Respiratory system

The partial pressures of carbon dioxide pCO2 and oxygen PO2 in the atmosphere at sea level are 0.3 mm Hg and 160 mm Hg respectively, but the partial pressures of these gases in blood leaving the lungs are 40 mmHg P CO2 mm Hg and 95 mm Hg p O2. What factor most likely accounts for this difference?

CO2 is more soluble in the blood than O2

Which of the following has the greatest effect on respiration rate?

PCO2

Which respiratory center is not located in the medulla oblongata?

PRG

The rate of oxygen diffusion across the respiratory membrane depends upon all of the following except:

Partial pressure of carbon dioxide in the blood

The pressure exerted by each type of gas in a gas mixture is?

Partial pressure of that gas

Apneustic breathing occurs as a result of damage to which respiratory center?

Pontine respiratory group

All of the following are part of the conduction zone except?

Respiratory bronchioles

Which of the following delivers air to the lobes of the lungs?

Secondary Bronchi

Surfactant decreases the __________ in the alveoli.

Surface tension

The majority of carbon dioxide is transported as

bicarbonate ions

If the mouth and nose are closed at the peak of a complete inspiration, but before expiration, and the breath is held, what is the pressure of gases within the alveoli relative to the pressure of atmospheric air?

Alveolar pressure is greater than the pressure of atmospheric air

Hemoglobin has the highest affinity for which of the following?

CO

How might central and peripheral chemoreceptors compare with regard to their role in the detection of respiratory gases resulting from a prolonged period of hypoventilation?

Central chemoreceptors and peripheral chemoreceptors may both respond to the resultant increase in pCO_2 but only peripheral chemoreceptors could respond to the decrease in pO2

An increase in the volume of a container filled with air would have what effect on the pressure of the container?

Decrease the pressure

What produces the force which drives normal exhalation, and is the process active or passive?

Elastic Force, passive

The structure that prevents food from entering the airway

Epiglottis

In a situation where the respiratory bronchioles become inflamed and narrowed, such as is seen in asthma, which aspect of respiration would be most mechanically impaired?

Forced expiration

Divers developing the "bends" is a clinical application of which gas law?

Henry's Law

In the tissues, hemoglobin will release some oxygen and bind to

Hydrogen ions

A decrease in pH will have what effect on the respiration rate?

Increase

Many respiratory diseases affect pulmonary function by altering the ability of alveoli to participate in gas exchange. What physical change would most greatly reduce the degree to which a particular alveolus is ventilated?

Increased alveolar elastic recoil

When holding our breath for a long time we get the urge to breathe because of

an increase in CO2

The amount of air that can forcefully inhaled after a normal tidal volume inspiration is termed the

Inspiratory reserve volume

Air passing from the pharynx to the trachea must pass through the

Larynx

Bronchodilators are a class of drug often used in the treatment of asthma and COPD, which act on β-adrenergic receptors of the airways to induce smooth muscle relaxation. The anatomic distribution of these receptors is closely correlated to the function of each structural component of the lungs. What structural component(s) of the airway would be most affected by the use of a bronchodilator, and in what functional zone(s) are they found?

Lobar bronchi, which are found in the conducting zone

The inflation reflex depends upon stimulation of which type of receptor?

Mechanoreceptors

Which is not one of the three main factors that influences external respiration?

Temperature of the respiratory membrane

Which of the following statements is false in regards to inspiration ?

The diaphragm is relaxed

Which of the following will increase hemoglobin's affinity for oxygen?

The presence of some O2 already bound to the hemoglobin

What is the pressure of gas within the alveoli at the peak of inspiration, just before expiration, relative to that of atmospheric air?

The same as atmospheric air

The atoms apple is located on which cartilage?

Thyroid cartilage

Which of the following is responsible for keeping the lungs from collapsing?

Transpulmonary pressure

The chloride shift refers to

chloride ions moving into or out of the red blood cell

Low PO2 and high PCO2 in the alveoli will cause __________ .

constriction of pulmonary capillaries and dilation of bronchioles