Term
| What are the advantages and disadvantages of air and water as mediums for gas exchange? |
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Definition
air-has higher concentration of molecular oxygen (18%) that water (less than 5%)
-oxygen diffuses faster through air than through water
-air is less dense and viscous than water (meaning less energy needed to move air over gas exchange surface) |
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Term
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Definition
| have adaptations that protect their respiratory surfaces from drying |
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Term
| adaptations for gas exchange in small aquatic animals |
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Definition
-exchange gases by diffusion
-no specialized respiratory structures |
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Term
| Adaptations for gas exchange in insects and some other arthropods |
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Definition
| air enters network of tracheal tubes (tracheae) through spiracles along body surface
-tracheal tubes brach and extend to all body regions |
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Term
| adaptations for gas exchange in aquatic animals |
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Definition
-have gills: thin projections of body surface
-chordates: gills usually internal, along edges of gill slits |
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Term
| adaptations for gas exchange in bony fishes |
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Definition
-operculum protects gills
-countercurrent exchange system (water flows one way and blood the other way) maximizes diffusion of oxygen into blood and carbon dioxide out of the blood
-Animals carry on ventilation: actively move air or water over respiratory surfaces |
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Term
| adaptations for gas exchange in terrestrial vertebrates |
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Definition
-have lungs and some means of ventilation them
-Amphibians and reptiles have lungs with some ridges or folds to increases surface area |
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Term
| adaptations for gas exchange in birds |
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Definition
-lungs have extensions (air sacs) that draw air
-2 cycles of inhalation and exhalation |
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Term
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Definition
-one-way flow of air through lungs from outside into posterior air sacs, to lung, through anterior air sacs, and out of the body
-gas exchanged through walls of parabronchi: crosscurrent arrangement (blood flow at right angles to parabronchi) increases amount of oxygen entering the blood |
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Term
| What does the human respiratory system contain? |
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Definition
| -lungs and system of airways |
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Term
| What is the cavity in which the lungs lie and what covers each lung? |
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Definition
-pleural cavity
-pleural membrane |
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Term
| Where all does air pass through in the human respiratory system? |
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Definition
| nostrils, nasal cavities, pharynx, larynx, trachea, bronchi, bronchioles, and alvioli |
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Term
| What are the mechanics of breathing? |
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Definition
-diaphragm contracts, expanding chest cavity
-membranous walls of lungs move outward along with chest walls lowering pressure within the lungs
-air rushes in through air passageways until pressure in lungs equals atmospheric pressure |
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Term
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Definition
| amount of air moved into and out of lungs with each normal breath |
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Term
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Definition
| amount of air moved into and out of lungs with each normal breath |
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Term
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Definition
| maximum volume exhaled after lungs fill to maximum extent |
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Term
| What is residual capacity? |
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Definition
| air volume remaining in lungs at end of normal expiration |
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Term
| What regulate respiration? |
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Definition
| respiratory centers in medulla and pons |
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Term
| How are chemoreceptors involved in the regulation of breathing? |
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Definition
-they are sensitive to increase in CO2 concentration
-they stimulate respiratory centers
-they respond to increase in H+ or very low O2 concentration |
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Term
| How do does gas exchange of oxygen and carbon dioxide occur? |
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Definition
| between alveoli and blood by diffusion |
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Term
| What determines the direction and rate of diffusion? |
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Definition
| the pressure of a particular gas (oxygen or carbon dioxide) |
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Term
| Dalton's law of partial pressures |
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Definition
| in a mixture of gases, total pressure is the sum of the pressures of the individual gases |
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Term
| What is a partial pressure? |
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Definition
-exerted by each gas
-same pressure as if the gas were present alone |
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Term
| What is the partial pressure of atmospheric oxygen at sea level? |
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Definition
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Term
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Definition
the greater the difference in pressure on two sides of a membrane, and the larger the surface area, the faster the gas diffuses across the membrane
-this explains why alveoli are in clusters, to maximize surface area |
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Term
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Definition
| a protein and respiratory pigment in vertebrate blood |
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Term
| What is the role of hemoglobin in oxygen transport? |
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Definition
-iron binds to oxygen forming hemoglobin (without iron one is anemic)
-red blood cells are packed with hemoglobin |
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Term
| What is 99% of oxygen in human blood transported as? |
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Definition
oxyhemoglobin (HbO2)
-other 1% dissolves in plasma |
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Term
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Definition
| maximum amount of oxygen that can be transported by hemoglobin |
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Term
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Definition
| actual amount of oxygen bound to hemoglobin |
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Term
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Definition
-ratio of oxygen content to oxygen-carrying capacity
-highest in pulmonary capillaries (around alveoli) |
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Term
| oxygen-hemoglobin dissociation curve |
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Definition
-example of positive feedback loop
-as oxygen concentration increases, the amount of hemoglobin that combines with oxygen progressively increases
-oxyhemoglobin dissociates more readily as CO2 concentration increases (CO2 combines with water and produces carbonic acid, which lowers pH)
-affected by pH, temperature, carbon dioxide, concentration |
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Term
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Definition
| displacement of oxygen-hemoglobin dissociation curve by change in pH |
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Term
| What is 60% of the carbon dioxide in blood transported as? |
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Definition
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Term
| What does 30% of carbon dioxide combine with? |
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Definition
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Term
| What happens to 10% of the carbon dioxide? |
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Definition
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Term
| In CO2 transport, what is formed when carbon dioxide combines with water? What catalyzes this reaction? |
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Definition
-carbonic acid
-catalyzed by carbonic anhydrase |
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Term
| In CO2 transport, what does carbonic acid dissociate to form? |
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Definition
| -bicarbonate ions (HCO3-) & hydrogen ions (H+) |
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Term
| What combines with the H+ that is formed from the dissociation of carbonic acid? |
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Definition
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Term
| What happens when hemoglobin combines with H+? |
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Definition
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Term
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Definition
| many bicarbonate ions diffuse into the plasma and are replaced by Cl- |
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Term
| What happens during hyperventilation? |
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Definition
too much CO2 is expelled, which lowers the pH and slows down the actual exchange of oxygen
-CO2 concentration in alveoli and blood are reduced
-a certain CO2 concentration in blood is needed to maintain normal blood pressure |
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Term
| How does altitude affect barometric pressure? |
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Definition
| as altitude increases, barometric pressure decreases and less oxygen enters the blood |
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Term
| What is the result of high altitudes? |
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Definition
| hypoxia aka "altitude sickness"-results in loss of consciousness, death |
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Term
| What can a rapid decrease in barometric pressure cause? |
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Definition
decompression sickness aka "the bends"
-among divers who ascend too rapidly
-as we go lower, pressure causes oxygen to dissolve in blood and if we come up to fast it bubbles out of the blood because pressure decreases |
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Term
| What do diving mammals have in their muscles that stores oxygen? |
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Definition
| high concentrations of myoglobin |
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Term
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Definition
-group of physiological mechanisms
-including decrease in metabolic rate
-activated when a mammal dives to its limit |
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Term
| What are the defense mechanisms for the respiratory system? |
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Definition
| -ciliated mucous lining traps inhaled particles in the nose, pharynx, trachea, and bronchi |
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Term
| What does inhaling polluted air or cigarette smoke result in? |
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Definition
bronchial constriction, increases mucus secretion, damage to ciliated cells, coughing
-can cause chronic bronchitis, pulmonary emphysema, and lung cancer |
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