the primary functions of the respiratory system are…
- to move air to and from the exchange surfaces of the lungs
- to provide an area for gas exchange between air and circulating blood
- to protect respiratory surfaces from dehydration and environmental variations
the conversion of angiotensin I to angiotensin II in the lung capillaries indirectly assists in the regulation of…
blood volume and blood pressure
the air-filled pockets within the lungs where all the gas exchange between air and blood occurs are the…
alveoli
the “patrol force” of the alveolar epithelium involved with phagocytosis consists primarily of alveolar…
macrophages
the respiratory system consists of structures that…
- provide an extensive surface area for gas exchange between air and circulating blood
- permit vocalization and production of sound
- move air to and from the exchange surfaces of the lungs along the respiratory passageways
the entry of liquids or solid food into the respiratory passageways during swallowing is prevented by the…
epiglottis folding down over the glottis
structures in the trachea that prevent its collapse or overexpansion as pressures change in the respiratory system are the…
C-shaped tracheal cartilages
the trachea allows for the passage of large masses of food through the esophagus due to…
distortion of the posterior tracheal wall
the function of the hilum along the medial surface of the lung is to…
provide access to pulmonary vessels and nerves
pulmonary surfactant is a phospholipid secretion produced by alveolar cells to…
reduce the cohesive force of H2O molecules and lower surface tension
dilation and relaxation of the bronchioles is possible because the walls of bronchioles contain….
smooth muscle tissue regulated by the ANS
structural features that make the lungs highly pliable and capable of tolerating great changes in volume are…
the elastic fibers in the trabeculae, the septa, and the pleurae
after passing through the trachea, the most complete pathway a molecule of inspired air would take to reach an alveolus is:
primary bronchus->secondary bronchus->bronchioles->terminal bronchioles->respiratory bronchioles->alveolus
the serous membrane in contact with the lung is the….
visceral pleura
the diffusion of gases between interstitial fluid and cytoplasm is…
internal respiration
breathing, which involves the physical movement of air into and out of the lungs, is…
pulmonary ventilation
the process that prevents the buildup of carbon dioxide in the alveoli and ensures a continuous supply of oxygen that keeps pace with absorption by the bloodstream is…
alveolar ventilation
the absorption of oxygen and the release of carbon dioxide by cells is…
internal respiration
a single respiratory cycle consists of…
inspiration and expiration
air enters the respiratory passageways when the pressure inside the lungs is lower than the __________ pressure.
atmosphere
the movement of air into and out of the lungs is primarily dependent on…
pressure differences between the air in the atmosphere and air in the lungs
during inspiration, there will be an increase in the volume of the thoracic cavity and an…
increasing lung volume, decreasing intrapulmonary pressure
during expiration, the diaphragm…
relaxes and the dome rises into the thoracic cage
stiffening and reduction in chest movement effectively limit the…
respiratory minute volume
during expiration, there is an…
increase in intrapulmonary pressure
a lack of surfactant secretion onto alveolar surfaces causes the alveoli to…
collapse
if there is a PO2 of 104 mm Hg and a PCO2 of 40 mm Hg in the alveoli, and a PO2 of 40 mm Hg and a PCO2 of 45 mm Hg within the pulmonary blood, there will be a net diffusion of…
O2 into the blood from the alveoli; CO2 from the blood into the alveoli
when the partial pressure difference is greater across the respiratory membrane, the rate of gas diffusion is…
faster
the arrangement that improves the efficiency of pulmonary ventilation and pulmonary circulation occurs when…
blood flow and air flow are coordinated
if the partial pressure of oxygen is lower in the pulmonary capillaries than in the alveolus, then…
O2 will diffuse out of the alveolus into the pulmonary capillary
blood entering the systemic circuit normally has a PCO2 of 40 mm of Hg, while peripheral tissues have a PCO2 of 45 mm of Hg; therefore…
CO2 diffuses into the blood
each molecule of hemoglobin has the capacity to carry ___________ molecules of oxygen
four
what percentage of total oxygen is carried within red blood cells chemically bound to hemoglobin?
98 percent
factors that cause a decrease in hemoglobin saturation at a given PO2 are…
increasing 2, 3-bisphosphoglycerate (BPG), increasing temperature, and decreasing pH
each hemoglobin molecule consists of…
four globular protein subunits, each containing one heme unit
when hemogolbin binds with molecules of oxygen, the end product is…
oxyhemoglobin
carbon dioxide is transported in the blood by…
- conversion to a molecule of carbonic acid
- binding to the protein part of the hemoglobin molecule
- disolving in plasma
if the rate and depth of respiration exceed the demands for oxygen delivery and carbon dioxide removal, the condition is called…
hyperventilation
under normal conditions, the greatest effect on the respiratory centers is initiated by…
increases and decreases in PCO2
emotional states that initiates sympathetic activation in the ANS cause….
bronchodilation and increase the respiratory rate
the initiation of inspiration originates with discharge of inspiratory neurons in the…
medulla
examples of protective reflexes that operate when you are exposed to toxic vapors, chemical irritants, or mechanical stimulation of the respiratory tract include…
sneezing, coughing, and laryngeal spasms
as the volume of the lungs increases during times of forced breathing, the…
inspiratory center is inhibited, the expiratory center stimulated
with increasing age, elastic tissue deterioration and stiffening and reduction in chest movement effectively limit…
the respiratory minute volume
the nervous system interacts with the respiratory system by…
monitoring respiratory volume, blood gas levels, and blood and CSF pH
the paranasal sinuses include…
frontal, sphenoid, ethmoid, and maxillary
a rise in arterial PCO2 elevates cerebrospinal fluid (CSF) carbon dioxide levels and stimulates the chemoreceptive neurons of the medulla to produce…
hyperventilation
the primary function of pulmonary ventilation is to maintain adequate…
alveolar ventilation
the purpose of the fluid in the pleural cavity is to…
reduce friction between the parietal and visceral pleura
when the diaphragm and external intercostal muscles contract….
intrapleural pressure decreases
if a person is stabbed in the chest and the thoracic wall is punctured but the lung is not penetrated, the…
lung will probably collapse
the most important factor determining airway resistance is…
the airway radius
the sympathetic division of the ANS causes __________ of airway smooth muscle; therefore, resistance is __________.
relaxation; decreased
the substance often administered during an asthmatic attack to decrease resistance via airway dilation is…
epinephrine
decreased amounts of CO2 concentration in the bronchioles cause an…
increase in bronciolar constriction
matching air flow and blood flow in the right proportion at each alveolus improves…
external respiration
if a person is breathing 15 times a minute and has a tidal volume of 500 ml, the total minute respiratory volume is…
7500 ml
the residual volume is the volume of air….
that remains in lungs after maximal expiration
the maximum amount of air moved in and out during a single respiratory cycle is the…
vital capacity
if a person is breathing 12 times per minute, the tidal volume is 350 ml, and the volume in the anatomic dead space is 150 ml, what is the alveolar ventilation rate?
2400 ml/min
the most effective means of increasing alveolar ventilation is to…
breathe slowly and deeply
when a person does not produce enough surfactant and becomes exhausted by the effort required to keep inflating and deflating the lungs, the condition is called…
respiratory distress syndrome
the partial pressure of O2 in the atmosphere at sea level is…
160 mm Hg
what is not a process involved with internal respiration?
hemoglobin binds more oxygen
movement of air into and out of the lungs is accomplished by the process of _________, while all movement of gases across membranes is by ________.
bulk flow; passive diffusion
the correct sequential transport of O2 from the tissue capillaries to O2 consumption in cells is:
erythrocytes, plasma, interstitial fluid, cells
it is important that free H+ resulting from dissociation of H2CO3 combine with hemoglobin to reduce the possibility of…
an acidic condition within the blood
intracellular bicarbonate ions are exchanged for extracellular chloride ions, resulting in a mass movement of chloride ions into the…
red blood cells
a respiratory disorder characterized by fluid leakage into the alveoli or swelling and constriction of the respiratory bronchioles is…
pneumonia
in the chronic, progressive condition on emphysema….
respiratory bronchioles and alveoli are functionally eliminated
