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118 Cards in this Set
- Front
- Back
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what can thin air do the to the body?
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-weaken muscles
-cloud minds -sometimes fill lungs w/ fluid |
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how can geese fly at such great heights?
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-they have efficent lungs
-draw more o2 from the air than we can -have blood w/ hemoglobin w/ high affinity for o2, picking it up in the lungs and carrying it to tissues throughout the body -theird circulatory system has a large # of capillaries that carry o2-rich blood to flight muscles, and the muscles themselves pack a protein that stores a ready supply of o2 |
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what happens when we don't have o2
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metabolic machinery that releases energy from food molecules shuts down.
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define GAS EXCHANGE/RESPRIATION
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interchange of o2 and the waste product of CO2 btwn an animal and its environment
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what does gas exchange involve?
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breathing
transport of gases exchange of gases w/ tissue cells |
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phase 1 of gas exchange in an animal w/ lungs
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1. breathing is the first phase of the gas exchange process. when an animal breathes, a large, moist internal surface is exposed to air. o2 diffuses across the cells lining th elungs and into surroudning blood vessels. at the same time, co2 diffuses out of ht eblood and into th elungs. as the animal exhales, co2 is removed from the body.
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phase 2 of gas exchange in an animal w/ lungs
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a second phase of gas exchange is the trnasport of gases by the circulatory system. the o2 that has diffused into the blood attaches to hemoglobin in red blood cells and is carried from the lungs to the body's tissues. co2 is also transported in blood from th etissues back to the lungs.
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phase 3 of gas exchange in an animal w/ lungs
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in the third phase of gas exchange, body cells take up o2 from the blood and release co2 to the blood. this o2 is required for cells to obtain energy from the food moelecules the body has digested and absorbed.
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cellular respiration
-o2 functions as |
o2 functions in cellular respriation as th final electron accpetor in the stepwise breakdown of fuel molecules.
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cellular respiration
-waste product -produce |
h2o and co2
ATP |
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what two systems does gas exchange involve?
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circulatory system and respiratory system
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why can't humans survive for more than a few min w/o o2?
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cells require a steady supply of ATP in order to function. cellular resptiation requires o2 to produce this ATP. w/o ATP, cells and the organism die.
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define RESPIRATORY SURFACE
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the part of an animal where gases are exchanged with the environment
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what is respriatory surfaces made up of?
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living cells, whose plasma membranes must be wet to function properly
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gases must be dissolved in what
and why |
in water
to diffuse across them |
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describe the surface area of the respiratory surface
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it must be extensive to take up sufficeint o2 for every cell in the body and to dispose of all waste co2
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how do earthworms breathe?
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they use their outer skin as a gas exchange organ
-oxygen diffuses into a dense net of thin-walled capillaries lying just beneath the skin. -lack specialized gas exchange organs *small size/flatness provides a high ratio of respiratory surface to body volume, allowing for sufficient gas exchange for the entire body |
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what parts of the body have adapted as respiratory surfaces?
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-gills have eveoled in most aquatic animals
-lungs or an internal system of gas exchange tubes called TRACHAE have evolved |
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define GILLS
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extentions, or outfoldings, of the body surface specialized for gas exchange
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how do gills work
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-o2 diffuses across the gill surfaces into capillaries
-co2 diffuses in the opposite dirction, out of the capillaries and into teh external environment |
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define TRACHEAL SYSTEM
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in insects, it is the extensive system of branching internal tubes
-smallest branch exchange gases directly w/ body cells req no assistance from circulatory system |
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define LUNGS
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internal sacs lined w/ moist epithelium
-the inner surfaces of the lungs branch extensively, forming a large respiratory surface. gases are carried btwn the lungs and the body cells by circ system |
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what is the main difference btwn gills and lungs in terms of their spatial relationship to the rest of an animal's body?
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the extensive respiratory surfae of gills extends outward from the body into the surrounding environment (water)
lungs are internal sacs w/ respiratory surfaces |
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what's an advantage of exchanging gases in water
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no problem keeping the respiratory surface wet
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what's disadvantage of exchanging gases in water
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the amount of available oxygen in water is only about 3-5% of what it is in the air
the warmer and the saltier the water, teh less disolved o2 it holds |
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four supporting gill arches
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-two rows of gill filaments project from each arch
-each filament bears many platelike structures called LAMELLAE, which are the actual respiratory surfaces |
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define LAMELLAE
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platelike structures, which are the actual respiratory surfaces
-full of tiny capillaries that are separted from the outside by only one or a few layers of cells *capillaries are so narrow that red blood cells must pass through them in single file ~red blood cells come in close contact w/ o2 dissolved in the h20 |
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define VENTILATION
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any mechanism that increases the flow of the surrounding water or air over the respiratory surface (gills, tracheae, or lungs)
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define COUNTERCURRENT EXCHANGE
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transfer of something from a fluid moving in one direction to another fluid moving in the opposite direction
-opposite flow maintains a diffusion gradient that enhances transfer of the substance |
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what would be the max percentage of the water's oxygen a gill could extract if its blood flowed in the saem direction as the water instead of counter to it?
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50%. as o2 diffsued from the water into the blood as they flowed in the same direction, the concentration gradietn would become less and less steep until there was the same amount of o2 dissolved in both, and the o2 could no longer diffuse from water to blood
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what are two big advantages to exchanging gases by breathing air
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-air contains a much hihger concentration of o2
-air is much lighter and easier to move than water *terrestrial animal expends much less energy than an aquatic animal ventilating its repiratory surace |
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what's th eproblem facing any air-0breaking animal?
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lose of water to the air by evaporation
*w/ respiratory suraces occuring as tiny tubes deep in th ebody of an incsect, evaporation is reduced, and the respiratory system loses very little water |
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what is the tracheal system of insects made up of?
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air tubes that branch throughout the body. the lragest tubes, called TRACHEAE, open to the outside and are reinforced by rings of chitn
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what are the smallest branches called
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TRACHEOLES, they extend ot every cell in the insect's body. tiny tips of the tracheoles are closed and contain fluid. gas is exchanged w/ body cells by diffusion across the moist epithelium that lines these tips.
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an insect in flight has a very high metabolic rate
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consumes 10-200 times more o2 than it does at rest
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four supporting gill arches
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-two rows of gill filaments project from each arch
-each filament bears many platelike structures called LAMELLAE, which are the actual respiratory surfaces |
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define LAMELLAE
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platelike structures, which are the actual respiratory surfaces
-full of tiny capillaries that are separted from the outside by only one or a few layers of cells *capillaries are so narrow that red blood cells must pass through them in single file ~red blood cells come in close contact w/ o2 dissolved in the h20 |
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define VENTILATION
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any mechanism that increases the flow of the surrounding water or air over the respiratory surface (gills, tracheae, or lungs)
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define COUNTERCURRENT EXCHANGE
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transfer of something from a fluid moving in one direction to another fluid moving in the opposite direction
-opposite flow maintains a diffusion gradient that enhances transfer of the substance |
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what would be the max percentage of the water's oxygen a gill could extract if its blood flowed in the saem direction as the water instead of counter to it?
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50%. as o2 diffsued from the water into the blood as they flowed in the same direction, the concentration gradietn would become less and less steep until there was the same amount of o2 dissolved in both, and the o2 could no longer diffuse from water to blood
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what are two big advantages to exchanging gases by breathing air
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-air contains a much hihger concentration of o2
-air is much lighter and easier to move than water *terrestrial animal expends much less energy than an aquatic animal ventilating its repiratory surace |
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what's th eproblem facing any air-0breaking animal?
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lose of water to the air by evaporation
*w/ respiratory suraces occuring as tiny tubes deep in th ebody of an incsect, evaporation is reduced, and the respiratory system loses very little water |
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what is the tracheal system of insects made up of?
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air tubes that branch throughout the body. the lragest tubes, called TRACHEAE, open to the outside and are reinforced by rings of chitn
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what are the smallest branches called
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TRACHEOLES, they extend ot every cell in the insect's body. tiny tips of the tracheoles are closed and contain fluid. gas is exchanged w/ body cells by diffusion across the moist epithelium that lines these tips.
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an insect in flight has a very high metabolic rate
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consumes 10-200 times more o2 than it does at rest
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in what basic way does hte process of gas exchange in insects differ from that in both fish and humans?
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the circulatory system of insects is not involved in transporting gases to and from the body cells
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amphibians have small lungs
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rely on diffusion of gases across body surfaces
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skin of frogs
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supplements gas exchange in the lungs
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reptiles and mammlas
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rely on lungs for gas exchange
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the size and complexity of lungs are correlated with
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an animal's metabolic rate
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define DIAPHRAGM
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sheet of muscle that keeps the lungs bounded
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list th eparts of the respiratory system in order that an inhaled breath of air would encounter them
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nasal cavity
pharynx larynx trachea bronchus bronchiole alveolus |
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define PHARYNX
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where paths for air and food cross
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DEFINE larynx
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voice box
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DEFINE vocal cords
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when we exhale, the outgoing air rushes by a pair of vocal cords in the larynx
prodcue sounds by voluntairly tensing muscles in the voice box, stretching the cords and making them vibrate we produce high pitched sounds when our vocal cords are tense and vibrating fast when the cords are less tense, they vibrate slowly and produce low-pitched sounds |
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define TRACHEA
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windpipe
rings of cartilage maintain the shape of the trachea |
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define BRONCHI
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the trachea forks into two BRONCHI, one leading to each lung
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define BRONCHIOLES
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finger tubes
whini th elung, the BRONCHUS branches repeatedly into finer and finer tubes called BRONCHIOLES |
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what is bronchitis
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condition in which these small tubes beecome inflamed and constricted, making breathing difficult
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define ALVEOLI
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clusters of air sacs. each of our lungs contains millions of these tiny sacs
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the inner urface of each alveolus is lined with
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a thin layer of epithelial cells that form the respiratory surface
the o2 in inhaled air dissolves in a firlm of moisture on the epithelial cells it then diffuses across the epithelium and into a web of blood capillaries that surrounds each alveolus the co2 diffuses the opposite way- from the capillaries, across th eepithelium of th ealveolus, into the air space of the alveolus, and finally out in th eexhalled air |
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the trachea and major branches of the respiratory system are lihned by
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a moist epithelium covered by cilia and a thin film of mucus
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the cilia and mucus are th esystem's cleaning elements
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the mucus traps dust, pollen, and other contaminants, and the beating cilia move the mucus upward to the pharynx, where it is swallowed
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the visible smoke from a cigarette, cigar, or pipe is microscopic particles of
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carbon
-sticking to the carbon particles ar emany toxic chemicals cancer causing agents |
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what does tobacco smoke do
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it irritates the cells lining th ebronchi, inhibiting or destroying their cilia
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smokes particles kill macrophases, defensive cells that reside in teh respiratory tract and engult fine particles and microorganisms
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smoking disables th enormal cleansing and protective mechanisms of the respiratory system, allowing even more toxin-laden particles to reach th elung's delicate alveoli
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define EMPHYSEMA
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dsiease in which the walls of the alveoli lsoe their elasticity and deteriorate, reducing the lungs' capacity for gas exchange
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smoking can also cause cardiovascular disease
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smoking raises blodo pressure and increases harmful cholesterol levels in the blood
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what causes smoker's cough
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tobacco smoke damages cilia, inhibiting their ability to sweep mucus and trapped particles out of the respiratry tract. the body tries to sompensate by coughing
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define BREATHING
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alternation of inhalation and exhalation
-the ventailation of our lungs maintains hih o2 and low co2 concentrations at the respiratory surface |
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what occurs in our rib cage, cheszt cavity, and lungs during breathing
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during inhalation, both the rib cage and chest cavity expand, and th elungs follow suit. the ribs move upward and the rib cage expands as muscles between the ribs contract. the diaphragm contracts, moving downward and expanding the chest cavity as it goes.
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what does the increase in the volume of th elungs do during inhaltion?
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it lowers the air pressure in the alveoli to less than atmospheric pressure.
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define NEGATIVE PRESSURE BREATHING
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air rushes through the nostrils and down the breathing tubes to the alveoli
-flowing from a region of higher pressure to one of th elower pressure |
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what happens during exhalation?
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the rib muscles and diaphragm both relax, decreasing the volume of the rib cage and the chest cavity and forcing air out of the lungs
-the diaphragm curves upward into the chest cavity when relaxed |
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define VITAL CAPACITY
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the maximum volume of air that we can inhale and exhale during forced breathing
*the lungs hold mor eiar than vital capacity |
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because the alveoli don't completely collapse
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a residual volume of "dead" air remains in the lungs even afer we blow out as much air as we can
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as lungs lose resilience/springiness with age or result of disease
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our residual volume increases as the expense of vital capacity
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unlike the in-and-outu flow of air in the human alveoli, birds have a one way flow of air through the lungs
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birds have several large air sacs in addition to thier lungs. these don't function directly in gas exchange, but act as bellows that keep air flowing through the lungs
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both sets of th ebirds/' air sacs expand during inhalation.
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the posterior sacs fill w/ fresh air from teh outside, while the anterior sacs fill w/ stale air from the lungs
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during exhalation of a bird
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both sets of air sacs deflate forcing air from the posterior sacs into the lungs, and air form the anterior sacs out of hte system via the trachea
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instead of alveoli, what do birds' lungs have?
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birds lungs contain tiny parallel tubes.
gas exchange occurs across the walls of these tubes as air passes one way through them. |
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b/c of hte one way flow of air
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there is no dead air in teh bird lung, so lung o2 concentrations are higher in birds than in mammals
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compare the pathway of air flow in the lungs of mammals and birds
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Mammals: air enteres and leaves th elungs by the same pathway, and newly inhaled air mixes with o2-depleated residual air
birds: air flows undirectionally through the lungs |
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where are our BREATHING CONTROL CENTERES locateD?
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in parts of the brain called the PONS and MEDULLA OBLONGATA
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nerves from the medulla's control center signal the diaphragm and th erib muscles to contract
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making us inhale
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the control center in the pons smooths out the basic rhythm of breathing set by the medula
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btwn in halations, the muscles relax, and we exhale
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how does the medulla's control center adust our breathing rate in response to the body's varying needs?
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the control center monitors the co2 level ov ehte blood and regulates breathing rate in response. its main cues about co2 concentrationi come from slight changes in the pH of th eblood and in th efluid bathing the brain
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the pH starts to drop wheN?
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the amount of co2 increases in the blood
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when we exercise, our metabolism speeds up and our body cells generate more co2 as weawste product
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the co2 goes into the blood wehre it reacts w/ water to form carbonic acid
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the acid lowers the pH of th eblood and cerebrospinal fluid slightly. when te medulla sense this pH drop, it's breathing clontrol center increases the brathing rate and depth
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more co2 is eliminated in the exhaled air, and pH returns to normal
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define HYPERVENTILATION
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excessively taking rapid, deep breaths
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deep, rapid breathing purges the blood of CO2
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the control center ceases to send signals to the rib muscles and diaphragm. breathing stop suntil th eco2 level increases enough to switch the brathing center back on
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our breathing control center responds directly to co2 levels
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it usually doesn't respond directly to o2 levels. since the same process that consumes o2 also produces co2, a rise in co2 is a good indication of a drop in blood o2.
by responding to a lowered pH, the brathing contorl center also controls blood o2 level |
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secondary control over breathing is exerted by
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sensors in the aorta and carotid arteries that monitor concentrations of o2 and co2
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when the o2 level in the blood is severely depressed
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these sensors signal the control center via nerves to increase the rate and depth of breathing
this response may occur at high altitutdes, wehre th air si so thin that we can't get enough o2 by breathing normally |
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the breathing control center responds to
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a variaety of nervous and chemical signals to keep the rbeathing rate and depth in tune w/ the changing demand sof hte body
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breathing rate must be coordinated w/
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the acitivy of the circulatory system
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explain how hyperventilation disrupts the control of breathing
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by purging the blood of co2, which indicretly stimulates inhalation via its action on the breathing control center, hyperventtilation remporarly suspends breathing
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o2 poor and rich
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poor blod returns to the heart from the capillaries in body tissues
the heart pumps this blood to the alveolar capillaries in the lungs |
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gases are exchange dbtwn air in the alveolar spaces and blood in the alveolar capillaries
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blood leaves the alveolar capillaries, hacng lost co2 and gained o2
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o2 rich blood retusn to the heart and is
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pumped out to body tissues
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the exchange of gasees btwn capillaries and the cells around them occurs by the diffusion of gases down gradients of pressure
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a mixture of gases exerts pressure
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define PARTIAL PRESSURE
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each kind of gas in a mixture
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molecules of each kind of gas will diffuse down a gradient of its own partial pressure independent of other gase
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o2 moves from o2 rich blood, through interstitial fluid, and into tissue cells bc it diffuses from a region higher partial pressure to a region of lower partial pressure
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tissue cells maintain this gradient as they consume o2 in cellular respiration
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the co2 produced as a wawste product of cellular repiration diffuses down its own partial pressure gradient out of the cells and into the capillaries.
diffusion also accounts for gas exchange in the alveoli |
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what is the physical process underlying gas exchange?
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diffusion of each gas down its partial pressure gradient.
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what does hemoglobin do?
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it carries o2 and helps transport co2 and buffer the blood
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o2 is not soluble in water
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most of th eo2 in blood is carried by hemoglobin in the red blood cells
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what does a HEMOGLOBIN molecule consist of?
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four polypeptide chains of two different types
attached to each polypeptide is a chemical group called a HEME, at the center of which is an iron atom |
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each iron atom can carry one o2 molecule
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every hemoglobin molecue can carry up to four o2 molecules
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when co2 leaves a tissue cell, it diffuses through the interstitial fluid, across teh wall of a capillary, and into the blood fluid/plasma
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most of the co2 enters the red blood cells, wehre it combines w/ hemoglobin
the rest reacts w/ water molecules, forming carbonic acid |
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red blood cells contain an enzyme that hastens this formign of carbonic acid
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h2co3 breaks apart into a h ion (h+) and a bicorbonate ion (hco3-)
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hemoglobin binds most of th eh+, mnimizing hte change in blodo pH
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the bicarbonate ions diffuse into the pasma, wehre they are carried to the lungs
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as blood flows through capillaries in the lungs, this process is reverse
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-carbonic acid forms when bicarbonate combines w/ H+
-the carbonic acid is converted back to co2 and water -co2 diffsues from teh blood into the alveoli and out of the body in exhaled air |
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o2 in the blood is transported bound to ___________ within ________ ____________ cells, whil co2 is transported as _____________ ions in the plasma
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hemoglobin
red blood bicarbonate |
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placenta in baby, how he/she breathes
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a large net of capillaries fans out into the placenta from blood vessels in the umbilical cord of the fetus
-these fetal capillaries exchange gases w/ the maternal blood that circulates in the placenta, and the maternal circulatory system carries the gases to wand from the mother's lungs |
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what aids o2 uptake by the fetus
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fetal humoglobin, a special type that attracts o2 more strongly than does adult hemoglobin
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what happens when a baby is born, how he/she breathes?
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suddenly placental gas exchange stops
-baby's lungs must begin to work co2 in fetal blood acts as a signal -as co2 stops diffusing from the fetus into th eplacenta, a co2 rise in fetal blood causes blood pH to fall, stimulating th ebreathing control centers in the infants brain |
