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