front 1 Why is epinephrine injected as a treatment for the respiratory signs and symptoms of anaphylaxis? | back 1 Epinephrine enhances sympathetic activity to dilate airways and decrease airway resistance, which had been elevated by the effects of histamine on the bronchioles. It also raises blood pressure, which enhances oxygen delivery to tissues by increasing flow. |
front 2 Describe and explain the effects of smoking on the functioning of the respiratory system. | back 2 Nicotine constricts terminal bronchioles to increase airway resistance, as does the increased mucus secretion and swelling of the mucosa. Smoke inhibits the movement of cilia, which allows buildup of substances and microbes normally removed. Over time, smoking leads to destruction of elastic tissue, which decreases compliance, and ultimately to the effects of emphysema. |
front 3 Describe the neural, chemical, and physical changes that increase the rate and depth of ventilation during exercise. | back 3 Anticipation of exercise generates neural input to the limbic system. Sensory input is provided from proprioceptors and motor input is provided from the primary motor cortex. As the partial pressure of oxygen falls due to increased consumption, the partial pressure of carbon dioxide and the temperature increase due to metabolic activity in muscle fibers. Also, carbon dioxide is added via the buffering of the hydrogen ions produced as a result of lactic acid production. Chemoreceptors sense the changes in partial pressure and notify the medullary rhythmicity center to increase the rate and depth of breathing. |
front 4 In chronic emphysema, some alveoli merge together and some are replaced with fibrous connective tissue. In addition, the bronchioles are often inflamed, and expiratory volume is reduced. Using proper respiratory system terminology, explain at least four reasons why affected individuals will have problems with ventilation and external respiration. | back 4 Answers could include: reduced compliance (reduces ability to increase thoracic volume); increased airway resistance (decreases tidal volume); decreased diffusion due to increased diffusion distance, decreased surface area, and changes in partial pressures of gases (altering gradients). Other answers may be acceptable. |
front 5 The upper respiratory system includes | back 5 the nose, nasal cavity, pharynx, and associated structures |
front 6 the lower respiratory system includes | back 6 the larynx, trachea, bronchi, and lungs. |
front 7 As air passes through the nose | back 7 it is warmed, filtered, and moistened; and olfaction occurs. |
front 8 The external nose has a | back 8 cartilaginous framework and a bony framework |
front 9 The glottis consists of | back 9 a pair of folds of mucous membrane in the larynx (the vocal folds) and the space between them (the rima glottidis). |
front 10 The bronchial tree consists of | back 10 macroscopic airways that begin at the trachea and continue through the terminal bronchioles. |
front 11 The parietal pleura lines the | back 11 the thoracic cavity, and the visceral pleura covers the lungs |
front 12 The oblique fissure | back 12 divides the left lung into two lobes. |
front 13 The oblique and horizontal fissures | back 13 divide the right lung into three lobes. |
front 14 Alveolar sacs consist of | back 14 of two or more alveoli that share a common opening. |
front 15 The exchange of respiratory gases occurs by | back 15 diffusion across the respiratory membrane. |
front 16 The volume of a gas varies | back 16 inversely with its pressure |
front 17 During normal, quiet inhalation, | back 17 the diaphragm and external intercostals contract, the lungs expand, and air moves into the lungs; during normal, quiet exhalation, the diaphragm and external intercostals relax and the lungs recoil, forcing air out of the lungs. |
front 18 Air moves into the lungs when | back 18 alveolar pressure is less than atmospheric pressure, and out of the lungs when alveolar pressure is greater than atmospheric pressure. |
front 19 Lung capacities are | back 19 combinations of various lung volumes. |
front 20 Gases diffuse from | back 20 areas of higher partial pressure to areas of lower partial pressure. |
front 21 Most O2 is transported by | back 21 hemoglobin as oxyhemoglobin (Hb–O2) within red blood cells |
front 22 most CO2 is transported in | back 22 blood plasma as bicarbonate ions (HCO3_). |
front 23 As PO2 increases, | back 23 more O2 combines with hemoglobin. |
front 24 As temperature increases | back 24 the affinity of hemoglobin for O2 decreases |
front 25 Fetal hemoglobin has a higher | back 25 affinity for O2 than does adult hemoglobin. |
front 26 The respiratory center is composed of | back 26 neurons in the medullary respiratory center in the medulla plus the pontine respiratory group in the pons. |
front 27 During normal quiet breathing | back 27 the ventral respiratory group is inactive |
front 28 during forceful breathing | back 28 the dorsal respiratory group activates the ventral respiratory group. |
front 29 Which structures are part of the conducting zone of the respiratory system? | back 29 The conducting zone of the respiratory system includes the nose, pharynx, larynx, trachea, bronchi, and bronchioles (except the respiratory bronchioles). |
front 30 What is the path taken by air molecules into and through the nose? | back 30 The path of air is external nares --> vestibule --> nasal cavity internal nares. |
front 31 Which part of the nose is attached to the frontal bone? | back 31 The root of the nose attaches it to the frontal bone. |
front 32 How does the epiglottis prevent aspiration of foods and liquids? | back 32 During swallowing, the epiglottis closes over the rima glottidis, the entrance to the trachea, to prevent aspiration of food and liquids into the lungs. |
front 33 What is the main function of the vocal folds? | back 33 The main function of the vocal folds is voice production. |
front 34 What is the benefit of not having complete rings of tracheal cartilage between the trachea and the esophagus? | back 34 Because the tissues between the esophagus and trachea are soft, the esophagus can bulge and press against the trachea during swallowing. |
front 35 How many lobes and secondary bronchi are present in each lung? | back 35 The left lung has two lobes and two lobar bronchi; the right lung has three of each. |
front 36 What type of membrane is the pleural membrane? | back 36 The pleural membrane is a serous membrane. |
front 37 Why are the right and left lungs slightly different in size and shape? | back 37 Because two-thirds of the heart lies to the left of the midline, the left lung contains a cardiac notch to accommodate the presence of the heart. The right lung is shorter than the left because the diaphragm is higher on the right side to accommodate the liver. |
front 38 What types of cells make up the wall of an alveolus? | back 38 The wall of an alveolus is made up of type I alveolar cells, type II alveolar cells, and associated alveolar macrophages. |
front 39 How thick is the respiratory membrane? | back 39 The respiratory membrane averages 0.5 _m in thickness. |
front 40 If the volume is decreased from 1 liter to 1/4 liter, how would the pressure change? | back 40 The pressure would increase fourfold, to 4 atm. |
front 41 Right now, what is the main muscle that is powering your breathing? | back 41 If you are at rest while reading, your diaphragm is responsible for about 75% of each inhalation. |
front 42 How does the intrapleural pressure change during a normal, quiet breath? | back 42 At the start of inhalation, intrapleural pressure is about 756 mmHg. With contraction of the diaphragm, it decreases to about 754 mmHg as the volume of the space between the two pleural layers expands. With relaxation of the diaphragm, it increases back to 756 mmHg. |
front 43 If you breathe in as deeply as possible and then exhale as much air as you can, which lung capacity have you demonstrated? | back 43 Breathing in and then exhaling as much air as possible demonstrates vital capacity |
front 44 What causes oxygen to enter pulmonary capillaries from alveoli and to enter tissue cells from systemic capillaries? | back 44 A difference in PO2 promotes oxygen diffusion into pulmonary capillaries from alveoli and into tissue cells from systemic capillaries. |
front 45 What is the most important factor that determines how much O2 binds to hemoglobin? | back 45 The most important factor that determines how much O2 binds to hemoglobin is the PO2. |
front 46 What point on the curve represents blood in your pulmonary veins right now? In your pulmonary veins if you were jogging? | back 46 Both during exercise and at rest, hemoglobin in your pulmonary veins would be fully saturated with O2, a point that is at the upper right of the curve. |
front 47 In comparison to the value when you are sitting, is the affinity of your hemoglobin for O2 higher or lower when you are exercising? How does this benefit you? | back 47 Because lactic acid (lactate) and CO2 are produced by active skeletal muscles, blood pH decreases slightly and PCO2 increases when you are actively exercising. The result is lowered affinity of hemoglobin for O2, so more O2 is available to the working muscles. |
front 48 Is O2 more available or less available to tissue cells when you have a fever? Why? | back 48 O2 is more available to your tissue cells when you have a fever because the affinity of hemoglobin for O2 decreases with increasing temperature. |
front 49 The PO2 of placental blood is about 40 mmHg. What are the O2 saturations of maternal and fetal hemoglobin at this PO2? | back 49 At a PO2 of 40 mmHg, fetal Hb is 80% saturated with O2 and maternal Hb is about 75% saturated. |
front 50 Would you expect the concentration of HCO3 _ to be higher in blood plasma taken from a systemic artery or a systemic vein? | back 50 Blood in a systemic vein would have a higher concentration of HCO3_. |
front 51 Which area contains neurons that are active and then inactive in a repeating cycle? | back 51 The medullary respiratory center in the medulla contains neurons that are active and then inactive in a repeating cycle. |
front 52 Which nerves convey impulses from the respiratory center to the diaphragm? | back 52 The phrenic nerves innervate the diaphragm. |
front 53 Which chemicals stimulate peripheral chemoreceptors? | back 53 Peripheral chemoreceptors are responsive to changes in blood levels of oxygen, carbon dioxide, and H_. |
front 54 What is the normal arterial blood PCO2? | back 54 Normal arterial blood PCO2 is 40 mmHg. |
front 55 When does the respiratory system begin to develop in an embryo? | back 55 The respiratory system begins to develop about 4 weeks after fertilization. |