Ch. 23: Respiratory System (HtM)

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General functions of the respiratory system. Fill in the blanks
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The respiratory tract is a passageway for air between the external environment and the ALVEOLI (air sacs) of the lungs.

There are two gases that are exchanged during respiration. Carbon dioxide diffuses from the blood into the alveoli while the other gas, OXYGEN, diffuses from the alveoli into the blood.

Receptors located in the superior regions of the nasal cavity called OLFACTORY receptors detect odors as air moves across them.

The vocal cords of the LARYNX (voice box) vibrate as air moves across them to produce sound. Sounds then resonate in upper respiratory structures.
The nasal cavity extends from the nostrils to paired openings called CHOANAE or posterior nasal apertures.

These paired openings lead into the PHARYNX.The floor of the nasal cavity is formed by the hard and soft PALATE.

The roof of the nasal cavity is composed of the nasal, frontal, ethmoid, and SPHENOID bones.

The nasal SEPTUM divides the nasal cavity into left and right portions.

The bony part of this divider is formed by the perpendicular plate of the ethmoid and the VOMER.

Three paired, bony projections called nasal CONCHAE are located along the lateral walls of the nasal cavity.

These projections partition the nasal cavity into separate air passages, each called a nasal MEATUS.
The respiratory membrane consists of an alveolar epithelium and its basement membrane, and a(n) CAPILLARY endothelium and its basement membrane.

The gas that diffuses from the alveolus, across the respiratory membrane, and into the pulmonary capillary is OXYGEN.

This gas is then transported by the blood to TISSUE cells.

Conversely, CARBON DIOXIDE gas diffuses from the blood in the capillary through the respiratory membrane.

This gas then enters the ALVEOLI and is eventually expired into the external environment.
The open ends of the tracheal cartilages are attached posteriorly by both the ____ and an elastic ligamentous membrane.trachealis muscleThe smallest respiratory bronchioles subdivide into thin airways called _____.alveolar ductsThe pharynx is a shared region between which two body systems?respiratory and digestiveVestibular and vocal folds are found in theLarynxTerminal bronchioles divide into the (correct order)Respiratory bronchiole > alveolar duct > alveolar sacThe lower respiratory tract includeslarynxExpiration involveselastic recoil of the lungsElevation of the ribs increases thoracic cavitywidthDuring volume changes in the thoracic cavity, what is primarily responsible for changes in length?The diaphragmCheck the conducting zones of the respiratory system-nose -nasal cavity -bronchioles -larynx -trachea (x) alveoliAlveolar cellsAlveolar Cell type I - squamous alveolar cells - involved in the diffusion of gases Alveolar Cell Type II - septal cells -secretes surfactant Alveolar Macrophages: - engulf microorganisms - dust cellsBronchioles have a proportionately thicker layer of smooth muscle than bronchi and contraction of this smooth muscle narrows the diameter of the bronchiole, referred to as bronchodilation. T/FfalseThe respiratory membrane is only 0.5 micrometer thick and consists of an alveolar epithelium and its basement membrane, and a capillary endothelium and its basement membrane.trueThe ___ division of the respiratory system transports air to and from the lung, but does not involve the exchange of gases between air and blood.conductingChemoreceptors and breathing reflexesThe most important stimulus affecting breathing rate and depth is BLOOD P(CO2). Central chemoreceptors monitor CSF and peripheral chemoreceptors monitor BLOOD. The peripheral chemoreceptors differ from central chemoreceptors because they are stimulated by changes in H+ produced independently of P(CO2)In general, DECREASED P(O2), INCREASED P(CO2), and production of H+, will cause greater stimulation of the respiratory center.Change in the _______ of breathing is accomplished by altering the amount of time spent in both inspiration and expiration, whereas altering the _______ of breathing is accomplished through stimulation of accessory muscles, which results in greater thoracic volume changes.rate; depthStructural differences between lungsRight lung: -larger and wider -has horizontal fissure - 10 bronchopulmonary segments -main bronchus is shorter and wider Left lung: - oblique fissure separates superior and inferior lobe -has the lingua - has a cardiac notch - 8-10 bronchopulmonary segmentsResistance and airflow. Which of these events leads to increased airflow and decreased airflow?Decreased airflow: - decreased surfactant -scar tissue from tuberculosis - an anaphylactic reaction caused by bee sting -breathing sub-zero air Increased airflow: -bronchodilatation from an inhaler used to treat asthma -aerobic exerciseLung volume and capacitiesThe RESIDUAL VOLUME is the amount of air remaining in the lungs after a forced expiration. The volume of air exchanged during normal breathing is called the TIDAL VOLUME. After a normal inspiration, the amount of air that can then be inspired forcefully is called the INSPIRATORY RESERVE VOLUME.T he total lung capacity minus the residual volume equals the VITAL CAPACITY. The vital capacity minus the EXPIRATORY RESERVE VOLUME equals the inspiratory capacity. The effects of obstructive diseases such as asthma or emphysema may be determined by measuring the FORCED EXPIRATORY VOLUME.Alveolar and systemic gas exchangeThe law of partial pressure, also known as DALTON'S LAW, states that the individual gases in the air contribute to the total atmospheric pressure as a function of the percentage each gas contributes to the total volume. If two gases have the same partial pressure, but gas A has a higher water solubility coefficient than gas B, then GAS A will diffuse at a faster rate. HENRY'S LAW states that the amount of a gas that dissolves in water is a function of its partial pressure and its solubility coefficient. If the alveolar partial pressure of gas A is 110 mm Hg and the partial pressure of gas B is 135, then GAS B will diffuse into the blood at a faster rate. If the P(CO2) in the tissues increases, then the P(CO2) in the systemic venous blood will INCREASE.Partial Pressures and gas exchangeA red blood cell arrives in the ALVEOLUS where it is exposed to a P(O₂) of 104 mm Hg. Blood enters the pulmonary vein with close to 100% of the binding sites for oxygen saturated. Arriving at the arterial end of the tissue capillaries, the blood P(O₂) is 95 mm Hg. As RBCs pass through the SYSTEMIC CAPILLARIES they experience oxygen unloading and increasing carbonic acid conversion. After passing through the systemic capillary, 75% of the binding sites for oxygen are now bound with oxygen. Returning to the inferior vena cava, the blood is known to have a P(CO₂) of 45 mm Hg. Passing through the pulmonary artery, the P(O₂) is approximately 40 mm Hg.Volumes and pressures associated with breathingThe pressure gases in the air exert in the environment is ___atmospheric pressure. The value for this pressure at sea level is ___760 mm Hg. The ___thoracic cavity contains the lungs. The collective amount of the alveoli within the lung is called the ___alveolar volume, and its associated pressure is the ___intrapulmonary pressure. The pressure exerted within the pleural cavity is called the ___intrapleural pressure. This pressure is always lower than intrapulmonary pressure and prior to inspiration, it is generally ___756 mm Hg.Quiet Breathing changesInspiration changes: - contraction of the diaphragm and external intercostals - pleural cavity volumes increases and pressure decreases - alveolar volume increases and pressure decreases - air movement into the lungs Expiration changes: - air movement out of the lungs - alveolar volumes decreases and pressure increases -pleural cavity volumes decreases and pressure increases - relaxation of the diaphragm and external intercostalsPressure gradient vs resistanceResistance: - suface tension - bronchiole diameter -chest wall elasticity Pressure gradient: - P atm - P alvAnatomic dead space and physiologic dead spaceOnly the air reaching the ALVEOLI is available for gas exchange. When air is moved from the atmosphere into the respiratory tract, a portion of it remains in the CONDUCTING ZONE. This collective space, where there is no exchange of respiratory gases, is referred to as the ANATOMIC DEAD SPACE, and it has an average volume of approximately 150 mL. The normal anatomic dead space plus any loss of alveoli is the PHYSIOLOGIC DEAD SAPCE. The usual loss of alveoli is minimal in a healthy individual, so the anatomic dead space is EQUIVALENT TO the physiologic dead space.Forced expiratory volume and maximum voluntary ventilationForced expiratory volume is the percentage of the __vital capacity__ that can be expelled in a specific period of time. This value is obtained by inspiring as much air as possible and then expelling the air from the lungs ___as quickly as possible__. Individuals with decreased ability to expire typically exhibit __decreased__ FEV values. Maximum voluntary ventilation is the greatest amount of air that can be taken into, and then expelled from, the lungs in __1 minute.Partial pressure and gas movementAir from the environment is inhaled DIRECTLY into the lungs. The partial pressures of the gases within the alveoli are different from the respective atmospheric partial pressures measured for several reasons: (1) Air from the environment mixes with the air remaining in the ANATOMIC DEAD SPACE in the respiratory tract; (2) OXYGEN diffuses out of the alveoli into the blood, and CARBON DIOXIDE diffuses from the blood into the alveoli; and (3) more WATER VAPOR is present within the alveoli because of the higher humidity there. Consequently, the percentage of oxygen in the alveoli is LOWER and the percentage of carbon dioxide in the alveoli is HIGHER than in the atmosphere.EmphysemaEmphysema is an irreversible loss of _____pulmonary____ gas exchange areas due to inflammation of the ____terminal bronchioles______ and alveoli, in conjunction with widespread destruction of pulmonary elastic connective tissue. These combined events lead to a(an) ______increase____ in the diameter of individual alveoli and merging of individual alveoli with others. The result is a(an) ____decrease ____ in the total number of alveoli, and the subsequent loss of gas exchange surface area. A person with advanced emphysema is unable to ___expire ___ effectively and oxygen-poor air builds up within the abnormally large alveoli. Most cases of emphysema result from damage caused by __smoking____.Systemic Gas exchangeThe P(O₂) in the tissue cells is 40 mm Hg. The blood as it enters the surrounding systemic capillaries has a P(O₂) of 95 mm Hg. Therefore, oxygen diffuses OUT OF the systemic capillaries DOWN its partial pressure gradient into the cells. Simultaneously, carbon dioxide is diffusing in the opposite direction. The P(CO₂) in tissue cells is 45 mm Hg, and the blood entering the systemic capillaries is 40 mm Hg. Carbon dioxide diffuses DOWN its partial pressure gradient from the cells into the blood until blood P(CO₂) is 45 mm Hg.The right lung has ______ lobes; the left lung has ______ lobes.3; 2The pleural cavityis a potential space that contains a lubricating fluid that allows the visceral and parietal pleura to slide by each other easilypulmonary ventilation (breathing) can also be described asthe movement of air into and out of the lungsDuring inhalation, the thoracic cavity ___________; during exhalation, the thoracic cavity ___________. A. returns to its normal, resting size; becomes smaller than its resting size B. becomes larger; becomes smaller than its resting size C. becomes larger; returns to its original size D. obtains its original size; becomes smaller due to muscles of exhalationC. becomes larger; returns to its original sizeThe amount of air that is moved from between the atmosphere and alveoli in one minute isalveolar ventilationDuring alveolar gas exchange, blood P(CO2)decreases from 45 mm to 40 mm HgDuring systemic gas exchange, blood P(O2)decreases from 95 mm to 40 mm Hginspiration begins asthe diaphragm contractsThe result of inspiration isincreased alveolar volume causes decreased alveolar pressureDuring expirationdecreased alveolar volume causes increased alveolar pressure.At the arterial ends of the pulmonary capillaries the P(O2) isthe Po2 is lower in the capillaries than in the alveoli.The ranking from highest to lowest Po2 in the area of the arterial ends of the tissue capillaries is... A. capillaries, tissue fluid, cells. B. cells, tissue fluid, capillaries. C. cells, capillaries, tissue fluid. D. tissue fluid, capillaries, cells. E. all three are equal.A. capillaries, tissue fluid, cells.At the venous ends of the pulmonary capillaries the Pco2the Pco2 is equal in the capillaries and in the alveoli.Check all of the ways resistance may be increased-Decreased elasticity of chest wall -Bronchoconstriction -Increased alveolar surface tension.True/False: The respiratory center is composed of the medullary respiratory center and the pontine respiratory center.trueShallow breathing is more effective for maximizing alveolar ventilation than slower, deeper breathing. (t/f)falseA healthy person should be able to expel 75-85% of the vital capacity in 1 second.trueOxygen diffuses across the respiratory membrane from the alveoli into the capillaries because of the P(O2) partial pressure gradient. (t/f)trueGases diffuse because of differences in partial pressures from areas of higher pressure to areas of lower pressure. (t/f)trueAs the lungs expand while breathing, the pressure in the lungs decreases. (t/f)trueAs the diaphragm relaxes, it is depressed (moves inferiorly). (t/f)falsemain function of the sympathetic innervation on the lungsbronchodilationIf no other forces were acting on the lungs, they would collapse. What is the reason for this?the elastic tissue content of the lungThe lungs remain inflated despite their tendency to collapse. What is the reason for this?The negative intrapleural pressure relative to intrapulmonary pressureTransport of oxygen. Classify the items based upon how they will affect the level of oxyhemoglobin.Decreases oxyhemoglobin - increased temp -decreased pH -heavy exercise Increases oxyhemoglobin levels - decreased P(co2) -increased P(o2)Carbon Dioxide TransportThe solubility coefficient of carbon dioxide is 0.57. Due to both this value and the __small__ partial pressure gradient for CO₂, approximately __7%__ of carbon dioxide is transported to the alveoli __as a dissolved gas__within the plasma of blood. Hemoglobin is capable of transporting about __23%__ of the CO₂ as a __carbaminohemoglobin__ compound. The remaining __70%__ of the CO₂ diffuses into erythrocytes and combines with water to form bicarbonate and H⁺. Thus, the largest percentage is carried from the tissue cells to the lungs in plasma as __dissolved bicarbonate.__Hyperventilation vs hypoventilationHyperventilation: -can be caused by anxiety - can be caused by ascending to a high altitude - PO2 levels increase and PCO2 levels decrease in alveoli -hypocapnia can occur Hypoventilation: - can be caused by obesity - can be caused by hypopnea -O2 levels decrease and CO2 levels increase in alveoli - can be caused by bradypneaThe largest percentage of carbon dioxide is transported in the bloodas bicarbonate dissolved in the plasma.Hemoglobin is capable of transportingcarbon dioxide bound to the globin.a condition called is when p(co2) decreases below normal levelshypocapniaDuring exercise, both oxygen consumption and carbon dioxide production increase in response to elevated rates of cellular respiration but blood P(O2) and P(CO2) levels remain relatively the same. (T/F)trueOxygen unloading occurs at the _________________________ This process causes a(n) _________________ in the oxygen partial pressure of the blood leaving this region.tissues; decreasesPlace the following in order from highest to lowest expected partial pressure oxygen levels.- atmospheric air - alveoli of lungs - pulmonary capillaries - systemic capillaries - cells of the systemic tissuesHyperpnea would result in ___________________________ within the increase in Pressure (oxygen) and a decrease in Pressure (carbon dioxide)Decreased Pressure (carbon dioxide) results in an increase in blood pH levels. Both of these conditions result in a shift of the oxygen-hemoglobin dissociation curve to the ______________________. This shift _______________ hemoglobin's affinity for oxygen.left; increasesIncreased 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.Using the graph provided, determine the correct oxygen partial pressure associated with the classification of "high altitude."112 mm HgThe altitude of Kabul, Afghanistan is approximately 6000 feet. What is the approximate alveolar oxygen partial pressure found here?85 mm HgUnder normal conditions, the alveolar oxygen partial pressure is ______________________ than the atmospheric oxygen partial pressure.always lowerWithin 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 populationNo genetic differences were found among the Andean population in either oxygen-hemoglobin saturation levels, nor hemoglobin concentrations. However, this group as a whole displayed higher hemoglobin concentration levels than their lower altitude neighbors. The most accurate explanation for this finding is that individuals constantly exposed to lower atmospheric partial pressures for oxygen would have a physiologic response which would _______________________.increase the cumulative number of red blood cellsDuring normal quiet breathing, the _____ is inactive and exhalation is a passive event that does not require nervous stimulation.ventral respiratory group