Chapter 23 - Respiratory System

Which way would O2 and CO2 diffuse during internal respiration?

O2 would diffuse into the cells, and CO2 would diffuse into the systemic capillaries.

The normal rate and depth of breathing is established by the ________ center(s).

DRG and VRG

External respiration involves the

diffusion of gases between the interstitial fluid and the external environment

When does oxyhemoglobin form during respiration?

during external respiration

When the inspiratory muscles relax, the rib cage returns to its original position as a result of

elastic rebound

In which direction does carbon dioxide move during internal respiration?

from the tissue cells into the blood

Air moves out of the lungs when the pressure inside the lungs is

greater than the pressure in the atmosphere

Low partial pressure of oxygen in tissues is a condition called

hypoxia

During quiet breathing,

inspiration involves muscular contractions and expiration is passive

Expiratory movements are produced by contraction of the ________ muscle.

internal intercostal

All these muscles participate in inhalation EXCEPT __________. external intercostals internal intercostals scalenes diaphragm

internal intercostals

The process by which dissolved gases are exchanged between the cells and interstitial fluids is

internal respiration

Which pressure remains negative throughout the respiratory cycle?

intrapleural

Boyle's law states that the pressure of a gas is

inversely proportional to the volume of its container.

Hemoglobin

is a protein that can bind four molecules of oxygen.

Inhaling through the nostrils is preferred over the mouth because

it allows better conditioning of the inhaled air.

After blood becomes oxygenated,

it returns to the heart, and is then pumped to body cells.

The vocal folds are located within the

larynx

According to these graphs, more oxygen is released when the pH is (higher or lower) than normal and when temperature is (higher or lower) than normal.

lower; higher

Cystic fibrosis is an inherited respiratory disorder in which the mucociliary escalator no longer functions because of the presence of excessively dense and viscous mucus. What components of the respiratory system are affected by cystic fibrosis?

lungs, cilia, goblet cells

At a PO2 of 70 mm Hg and normal temperature and pH, hemoglobin is ________ percent saturated with oxygen.

more than 90

An important component of the lamina propria in the upper respiratory system is

mucus glands.

What is the name of the structures projecting from the lateral surfaces of the nasal cavity that function to create turbulence and help humidify and warm the incoming air?

nasal conchae

The glottis is

opening to the larynx

The ________ is shared by the respiratory and digestive systems.

pharynx

Accidently sending fluid up out of the nose happens when the ________ fails to close off the ________.

soft palate; nasopharynx

Lungs are held tightly to the wall of the thorax due to

surface tension of the pleural fluid and negative pressure in the cavity

During inhalation,

the diaphragm and rib muscles 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

Very aggressive pathogens such as the bacterium responsible for tuberculosis can easily overwhelm the protective features of the respiratory system. Less aggressive pathogens may be stopped by all of the following EXCEPT __________.

the olfactory epithelium

Higher brain centers that alter the activity of the respiratory centers include all of the following except

the precentral motor gyrus.

When there is no air movement, the relationship between the intrapulmonary and atmospheric pressure is that

they are equal

A common site to place a tracheostomy tube is through the ligament that connects the cricoid cartilage to the ________ cartilage.

thyroid

________ is the amount of air that moves into the respiratory system during a single respiratory cycle.

tidal volume

The chloride shift occurs in order to

transport bicarbonate ions into the blood plasma.

The serous membrane that covers the lungs is the

visceral pleura

If a patient inhales as deeply as possible and then exhales as much as possible, the volume of air expelled would be the patient's

vital capacity.

How would the partial pressures of O2 and CO2 change in an exercising muscle?

The partial pressure of O2 would decrease, and the partial pressure of CO2 would increase.

In a condition known as pneumothorax, the integrity of the pleural cavity is lost, which leads to a collapsed lung. What is one explanation for why this occurs?

The pleural fluid that bonds (surface tension) the visceral and parietal pleurae together is broken by air.

Which of the following variables is NOT monitored by the medullary breathing centers?' Air humidity Partial pressure of CO2 Amount of stretch in the lungs Blood acidity

air humidity

Carbon monoxide poisoning is possible because carbon monoxide binds readily with heme at very low partial pressures compared to those of oxygen. Besides partial pressure, what else determines the affinity of oxygen molecules for heme? temperature BPG concentration pH levels

all of the above

From which structures do oxygen molecules move from the lungs to the blood?

alveoli

Air that remains in conducting passages and doesn't participate in gas exchange is termed

anatomic dead space

Both sneezing and coughing are examples of protective reflexes triggered by irritation. Sneezing and coughing both involve a disruption in respiration. What is the formal name for the period when respiration is suspended?

apnea

What would be the immediate effect of damage to the Dorsal Respiratory Group (DRG)?

apnea (no breathing)

Which breathing center promotes inhalation by stimulating the DRG?

apneustic center

Most of the carbon dioxide in the blood is transported as

bicarbonate ions

Most of the oxygen transported by the blood is

bound to hemoglobin

The most important chemical regulator of respiration is

carbon dioxide

Which structures in the respiratory epithelium help transport mucus out of the lower respiratory system and into the pharynx for expulsion?

cilia

Which of the following descriptions best matches the term bronchiolar smooth muscle? contraction increases airway resistance affects lung compliance accessory muscle of expiration primary muscle of inspiration accessory muscle of inspiration

contraction increases airway resistance

Which of the following factors would increase the amount of oxygen discharged by hemoglobin to peripheral tissues?

decreased pH

Name the primary muscles of inspiration.

diaphragm and external intercostal muscles

The following is a list of some airways. What is the order in which air passes through them?1. lobar bronchus2. bronchioles3. alveolar ducts4. primary bronchus5. respiratory bronchiole6. alveoli7. terminal bronchiole

4, 1, 2, 7, 5, 3, 6

The partial pressure of oxygen in the interstitial space of peripheral tissues is approximately

40 mm Hg

The partial pressure of carbon dioxide in the interstitial space of peripheral tissues is approximately

45 mm Hg

The partial pressure of carbon dioxide in venous blood is approximately

45 mm Hg

The partial pressure of oxygen in arterial blood is approximately

100 mm Hg

The blood air barrier consists of

2 layers of simple squamous epithelium

How much difference is there in the ability of hemoglobin to hold oxygen when comparing slightly alkaline blood to slightly acidic blood at a Po2 of 40 mm Hg?

Between 15 and 20 percent more oxygen can be held in alkaline blood at a Po2 of 40 mm Hg.

Despite the fact that the partial pressure difference is so much smaller for CO2, why is there as much CO2 exchanged between the alveoli and blood as there is O2, ?

CO2 is much more soluble in blood than O2.

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

CO2; alveoli

Which statement is correct? -During internal respiration, carbon dioxide is unloaded from the blood. -During external respiration, oxygen is unloaded from the blood. -During external respiration, equilibrium is reached for O2 when the partial pressure for O2 in the pulmonary capillaries and the alveoli are the same. -The greater the available surface area the lower the amount of gas exchange during internal respiration.

During external respiration, equilibrium is reached for O2 when the partial pressure for O2 in the pulmonary capillaries and the alveoli are the same.

If the volume of the lungs increases, what happens to the air pressure inside the lungs?

It decreases.

No air is moving in or out of the lungs in this image. Which of the following describes the pressures of the atmosphere ("P outside") and the lungs ("P inside")?

P inside = P outside

Which of the following statements correctly contrasts the dorsal respiratory group (DRG) and the ventral respiratory group (VRG)?

The DRG is mainly active during inspiration, while the VRG is primarily active during expiration.

The structure of the respiratory epithelium changes along the respiratory tract. In addition to mucous cells, what other type of cells are found lining the nasal cavity, nasopharynx, and the superior portion (trachea and bronchi) of the lower respiratory system?

pseudostratified ciliated columnar epithelial cells

The respiratory epithelium of the conducting airways consists of

pseudostratified ciliated columnar epithelium.

Blockage of pulmonary blood flow by a traveling clot or similar obstruction is

pulmonary embolism

The physical movement of air into and out of lungs is termed

pulmonary ventialtion

During exercise, which of the following contract for active exhalation?

rectus abdominis and internal intercostal muscles

External respiration includes all of these processes EXCEPT __________. release of carbon dioxide by tissue cells gas diffusion across respiratory membrane gas transport breathing

release of carbon dioxide by tissue cells