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188 Cards in this Set
- Front
- Back
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respiratory sytsem |
composed of structures involved in ventilation and gas exchange.
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functions of the respiratory system |
1. providing extensive surface area for gas exchange between air and circulating blood. 2. moving air to and from the surfaces of the lungs along the resp. passageways. 3. protect resp. surfaces from dehydration, temp change, envir. variations, and defend the resp. system and other tissues from invasion by pathogens. 4. produce sounds for communication. 5. Facilitating detection of odors. |
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Respiratory system and Blood pressure |
help to regulate blood volume/ pressure through the conversion of Angiotension I to Angiotensin II. |
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Upper Respiratory System |
-these passageways filter, warm, and humidify incoming air, protecting the more delicate surfaces of the LRS. -also absorb water and heat from the outgoing air. |
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Lower Respiratory System |
-by the time air reaches the alveoli, most foreign particles and pathogens have been removed, and the humidity and temperature are within acceptable limits. |
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Respiratory tract |
passageways that carry air to and from the exchange surfaces of the lungs. |
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conducting portion of the respiratory tract |
begin at the entrance of the nasal cavity and extends through the pharnyx, larynx, trachea, bronchi, and larger bronchioles.
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respiratory portion of the respiratory tract |
includes the smallest, thinnest bronchioles and the associated alveoli. |
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conditioning process |
the success of this is due to the respiratory mucosa. |
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Respiratory Mucosa |
lines the conducting portion of the respiratory system. |
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lamina propria |
the underlying layer of areolar tissue that supports the respiratory epithelium. -contains mucous glands that discharge their secretions onto the epithelial surfaces. |
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respiratory defense system |
debris or pathogens in inhaled air can severely damage the delicate exchange of the respiratory system, so a series of filtration mechanisms prevent such contamination. |
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defense in the nasal cavity |
cilia sweep mucus and any trapped debris or microbes towards the pharnyx. -there it is swallowed and exposed the acids and enzymes of the stomache.
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mucus escalator |
In the LRS, the cilia beat toward the pharnyx, moving a carpet of mucus in that direction and cleaning the respiratory surfaces. |
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rate of mucus production in the nasal cavity and paranasal sinuses |
speeds up upon exposure to unpleasant stimuli, such as noxious vapors, large quantities of dust and debris, allergens, or pathogens. |
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Tuberculosis |
results from an infection of the lungs by the bacterium Mycobacterium tuberculosis. |
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cystic fibrosis |
most common lethal inherited disease in individuals of Northern European descent. |
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external nares |
air normally enters through these. "nostrils" -open to the nasal cavity. |
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nasal vestibule |
space contained within the flexible tissues of the nose. -epithelium contains hairs that extend across the external nares to trap sand, sawdust, or even insects. |
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mucus secretions produced in the paranasal sinuses |
help keep the surfaces of the nasal cavity moist and clean. ` |
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superior, middle, and inferior meatuses |
narrow grooves. -incoming air bounces off and churns like a stream flowing over rocks. -the turbulence serves several purposes. |
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turbulence in the meatuses |
as the air swirls, small airborne particles are likely to come in contact with the mucus that coats the lining of the nasal cavity. -also provides extra time for warming and humidifying incoming air. -also creates circular air currents that bring olfactory stimuli to the olfactory receptors |
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patients on breathing on a respirator |
must receive air that has been externally filtered and humidified. -chilling and drying of respiratory surfaces is disastrous. -so it elimination of preliminary filtration. heating and humidifying from breathing through the mouth. |
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breathing through your nose |
helps prevent heat loss and water loss. -because it warms the nasal mucosa and moisture condenses on the epithelial surfaces. |
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epistaxis |
"nosebleed" -made by the extensive vascularization of the nasal cavity and the vulnerable position of the nose -generally involves vessels of the mucosa covering the cartilaginous portion of the septum. causes: face punch, drying, infection, allergy, clotting disorder. (also hypertension, rupturing small vessels of the lamina propria) |
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pharynx |
"throat" chamber shared by the digestive and respiratory systems. |
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larynx |
a cartilaginous tube that surrounds and protects the glottis (voice box) |
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three large, unpaired cartilages form the larynx: |
1. thyroid cartilage 2. cricoid cartilage 3. epiglottis |
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thyroid cartilage |
is the largest laryngeal cartilage. -made of hyaline cartilage, it forms most of the anterior and lateral walls of the larynx |
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cricoid + thyroid cartilages |
protect the glottis and the entrance to the trachea. -their broad surfaces provide sites for the attachment of important laryngeal muscles and ligaments. |
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epiglottis |
-during swallowing, the larynx is elevated and this folds back over the glottis, preventing both liquids and solid food from entering the respiratory tract. |
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Phonation |
"sound production" air passing through your open glottis vibrates its vocal folds. |
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sound pitch |
depends on the diameter, length, and tension of your vocal folds. |
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directly related to size of your larynx |
the diameter and length |
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controlling the tension of vocal folds |
by contracting voluntary muscles that reposition the arytenoid cartilages relative to the thyroid cartilages. -distance increase = higher pitch -distance decrease = pitch fall |
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articulation |
clear speech requires this. -the modification of sounds by other structures, such as the tongue, teeth, and lips to form words. |
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amplification and resonance |
take place with pharynx, oral cavity, nasal cavity, and paranasal sinuses. |
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laryngitis |
infection or inflammation of the larynx. -commonly affects the vibrational qualities of the vocal folds. |
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acute epiglottitis |
swelling that causes closing of the glottis and suffocation. -can develop rapidly after a bacterial infection of the throat. -most likely in children. |
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muscles of the neck and pharnyx |
position and stabilize the larynx. |
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smaller intrinsic muscles of the larynx |
control the tension in the glottal vocal folds or open and close the glottis. -these insert on the thyroid, arytenoid, and corniculate cartilages. |
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bolus |
food is crushed and chewed into this pasty mass, before being swallowed. |
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coughing reflex |
food or liquids that touch the vestibular folds or glottis trigger this. -the glottis is kept closed while the chest and abdominal muscles contract, compressing the lungs. -when the glottis is suddenly opened, a blast of air from the trachea ejects materials that blocks the entrance to the glottis. |
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trachea, and right/left primary bronchi |
three large, extrapulmonary airways associated with the lungs. |
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trachea |
"windpipe" -a tough flexible tube. |
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tracheal cartilages |
there are about 15-20. serve to stiffen the tracheal walls and protect the airway. -also prevent it from collapsing or over-expanding as pressures change in the respiratory system. |
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tracheal cartilages are not continuous |
the posterior tracheal wall can easily distort when you swallow, allowing large masses of food to pass through the esophagus. |
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trachealis muscle |
a band of smooth muscle that connect the ends of each tracheal cartilage. -contracts and relaxes the trachea. -primarily under SNS control. |
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carina |
internal ridge that separates the two primary bronchi. |
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right primary bronchus |
-larger in diameter than the left. -descends towards the right lung at a steeper angle. -most foreign objects that enter the trachea find their way here rather than the left. |
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hilum of the lung |
groove along the medial surface of the lung where each bronchus travels. -also provides access for entry to pulmonary vessels, nerves, and lymphatics. |
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root of the lung |
entire array is firmly anchored in this meshwork of dense connective tissue that attaches to the mediastinum and fixes the position of the major nerves, blood vessels, and lymphatic vessels. |
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anatomy of the lungs |
-lobes -right is bigger than left b/c most of the heart and great vessels project into the left thoracic cavity. -left is longer b/c the diaphragm rises on the right side to accommodate the mass of the liver. |
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cardiac notch |
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extrapulmonary bronchi |
left and right primary bronchi are outside the lungs. |
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intrapulmonary bronchi |
branches of bronchi within the lungs. |
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lobar bronchi |
secondary bronchi that are formed from the division of each primary bronchus. -in the lungs, one goes to each lobe. -right lung has three -left lung has two. |
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branching pattern of the left primary bronchus |
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bronchitis |
during a respiratory infection, the bronchi and bronchioles become inflamed and constricted, increasing resistance. -individual has difficulty breathing. |
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terminal bronchioles |
finest conducting branches. -changes in the diameter of these control the resistance to airflow and the distribution of air in the lungs. |
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ANS regulation |
controls the diameter of the bronchioles. regulates the activity in the smooth muscle tissue. -bronchodilation -bronchoconstriction -direct airflow toward or away from specific portions of the respiratory exchange surfaces. |
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bronchoconstriction |
-takes place during allergic reactions such as anaphylaxis, in response to histamine released by activated mast cells and basophils. |
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asthma |
excessive stimulation of smooth muscles commonly causing bronchiole mucosa to form a series of folds that limits airflow. -can almost completely prevent airflow along the terminal bronchioles. |
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lungs parenchyma |
functional cells |
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relationship between the lungs and heart |
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interlobular septa |
finest partitions divide the lung into pulmonary lobules. |
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respiratory bronchioles |
the thinnest and most delicate branches of the bronchial tree. they deliver air to the gas exchange surfaces of the lungs. -if particles or pathogens reach these, there is little to prevent them from damaging the delicate exchange. |
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alveolar ducts |
respiratory bronchioles are connected to individual alveoli and multiple alveoli along these regions. |
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alveolar sacs |
alveolar ducts end at these common chambers connected to multiple individual alveoli. |
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alveoli |
gives the lung an open, spongy appearance. -there are 150 million in each lung. -each one is associated with an extensive network of capillaries. -a network of elastic fibers surrounds the capillaries. |
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elastic fibers surrounding capillaries in alveoli |
help maintain the relative positions of the alveoli and respiratory bronchioles. -when these recoil during relaxation, they reduce the size of the alveoli and help push air out of the lungs. |
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type 1 pneumocytes |
"type 1 alveolar cells" -squamous epithelial cells of the alveolar epithelium. -usually thin and are the sites of gas diffusion. |
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dust cells |
"alveolar macrophages" -patrol the epithelial surface -phagocytize any particles that have eluded other defenses. |
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type II pneumocytes |
"type II alveolar cell" -large -scattered among the squamous cells -produce surfactant and secrete it onto the alveolar surfaces. |
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surfactant |
-an oily secretion containing phospholipids and proteins -forms a superficial coating on the alveolar surfaces over a thin layer of water. -reduces the surface tension in the liquid coating the alveolar surface, keeping the alveoli open. |
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surface tension |
-results from the attraction between water molecules at an air-water boundary. -creates a barrier that keeps small objects from entering the water. -also tends to collapse small air bubbles. |
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inadequate production of surfactant |
-respiration becomes difficult. -the alveoli collapse after each exhalation. -each inhalation must be forceful enough to pop open the alveoli. |
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respiratory distress syndrome |
a person without enough surfactant is soon exhausted by the effort of inflating and deflating the lungs. |
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respiratory membrane |
-gas exchange occurs across this. Has three layers: 1. squamous epithelial cells lining the alveolus 2. the endothelial cells lining an adjacent capillary 3. fused membranes that lie between the alveolar and endothelial cells. |
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total distance between alveolar air from blood |
can be as little as 0.1 micrometers, but averages about 0.5 micrometers. -diffusion happens quite rapidly because of the short distance and both oxygen/carbon dioxide are small, lipid-soluble molecules. |
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pneumonia |
develops from an infection or any other stimulus that causes inflammation of the lobules of the lung. -as inflammation occurs, fluid leaks into the alveoli, the bronchioles swell, narrowing the passageways and the passage of air is restricted. -respiratory function deteriorates. |
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bacteria that cause respiratory issues |
-they are generally types that normally inhabit the mouth and pharynx but have managed to evade the respiratory defenses. |
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angiotensin-converting enzyme (ACE) |
-endothelial cells of the alveolar capillaries are the primary source for this enzyme. -converts circulating angiotensin I into angiotensin II. -important roll in circulating blood volume and pressure. |
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broncial arteries |
-branch from the thoracic aorta -supply oxygen and nutrients to the lungs
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venous blood return from the lungs |
-about 1/8th of the venous blood drains into the bronchiole veins, passes through the azygos, hemiazygos, and highest intercostal vein, and enters the superior vena cava. -the larger fraction of the venous blood enters anastomoses and drains into the pulmonary veins. (this venous blood dilutes the oxygenated alveolar blood within the pulmonary veins. |
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pulmonary embolism |
blockage (by a large emboli) of a branch of a pulmonary artery stops blood flow to a group of lobules or alveoli -> if it is in place for several hours, the alveoli will permanently collapse. -> congestive heart failure can result. |
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very small blood clots |
-occasionally form in the venous system. -they are usually trapped within the pulmonary capillary network where they soon dissolve. |
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thoracentesis |
procedure of sampling pleural fluid. -sample obtained from a long needle inserted between the ribs. -for diagnostic purposes. -the extracted is examined for bacteria, blood cells, or other abnormal components. |
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pleurisy |
pain and pleural inflammation when friction between the visceral and parietal pleura is not prevented. -secretion of pleural fluid may be excessive -or the inflamed pleurae may adhere to one another. -breathing is difficult and prompt medical attention is required. |
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external respiration |
includes all the processes involved in the exchange of oxygen and carbon dioxide between the body's interstitial fluid and the external environment. -purpose = to meet respiratory demands of the cells. |
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internal respiration |
absorption of oxygen and the release of carbon dioxide by cells. -cellular respiration pathways are involved. |
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Three integral steps in External Respiration |
1. Pulmonary Ventilation (breathing) 2. Gas Diffusion (across the respiratory membrane and between alveolar spaces and alveolar capillaries, and across capillary walls between blood and other tissues) 3. Transport of O2 and CO2 (between alveolar capillaries and capillary beds in other tissues) |
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Hypoxia |
low tissue oxygen levels -places severe limits on the metabolic activities or the affected area. -ex. coronary ischemia is a result. |
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Anoxia |
The oxygen supply is cut off completely. -kills cells very quickly. -damage from strokes or heart attacks are results. |
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Alveolar Ventilation |
movement of air into and out of the alveoli. -prevents the buildup of CO2 in the alveoli. -ensures continuous supply of O2 that keeps pace with absorption by the bloodstream. (= breaths/min x (tidal volume-anatomic dead space)) |
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atmospheric pressure |
the weight of the Earth compresses our bodies and everything around us. -air moves into and out of our RT as the air pressure in the lungs cycle below and above this. |
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The relationship between Gas pressure and volume |
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Boyle's Law |
-If you decrease the volume of a gas, its pressure will increase. -If you increase the volume of the gas, its pressure will decrease. |
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Inhalation & Exhalation (Inspiration & Expiration) |
-involve changes in the volume of the lungs -these volume changes create pressure gradients that move air into or out of the RT. -air moves from an area of higher pressure to lower pressure. |
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compliance of the lungs |
-is an indication of their expandability, or how easily the lungs expand. |
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factors affecting the compliance of the lungs |
-Connective Tissue of the Lungs -Level of surfactant production -The mobility of the Thoracic cage. |
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emphysema |
loss of supporting tissue due to alveolar damage. -increases compliance. |
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Pressure and Volume changes during Inhalation and Exhalation |
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Respiratory Pump |
-The cyclical changes in the intrapleural pressure create this, which assists the venous return to the heart. |
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tidal volume |
the amount of air you move into/out of your lungs during a single respiratory cycle. -about 500 mL. |
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The respiratory Muscles |
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muscles in inhalation |
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muscles in exhalation |
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pneumothorax |
-air can enter the pleural cavity due to an injury to the chest wall that penetrates the parietal pleura, or a rupture of the alveoli that breaks through the visceral pleura. -breaks the fluid bond between the pleurae and allows the elastic fibers to recoil, resulting in collapsed lung.
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atelectasis |
"collapsed lung" -treatment: remove as much air as possible from the cavity and then sealing the opening, lowers the intrapleural pressure and reinflates the lung. |
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quiet breathing "eupnea" |
inhalation involved muscular contractions, but exhalation is passive process. |
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deep breathing "diaphragmatic" |
-contraction of the diaphragm provides the necessary change in thoracic volume. -Air is drawn into the lungs as the diaphragm contracts. -Air is exhaled when the diaphragm relaxes.
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shallow breathing "costal breathing" |
-the thoracic volume changes because the rib cage alters its shape. -inhalation = contractions of the external intercostal muscles raise the ribs and enlarge the thoracic cavity. -exhalation = passive when muscles relax. |
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forced breathing "hypernea" |
-involves the active inspiratory/expiratory movements. -our accessory muscles assist with inhalation. -exhalation involves the contraction of the internal intercostal muscles. (abdominal muscles take part at max levels) |
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contraction of abdominal muscles |
compresses the abdominal contents, pushing them up against the diaphragm. -this further reduces the volume of the thoracic cavity. |
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respiratory rate |
-the number of breaths you take each minute. - normal resting adult: 12-18 breaths per min (one for every four heartbeats) |
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respiratory minute volume |
-amount of air moved each minute. (Ve) -respiratory rate x tidal volume. (12 breaths/min x 500 ml = 6 liters/min) |
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anatomic dead space |
the volume of air in the conducting passages that does not make it to the alveoli. |
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Pulmonary Volumes and Capacities |
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spirometer |
instrument that obtains measurements of pulmonary volumes and capacities -values are useful in diagnosing problems with pulmonary ventilation. |
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Expiratory Reserve Volume (ERV) |
-amount of air that you can voluntarily expel after you have completed a normal, quiet respiratory cycle. |
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residual volume |
amount of air that remains in your lungs after max exhalation. |
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minimal volume |
a component of residual volume, is the amount of air that would remain in your lungs if they were allowed to collapse. -cannot be measured in a healthy person. -surfactant prevents collapse. |
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inspiratory reserve volume (IRV) |
amount of air that you can take in over and above the tidal volume. |
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inspiratory capacity |
amount of air that you can draw into your lungs after you have completed a quiet respiratory cycle. |
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functional residual capacity (FRC) |
the amount of air remaining in your lungs after you have completed a respiratory cycle. - sum of the expiratory reserve volume and residual volume. |
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vital capacity |
max amount of air that you can move in/out of your lungs in a single respiratory cycle. -sum of the expiratory reserve volume, tidal volume, and inspiratory reserve volume. |
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total lung capacity |
the total volume of your lungs. (vital capacity + residual volume) |
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Partial Pressure and Normal Gas Concentrations in Air |
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Henry's Law and the Relationship between Solubility and Pressure |
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Dalton's Law |
each of the gases contribute to the total pressure in proportion to its relative abundance. (partial pressure) |
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Henry's Law |
at a given temperature, the amount of a particular gas in solution directly proportional to the partial pressure of the gas. |
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decompression sickness |
-a sudden drop in ATM pressure causes nitrogen (which has a high partial pressure in air) to come out of solution, forming bubbles in joint cavities, bloodstream, or CSF. -curling from pain = bends. |
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Gas exchange efficiency |
1. differences in partial pressures across the respiratory membrane are substantial. 2. distances involved are short. 3. gases are lipid-soluble. 4. the total surface area is large. 5. Blood flow and air flow are coordinated. |
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Partial Pressures in Respiration |
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Peripheral tissues need more oxygen and generate more CO2 than that plasma alone can absorb and transport |
-RBCs solve this problem. -when [CO2] and [O2] in blood plasma are high, RBCs remove excess molecules. -when [CO2] and [O2] are too low, the RBCs release their stored reserves. |
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hemoglobin saturation |
percentage of heme units containing blood oxygen at any given moment. Factors affecting hemoglobin: -pressure of oxygen in blood -blood pH -temperature -ongoing metabolic activity within RBCs. |
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oxygen-hemoglobin saturation curve |
-relates the Hb saturation to the partial pressure of O2. |
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The effects of pH on Hb saturation |
-Bohr effect -Co2 is the primary compound responsible. |
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The effects of temperature on Hb saturation |
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carbonic anhydrase |
-an enzyme that catalyzes the reaction of CO2 with water mocules in RBCs. -product = carbonic ACID. |
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2,3-bisphosphoglycerate (BPG) |
the metabolic pathways involved in glycolysis in an RBC generate this compound and lactic acid. -this compound has a direct effect on oxygen binding and release. -higher concentration = more release of oxygen by Hb molecules. (levels rise when pH decreases) |
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BPG levels can increase in response to: |
-high blood pH -thyroid hormones -growth hormones -epinephrine -androgens (% decreases when RBC ages) |
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carbon monoxide poisoning |
-CO competes with oxygen molecules for the binding sites on heme units. -CO usually wins. -makes heme unit inactive for respiratory purposes. Treatment: administer pure O2, transfuse compatible RBCS. |
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Carbon Dioxide after entering the blood |
1. is converted to a molecule of carbonic acid 2. binds to hemoglobin within RBCs 3. dissolves in plasma.
(all three are reversible) |
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pH buffer |
Hb acts as this as it tries to tie up the released hydrogen ions before the ions can leave the RBCs and lower to pH of the plasma. |
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chloride shift |
bicarbonate ions move into the plasma with the aid of a countertransport mechanism that exchanges intracellular bicarbonate ions for extracellular chloride ions. -this does not require ATP. -results is mass movement of chloride ions into the RBCs. |
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Summary of the Primary Gas Transport Mechanisms |
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homeostatic mechanisms that intervene to restore equilibrium if diffusion rates at the peripheral and capillaries become unbalanced |
1. changes in blood flow and oxygen delivery that are regulated at the local level 2. changes in depth and rate of respiration under the control of the brain's respiratory centers (medulla oblongata and pons) |
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Basic Regulatory Patterns of Respiration |
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respiratory centers |
-are three pairs of nuclei in the reticular formation of the medulla oblongata and pons. |
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motor neurons in the spinal cord |
-generally controlled by respiratory reflexes -can also be controlled voluntarily through commands delivered by the corticospinal pathway. |
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respiratory rhythmicity centers |
-in medulla oblongata -play a key role in establishing the pace of respiration. -each can be divided into a dorsal respiratory group (DRG) and ventral respiratory group (VRG) |
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DRG |
-mostly concerned with inspiration -both quiet and forced breathing. |
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VRG |
-mostly concerned with expiration -only forced breathing -respiratory center contains neurons involved in max inhalation (gasping) |
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nuclei involved in respiratory control form a complex network that involves: |
1. the rhythmicity centers 2. centers in the pons that are modulated by peripheral and higher central inputs 3. an area in the ventrolateral medulla, known as the central pattern generator (pre-Botzinger complex) |
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pre-Botzinger complex |
-essential to all forms of breathing. |
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CNS stimulants |
-amphetamines or caffeine -increase the respiratory rate by facilitating the respiratory centers. -actions are opposed by CNS depressants (barbiturates or opiates) |
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apneustic and pneumotaxic centers of the pons |
regulate the depth and rate of respiration is response to sensory stimuli or input from other centers of the brain. |
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Each apneustic center |
provides continuous stimulation to the DRG on that side of the brain. -during quiet breathing, stimulation from this center helps increase the intensity of inhalation over the next 2 seconds. -inhibited after 2 seconds from the pneumotaxic center on that side. |
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pneumotaxic centers |
inhibit the apneustic centers and promote passive or active exhalation. -centers in the hypothalamus and cerebrum can alter its activity, as well as the respiratory rate and depth. |
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Sudden infant death syndrome |
"crib death" -infant stops breathing, turns blue, and relaxes. -results from a problem in the interconnection process that disrupts the reflexive respiratory pattern. |
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Level 1 in Respiratory Control |
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Level 2 in Respiratory Control |
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Level 3 in Respiratory Control |
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Respiratory Centers and Reflex Controls |
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The activities of the respiratory centers are modified by sensory info from many sources: |
-Chemoreceptors in blood and CSF -Stretch receptors in lungs -irritations -pain, body temperature, abnormal visceral sensations |
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glossopharyngeal nerves |
carry chemoreceptive info from the carotid bodies, adjacent to the sinuses. -bodies are stimulated by a decrease in O2 of the blood. |
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Vagus Nerve |
monitor chemoreceptors in the aortic bodies, near the aortic arch. |
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chemoreceptor location |
-ventrolateral surface of the medulla oblongata in a region known as the chemosensitive area. -neurons in that area only respond to CO2 pressure and the pH of CSF. (neurons often called central chemoreceptors) |
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Hypercapnia |
an increase in the partial CO2 pressure of arterial blood. |
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hypoventilation |
-most common cause of hypercapnia -abnormally low respiratory rate cannot meet demands for normal oxygen delivery and CO2 removal. -CO2 accumulation. |
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hyperventilation |
-causes hypocapnia -the rate and depth of respiration exceed the demands for O2 delivery and CO2 removal. |
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Hypocapnia |
-abnormally low partial CO2 pressure. -chemoreceptor activity falls and respiratory rate decreases. -continues until homeostatis is restored. |
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Hering-Breuer reflexes |
-sensory info from these reflexes goes to the apneustic centers and the ventral respiratory group (VRG). -not involved in normal quiet breathing or tidal volumes under 1000 mL. -Two such reflexes: inflation, and deflation reflex. |
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inflation reflex |
-prevents overexpansion of the lungs during forces breathing. -stimulated stretch receptors, inhibits DRG & stimulates VRG. -active exhalation begins. |
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deflation reflex |
-normally functions only during forced exhalation, when both inspiratory and expiratory centers are active. -inhibits the expiratory centers and stimulates the inspiratory centers when the lungs are deflating. -exhalation stops and inhalation begins. |
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protective reflexes |
-operate when you are exposed to toxic vapors, chemical irritants, or mechanical stimulation of the RT. -receptors involved are located in the epithelium of the RT. -ex. sneeze, cough, laryngeal spasms. |
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anpea |
a period in which respiration is suspended. -involved in sneezing and coughing. |
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laryngeal spasms |
-result when chemical irritants, foreign objects, or fluids enter the area around the glottis. -generally closes the airway temporarily. |
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toxic gas |
-could close the glottis so powerfully that you could lose consciousness and die without taking another breath. |
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abilities to override the respiratory centers have limites |
for example: you cannot kill yourself by holding your breath because the chemoreceptor reflexes are so powerful in stimulating respiration that the increase in CO2 will force you to take a breath. |
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conscious control over respiratory centers |
-may bypass, using pyramidal fibers that innervate the same lower motor neurons that are controlled by the DRG and VRG -important for timed activies (singing etc.) |
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Decline in respiratory performance with age and smoking |
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Decline in Respiratory efficient with age: |
-elastic tissue deteriorates -chest movements restricted by arthritis -some degree of emphysema |
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emphysema |
a chronic, progressive condition characterized by shortness of breath and an inability to tolerate physical exertion. -destruction of alveolar surfaces and inadequate surface area for oxygen and CO2 exchange. |
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lung cancer |
"bronchopulmonary carcinoma" -aggressive malignancy. -affect endothelial lining of conducting passageways, mucous glands, or alveoli. |
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System Integrator for the Respiratory System |
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