We noted in Chapter 10 that dogs are believed to benefit when they pant by breathing at a fixed resonant frequency. Although dogs inhale and exhale exclusively through the nose when not under heat stress, they exhale orally to some (variable) extent when panting. Air exhaled by way of the mouth remains nearly at deep-body temperature. Explain how a panting dog could vary its rate of evaporative cooling—even while breathing at a fixed frequency—by modulating how much it exhales by way of its nose or mouth.

We noted in Chapter 10 that dogs are believed to benefit when they pant by breathing at a fixed resonant frequency. Although dogs inhale and exhale exclusively through the nose when not under heat stress, they exhale orally to some (variable) extent when panting. Air exhaled by way of the mouth remains nearly at deep-body temperature. Explain how a panting dog could vary its rate of evaporative cooling—even while breathing at a fixed frequency—by modulating how much it exhales by way of its nose or mouth.

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter13: The Respiratory System

Section: Chapter Questions

Problem 1TAHL

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Which of the following statements regarding control of respiration is TRUE? At high altitude, a decrease in PC02 of the blood stimulates an increase in ventilation. An increase in the HCO3- concentration in blood stimulates ventilation. A slight decrease in arterial PO2 is a stronger stimulus for increased ventilation than is a comparable decrease in arterial PCO2. The most important signal for regulating ventilation is the H+ concentration of arterial blood. Increased concentrations of lactic acid stimulate ventilation primarily by acting on peripheral chemoreceptors.
(a) The partial pressure of CO2 in the lungs can be varied rapidly by the rate and depth of breathing. For example, a common remedy to alleviate hiccups is to increase the concentration of CO2 in the lungs. This can be achieved by holding one’s breath, by very slow and shallow breathing (hypoventilation), or by breathing in and out of a paper bag.Under such conditions, pCO2 in the air space of the lungs rises above normal. Qualitatively explain the effect of these procedures on the blood pH.(b) A common practice of competitive short-distance runners is to breathe rapidly and deeply (hyperventilate) for about half a minute to remove CO2from their lungs just before the race begins. Blood pH may rise to 7.60. Explain why the blood pH increases.(c) During a short-distance run, the muscles produce a large amount of lactic acid (CH2CH(OH)COOH; K2 = 1.38 × 10 –4 M) from their glucose stores. Why might hyperventilation before a dash be useful?
You are studying with a friend who is describing the Bohr effect. She tells you that in the lungs, hemoglobin binds oxygen and releases hydrogen ion; as a result, the pH increases. She goes on to say that in actively metabolizing muscle tissue, hemoglobin releases oxygen and binds hydrogen ion and, as a result, the pH decreases. Do you agree with her reasoning? Why or why not?
In our discussion of oxygen binding, we saw how oxygen affinity may be affected by temperature. The book mentions that "temperature effects may become a problem in the hypothermic limbs of mammals in Arctic climates," (pg. 650) but it doesn't explain why. Given what you understand about oxygen binding affinity and temperature, why would these animals have an issue? O The cold temperatures increase the binding affinity of oxygen to myoglobin. The cold temepratures decrease the binding affinity of oxygen to hemoglobin. The cold temperatures increase the binding affinity of oxygen to hemoglobin. The cold temperatures decrease the bindingg affinity of oxygen to myoglobin.
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Which of the followingstatement is FALSE about myoglobin? Select one: a) Oxygen dissociation curve for myoglobin is non-sigmoidal b)It has only one hemocyanin for anaerobic respiration c) It has higher affinity for oxygen even at high partial pressure of carbon dioxide d)It can be found in the skeletal muscle tissue
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You have read about the Respiratory system in your Animal Physiology classes and are very excited to share the knowledge with one of your friend in the Chemistry Department. You explain to him the gas exchange between tissues and blood. However, your friend is very confused about the fact that how almost an equal amount of O2 & CO2 is exchanged in normal human (even during exercise) when the diffusion coefficient of CO2 is 20 times that of O2 (as CO2 is much more soluble in body tissues than O2). a) Explain the reason for the same to your friend. b) Why this equilibrium can’t be maintained in people who have a diseased lung with thickened walls?
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Messner and Habeler's 1978 ascent of Mount Everest without oxygen-breathing apparatus is often described as one of the most remarkable physical accomplishments achieved by humans. Table 1 shows respiratory gas and arterial pH values measured in a resting mountaineer at sea level, Everest base camp and Everest summit. Use the differences in these values to explain how breathing regulation changes when at rest at the 3 altitudes indicated. Calculations are not required but you may wish to consider the role of central and peripheral chemoreceptors and their relationship to paCO,, minute ventilation and alveolar pO, in your response. Table 1: Respiratory gas composition and arterial pH measured in a resting mountaineer at sea-level, Everest base-camp and Everest summit. Arterial Barometric Alveolar Inspíred p02 (FIO2) pO2 (PAO2) pCO2 (расо2) Altitude Pressure Arterial (m) pH mmHg mmHg mmHg mmHg Sea Level 760 150 106 36 7.4 Everest Base 5,400 404 75 51 20.4 7.6 Camp Everest 8,848 252 43 34…