BIO 315 Ch 22
Principal organs of the respiratory system
nose, pharynx, larynx, trachea, bronchi, lungs
Histotoxic hypoxia
occurs when a poison prevents the tissues from using oxygen
___ is used to sustain metabolic activities within the cells and ___ is produced as a result of these activities.
oxygen; carbon dioxide
The ___ ___ ___ determines the direction of gas movement.
partial pressure differences
Respiratory arrest
permanent cessation of breathing (unless there is medical intervention)
The duration of an inspiration is set by the ___ ___.
pneumotaxic center
The great alveolar cells secrete a phospholipid-protein mixture called ___.
pulmonary surfactant
Kussmaul respiration
rapid breathing induced by acidosis
When this negative pressure stops being applied, the lungs ___ and the intrapulmonary pressure ___.
recoil; increases
Carbonic anhydrase is found in the ___ where it directly catalyzes the formation of ___.
red blood cells; carbon dioxide gas into carbonic acid
Hypoventilation
reduced pulmonary ventilation
The inspiratory muscles ___ during normal exhalation resulting in ___ in the thoracic volume.
relax; decrease
The largest air passages that engage in gas exchange with the blood are the ___ ___.
respiratory bronchioles
Increased levels of 2,3 BPG occur in response to decreased blood pH levels. With all other variables unchanged, an increased concentration of 2,3 BPG in the blood would ___.
result in a shift of the oxygen-hemoglobin dissociation curve to the right enhancing unloading of oxygen at the tissues
Increased production of surfactant would ___.
result in an increase in the thickness of the respiratory membrane, which would decrease diffusion of respiratory gases.
Ischemic hypoxia
results from inadequate circulation of the blood, as in congestive heart failure
Which of the following would lead to anemic hypoxia?
sickle-cell disease
Respiratory gases cross the respiratory membrane by ___.
simple diffusion
Oxygen molecules bind ___ of the hemoglobin
specifically to the heme region
Carbon dioxide goes through a series of reactions resulting in the formation of bicarbonate. Where does this reaction occur?
systemic capillaries
Carbon dioxide enters the blood at the ___ capillaries. Here some of the carbon dioxide binds to the ___ region of the hemoglobin.
systemic; globin
Apnea
temporary cessation of breathing
Air consists of about 78.6% nitrogen, 20.9% oxygen, 0.04% carbon dioxide, and 0.5% water. At sea level, (760 mmHg), what is the PCO2?
0.3 mmHG
If intrapulmonary pressure was 760 mmHf, what would you expect the intrapleural pressure to be?
756 mmHg
Inspiration depends on the ease of pulmonary inflation, called ____, whereas expiration depends on ____, which causes pulmonary recoil.
compliance; elasticity
Inspiration begins as the diaphram ___.
contracts
According to ___, the warming of air as it is inhaled helps to inflate the lungs.
Charle's law
Which of the following statements about partial pressures of gases in the tissues is true?
Po2 in the blood > PO2 in the tissues, PCO2 in the blood < PCO2 in the tissues
Which of the following statements about partial pressures of gases in the lungs is true? (only one right answer)
Po2 in the lungs > PO2 in the blood, PCO2 in the lungs < PCO2 in the blood
Surfactant is produced by
Type II pneumocytes
Hypoxemic hypoxia (hypoxemia)
a state of low arterial PO2 due to poor pulmonary gas exchange
Insufficient surfactant production would result in ___.
a tendency for the lungs to collapse
At the arterial end of a tissue capillary, rank the following structures from highest to lowest PO2.
capillaries, tissue fluid, cells
Most of the CO2 that diffuses from the blood into an alveolus comes from ___ ___.
carbonic acid
Which of the following are bicarbonate ions exchanged for when they diffuse from plasma back into red blood cells?
chloride ions
Nitrogen bubbles can form in the blood and other tissues when a scuba diver ascends too rapidly, producing a syndrome called ___.
decompression sickness
Which of the following occurs during expiration?
decreased alveolar volume causes increased alveolar pressure
Increase in blood pH leads to the ___ rate of ___.
decreased; ventilation
The unloading of oxygen at the tissues results in the formation of ___. This configuration of hemoglobin ___ carbon dioxide
deoxyhemoglobin; more readily binds to
Dspnea
difficult or labored breathing
Blood pH decreases in response to the
dissociation of carbonic acid into bicarbonate and hydrogen ions
Negative pressure ventilation, demonstrated by iron lungs, allows a person to breath by producing an intermittent negative pressure that moves across the chest and diaphragm. This specific action would artificially induce the intrapulmonary pressure to ___ atmospheric pressure thus resulting in ___.
drop below; inspiration
Anemic hypoxia
due to the inability of the blood to carry adequate oxygen
Orthopnea
dyspnea (difficult) breathing when lying down
Which of the following is a lung disease marked by abnormally few but large alveoli?
emphysema
The superior opening into the larynx is guarded by a tissue flap called the ___.
epiglottis
At the venous end of the pulmonary capillaries, the PO2 is ___ in the capillaries then in the alveoli.
equal
Which of the following has no effect on oxyhemoglobin dissociation?
erythrocyte count
Blood banks dispose of blood that has low levels of biphosphoglycerate. What would be the probable reason for doing so?
erythrocytes low in BPG do not unload O2 very well
T/F: the rate of oxygen diffusion is affected by the pressure gradient of carbon dioxide
false
The nasal cavity is divided by the nasal septum into right and left ___.
fossae
What is the result of inspiration?
increased alveolar volume causes decreased alveolar pressure
Hyperpnea
increased breathing in response to exercise
Hyperventilation
increased pulmonary ventilation in excess of metabolic demand
The increase of alveolar PCO2 leads to the ___ rate of ___.
increased; ventilation
Renal retention of bicarbonate ___ blood pH acting as a compensatory mechanism for the condition of respiratory ___.
increases; acidosis
A person suffering from hypercapnia compensates by ___ ventilation.
increasing
Poor blood circulation causes ______ hypoxia.
ischemic
Which of the following does not contain ciliated cells? Nasal cavity Trachea Primary bronchus Terminal bronchiole Laryngopharynx
laryngopharynx
Decreased pressure (carbon dioxide) results in an increase in blood pH levels. Both of these conditions results in a shift of the oxygen-hemoglobin dissociation curve to the ____. This shift ______ hemoglobin's affinity for oxygen.
left; increases
A single hemoglobin displaying a saturation causes the oxygen-hemoglobin dissociation curve to shift to the ___, indicating that the carboxyhemoglobin is ___ likely to release bound oxygen.
left; less
The reason tetrodotoxin causes death so quickly is directly related to the ___ of respiratory muscle function, which disables a person's ability to appropriately adjust thoracic volumes and associated intrapulmonary pressures.
loss
At the arterial end of the pulmonary capillaries, the PO2 is ___ in the capillaries then in the alveoli.
lower
Respiratory arrest would most likely result from a tumor of the ___ ___.
medulla oblongata
The vagus and glossopharyngeal nerves carry afferent signals from peripheral chemoreceptors to a chemosensitive area in the ___.
medulla oblongata
Using new positive pressure ventilation produces an intermittent positive pressure that moves air into the airways. This action would artificially induce the intrapulmonary pressure to ___ atmospheric pressure thus resulting in ___.
move above; inspiration
Oxygen unloading occurs at the ___. This process causes a ___ in the oxygen partial pressure of the blood leaving this region.
tissues; decrease
T/F: the pleurae and pleural fluid help prevent the spread of pulmonary infection to the pericardium
true
The expansion of the lungs during inspiration generates a pressure gradient causing air to flow into the lungs. This is an example of Boyle's law.
true
Two meanings of the word respiration
ventilation of the lungs (breathing) or the use of oxygen in cellular metabolism (ch 22 deals with the first process).
The matching of airflow to blood flow in any region of the lungs is called ___-___ ___.
ventilation-perfusion coupling
Which of these values would normally be the highest?
vital capacity
Metabolically active tissues have which of the following sets of conditions that shift the oxyhemoglobin dissociation curve to the right?
↓PO2, ↑PCO2, ↑temperature, ↑BPG
In one passage through a bed of systemic blood capillaries, the blood gives up about what percentage of its oxygen?
20-25%
Emphysema is a COPD that may lead to:
Alveolar wall breakdown Reduced respiratory membrane surface area and gas exchange Hypoxemia, hypercapnia, and respiratory acidosis Polycythemia
Which of the following issues output to the VRG to adjust the respiratory rhythm?
DRG
The empirical formula for bicarbonate is ___.
HCO3-
Polio can sometimes damage the brainstem respiratory centers and result in which condition?
Ondine's curse
Tom is in respiratory arrest due to an electrical shock. Why does a good samaritan have up to 4 or 5 minutes to begin CPR and save Tom's life?
There is a venous reserve of oxygen in Tom's blood
Tachypnea
accelerated respiration
A blood pH > 7.45 is called ___ and can be caused by a CO2 deficiency called ___.
alkalosis, hypocapnia
Which environment separated by the respiratory membrane would display the highest oxygen partial pressure?
alveolar air
Under normal conditions, the alveolar oxygen partial pressure is ___ than the atmospheric oxygen partial pressure
always lower
What would slow down gas exchange between the blood and alveolar air?
an increase in membrane thickness
Hyperpnea would result in _____ within the blood.
an increase in pressure (oxygen) and a decrease in Pressure (carbon dioxide)
Some inhaled air does not participate in gas exchange because it fills the _____ of the respiratory tract.
anatomical dead space
During exercise, which of the following directly increases respiratory rate? - Increased H+ level in the blood - The Bohr effect - Reduced blood pH - Reduced oxyhemoglobin - Anticipation of the needs of exercising muscle
anticipation of the needs of exercising muscle
The intrinsic laryngeal muscles regulate speech by rotating the ___ ___.
arytenoid cartilages
Under normal conditions, the region expected to have the lowest PCO2 is the ___.
atmosphere
Intrapulmonary pressure must be lower than ___ pressure for inspiration to occur.
atmospheric
Within the lungs, air flows along a dead-end pathway consisting essentially of ___.
bronchi --> bronchioles --> alveoli. Incoming air stops in the alveoli (millions of tiny tin-walled air sacs), exchanges gases with the bloodstream through the alveolar wall, and then flows back out.
Within each lung, the airway forms a branching complex called the ____.
bronchial tree
In a health person, which of the following will have the greatest influence on resistance to pulmonary airflow? Atmospheric pressure Respiratory rate Bronchiole diameter Quantity of surfactant Contraction of the diaphragm
bronchiole diameter
Increase in contractions of the respiratory muscles leads to an ___ rate of ___.
increase; ventilation
Functions of the respiratory system (8)
gas exchange: provides oxygen and carbon dioxide exchange between the blood and air communication: serves for speech and other vocalizations (laugh/cry) olfaction: sense of small, food selection, and avoiding danger (ex. gas leak/bad food) acid-base balance: eliminating CO2 helps control the pH of the body fluids. excess CO2 reacts with water and generates acid; therefore if respiration doesn't keep pace with CO2 production, acid accumulates and body fluids have an abnormally low pH (acidosis) blood pressure regulation: lungs carry out a step in synthesizing angiotensin II, which helps regulate blood pressure blood and lymph flow: breathing creates pressure gradients b/w thorax and abdomen that promote the flow of lymph and venous blood. blood filtration: the lungs filter small blood clots from the bloodstream and dissolve them, preventing clots from obstructing more vital pathways such as coronary, cerebral, and renal circulation. expulsion of abdominal contents: breath holding and abdominal contraction help to expel abdominal contents during urination, defecation, and childbirth.
The intrapulmonary pressure is ____ then the atmospheric pressure during exhalation.
higher
Under normal conditions, the partial pressure of carbon dioxide within the tissues is ___ than the partial pressure of carbon dioxide within the systemic capillaries
higher
At the respiratory membrane, the partial pressure of carbon dioxide in the plasma is ___ than in the ___ of the lungs.
higher; alveoli
Within the Tibetan highlander population, genetic variation has been found to determine relative oxygen-hemoglobin saturation levels. Individuals within this population may be homozygous for either the low oxygen saturation gene or the high oxygen saturation gene. Individuals may also be heterozygous, carrying one low and one high oxygen saturation gene. Based on this information, individuals within the population carrying ___ alleles are expected to demonstrated a physiological advantage for survival.
homozygous high oxygen saturation population
The addition of CO2 to the blood generates ________ ions in the RBCs, which in turn stimulates RBCS to unload more oxygen
hydrogen
Hypocapnia will lead to which of the following conditions?
hypoventilation due to alkalosis
Acute carbon monoxide poisoning would result in ___ of the tissues because oxygen ___.
hypoxia; is not released from hemoglobin in sufficient amounts at the tissues
If the atmospheric pressure (CO2) exceeded the alveolar pressure (CO2) the pulmonary capillary pressure (CO2) would ___.
increase well above normal range
Contraction of the diaphragm and external intercostal muscles results in ______ in the thoracic volume which results in ________ of the intrapulmonary pressure.
increase, decrease
Hypoventilation results in a ___ in the arterial partial pressure of carbon dioxide, which may result in respiratory ___.
increase; acidosis
