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42 Cards in this Set

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Describe the 3 main functions of the respiratory system
-moves O2 from the atmosphere into the body for aerobic respiration
-moves CO2 from the body to the atmoshpere
-maintainsa homeostatic value for body pH
Define the 4 processes that occur to supply cells with oxygen while ridding the body of carbon dioxide
-pulmonary ventilation (breathing-movement of air into and out of the lungs)
-external respiration (gas exchange between the airways and blood)
-transport (movement of O2 and CO2 between the lungs and cells)
-internal respiration (gas exchange between blood and intersitial fluid surrounding the cells of the body)
Describe the anatomy of the ocnducting zone. What happend to the number of airways as air is inspired? What happens to th diameter of airways as air is inspired? Gas exchange between the blood and the lung does not occur in the conducting zone. Why is this the case
The conducting zone is made of rigid, thick walled tubes that allow air to enter or exit the lungs mainly supported by hyaline cartilage and smooth muscle. As air is inspired, the amount of airways is incresed and each branch is smaller in diameter. the thin epithelial tissue in the resp. zone allows for rapid exchange of O2 and CO2 between the lumen of the lung and blood.
Trace the path of air as it is inspired through the conducting zone
mouth/nose->pharynx->larynx->trachea->primary bronchi->bronchiole->terminal bronchiole
What are the functions of each segment of the conducting zone?
-mouth/nose warms and humidifies inspired air
-larynx produces sound
-trachea prevents collapse while breathing and secretes mucus to trap debis in inspired air
What is the function of cartilage in the conducting zone?
To prevent collapse when breathing
What is the function of cilia in the conducting zone?
move phlegm up towards the mouth
What is the function of goblet cells in the conduccting zone?
secrete mucus to trap debris in inspired air
What happens when the smooth muscle of the conducting zone contracts? Relaxes? What is the consequence (result)of both its contraction and relaxation in terms of pulomary ventiliation?
The diameter of the bronchioles decrease. During relaxation, the diamater increases bronchodilation. The consequence of bronchoconstriction is an asthma attack
Describe the anatomy of the respiratory zone. Gas exchange between the blood and the lung does occur in the respiratory zone. Why is this the case?
Thin epithelial tissue for rapid exchange of O2 and CO2. Enormous surface area,compliant, elastic
Trace the path of air as it is inspired through the respiratory zone
bronchioles->alveloar sacs->alveoli
Besides the visceral pleura, what surrounds the outer surface of the alveoli? What are the function of each of these?
The parietal pleura surrounds theouter surface of alveoli and intrapleural space. The function of the parietal pleura is it covers the thoracic wall and superior face of the diaphragm. The intrapleural space holds the 2 pleura tightly together by surface tension.
What shape are the 2 different alveolar cells? What are the functions of the 2 types of alveolar cells? How is the shape of the Type I cell related to its function?
The 2 alveolar cells are squamous and cuboidal. The function of type I cells are for rapid exhange of O2 and CO2 with the blood. The way type I's shape is related to its function is th short diffusional distance allows for rapid exhange.
What are the 2 layers of the pleura? What is their location in relation to one another, the lungs and the internal surface of the thoracic cavity? What is between the 2 layers and what is its function?
-Parietal and visceral
-Parietal covers thoracic wall, superior face of diaphragm and around heart between lungs.
-intrapleural space is between and holds the 2 pleura together.
What are the muscles od respiration and where are they located? What happens to thoracic volume when they contract? What happens to thoracic volume when they relax?
The muscles of respiration are the diaphragm and its located between the thoracic and abdominal cavities.
The intercostal muscles between the ribs and abdominal muscles on wall of anterior abdominal cavity.
What happens to alveolar (lung) volume when the thoracic volume increases? How does this happen?
When thoracic volume increases, the alveolar volume increases. This happens when contraction of diaphragm causes it to flatten and drop toward abdominal cavity.
What happens to alveolar (lung) volume when the thoracic volume decreases? How does this happen?
When thoracic volumes decreases, the alveolar volume decreases. Contraction of inerenal intercoastal mouscles pushes the ribcage downward and inward
Define Boyle's law. What is the relationship beween pressure and volume of a gas in a container?How can this be related to the respiratory system?
Boyles law is the inverse relationship between the pressure and volume of a gas in a container. The relationshpis between pressure and volume of a gas in a container is if volume increases, pressure decreases. In the respiratory system, if the volume of alveoli increases, the pressure decreases.
COmpare and contrast the air pressure gradient during inspiration and expiration. Explain where the pressure is higher or lower (direction of the gradient) during each.
-when alveolar pressure is less that atmospheric pressure, inspiration occurs and air moves into the lungs.
-when alveolar pressure is greater than atmospheric pressure, expiration occurs and air flows out of lungs
Describe the sequence of events that occur from the initiation of inspiration to the end of inspiration. How do these events cause the movement of air into the lungs?
-before inspiration, alv=atm.
-contraction of diaphragm causes an increase in alveolar volume and decrease in alveolar pressure.The pressure decreases below atm causing air to move into lungs. Alveolar pressure increases until it equals atm and then inspiration ends
Describe the sequence of events that occur from the initation of expiration to the end of expiration. How do these events cause the movement of air out of the lungs?
relaxation of diaphragm allows the lungs to collapse, resulting in a decrease in alveolar volum and an increase in alveolar pressure. The alveolar pressure increases above atm causing air to move out of the lungs. Air moves out of lungs and continues to decrease pressure until it equals atm pressure.
What are the 2 forces that cause the lung to recoil? Which is major and minor?
-Surface tension (major).
-Elastic fibers (minor)
What causes surface tension in the lumen of the lung? Will an increase in surface tension in the lumen of the lung make inspiration easier or more difficult?
A very thin layer of water lines the luminal surface of the alveoli and creates a very strong force that pulls the alveoli inward. An increase in surface tension in the lumen will make inspiration more difficult.
What molecule causes a decrease in surface tension? What makes it and where is it secreted?
Surfactant causes a decrease in surface tension. It is secreted by Type II alveolar cells into the lumen of the alveoli.
Compare and contrast quiet and forced ventilation. What muscles are involved in each? When do these muscles contract and relax during quiet and forced ventilation?
Quiet ventilation is the contraction and relaxation of the diaphragm only. Moves air into and out of lungs. Forced ventilation is the contraction and relaxation of the diaphragm, intercostals, and abdominals.
Describe the following lung volumes: tidal, inspiratory reserve, expiratory reserve, residual.
-tidal volume: volume of air that moves into and out of the lungs with each breath during quiet ventilation.
-inspiratory reserve: additional volume of air that can be inspired forcibly into the lungs after a tidal inspiration.
-expiratory reserve: additional volume of air that can be expired forcibly from the lungs after a tidal expiration.
-residual volume: volume of air left in the lungs after forced expiration.
Describe the following lung capacities: inspiratory, vital, functional residual, total lung.
-Inspiratory: total amount of air that can be inspired after a tidal volume
-Vital: total amount of air capable of entering/exiting the airways
-functional residual: amount of air remaining in lungs after a tidal expiration
-total lung capacity: sum of all lung volumes
Define Dalton’s law of partial pressure.
The partial pressure of a gas is proportional to its percentage in the mixture.
What is the normal values of PO2 and PCO2 in the alveolar volume?
Poxygen=104 mmHg
Pcarbon dioxide= 40mmHg, 760 mmHg
How is O2 transported by blood?
-bound to molecules of the protein hemoglobin within RBC
-dissolved as gas bubbles in the liquid portion of blood
Describe the binding of O2 to a molecule of hemoglobin (permanent or temporary, reversible or irreversible)
-hemoglobin contains a heme group which contains an atom of iron in the center which is capapble of reversibly binding to one molecule of O2. A single molecule of hemoglobin can carry up to 4 O2.
What is the relationship between the PO2 in the blood and the amount of O2 that is bound to hemoglobin (% saturation)?
Hemoglobin is almost completely saturated at a PO2 of 70 mm Hg. During systemic circuit, 25% of Hb-bound O2 is unloaded to the tissues.
What is the relationship between the RBC concentration of DPG, temperature, [H+], PCO2 of the blood ad the amount of O2 that is bound to hemoglobin (% saturation)? What happens to the amount of O2 that is bound to hemoglobin when any of the conditions above are increased? In what situation would you expect to see all 4 of these variables increased? What will these increases do to the amount of O2 that is unloaded at the cells of the body? What happens to the amount of O2 that is bound to hemoglobin when any of the conditions above are decreased?
An increase in any of these factors will decrease the amount of O2 bound to Hb at systemic tissues. "right shift" of the O2 -Hb dissociation curve. These are all increased in the blood during exercise. A decrease in any of these factors will increase the amount of O2 bound to Hb at systemic tissues.
What are the 3 ways that the blood transports CO2?
-as bicarbonate ion in plasma (70%)
-as carbaminohemoglobin, bound to amino acids (not heme)
-as dissolved gas in plasma (10%)
Describe the series of events that convert CO2 produced by the cells of the body (during internal respiration) into bicarbonate ions. Where does this conversion occur (be very specific)? What is the name of the enzyme that catalyzes this reaction? Where do the bicarbonate ions go after they are made? What is the cause of their movement? Discuss the significance of chloride ions in this process?
-CO2+H2O->H2CO3->H+ + HCO3-
-occurs in RBC
-Carbonic anhydrase combines CO2 and H2O forming carbonic acid.
-Bicarbonate ions them move into the RBC cytosol
-Chloride ions are in the chloride shift of bicarbonate
What are the names of the 4 respiratory centers and where are they located? How do they each function (what are the effectors that they control and when do they stimulate/inhibit their respective effectors)?
-The dorsal respiratory group or inspiratory center is in the medulla. Spontaneously fires action potentials every 5 seconds and they travel down phrenic nerve which stimulates contraction of diaphragm and results in inspiration.
-VRG/expiratory center:located in medulla, fire actino potentials only during forced ventilation, increases the amount of air that enters and exits the lungs.
-depth and rate of ventiation-sensed by chemoreceptors or mechaoreceptors, will influence the contraction and relaxation pattern of resp. muscles
-pneumotaxic center: in the pons, sends action potentials to DRG which inhibits DRG ending inspiation
Where are the mechanoreceptors and chemoreceptors located in the body that, when stimulated will cause a change in the rate and/or depth of ventilation? What stimuli do each respond to with respect to the respiratory system?
-central chemoreceptors are in brain and respond to changes in levels of CO2 or H+ in cerebral spinal fluid
-peripheral chemoreceptors are found in arteries near the heart and neck and respond to changes in levels of CO2, H+, or O2 in blood
-Mechanoreceptors in the walls of airway will respond to mechanical stimuli such sa stretch and presence of irritants in the airways.
Describe the Hering-Breuer (inhalation) and the irritant reflexes from receptor to effector.
-irritant reflexes stimulate mechanoreceptors to stimulate contraction of bronchiolar smooth muscle and the VRG to cause forced expiration.
-Hering-breuer reflex stimulates mechanoreceptors during deep inspirations and inhibits DRG to stop further respiration.
How will an increase in either CO2, H+, or O2 in the blood affect the respiration rate and/or depth? How will a decrease in either CO2, H+, or O2 in the blood affect the respiration rate and/or depth?
-An increase in CO2 or H+ will stimulate the DRG and result in an increase in respiration rate and depth. A decrease will result in a decrease in resp rate and depth
-a decrease in O2 will stimulate DRG and result in an increase in resp rate and depth. An increase in O2 will result in decrease of resp rate and depth.
What is the normal pH of the blood?
7.4
What does voluntary hypoventilation, breath holding or exercise do to the CO2 level in the blood? What effect does this have on the H+ level in the blood? Describe the relationship between CO2 ad H+ levels in the blood? What happens to the pH of the blood? What is this condition called?
-Hypoventilation causes a decrease in CO2. The longer breath holding occurs, the less CO2 present. Exercise increases CO2
-an increase in CO2 results in the synthesis of excessive amounts of H+ causing body pH to decrease-respiratory acidosis
What is the response of the respiratory system in terms of ventilation rate and/or depth to voluntary hypoventilation, breath holding or exercise? What does this response do to the CO2 level in the blood? What effect does this have on the H+ level in ht blood? What happens to the pH of the blood? Until when?
-hyperventilation increases ventilation rate, decreases CO2 levels and decreases H+. Increases body pH to 7.4