physiology: respiratory: exam 4
respiratory alkalosis
Caused by excessive elimination of carbon dioxide
Respiratiory Acidosis
Caused by excessive retention of carbon dioxide
low local PCO2...
Causes local bronchoconstriction, diverting air away from poorly perfused areas
low local PO2
Causes local pulmonary arteriolar vasoconstriction, diverting blood away from poorly ventilated areas; mitigates detrimental effect
Identify the term for an instrument used to measure respiratory volumes in pulmonary function tests.
spirometer
Doubling the amount of carbon dioxide in inspired air ______.
stimulates chemoreceptors and increases ventilation
At an air-water interface, the attractive forces between the water molecules, known as _____ , make the water lining like a stretched balloon that constantly tends to shrink and resists further stretching.
surface tension
At an air-water interface, the attractive forces between the water molecules, known as ____________, make the water lining like a stretched balloon that constantly tends to shrink and resists further stretching.
surface tension
A leading cause of death in premature infants is respiratory distress syndrome. It affects infants who are deficient in the production of _________
surfactant
What is secreted by type II alveolar cells and reduces the surface tension between water molecules on the alveolar surface?
surfactant
Compared to the resting state, in which of these blood vessels does PO2 usually remain unchanged during moderate exercise?
systemic arterial
The pressure a gas exerts is proportional to _____ and the _____ of the gas.
temperature ; concentration
Increasing the ______ of gas molecules increases their ______, and this ______ the pressure it exerts.
temperature ; rate of movement ; increases
With regard to gas properties, Henry's law states ______.
that the amount of gas dissolved in a liquid will be directly proportional to the partial pressure of the gas with which it is in equilibrium
The most effective way to increase alveolar ventilation is to increase ______.
the depth of breathing
The major cause of the slight ventilation-perfusion inequality observed in most healthy people at rest is ______.
the differential effect of gravity on blood flow and airflow in the lung
At the end of an unforced expiration when the respiratory muscles are relaxed and there is no airflow, ______.
the intrapleural pressure is less than atmospheric pressure
The concentration of a gas dissolved in a liquid is directly proportional to ______. the partial pressure of the gas the solubility of the gas in the liquid the molecular weight of the gas the temperature of the liquid
the partial pressure of the gas the solubility of the gas in the liquid
The most important determinant of airway resistance is ______.
the radius of the airways
When airway radius decreases, ______.
the resistance to airflow increases
How does a reduction in local alveolar PO2 affect nearby arterioles?
they constrict
The total ventilation per minute—the minute ventilation—is equal to the _____ volume multiplied by the respiratory _____.
tidal ; rate
What term describes the volume of gas inspired or expired in an unforced respiratory cycle?
tidal volume
the lungs consist mainly of...
tiny air containing sacs called alveoli
step 3 in the respiratory cycle:
transport of O2 and CO2 through pulmonary and systemic circulation by bulk flow
During the inspiratory portion of a respiratory cycle, the airway resistance is reduced because the distending force exerted by the positive ______ pressure keeps the smaller airways that lack cartilage from collapsing.
transpulmonary
The specific name for the difference in pressure between the inside of the alveoli and the intrapleural space is the ______ pressure.
transpulmonary
during inspiration, _____ increases
transpulmonary
During moderate exercise, the alveolar and arterial PCO2 do not change.
true
It is not necessary for minute ventilation to increase significantly unless arterial PO2 decreases below 60 mmHg, because the saturation of hemoglobin with oxygen does not decrease significantly until the PO2 decreases below 60 mmHg.
true
Respiration can be voluntarily altered so that PCO2 and PO2 deviate from their normal homeostatic values.
true
airways:
tubes through which air flows between external environment and lung alveoli and back
During strenuous exercise systemic there is a decrease in ______ PO2.
venous
During strenuous exercise, blood PCO2 levels increase in systemic ______ blood.
venous
A mismatch of alveolar airflow and capillary blood flow in the lung is known as _____-_____ inequality.
ventilation-perfusion
The maximal amount of air that can be expired after a maximal inspiration is called _________
vital capacity
Which best describes the pattern of respiratory neuron firing during exercise?
Neurons to inspiratory muscles fire during the inhale, and neurons to expiratory muscles fire during the exhale.
restrictive diseases...
Normal ratio of FEV1 to vital capacity
Which structures are part of the anatomical dead space? Nose Alveoli Bronchi Trachea
Nose Bronchi Trachea
Which is the best indicator that hypoventilation is occurring?
Systemic arterial PCO2 is above normal.
Which of these is the best indicator that hyperventilation is occurring?
Systemic arterial PCO2 is below normal.
List some of the major components of pulmonary surfactant. Proteins Bile salts Phospholipids Carbonic anhydrase Enzymes
Proteins Phospholipids
obstructive diseases...
Reduced ratio of FEV1 to vital capacity
Which of the following is characteristic of restrictive lung disorders?
Reduced vital capacity, but normal ratio of FEV1 to vital capacity
Which term describes an acid-base disorder involving increased PCO2?
Respiratory acidosis
When a person loses a significant amount of H+ from the body due to vomiting, which of these describes how the respiratory system helps to compensate?
Ventilation is decreased and arterial PCO2 is increased, changing H+ levels back toward normal.
The sum of the expiratory reserve volume, tidal volume, and inspiratory reserve volume is equal to which of these?
Vital capacity
Hypoventilation exists when there is an increase in the ratio of carbon dioxide production to _____ ventilation.
alveolar
hyperventilation:
alveolar PCO2 and systemic arterial PCO2 decreases
The volume of air located in non-functional alveoli makes up the _____ space.
alveolar dead
The volume of fresh inspired air that enters alveoli that have no associated blood supply is known as the _____ space.
alveolar dead
The value that is calculated by the equation (Tidal volume − Dead space) × Respiratory rate is the _____ rate.
alveolar ventilation
In pulmonary edema, some of the _____ may become filled with fluid.
alveoli
The main sites of gas exchange between atmospheric air and the bloodstream are the ______.
alveoli
a decrease in volume causes
an increase in pressure
The volume of fresh atmospheric air entering the alveoli during each inspiration equals the tidal volume minus the _____ space.
anatomical
The air that remains in the conducting airways during a respiratory cycle is termed _____ space (VD).
anatomical dead
A deficiency of red blood cells and/or hemoglobin in the blood is termed _____.
anemia
When the hemoglobin concentration of blood is below normal (due to low hematocrit for example), the condition is called...
anemia
The most important inputs to the medullary respiratory neurons come from chemoreceptors called the _____ and _____ bodies.
aortic ; carotid
Fine-tunes activity of the medullary inspiratory neurons and helps terminate inspiration:
apneutsic center
Which systemic blood compartment does not usually increase in PCO2 during exercise?
arterial
For this figure showing the effects of increasing levels of exercise, indicate which labels should be associated with the Y-axis for each graph. C is...
arterial PCO2
When a person gradually goes from a resting state to one of maximal exercise, which of the following normally decreases?
arterial PCO2
For this figure showing the effects of increasing levels of exercise, indicate which labels should be associated with the Y-axis for each graph. B is...
arterial PO2
For this figure showing the effects of increasing levels of exercise, indicate which labels should be associated with the Y-axis for each graph. D is...
arterial [H+]
What does the arterial PCO2 most directly influence?
arterial pH
Most of the CO2 produced by tissues is transported to the lungs ______.
as dissolved HCO3- in the plasma
Inspiration is initiated by a burst of action potentials in the spinal motor neurons to inspiratory muscles like the diaphragm. Then the action potentials cease, the inspiratory muscles relax, and expiration occurs ______.
as the elastic lungs recoil
Which of the following is a disease characterized by intermittent episodes in which airway smooth muscle contracts strongly, markedly increasing airway resistance?
asthma
For airflow into or out of the lungs, the gas pressure at the nose and mouth is normally the ___________ pressure.
atmospheric
The factors that determine the precise value of alveolar PO2 are: 1) the PO2 of _____ air 2) the rate of alveolar _____ 3) the rate of total-body oxygen _____
atmospheric ; ventilation ; consumption
Surface tension that decreases the compliance of the lungs results from ______.
attraction forces between water molecules at the air-water interface within alveoli
Net diffusion of oxygen occurs from ______, while net diffusion of carbon dioxide occurs from ______.
blood to cells ; cells to blood
The physical principle stating that gas pressure in a closed space increases as its volume decreases is known as __________'s law
boyle
In the respiratory condition known as chronic _____, there are chronic inflammatory changes in small airways along with excessive mucus production in the bronchi.
bronchitis
The alveolar walls contain _________ , which carry the RBCs, and a very small ___________ space, which in many places is absent altogether.
capillaries ; interstitial
The respiratory quotient is greatest when tissues are metabolizing ______.
carbohydrates
Carbonic anhydrase catalyzes a reaction that converts ______.
carbon dioxide and water into carbonic acid
The gas _____ has a higher binding affinity for the heme site of hemoglobin than oxygen, and it also decreases the unloading of oxygen from hemoglobin in the tissues.
carbon monoxide
this enzyme is present in the erythrocytes, but not in the plasma, so this molecule and its reactions occurs mainly in the erythrocytes.
carbonic anhydrase
In healthy individuals, what is the limiting factor in strenuous exercise?
cardiac output
The predominant peripheral chemoreceptors involved in the control of respiration are the ______.
carotid bodies
step 5 of respiratory cycle:
cellular utilization of O2 and production of CO2
Of the two sets of receptors involved in the reflex response to increases in PCO2, the _____ chemoreceptors are the more important, accounting for about 70% of the increased ventilation.
central
What chemoreceptors are located within the medulla oblongata?
central
Voluntary control of breathing is accomplished by descending pathways from the _____ to the motor neurons of the respiratory muscles.
cerebral cortex
As blood passes through tissue capillaries, _____ ions move into red blood cells in exchange for bicarbonate ions, which move out of red blood cells.
chloride
What COPD is characterized by excessive mucus production in the bronchi and chronic inflammatory changes in the small airways and may be caused by a virus or smoking?
chronic bronchitis
Most of the oxygen diffusing into the blood from the alveoli ______. Therefore, the blood PO2 normally stays ______ than the alveolar PO2 until hemoglobin is virtually 100% saturated.
combines with hemoglobin ; lower
The physical characteristic of the lung that determines how much the volume changes for a given change in transpulmonary pressure is called the lung _____.
compliance
The physical characteristic of the lung that determines how much the volume changes for a given change in transpulmonary pressure is called the lung _______
compliance
with inspiration what is the flow of actions taking place?
diaphragm and inspiratory muscles contract thorax expands Pip becomes more subatmospheric increase in transpulmonary pressure lungs expand Palv beomes more subatmospheric air flows into alveoli
Is the partial pressure of a gas directly or indirectly proportional to its concentration?
directly
The relationship between O2 binding and partial pressure of oxygen is known as the oxygen-hemoglobin _____.
dissociation curve
Of the carbon dioxide transported from tissues to the lungs, 10% is ______, 25-30% is ______, and 60 to 65% is ______.
dissolved ; bound to hemoglobin ; converted to HCO3-
The presence of carbon monoxide ______ arterial PO2, and so peripheral chemoreceptors output is ______.
does not affect ; unaltered
Neurons of the _____ respiratory group primarily fire during inspiration, while the neurons of the _____ respiratory group contains expiratory neurons, and fires mainly when large increases in ventilation are required.
dorsal ; ventral
There are two main anatomical components of the medullary respiratory center: the _____ respiratory group and the _____ respiratory group.
dorsal ; ventral
The clinical term for "shortness of breath" is _____
dyspnea
The feeling that breathing is labored or difficult is called _____
dyspnea
When interstitial spaces and alveoli within the lung become filled with fluid, it is known as pulmonary _____
edema
The syndrome COPD (chronic obstructive pulmonary disease) includes which of the following? Parkinson's disease Cystic fibrosis Chronic bronchitis Emphysema Asthma
emphysema chronic bronchitis
if surface tension is decreased by surfactant, it makes the pressures _____. This is true because a bigger alveoli will have more volume than a smaller alveoli, which means that an increase in volume will cause a decrease in pressure, and a decrease in volume will cause an increase in pressure. surfactant decreases the surface tension which makes the lungs more compliant so the high pressure in the smaller alveoli will not have an affect on the pressure in the bigger alveoli.
equal
the pharynx branches into 2 tubes: 1. ______________: through which food passes through stomach 2. ______________: part of the airways, housing vocal cords
esophagus ; larynx
step 2 in the respiratory cycle:
exchange of O2 and CO2 between alveolar air and blood in lung capillaries by diffusion
step 4 of respiratory cycle:
exchange of O2 and CO2 between blood in tissue capillaries and cells in tissues by diffusion
step 1 in the respiratory cycle: ventilation:
exchange of air between atmosphere and alveoli by bulk flow
The additional volume of gas that can be expired after a tidal volume has just been is expired is known as the _____ volume.
expiratory reserve
During exercise, active expiration occurs by reversing the direction of action potentials along neurons to the inspiratory muscles.
false
Even a moderate reduction in the amount of hemoglobin in the blood (anemia) will stimulate peripheral chemoreceptors and cause an increase in ventilation.
false
If a liquid is exposed to two different gases having the same partial pressures, at equilibrium the concentration of gases in the liquid will always be identical.
false
Small increases in arterial PCO2 stimulate ventilation, but at very high PCO2 levels, the medullary respiratory centers are inhibited and ventilation can cease.
false
True or false: Minute ventilation and alveolar ventilation always increase and decrease in proportion to each other.
false
True or false: The diaphragm and intercostal muscles contract mainly involuntarily, and are composed of smooth muscle.
false
True or false: When a tissue's metabolic activity increases, the difference between oxygen saturation of hemoglobin in the incoming arteries and outgoing veins is usually less than at rest.
false
A person takes a maximal inspiration and then exhales maximally as fast as possible. The measurement for this is termed ____________ volume in 1 sec, or FEV1.
forced expiratory
A hemoglobin protein is composed of ______.
four polypeptide subunits, each attached to a heme group
Central chemoreceptors in the medulla oblongata stimulate ventilation when there is increased ______ ion concentration of the extracellular fluid of the brain.
hydrogen
A ventilation rate that removes CO2 from the body faster than it is produced is known as
hyperventilation
Reflexively induced ______ minimizes the change in arterial H+ concentration when acids are produced in excess in the body.
hyperventilation
increasing alveolar ventilation will cause
hyperventilation, an increase in alveolar PO2 and a decrease in alveolar PCO2
A ventilatory rate that results in increased systemic arterial PCO2 is known as _____.
hypoventilation
decreasing alveolar ventilation will cause
hypoventilation, a decrease in the alveolar PO2, and an increase in the alveolar PCO2
The respiratory rhythm generator is located ______.
in the pre-Bötzinger complex of neurons in the upper part of the VRG
If other factors remain the same, decreasing ventilation will ______ alveolar PCO2.
increase
With other factors remaining the same, if tissue metabolic rate increases, alveolar PCO2 will ______.
increase
When a person breathes a gas mixture that contains CO2, ______.
increased [H+] stimulates both central and peripheral chemoreceptors
What effect does an increase in plasma epinephrine concentration have on ventilation rate?
increased ventilation
during expiration, intrapleural pressure _____ and transpulmonary pressure _____
increases ; decreases
During inspiration as the lungs expand, transpulmonary pressure ______, and airway radius becomes ______ and airway resistance ______.
increases ; larger ; lower
during expiration, after the changes with the intrapleural pressure and transpulmonary pressure alveolar pressure _____ above atmospheric pressure, and air flows _____ of the lung
increases ; out
J receptors are stimulated by ______ in pulmonary interstitial fluid pressure, and the main reflex effects are ______.
increases ; rapid breathing and a dry cough
The extremely thin fluid layer that is between membranes surrounding the lungs and lubricates their surfaces is know as the ___________ fluid.
intrapleural
The hydrostatic pressure responsible for causing the lungs and thoracic wall to move in and out together during normal breathing is the ______.
intrapleural pressure
In addition to producing CO2, muscle cells generate _____ during strenuous anaerobic exercise, which causes an increase in arterial H+ concentration.
lactic acid
What is released into the blood during strenuous anaerobic exercise that causes the pH of blood to decrease?
lactic acid
Irritant receptors located between epithelial cells in the wall of the ______ cause coughing when stimulated by irritants. larynx trachea nose alveoli bronchi
larynx trachea bronchi
The process that holds airways open by elastic connective tissue fibers linking alveoli to surrounding tissues is called ________
lateral traction
The process that holds airways open by elastic connective tissue fibers linking alveoli to surrounding tissues is called...
lateral traction
What is the term used to describe how airways are pulled open during inspiration by elastic connective tissue fibers linking the outside of the airways to the surrounding alveolar tissue?
lateral traction
The factors that determine airway resistance are analogous to those determining vascular resistance in the circulatory system: tube ________ , tube _________ , and interactions between moving molecules (gas molecules, in this case).
length ; radius
Because the mitochondria of all cells are utilizing oxygen, the cellular PO2 is ______ the PO2 of the surrounding interstitial fluid. Therefore, oxygen is continuously diffusing ______ the cells.
less than ; into
The following graph shows the oxygen-hemoglobin dissociation curves of three different acidity levels. Match each curve to the appropriate medium. A = ...
low acidity
An exercising muscle consumes more oxygen, thereby ______ its intracellular and interstitial PO2. This ______ the blood-to-cell PO2 gradient.
lowering ; increases
surfactant _____ the surface tension, which increases _____. this makes it easier to expand the lung
lowers ; lung compliance
The vital capacity is best defined as the ______.
maximal volume expired
Central chemoreceptors are located within the region of the central nervous system called the _____.
medulla
The primary centers for controlling the alternation of inhaling and exhaling during respiration are located in the _____ region of the brainstem.
medulla oblongata
Very high levels of carbon dioxide act directly on the ______ ventilation.
medulla to inhibit
Action potentials in the afferent nerve fibers from the pulmonary stretch receptors travel to the brain and inhibit the activity of the _____ neurons.
medullary inspiratory
The acid-base disorder that involves an increase in arterial H+ concentration caused by something other than elevated PCO2 is known as _____
metabolic acidosis
There are many normal and pathological situations in which a change in arterial H+ concentration is due to some cause other than a primary change in PCO2. When H+ concentration is increased the condition is termed _____ , and when it is decreased, _____ occurs.
metabolic acidosis ; metabolic alkalosis
A decrease in arterial H+ concentration caused by something other than a change in arterial PCO2 is called ______.
metabolic alkalosis
For this figure showing the effects of increasing levels of exercise, indicate which labels should be associated with the Y-axis for each graph. A is...
minute ventilation
The _____ = tidal volume × respiratory rate.
minute ventilation
At a PO2 of 40 mmHg, the fetal isoform of hemoglobin binds ______ oxygen compared to the adult isoform.
more
inspiration (inhalation):
movement of air from external environment, through airways, into alveoli during breathing
Compared to the diameter of a red blood cell, the alveolar and endothelial cell barrier that separates alveolar air from capillary blood is ______.
much thinner
Chronic bronchitis is characterized by excessive production of _____ in the bronchi and chronic inflammatory changes in the small airways.
mucus
Chronic bronchitis is characterized by excessive production of _________ in the bronchi and chronic inflammatory changes in the small airways.
mucus
when lung compliance is abnormally low, more stiff, intrapleural pressure (Pip) must be made even more subatmospheric, or _____, than normal inspiration to achieve _____. This means there is a _____ increase in _____ for any given increase in _____.
negative ; lung expansion ; lesser ; lung volume ; transpulmonary pressure
Restrictive lung diseases are characterized by ______ airway resistance and ______ respiratory movements.
normal ; impaired
The following graph shows the oxygen-hemoglobin dissociation curves of three different acidity levels. Match each curve to the appropriate medium. B = ...
normal arterial acidity
upper airways consist of:
nose, mouth, pharynx, larynx
respiratory cycle:
one complete inspiration and expiration
Conditions causing purely diffusional problems in the alveoli like pulmonary edema and interstitial fibrosis typically restrict movement of which gas the most?
oxygen
As blood flows through pulmonary capillaries, there is net diffusion of ______.
oxygen into the blood and carbon dioxide out of the blood
When arterial PO2 is near a normal value of 90-100 mmHg, minute ventilation will not increase with small reductions in arterial PO2 because ______.
oxygen-hemoglobin saturation does not decrease significantly
The term used to designate hemoglobin that is bound to oxygen is
oxyhemoglobin
The aortic bodies and carotid bodies are locations for ______ chemoreceptors involved in the automatic control of ventilation.
peripheral
When the PO2 of arterial blood decreases significantly, the _____ chemoreceptors stimulate ventilation.
peripheral
Both _____ and _____ chemoreceptors can initiate pathways by which increased arterial PCO2 stimulates ventilation.
peripheral ; central
During inspiration, air passes through the nose or the mouth (or both) into the _________, a passage common to both air and food.
pharynx
The structure that is posterior to the oral cavity, and which is a common pathway for food moving toward the esophagus and air moving toward the larynx, is called the ______
pharynx
What structure would air flow through next after passing through the nose?
pharynx
during inspiration, air passes through the nose or mouth (or both) into the _________
pharynx
when activation of the motor neurons within the _____ innervating the _____ causes it to contract, its dome moves _____.
phrenic nerve ; diaphragm ; downwards into abdomen
Air that is inspired but does not participate in gas exchange with blood flowing through the lungs is referred to as _____ space.
physiologic dead
The sum of the anatomical and alveolar dead spaces is known as the _____ space
physiological
Fetal hemoglobin binds considerably more oxygen than adult hemoglobin at any given PO2. This allows an increase in oxygen uptake across the _____ diffusion barrier.
placental
Helps to smooth transitions between inspiration and expiration:
pneumotaxic center
The _____ respiratory group helps smooth the transition between inspiration and expiration.
pontine
because the lungs alway shave air in them, the Ptp of the lungs must always be _____ so, Palv > Pip
positive
By definition, if there is no airflow and the airways are open to the atmosphere, Palv must equal Patm. Because the lungs always have air in them, the transmural pressure of the lungs (Ptp) must always be ______; therefore, ______.
positive ; Palv > Pip
The impaired diffusion of gases between alveoli and capillaries due to fluid filling the alveoli is referred to as which condition?
pulmonary edema
Which of these reside in the airway smooth muscle and produce signals that terminate inspiration?
pulmonary stretch receptors
The substance 2,3-DPG, which is produced by ______, binds to hemoglobin and ______ its affinity to oxygen.
red blood cells ; decreases
During the entire respiratory cycle, which chamber of the heart pumps blood into the pulmonary arteries?
right ventricle
The ______ shape of the oxygen-hemoglobin dissociation curve indicates ______ among the subunits of hemoglobin for oxygen binding.
sigmoidal ; cooperativity
alveoli:
sites of gas exchange with the blood
The muscles of respiration are composed of ______.
skeletal muscle
The more compliant a person's lungs, the ______ the amount of force that must be generated by inspiratory muscles to expand them.
smaller
Receptors found between epithelial cells of the nose and pharynx cause a reflex called _____ when stimulated by irritant particles.
sneeze
how do you find partial pressures?
% x mmHg =
The following events occur in the reflex to low arterial PO2. Place them in sequence, starting with the earliest at the top. 1. decrease in inspired PO2 2. decrease in alveolar PO2 3. decrease in arterial PO2 4. increase in firing of peripheral chemoreceptors 5. increase in contraction of respiratory muscles 6. increase in ventilation 7. return of alveolar and arterial PO2 toward normal
1. decrease in inspired PO2 2. decrease in alveolar PO2 3. decrease in arterial PO2 4. increase in firing of peripheral chemoreceptors 5. increase in contraction of respiratory muscles 6. increase in ventilation 7. return of alveolar and arterial PO2 toward normal
The following are events that occur during inspiration. Place them in sequence, with the first at the top of the list. 1. diaphragm and inspiratory intercostals contract 2. thorax expands 3. Pip becomes more subatmospheric 4. increase in transpulmonary pressure 5. lung expands 6. Palv becomes more subatmospheric 7. air flows into alveoli
1. diaphragm and inspiratory intercostals contract 2. thorax expands 3. Pip becomes more subatmospheric 4. increase in transpulmonary pressure 5. lung expands 6. Palv becomes more subatmospheric 7. air flows into alveoli
In a normal, healthy person at rest, the PO2 in alveolar air and the blood first reaches diffusion equilibrium when the blood has traveled approximately ______% of the length of the pulmonary capillary.
30
How many oxygen molecules can bind to a single hemoglobin molecule?
4
The number of polypeptide subunits that make up a molecule of hemoglobin is...
4
The partial pressure of O2 in pulmonary artery blood:
40 mmHg
In a normal resting person, the systemic venous PO2 is approximately ______ and hemoglobin is approximately ______ saturated with O2.
40 mmHg ; 75%
At an altitude where the total atmospheric pressure is 200 mmHg, what is the partial pressure of oxygen in the atmosphere?
42 mmHg
The partial pressure of CO2 in pulmonary artery blood:
46 mmHg
Typical cardiac output in liters per minute...
5
Total oxygen transport by the blood is not really decreased very much until the arterial PO2 decreases below about ______.
60 mmHg
In a plot of minute ventilation (Y-axis) vs arterial PO2 (X-axis), the minute ventilation increases most steeply when PO2 decreases from ______.
60 to 50 mmHg
Atmospheric air consists of approximately 79% nitrogen. Therefore, the PN2 of atmospheric air at sea level is about ______.
600 mmHg
Red blood cells have an average diameter of approximately ______, and the thickness of the barrier separating alveolar air from pulmonary capillary blood is approximately ______.
7 micrometers ; 0.2 micrometers
What is the percent oxygen saturation of hemoglobin in a typical resting person's systemic venous blood?
75 %
At the typical atmospheric pressure found at sea level, a jar containing 10% oxygen would have an oxygen partial pressure of _____ mmHg.
76 mmHg
According to the oxygen-hemoglobin dissociation curve, at a PO2 of 60 mmHg, approximately ______% of the total hemoglobin is combined with oxygen.
90
In a normal systemic arterial blood sample, approximately what fraction of the total oxygen content is bound to hemoglobin?
98.5 %
Which of these would not stimulate peripheral chemoreceptors and result in an increase in ventilation? Change in the PO2 of systemic arterial blood to a value of 50 mmHg Change in the pH of arterial blood to a value of 7.1 A 10% reduction in the amount of hemoglobin in the blood Inhaling atmospheric air containing 5% carbon dioxide Inhaling atmospheric air containing a trace concentration of carbon monoxide
A 10% reduction in the amount of hemoglobin in the blood Inhaling atmospheric air containing a trace concentration of carbon monoxide
In this figure, the letters A, B and C represent the pressures in each region. Which of these equations defines the transpulmonary pressure (Ptp)?
B - C
What colorless, odorless gas has an affinity for the oxygen-binding sites on hemoglobin that is 210 times greater than that of oxygen?
Carbon monoxide
What sensory receptors are normally dormant but are stimulated by an increase in lung interstitial pressure caused by fluid collecting in the interstitium?
J receptors
Ventilation is stimulated during exercise by an increase in the plasma ______ concentration due to movement of this ion out of the exercising muscles.
K+
What is the term describing the volume of air in alveoli that is normally ventilated but which has lost its blood supply?
Alveolar dead space
Which of the following reduces the oxygen saturation of hemoglobin at a given PO2?
An increase in 2,3 DPG
Afferent neural activity from peripheral chemoreceptors is stimulated by which of the following? A decrease in arterial PCO2 A decrease in arterial [H+] An increase in arterial [H+] An increase in arterial PO2 A decrease in arterial PO2
An increase in arterial [H+] A decrease in arterial PO2
When areas of the lung have normal blood flow but the alveolar ventilation to the area is blocked, it is referred to as ______.
a shunt
The following represent mechanisms by which carbon dioxide is transported in the body. Match each to its appropriate percentage. Dissolved in plasma:
about 10 %
The following represent mechanisms by which carbon dioxide is transported in the body. Match each to its appropriate percentage. In the form of carbamino compounds:
about 25 - 30 %
The following represent mechanisms by which carbon dioxide is transported in the body. Match each to its appropriate percentage. In the form of carbonic acid:
about 60 - 65 %
Hypoventilation can lead to a reduction in CO2, a clinical condition known as respiratory...
acidosis
An increase in arterial H+ concentration due to CO2 retention is termed respiratory _____ and a decrease in arterial H+ due to excess exhalation of CO2 is termed respiratory _____.
acidosis ; alkalosis
expiration (exhalation):
air movement in the opposite direction from inspiration; from the alveoli, into the airways, into the external environment
Hyperventilation can lead to a reduction in CO2, a clinical condition known as respiratory _____
alkalosis
Hyperventilation can lead to a reduction in CO2, a clinical condition known as respiratory _____.
alkalosis
Hyperventilation can lead to a reduction in CO2, a clinical condition known as respiratory...
alkalosis
CO2 and H+ influence the affinity of hemoglobin to oxygen by combining with the globin portion and altering the conformation of the entire hemoglobin molecule. Therefore, these effects are a form of _____ modulation.
allosteric
The partial pressure of O2 in pulmonary venous blood:
100 mmHg
Total milliliters of oxygen normally delivered by systemic arterial blood each minute...
1000
The partial pressure of O2 in alveolar air:
105 mmHg
Milliliters of oxygen normally bound to hemoglobin in 1 liter of systemic arterial blood...
197
Over what range of PO2 values does the oxygen-hemoglobin dissociation curve undergo the largest change in oxygen saturation?
20 - 60 mmHg
The total milliliters of oxygen dissolved and bound to hemoglobin in 1 liter of systemic arterial blood is approximately ______.
200
Consider a typical male at rest with a respiratory quotient (RQ) of 0.8. This likely indicates that his oxygen consumption is approximately ______ and his carbon dioxide production is approximately ______.
250 mL/min ; 200 mL/min
Milliliters of oxygen normally dissolved in 1 liter of systemic arterial blood...
3
Which are drugs used to treat the condition asthma?
Anti-cholinergic drugs Beta-2 adrenergic receptor agonists Leukotriene inhibitors Glucocorticoids
Which are categories of drugs used to treat asthma?
Anti-inflammatory drugs Bronchodilator drugs
Which is true about the effect of arterial PCO2 on ventilation?
Any increase in PCO2 above 40 mmHg will result in a large increase in ventilation.
Despite the fact that large quantities of acid-forming CO2 enters the blood as it passes through the tissues, systemic venous blood is only slightly lower in pH than arterial blood. Why is that?
Because H+ binds to hemoglobin.
Which is TRUE about carbon dioxide in a typical person breathing normally at rest?
Blood leaving the lungs contains more than 90% of the amount of the total carbon dioxide that it contained when entering the lungs.
Which respiratory group primarily has input to the spinal motor neurons that activate the diaphragm and inspiratory intercostal muscles?
Dorsal respiratory group
In tissue capillary blood, what ion moves into red blood cells in exchange for bicarbonate ions that are leaving the red blood cells?
Cl-
In this experiment, oxygen molecules are depicted as the small clear circles, and the large balls are hemoglobin. Which is TRUE about the state shown?
Compartment A and B have the same PO2.
Which is TRUE about alveolar and atmospheric pressures with regards to bulk flow of air in the respiratory system?
During an expiration alveolar pressure is greater than atmospheric pressure.
______ has a much greater affinity for H+ than does ______, so it binds (buffers) most of the H+. In this form, hemoglobin is abbreviated ______.
Deoxyhemoglobin ; oxyhemoglobin ; HbH
Which of these acts as a hormone and relaxes airway smooth muscle?
Epinephrine
Which of the following statements is true about the effect of factors on airway smooth muscles?
Epinephrine relaxes them, while the leukotrienes contract them.
Which of the following increases oxygen transfer from a mother to a fetus?
Fetal hemoglobin, which has a higher affinity for oxygen than adult hemoglobin
Apneustic center:
Fine-tunes activity of the medullary inspiratory neurons and helps terminate inspiration
Which respiratory volume takes into consideration the rate at which air is exhaled?
Forced expiratory volume
Carbonic anhydrase catalyzes a reaction that combines which of the following?
H2O and CO2
Which is most likely true about a person with an abnormally low FEV1 measurement?
He has an obstructive lung disease.
Pneumotaxic center:
Helps to smooth transitions between inspiration and expiration
The amount of a gas dissolved in a liquid is directly proportional to the partial pressure of the gas with which the liquid is in equilibrium. This relationship is known as _____ Law.
Henry's
Which of these reflexes involves action potentials in afferent nerve fibers from pulmonary stretch receptors?
Hering-Breuer reflex
If a man ascended rapidly in a helicopter from sea level to the top of a mountain, but he maintained the same rate and depth of ventilation he was using at sea level, which of these changes would be most prominent at the higher altitude?
His alveolar PO2 would be lower than normal.
The single capital letter _____ designates the group of sensory receptors that are stimulated when accumulated fluid in lung interstitial fluid volume increases the pressure in that space.
J
Which best describes the condition in which a patient has increased arterial PCO2, decreased arterial PO2, and increased arterial [H+]?
Hypoventilation
Type ______ alveolar cells secrete _______ which reduces the cohesive forces between water molecules on the alveolar surface and makes it easier to expand the lungs.
II ; surfactant
Which of the following statements is true regarding carbon monoxide? It distorts the sigmoid shape of the oxygen-hemoglobin dissociation curve. It decreases the oxygen-carrying capacity of the blood. It binds to the globin portion of hemoglobin. It binds to the heme portion of hemoglobin. It maintains the sigmoid shape of the oxygen-hemoglobin dissociation curve. It increases the oxygen-carrying capacity of the blood.
It distorts the sigmoid shape of the oxygen-hemoglobin dissociation curve. It decreases the oxygen-carrying capacity of the blood. It binds to the heme portion of hemoglobin.
What does the law of Laplace state about alveolar pressure?
It is proportional to surface tension and inversely proportional to radius of an alveoli.
What is physiological dead space?
It is the anatomical and alveolar dead space combined.
In the absence of other changes, which of the following would NOT increase the PO2 in the alveoli?
Increasing the rate of total body oxygen consumption
Which of these would not stimulate peripheral chemoreceptors and result in an increase in ventilation? Inhaling atmospheric air containing 5% carbon dioxide Change in the pH of arterial blood to a value of 7.1 Inhaling atmospheric air containing a trace concentration of carbon monoxide Change in the PO2 of systemic arterial blood to a value of 50 mmHg A 10% reduction in the amount of hemoglobin in the blood
Inhaling atmospheric air containing a trace concentration of carbon monoxide A 10% reduction in the amount of hemoglobin in the blood
Which of the following is the term that describes the additional amount of air that can be inspired after a normal tidal volume is inhaled?
Inspiratory reserve volume
What is the correct definition for spirometer?
Instrument used to measure respiratory volumes
Which of the following statements is true?
Intracellular PO2 of a metabolizing tissue cell is lower than in arteriolar blood, and the intracellular PCO2 is higher than in arteriolar blood.
As carbon dioxide enters the blood in tissues and H+ and HCO3- are produced, what buffers the concentration of H+?
It binds to hemoglobin.
Which of these is a paracrine factor that increases airway resistance as part of the inflammation response?
Leukotrienes
Which of the following can result from very high levels of arterial blood PCO2? Loss of consciousness Severe headaches Inhibition of ventilation A large increase in arterial blood pH
Loss of consciousness Severe headaches Inhibition of ventilation
Which best describes inspiration?
Movement of air from the atmosphere into the respiratory tract
when Palv is greater than Patm:
Palv - Patm is positive and airflow is outward - expiration
how to measure transpulmonary pressure:
Palv - Pip
transpulmonary pressure at rest
Palv - Pip: 0 - (-4) = 4 mmHg pressure difference holding lungs open, which opposes inward elastic recoil of the lung which is what they want to do, the lungs want to go inward
As blood flows through systemic capillaries, the partial pressure of ______ in the blood decreases and the partial pressure of ______ in the blood increases.
O2 ; CO2
In an experiment, two sides of a chamber (A and B) separated by a semipermeable membrane initially contain solutions with equal quantities of dissolved oxygen. If hemoglobin molecules (which cannot penetrate the membrane) are added to the solution on side A, what will occur?
Oxygen will diffuse from side B to side A until an equilibrium is reached with both sides having equal PO2, but side A having more total oxygen.
What happens to the arterial blood when a person hypoventilates?
PCO2 increases and pH decreases
Which of the following lists two gas partial pressures that have the same value in a typical person at rest?
PO2 in systemic venous blood PCO2 in pulmonary venous blood
when Palv is less than Patm:
Palv - Patm is negative and airflow is inward - inspiration
Which term is used to describes the amount of bound oxygen carried by red blood cells?
Percent hemoglobin saturation
during inspiration, Palv and Pip both become more subatmospheric, which one of these comes first
Pip
chest wall pressure at rest
Pip - Patm: -4 - 0 = -4 mmHg pressure difference holding chest wall in, which opposes outward elastic recoil of the chest wall which is what the chest wants to do, the chest wants to go outward
How does surfactant affect the Law of Laplace, as it applies to alveoli?
Surfactant concentrates as alveoli become smaller, decreasing their surface tension.
During a normal cycle of respiration, there is a pause prior to inspiring a breath, and a pause in between inspiring and expiring the breath. Which of these conditions is the SAME during those two pauses? The alveolar pressure Atmospheric pressure Volume of the lung Transpulmonary pressure Intrapleural pressure Air flow
The alveolar pressure Atmospheric pressure Air flow
Which lists two quantities that are typically equal in a person breathing normally for 1 minute at rest?
The amount of oxygen crossing from alveolar air into the blood; the amount of oxygen consumed by tissue cells
Which is most likely to be true about blood in the veins coming from a tissue with increased metabolic activity (like an exercising muscle)?
The hemoglobin will be less than 75% saturated.
Which of the following statements regarding the solubility of a gas is true?
The more soluble the gas, the greater its concentration will be at any given partial pressure.
After a gas dissolves in a liquid and equilibration occurs between the gaseous and liquid compartments, which of the following quantities is always equal?
The partial pressure of the gas in the two phases
Which portion of the oxygen-hemoglobin dissociation curve provides a safety factor that maintains arterial oxygen saturation in situations where hypoventilation occurs?
The plateau portion of the curve, from 60 to 100 mmHg
What are the two main determinants of lung compliance? The diameter of the large airways The surface tension at the air-water interfaces within the lungs The amount and distensibility of connective tissues making up the lung tissue The presence or absence of tracheal rings in airways The viscosity of gases in the inspired and expired air
The surface tension at the air-water interfaces within the lungs The amount and distensibility of connective tissues making up the lung tissue
What are the two main determinants of lung compliance? The surface tension at the air-water interfaces within the lungs The amount and distensibility of connective tissues making up the lung tissue The viscosity of gases in the inspired and expired air The presence or absence of tracheal rings in airways The diameter of the large airways
The surface tension at the air-water interfaces within the lungs The amount and distensibility of connective tissues making up the lung tissue
The pressure of a gas within a closed, rigid-walled container depends on which two of these? The pressure in the atmosphere surrounding the container The thickness of the container's walls The temperature of the gas The number of atoms in each molecule of the gas The concentration of the gas
The temperature of the gas The concentration of the gas
Which of the following best describes the oxygen-hemoglobin dissociation curve at blood PO2 values between 60 mmHg and 100 mmHg?
There is a plateau in which little change in oxygen saturation occurs.
Which of these would decrease the compliance of the lung?
Thickening of the connective tissues present in the lungs
Fetal hemoglobin has ______ affinity for oxygen compared to adult hemoglobin.
a higher
What are the main adaptive effects of pulmonary arterial blood vessel vasoconstriction and bronchoconstriction? To redirect air toward diseased or damaged alveoli To supply more blood flow to poorly ventilated areas To redirect air away from diseased or damaged alveoli To supply less blood flow to poorly ventilated areas
To redirect air away from diseased or damaged alveoli To supply less blood flow to poorly ventilated areas
Which correctly describes the change in atmospheric oxygen with increasing altitude?
Total barometric pressure decreases, so the oxygen partial pressure decreases.
The resistance of small airways is reduced by a distending force resulting from the pressure inside the airway being greater than the pressure outside of the airway. What is the term describing that pressure gradient?
Transpulmonary pressure
Which of these is a step occurring during normal resting expiration?
Transpulmonary pressure decreases back toward its pre-inspiration value.
an increase in volume causes
a decrease in pressure
pharynx:
a passage common to both air and food
Receptors found between epithelial cells in the larynx, trachea, and bronchi typically cause _____ in response to irritants
coughing
Pressures of individual gases are independent of each other in a mixture of different gases. This is a statement of _____'s law.
dalton
According to _____ law, the total pressure of a gas mixture is ______ to the sum of the _____ of individual gases in the mixture.
daltons ; equal ; partial pressures
What gas law states that in a mixture of gases, the pressure that each gas exerts is independent of the pressure the other gases exert?
daltons law
What goes in the blank in this equation? Alveolar ventilation = (tidal volume −______) × respiratory rate
dead space
During strenuous exercise, a person may hyperventilate; thus, alveolar and systemic arterial PCO2 may actually ______.
decrease
In the lung, a local ______ in blood flow results in a local ______ in PCO2, which causes ______.
decrease ; decrease ; bronchoconstriction
Increased plasma PCO2 directly results in ______.
decreased plasma pH
lateral traction _____ airway resistance in inspiration
decreases
An increase in H+______ hemoglobin's affinity to oxygen by binding to the ______ portion of hemoglobin.
decreases ; globin
Carbon dioxide ______ the affinity of hemoglobin for oxygen by binding to the ______ portion of hemoglobin.
decreases ; globin
The term for hemoglobin without bound oxygen is...
deoxyhemoglobin
in a healthy adult, at rest, approximately 4 L of ________ enters and leaves the ________ per minute, while 5 L of blood, the ___________ flows through the ___________. during heavy exercise, the airflow can ___________ 20 - fold and the blood from 5-6 - fold
fresh air ; alveoli ; cardiac output ; pulmonary capillaries ; increase
The amount of air remaining in the lungs after a normal tidal expiration is called ____________ capacity.
functional residual
Which is NOT one of the five main steps involved in respiration?
gas exchange across pleural membranes
In a blood sample containing many hemoglobin molecules, the fraction of all the hemoglobin in the form of oxyhemoglobin is expressed as the percent _____.
hemoglobin saturation
The reflex that is signaled by stretch receptors to help terminate inspiration during very large tidal volumes to prevent over inflation of the lungs is the _____ - _____.
hering ; breuer
The following graph shows the oxygen-hemoglobin dissociation curves of three different acidity levels. Match each curve to the appropriate medium. C = ...
high acidity
If the alveoli were lined with a layer of pure water, lung expansion would ______.
require exhausting muscular work
The air that remains in the lungs even after a forceful expiration is called the __________ volume.
residual
What term describes the volume of gas remaining in the lungs after a maximum expiration?
residual volume
Hypoventilation results in ______.
respiratory acidosis
Hyperventilation causes ______.
respiratory alkalosis
during the entire ____________, the ____________ of the heart pumps blood through ____________ and arterioles, and into the ____________ surrounding each _____________.
respiratory cycle ; right ventricle ; pulmonary arteries ; capillaries ; alveolus
The ratio of CO2 produced to O2 consumed by tissue metabolism is known as the _____.
respiratory quotient
