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29 Cards in this Set
- Front
- Back
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What do respiratory systems rely on?
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The diffusion of gases down pressure gradients (in a moist surface)
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What does diffusion depend on?
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The surface area of the membrane and the differences in partial pressure of O2 and CO2
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What two factors influence gas exchange?
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Surface to volume ratio and transport pigments
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Why is gas exchange necessary?
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Because diffusion is not feasible due to the small surface to volume ratio, a system must move gases inward
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What is the main transport pigment and what is its structure?
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Hemoglobin; protein with 4 iron groups around it
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How does a fish's respiratory system work?
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Water enters the mouth and flows through the gills, with the blood flowing in opposite directions
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What is countercurrent flow and what are its advantages?
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When water and blood circulate in opposite directions; it extracts O2 from the water efficiently
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What do the lungs contain and what to they provide?
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They contain internal respiratory surfaces shaped as sacs/cavities
They provide a membrane for gaseous exchange with the blood |
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In what order does oxygen diffuse?
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Blood>interstitial fluid>cells
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In what order does CO2 diffuse?
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cells>interstitial fluid>blood
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What is the function of ventilation?
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It moves air into and out of lungs
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What are the tiny air sacs in the lungs?
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Alveoli (where gas exchange takes place)
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Why is breathing necessary for speech?
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Because when air is exhaled through the glottis, the folds of the cord vibrate to make sounds
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What are two functions of the respiratory system?
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Adjusts acid-base balance
Deals with airborne foreign mater |
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What happens to air when it enters the nasal cavity?
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It is warmed. Hair and cilia filter out dust and particles, mucus moistens the air
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What is the route that air follows?
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Pharynx>larynx>vocal cords>trachea>bronchi>branchioles>alveoli
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Where are lungs located?
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In the rib cage above the diaphragm
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What does each lung lie in?
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A thin-walled pleural sac
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What are alveoli in relation to bronchioles?
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Outpouchings of the wall
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What do alveoli provide?
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A large surface area for gaseous exchange with the blood
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What happens in inhalation?
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The diaphragm contracts and flattens, muscles lift the rib cage upward and outward increasing chest volume and decreasing internal pressure so air rushes in
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What happens in exhalation?
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The diphragm relaxes, muscles rest so the rib cage falls and decreases chest volume and increases pressure
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What is hemoglobin?
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A protein with four heme groups that bind O2 in the lungs (high concentration) to form oxyhemoglobin
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What does oxyhemoglobin do?
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Gives up its oxygen to tissues where oxygen is low and CO2 is higher
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What happens because CO2 is higher in tissues?
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It diffuses into the blood
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What are the percentages of forms of CO2?
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10% dissolved in plasma, 30% combines with hemoglobin to carbaminohemoglobin, and 60% is bicarbonate
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What enhances bicarbonate and carbonic acid formation?
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Carbonic anhydrase (in red blood cell)
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What does the nervous system control? How?
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O2 and CO2 levels for the body, by adjusting contraction rates of the diaphragm and chest wall muscles
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What does the brain monitor and why?
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Input from CO2 sensors in the bloodstream and from O2 partial pressure decrease sensors
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