lesson 10 respiratory system physiology

During normal quiet breathing, approximately 750 ml of air moves into and out of the lungs with each breath.

FALSE

The average individual has 500 ml of residual volume.

FALSE

The most important chemical stimuli leading to increased rate and depth of breathing is:

Hydrogen and carbon dioxide concentration of blood

Unlike inspiration, experiation is a passive act because no muscular contractions are involved. Expiration, however, depends on two factors. Which of the choices below lists those two factors?

The recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid.

Which of the following statements is true regarding the respiratory rate of a newborn?

The respiratory rate of a newborn is, at its highest rate, approximately 40-80 respirations per minute

Inspiratory capacity is:

The total amount of air that can be inspired after a tidal expiration

Tidal volume is air:

exchanged during normal breathing

As carbon dioxide enters systemic blood, it causes more oxygen to dissociate from hemoglobin (the Haldane effect), which in turn allows more CO2 to combine with hemoglobin and more bicarbonate ions to be generated (the Bohr effect).

false

In chronic bronchitis, mucus production is decreased and this leads to the inflammation and fibrosis of the mucosal lining of the bronchial tree.

false

Increased temperature results in decreased O2 unloading from hemoglobin.

false

The Hering-Breuer reflex is a potentially dangerous response that may cause overinflation of the lung.

false

The largest amount of carbon dioxide is transported in the bloodstream in the form of carbonic anydrase.

false

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

greater than the pressure in the atmosphere

The most powerful respiratory stimulus for breathing in a healthy person is

increase of carbon dioxide

The amount of air that can be inspired above tidal volume is called?

inspiratory reserve

Surfactant helps to prevent the alveoli from collapsing by:

interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid

Respiratory control centers are located in the:

medulla and pons

Which of the choices below is NOT a factor that promotes oxygen binding to and dissociation from hemoglobin?

number of red blood cells

In the plasma, the quantity of oxygen in solution is:

only about 1.5% of the oxygen carried in blood

The Bohr effect refers to the unloading of ________ in a RBC due to declining pH

oxygen

Which of the choices below determines the direction of respiratory gas movement?

partial pressure gradient

Which center is located in the pons?

pontine respiratory group (PRG)

intrapulmonary pressure is the:

pressure within the alveoli of the lungs

A premature baby usually has difficulty breathing. However the respiratory system is developed enough for survival by:

28 weeks

The relationship between gas pressure and gas volume is described by:

Boyle's law

The statement, "in a mixture of gases, the total pressure is the sum of the individual partial pressure of gases in the mixture" paraphrases:

Dalton's law

Which respiratory-associated muscles would contract if you were to blow up a balloon?

Internal intercostals and abdominal muscles would contract

Which of the following is NOT a stimulus for breathing? a.rising carbon dioxide levels b.rising blood pressure c.arterial PO2 below 60 mm Hg d.acidosis resulting from CO2 retention

b. rising blood pressure

Dalton's law states that the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in a mixture.

TRUE

Intrapleural pressure is normally about 4 mm Hg less than the pressure in the alveoli.

TRUE

Labored breathing is termed dyspnea.

TRUE

The alveolar ventilation rate is the best index of effective ventilation.

TRUE

ventilation perfusion coupling means that more blood flows past functional alveoli than past non-functional.

TRUE

Select the correct statement about tne enural mechanisms of respiratory control. a.The pons is thought to be instrumental in the smooth transition from inspiration to expiration b.The dorsal respiratory group neurons depolarize in a rhythmic way to establish the pattern of breath c.The pontine respirator group (PRG) continuousy stimulates the medulla to provide inspiratory drive d.The ventral respiratory group is contain within the pons

a.The pons is thought to be instrumental in the smooth transition from inspiration to expiration

which of the following is NOT possible? a.Gas flow equals pressure gradient over resistance b.Pressure gradient equals gas flow over resistance c.Resistance equals pressure gradient over gas flow d.The amount of gas flowing in and out of the alveoli is directly proportional to the difference in pressure or pressure gradient between the external atmosphere and the alveoli

b. Pressure gradient equals gas flow over resistance

How is the bulk of carbon dioxide carried in the blood?

b. as the bicarbonate ion in the plasma after first entering the red blood cells

Which of the following is NOT a form of lung cancer? a.adenocarcinoma b.Kaposi's sarcoma c.small cell carcinoma d.squamous cell carcinoma

b.Kaposi's sarcoma

The nose serves all of teh following functions EXCEPT: a.as a passageway for air movement b.as the direct initiator of the cough reflex c.warming and humidifying the air d.cleansing the air

b.as the direct initiator of the cough reflex

Select the correct statement about the physical factors influencing pulmonary ventilation. a.A decrease in compliance causes an increase in ventilation b.A lung that is less elastic will require less muscle action to perform adequate ventilation c.As alveolar surface tension increases, additional muscle action will be required d.Surfactant helps increase alveolar surface tension

c. As alveolar surface tension increases, additional muscle action will be required

Which statement about CO2 is incorrect? a.Its concentration in the blood is decreased by hyperventilation b.Its accumulation in the blood is associated with a decrease in pH c.More CO2 dissolves in the blood plasma than is carried in the RBCs d.CO2 concentrations are greater in venous blood than arterial blood.

c. More CO2 dissolves in the blood plasma than is carried in the RBCs

Which of the following counteracts teh movement of bicarbonate ions from the RBC? a.the Bohr effect b.the Haldane effect c.Chloride shifting d.Release of hydrogen ion

c.Chloride shifting

The erythrocyte count increases after a while when an individual goes from a low to a high altitude because the __________.

concentration of oxygen and/or total atmospheric pressure is lower at high altitudes

Select the correct statement about oxygen transport in the blood. a.during normal activity, a molecule of hemoglobin returning to the lungs carries one molecule of O2 b.During conditions of acidosis, hemoglobin is able to carry oxygen more efficiently c.Increased BPG levels in the red blood cells enhance oxygen-carrying capacity d.A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level that is higher than normal

d. A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level that is higher than normal

Which of the following determines lung compliance? a.Airway opening b.Flexibility of the thoracic cage c.muscles of inspiration d.alveolar surface tension

d. alveolar surface tension

Which of the following incorrectly describes mechansims of CO2 transport? a.7-10% of CO2 is dissolved into the plasma b.20% of CO2 is carried in the form of carbaminohemoglobin c.as bicarbonate ion in plasma d.attached to the heme part of hemoglobin

d. attached to the heme part of hemoglobin

Which of the fllowing does NOT influence hemoglobin saturation? a.temperature b.BPG c.carbon dioxide d.nitric oxide

d. nitric oxide

The law of partial pressure is called the ________ law.

dalton's

Which of the disorders below is characterized by destruction of the walls of the alveoli producing abnormally large air spaces that remain filled with air during exhalation?

emphysema

Possible causes of hypoxia include:

too little oxygen in the atmosphere

Changes in arterial pH can modify respiration rate and rhythm even when carbon dioxide and oxygen levels are normal.

true

Strong emotions and pain acting through the limbic system activate sympathetic centers in the hypothalamus, thus modulating respiratory rate and depth by sending signals to the respiratory centers.

true

The local matching of blood flow with ventilation is:

ventilation-perfusion coupling

The lung volume that represents the total volume of exchangeable air is the:

vital capacity

Factors that influence the rate and depth of breathing include:

voluntary cortical control