Ch 13 The Respiratory System Anatomy Pearson

Which pressure is a result of the natural tendency of the lungs to decrease their size or recoil, which is opposed by the natural tendency of the elastic chest wall to pull outward, enlarging the lungs?

Intrapleural pressure

Intrapleural pressure is the pressure within the pleural cavity. It is caused by opposing forces. The alveolar surface tension and lung elasticity pull the lungs inward, while the elasticity of the thoracic wall pulls the cavity outwards.

Which volume of air within the lungs is a result of the maximal contraction of the expiratory muscles?

Residual volume

Maximal contraction of the expiratory muscles reduces the lung volume below functional residual capacity to the residual volume. The residual volume represents the volume of air in the lungs that can not be expelled with maximal contraction of the expiratory muscles. This volume of air helps keep the airways and alveoli from collapsing.

Match the stages of the breathing cycle with the correct description of lung volume and respiratory pressures.

Lungs at rest before expiration: Intrapulmonary pressure is equal to atmospheric pressure and lung volume is high.

Inspiration: Intrapulmonary pressure is less than atmospheric pressure and lung volume is increasing.

Lungs at rest before inspiration: Intrapulmonary pressure is equal to atmospheric pressure and lung volume is low.

Expiration: Intrapulmonary pressure is greater than atmospheric pressure and lung volume is decreasing.

Drag the muscles to their respective locations (bins) to describe whether they contract during quiet or deep inspiration or quiet or forced expiration

Quiet Inspiration: Diaphragm (moderate contraction), External Intercostals (moderate contraction)

Deep Inspiration: Diaphragm (forceful contraction), External Intercostals (forceful contraction), Sternocleidomastoid, Scalenes

Quiet Expiration: (NONE)

Forced Expiration: Rectus abdominis, Internal oblique, Transversus abdominis, External oblique, Internal Intercostals

Match the changes in the factor affecting pulmonary ventilation with the resulting change in the respiratory system.

Increased surface tension: Makes ventilating the alveoli harder because the alveoli tend to collapse as occurs with respiratory distress syndrome.

Decreased resistance: Increases air flow to the alveoli because air can flow easily through the airways, as occurs with exercise and the release of epinephrine.

Increased compliance: Makes breathing easier because lungs will easily stretch with the expansion of the thoracic wall during inspiration.

Decreased compliance: Requires increased breathing effort during inspiration because the lungs will not stretch as easily, as occurs with pulmonary fibrosis.

Decreased surface tension: Makes inflating the alveoli easier because the alveoli will open more easily with inspiration.

Increased resistance: Decreases air flow to the alveoli because it's harder for the air to flow through the airways, as occurs with the release of acetylcholine or histamine.

Which of the following statements correctly describes the diffusion of carbon dioxide during tissue gas exchange?

PCO2 is greater in the tissue cells than in the blood of systemic capillaries entering tissues, so carbon dioxide diffuses into the blood.

During tissue gas exchange, carbon dioxide will diffuse down its partial pressure gradient from body tissues into the blood until the partial pressure is equal in both locations.

Select the statement that is TRUE comparing oxygen exchange and carbon dioxide transport and exchange at body tissues.

The partial pressure gradient is greater for oxygen than for carbon dioxide. However, carbon dioxide is more soluble in blood plasma, allowing for a large diffusion of carbon dioxide at body tissues.

Henry's law states that the amount of gas dissolved in a liquid is influenced by both the partial pressure gradient and the solubility of the gas. Oxygen has a large partial pressure gradient. Carbon dioxide has a higher solubility. This allows for adequate transport and diffusion of both gases at body tissues.

What is the purpose of the chloride shift during tissue carbon dioxide exchange?

The chloride shift helps maintain electrical neutrality as bicarbonate ions move out of red blood cells.

The chloride shift helps maintain electrical neutrality by exchanging chloride ions with bicarbonate ions (formed in carbonic acid dissociation) through the cotransport carriers. By lowering the concentration of bicarbonate ions, it continues the dissociation of carbonic acid, allowing for the continued formation of carbonic acid.

Match the term(s) in the left column to the blanks near their description on the right.

Biocarbonate ions: most important means of transporting carbon dioxide in the blood plasma, responsible for approximately 70%.

Biocarbonate ions and hydrogen ions: forms from the dissociation of carbonic acid.

Hydrogen ions: buffered by hemoglobin in the red blood cell, preventing a change in pH.

Carbon dioxide and water: molecules that combine in red blood cells, forming carbonic acid.

Carbonic acid: initially formed when carbon dioxide combines with water.

Carbonic anhydrase: enzyme that catalyzes the formation of carbonic acid inside red blood cells.

Carbaminohemaglobin: responsible for approximately 20% of the transport of carbon dioxide in the blood.

Chloride ions: enters red blood cells with the movement of bicarbonate ions out of red blood cells.

Dissolved carbon dioxide: responsible for approximately 7-10% of the transport of carbon dioxide in the blood plasma.

Sort the factors into the appropriate bin, according to whether each factor occurs during tissue carbon dioxide exchange or pulmonary carbon dioxide exchange.

Tissue CO2 Exchange: CO2 diffuses into the blood, Chloride ion moves into red blood cell in exchange for bicarbonate ion, carbonic anhydrase catalyzes the formation of carbonic acid, hemoglobin binds CO2, PCO2 increases in the blood plasma, bhor effect

Pulmonary CO2 Exchange: CO2 diffuses out of the blood, hemoglobin releases CO2, Chloride ion moves out of red blood cell in exchange for bicarbonate ion, Carbonic anhydrase catalyzes the breakdown of carbonic acid, Haldane effect, PCO2 decreases in the blood plasma

Which of the following statements correctly describes the diffusion of oxygen during pulmonary gas exchange?

PO2 is greater in the alveolus than the blood, so oxygen diffuses into the blood.

During pulmonary gas exchange, oxygen will diffuse down its partial pressure gradient from the alveolus into the blood until the partial pressure is equal in both locations.

Which of the following would occur if lung cancer restricts the airflow to a group of alveoli?

The PO2 in the affected alveoli would decrease, and their arterioles would vasoconstrict.

A restriction in airflow would decrease the PO2 in the affected alveoli, which would cause nearby arterioles to vasoconstrict. As a result, the affected alveoli would receive less blood, and blood would flow preferentially to better-ventilated alveoli with a higher PO2.

Match the location on the oxygen-hemoglobin dissociation curve to the correct statement regarding percent O2 saturation of hemoglobin.

Part A: Point showing the percent oxygen saturation of hemoglobin in the venous blood leaving a vigorously exercising muscle. Most of the hemoglobin in this blood is in the form of deoxyhemoglobin.

Part B: Point showing a relatively equal ratio of oxyhemoglobin and deoxyhemoglobin in the blood.

Part C: Point showing the percent oxygen saturation of hemoglobin in the venous blood leaving a resting muscle.

Part D: Point showing the percent oxygen saturation of hemoglobin in blood leaving the lungs of a person at moderately high altitude.

Part E: Point showing the percent oxygen saturation of hemoglobin in blood leaving the lungs at sea level.

Drag the factors to their respective locations (bins) to indicate whether they would tend to increase or decrease oxygen loading or unloading.

Increased Loading: Increased surface area of respiratoru membrane, Increased PO2 in the alveoli

Decreased Loading: Increased thickness of the respiratory membrane, Decreased ventilation of alveoli, Decreased atmospheric pressure

Increased Unloading: Decreased pH in the tissues, Increased PCO2 in the tissues, Decreased PO2 in the tissues

Decreased Unloading: Decreased temperature in the tissues, Decreased concentration of BPG

Arrange these events related to oxygen transport and exchange in sequence from earliest (at the lungs) to latest (at the body tissues).

First Event:

Oxygen diffuses from alveoli into plasma.

Oxygen diffuses from plasma into red blood cells.

Oxygen is loaded onto hemoglobin, forming oxyhemoglobin.

Oxygen is transported from the pulmonary circulation to the systemic circulation.

Oxygen is unloaded from hemoglobin, forming deoxyhemoglobin.

Oxygen diffuses from red blood cells into the plasma.

Oxygen diffuses from the plasma into body tissues.

(Last event)