Ch. 22 respiratory system
Squamous cell carcinoma
20-40% of cases, in bronchial epithelium; can spread and metastasize quickly
Calculate the intrapleural pressure if atmospheric pressure is 765 millimeters of mercury, assuming that the subject is at rest (not inhaling or exhaling). 4 millimeters of mercury 0 millimeters of mercury 761 millimeters of mercury 765 millimeters of mercury
761 millimeters of mercury The intrapleural pressure is always about 4 millimeters of mercury less than the intrapulmonary pressure, and the intrapulmonary pressure is equal to the atmospheric pressure if the subject is at rest. Intrapleural pressure is always about 4 millimeters of mercury less than intrapulmonary pressure, but this does not represent that actual pressure in the pleural cavity.
Where does gas exchange take place?
Begins as terminal bronchioles -> respiratory bronchioles -> alveolar ducts -> alveolar sacs
The relationship between gas pressure and gas volume is described by ________. Boyle's law Dalton's law Charles' law Henry's law
Boyle's law
Which of the following best describes the chloride shift as seen in the figure? Chloride is removed from hemoglobin when carbon dioxide binds to it. Chloride binds bicarbonate and allows more of it to be carried in the bloodstream. Chloride is taken out of the blood to counterbalance the inflow of carbon dioxide. Chloride rushes into RBCs to counterbalance the outflow of bicarbonate.
Chloride rushes into RBCs to counterbalance the outflow of bicarbonate. The outflow of negative bicarbonate ions from RBCs is balanced by the inflow of chloride ions. Chloride does not bind to hemoglobin in the chloride shift
Internal respiration
Circulatory system O2 and CO2 exchange between systemic blood vessels and tissues
Transport
Circulatory system O2 and CO2 in blood
Gases exit lungs
Expiration
Systemic capillaries Chloride shift
HCO3- quickly diffuses from RBCs into plasma Outrush of HCO3- from RBCs balanced as Cl- moves into RBCs from plasma
Gases flow into lungs
Inspiration
Under certain conditions, the vocal folds act as a sphincter that prevents air passage. True False
True
During inspiration, the external intercostal muscles can work to increase the volume changes that drive ventilation. True False
True When the external intercostal muscles are activated, the rib cage is elevated, increasing thoracic volume. This increases ventilation.
In children with infant respiratory distress syndrome (IRDS), the walls of the alveoli cling to each other and make them difficult to inflate. It is common in babies born prematurely. What cells in these infants are NOT fully developed and are NOT doing their job? type I alveolar cells type II alveolar cells alveolar macrophages endothelial cells of alveolar capillaries
Type II alveolar cells Type II alveolar cells secrete a detergent-like surfactant that lessens the surface tension on the alveolar walls, preventing them from sticking to each other. Infants with IRDS can be treated until their cells produce adequate surfactant.
What acts as a sphincter to prevent air passage?
Vocal folds
Which form of CO2 transport accounts for the least amount of CO2 transported in blood? as carbon monoxide in plasma dissolved in plasma chemically bound to hemoglobin as bicarbonate ion in plasma
dissolved in plasma Most CO2 is transported by combining with hemoglobin or dissolved in the plasma as bicarbonate. A very small percentage is dissolved into the plasma. Bicarbonate makes up about 70% of total CO2 in blood, its greatest fraction.
Which of the following pressures must remain negative to prevent lung collapse? [Pressures in and around lung tissue that relate to the action of breathing.] intrapulmonary pressure atmospheric pressure intrapleural pressure transpulmonary pressure
intrapleural pressure Intrapleural pressure is created as the lungs attempt to shrink away from the thoracic wall. This negative pressure, as well as the adherence due to moisture, is what keeps the lungs from collapsing.
Which of the following is NOT a physical factor that influences pulmonary ventilation? alveolar surface tension lung compliance partial pressure of oxygen in the air airway resistance
partial pressure of oxygen in the air Partial pressures affect the diffusion and dissolving of gasses into and out of the blood.
Complete the following statement using the choices below. Air moves out of the lungs when the pressure inside the lungs is greater than the intra-alveolar pressure. less than the pressure in the atmosphere. greater than the pressure in the atmosphere. equal to the pressure in the atmosphere.
greater than the pressure in the atmosphere
Which of the following is an appropriate response to carbon monoxide (CO) poisoning? slow breathing into a paper bag hyperventilation to exhale CO from the body immediate application of bicarbonate ions to facilitate removal of CO from Hb hyperbaric oxygen chamber to increase PO2 and clear CO from the body
hyperbaric oxygen chamber to increase PO2 and clear CO from the body
Hypoxia can be caused by ______. hyposecretion of erythropoietin having a fever slightly elevated level of lactic acid in the blood All of the listed responses are correct.
hyposecretion of erythropoietin Hypoxia occurs when a tissue or organ has an insufficient supply of oxygen. Erythropoietin is a hormone that stimulates the maturation of red blood cells in the bone marrow
Anemic hypoxia
impaired/blocked circulation (anaerobic)
Cyanosis
inadequate O2 delivery to tissues
Hyperventilation
increased depth and rate of breathing that exceeds body's need to remove C02
Which of the following refers to the movement of air into and out of the lungs? Which of the following refers to the movement of air into and out of the lungs? gas exchange pulmonary ventilation internal respiration external respiration
pulmonary ventilation
What type of epithelial tissue forms the walls of the alveoli? stratified squamous epithelium simple cuboidal epithelium pseudostratified ciliated columnar epithelium simple squamous epithelium
simple squamous epithelium Squamous epithelia are thin and easily passed by respiratory gases. The membrane is also kept thin by organizing the squamous cells in a single layer.
If the compliance of the thoracic wall is decreased, ______. the intrapleural pressure would not decrease normally during inhalation the intrapulmonary pressure would remain lower than the atmospheric pressure the airway resistance would be decreased None of the listed responses is correct.
the intrapleural pressure would not decrease normally during inhalation As the size of the thoracic cavity increases, so does its volume. This causes intrapleural pressure to go below atmospheric pressure so that air (gases) can move into the lungs during inspiration. If the thoracic cavity cannot change its size (volume), then air movement will not occur.
Small cell carcinoma
~20% of cases; contains lymphocyte-like cells that originate in primary bronchi and subsequently metastasize (known as the silent killer because it grows quickly and does not obstruct the bronchi)
Adenocarcinoma
~40% of cases, originates in peripheral lung areas- bronchial glands, alveolar cells; most common type
CO2 is transported in blood in 3 forms
-7 to 10 % dissolved in plasma -20% bound to globin of hemoglobin -70% transported as bicarbonate ions (HCO3-) in plasma
In pulmonary capillaries
-HCO3- moves into RBCs (while Cl- move out): binds with H+ to from H2CO3 (forms carbonic acid) -H2CO3 split by carbonic anhydrase into CO2 and water -CO2 diffuses into alveoli
Explain valsava's maneuver
-glottis closes to prevent exhalation -abdominal muscles contracts -intra abdominal pressure rises -helps to empty rectum or stabilize trunk during heavy lifting
Cystic fibrosis
-most common lethal genetic disease -abnormal, viscous mucus clogs passageways causes bacterial infections -life expectancy up to early 20s
There are two types of cells in the alveolar walls. Name them
-single layer of squamous epithelium called TYPE I ALVEOLAR CELLS -scattered cuboidal called TYPE II ALVEOLAR (they secrete surfactant and antimicrobial proteins)
For gas exchange to be efficient, the respiratory membrane must be ________. between 5 and 6 micrometers thick 0.5 to 1 micrometer thick at least 3 micrometers thick The thickness of the respiratory membrane is not important in the efficiency of gas exchange.
0.5 to 1 micrometer thick
Which of these cells would be most effective in the ingestion and disposal of microorganisms that may enter the alveoli? type I alveolar cells lymphocytes in blood circulating through lungs alveolar macrophages type II alveolar cells
Alveolar macrophages Alveolar macrophages wander freely, ingesting and destroying invading microorganisms or foreign matter. Proteins produced by these type II cells have an element of innate immunity. They do not ingest or transport microorganisms.
Connect adjacent alveoli *equalizes air pressure throughout lungs
Alveolar pores
Pulmonary ventilation
Respiratory system (breathing) movement of air into and out of lungs
External respiration
Respiratory system O2 and CO2 exchange between lungs and blood
Which of the following would induce the loss of oxygen from the hemoglobin and the blood? a decrease in blood temperature a drop in blood pH decreases in plasma carbon dioxide increase in hemoglobin that has oxygen bound to it already
a drop in blood pH The pH in blood tends to drop when plasma reacts with carbon dioxide, a common condition in tissue. This pH drop causes weakening of the Hb-O2 bond, a phenomenon called the Bohr effect. Carbon dioxide loss from the blood, as occurs in proximity to alveoli, tends to cause more oxygen to enter the blood.
Hypoxemic hypoxia
abnormal ventilation; pulmonary disease (COPD)
Keep alveolar surfaces sterile
alveolar macrophages
Quiet inspiration is __________, and quiet expiration is __________. a passive process; also a passive process a passive process; an active process an active process; also an active process an active process; a passive process
an active process; a passive process During quiet breathing, inspiration requires muscle actions, while expiration is caused by elastic recoil.
Which form of hypoxia reflects poor O2 delivery resulting from too few RBCs or from RBCs that contain abnormal or too little hemoglobin? ischemic (stagnant) hypoxia histotoxic hypoxia anemic hypoxia hypoxemic hypoxia
anemic hypoxia
How is the bulk of carbon dioxide transported in blood? chemically combined with the heme portion of hemoglobin chemically combined with the amino acids of hemoglobin as carbaminohemoglobin in the red blood cells as carbonic acid in the plasma as bicarbonate ions in plasma after first entering the red blood cells
as bicarbonate ions in plasma after first entering the red blood cells
What is the most common method of carbon dioxide transport? dissolved in the plasma chemically bound to hemoglobin as carbaminohemoglobin chemically bound to hemoglobin as oxyhemoglobin as bicarbonate ions in the plasma
as bicorbonate ions in the plasma Carbon dioxide reacts with water inside RBCs to form carbonic acid, which dissociates into bicarbonate and hydrogen ions. About 70% of carbon dioxide travels in the plasma as bicarbonate.
Which of the following INCORRECTLY describes mechanisms of CO2 transport? just over 20% of CO2 is carried in the form of carbaminohemoglobin as bicarbonate ions in plasma attached to the heme part of hemoglobin 7-10% of CO2 is dissolved directly into the plasma
attached to the heme part of hemoglobin
Histotoxic hypoxia
cells unable to use O2 as in metabolic poisons (mushrooms)
Most inspired particles such as dust fail to reach the lungs because of the ________. porous structure of turbinate bones ciliated mucous lining in the nose abundant blood supply to nasal mucosa action of the epiglottis
ciliated mucous lining in the nose
In babies born prematurely, pulmonary surfactant may not be present in adequate amounts ______. in the conducting zone structures of the lungs due to insufficient exocytosis in the type II alveolar cells to permit adequate surface tension in the alveoli because the presence of collapsed alveoli prevents surfactant production
due to insufficient exocytosis in the type II alveolar cells Type II alveolar cells make surfactant. Without surfactant, the surface tension created by the water vapor within the alveoli would cause them to collapse.
Carbon Monoxide poisoning
especially from fire; 200x greater affinity for Hb than oxygen *you never know you're not getting enough oxygen
The largest amount of carbon dioxide is transported in the bloodstream in the form of carbonic anhydrase. True False
false
The loudness of a person's voice depends on the ________. force with which air rushes across the vocal folds length of the vocal folds strength of the intrinsic laryngeal muscles thickness of vestibular folds
force with which air rushes across the vocal folds
Which of the following pressures rises and falls with the phases of breathing but eventually equalizes with the atmospheric pressure? transpulmonary pressure intrapulmonary pressure intrapleural pressure atmospheric pressure
intrapulmonary pressure Intrapulmonary pressure rises when the thorax volume is reduced (during exhalation) and drops when the thorax volume rises (during inhalation). When there is no change in thorax volume, intrapulmonary pressure equalizes with the atmospheric pressure.
Sound is shaped into language by______
muscles of the pharynx, tongue, soft palate and lips
In the plasma, the quantity of oxygen in solution is ________. only about 1.5% of the oxygen carried in blood greater than the oxygen combined with hemoglobin not present except where it is combined with carrier molecules about equal to the oxygen combined with hemoglobin
only about 1.5% of the oxygen carried in the blood
Why do we breathe?
to get oxygen into cells
Possible causes of hypoxia include ________. too little oxygen in the atmosphere obstruction of the esophagus taking several rapid deep breaths getting very cold
too little oxygen in the atmosphere
