the lungs as they expand and contract?

pleural fluid

The movement of air in and out of the lungs is called __________.

pulmonary ventilation

Which of the following reduces alveolar surface tension?

surfactant

Gas exchange occurs in all of the following EXCEPT:

terminal bronchioles.

During forced exhalation, _______.

the internal intercostals contract

Internal and external respiration depends on several factors. Which of the following is NOT an important factor in gas exchange?

the molecular weight of the gas

Bronchodilation may occur in response to:

the sympathetic nervous system.

Air inspired through the nasal cavity will travel through the nasopharynx, oropharynx, and then the laryngopharynx before entering the larynx.

true

Terminal bronchioles, part of the conducting zone, give rise to respiratory bronchioles, which are part of the respiratory zone.

true