Ch. 21

Each 100 mL of blood leaving the alveolar capillaries carries away roughly ________ of oxygen

20 mL

The partial pressure of oxygen in pulmonary veins during internal respiration is approximately

95 mm Hg.

Which statement regarding lung cancer is correct?

Since 1992, the incidence of lung cancer among women has been increasing

If the dorsal respiratory group of neurons in the medulla oblongata were destroyed bilaterally

a person would stop breathing

Each terminal bronchiole supplies air directly to

a single pulmonary lobule.

Alveolar ventilation refers to the

amount of air reaching the alveoli each minute.

Air remaining in the conducting portion of the respiratory system that does not reach the alveoli is known as

anatomic dead space

A period in which breathing has stopped, followed by a forceful expulsion of air is termed

apnea.

Prolonged deep inspirations can result from stimulating the ________ center.

apneustic

If the fluid bond between the parietal and visceral pleura is broken and the lung collapses, the resulting condition is termed

atelectasis

Most of the carbon dioxide in the blood is transported as

bicarbonate ions

The most important chemical regulator of respiration is

carbon dioxide.

The conchae

create turbulence in the air to trap particulate matter in mucus

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

decreased pH

The obstructive lung disease in which elastic fibers are lost, leading to collapse of alveoli and bronchioles, is called

emphysema.

The laryngeal cartilage composed of elastic cartilage that prevents entry of solids or liquids into the larynx when swallowing is the

epiglottis.

The respiratory defense system is important because it

helps warm the air. keeps out debris. helps filter the air. keeps out pathogens. (All of the answers are correct)

Dalton's law states that

in a mixture of gases such as air, the total pressure is the sum of the individual partial pressures of the gases in the mixture.

The common passageway shared by the respiratory and digestive systems is the

pharynx

Which structure is located most superior at the hilum of the left lung?

pulmonary artery

Which of the following can be calculated if the tidal volume and respiratory rate are known?

respiratory minute volume

During a choking episode, most foreign objects are more likely to become lodged in the ________ bronchus due to its larger diameter and steeper angle

right primary

In the lower respiratory tract, cartilage plates first appear at the

secondary bronchi.

During swallowing,

solids and liquids are prevented from entering the respiratory tract. the epiglottis folds back over the glottis. the larynx is elevated. (All of the answers are correct)

Air traveling from the tertiary bronchi must pass through the ________ to reach the pulmonary lobule

terminal bronchioles

The movement of chloride ions into the RBCs in exchange for bicarbonate ions is known as

the chloride shift

The glottis is

the opening to the larynx.

When the diaphragm and external intercostal muscles contract,

the volume of the thorax increases.

Air entering the body is filtered, warmed, and humidified by the

upper respiratory tract.

Damage to the type II pneumocytes of the lungs would result in

increased tendency to alveolar collapse. increased surface tension in the alveoli. a decreased rate of gas exchange. a loss of surfactant. (All of the answers are correct)

In quiet breathing,

inspiration involves muscular contractions and expiration is passive.

Absorption of O2 from blood and release of CO2 from tissue cells is known as

internal respiration.

Carbonic anhydrase

is an enzyme. can increase the amount of bicarbonate ion in plasma. can convert carbon dioxide into carbonic acid. is in RBCs. (All of the answers are correct)

The trachea, bronchi, bronchioles and alveoli all make up the

lower respiratory tract.

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

more than 90

Tension on the vocal cords is regulated by the

movement of the arytenoid cartilages and contraction of voluntary muscles

The beating of the cilia of the respiratory passages in the direction of the pharynx forms the

mucus escalator.

The auditory tubes open into the

nasopharynx

Emphysema:

occurs due to the destruction of alveolar surfaces and inadequate surface area for oxygen and carbon dioxide exchange

Starting at the ________, the epithelium changes to stratified squamous epithelium

oropharynx