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