27 terms

Chapter 42 Respiration and Gas Exchange

gas exchange
the uptake of molecular oxygen and discharge of co2
respiratory medium
source of oxygen (air/water)
respiratory surface
The part of an animal where gases are exchanged with the environment. happens entirely by diffusion. rate also depends on metabolic need, so endotherm will have larger area then ectotherm
outfoldings of the body surface that are suspended in water; high surface area
the warmer and saltier, the less oxygen it can dissolve
the bodily process of inhalation and exhalation, needed more in gills then lungs. in vertabrates, called breathing
countercurrent exchange
the opposite flow of adjacent fluids that maximizes transfer rates; for example, blood in the gills flows in the opposite direction in which water passes over the gills, maximizing oxygen uptake and carbon dioxide loss, so efficient, gills remove over 80% of the oxygen
tracheal system
A gas exchange system of branched, chitin-lined tubes that infiltrate the body and carry oxygen directly to cells in insects. larger flying insects aid diffusion with rhythmic body movements to compress and inflate trache
restricted to one location and musst be bridged by circulatory system. contain dense net of cappilaries. size related to metabolic rate
air entering
nose, pharynx, larynx, eppiglottis, vocal chords, trachea, bronchi, bronciolies (inverted trees covered in cillia and mucus), aveoli,
gas exchange occurs on their thin membranes, oxygen entering diszzolves in moist film and rapidly diffuses across into cappilaries. co2 opposite direction
positive pressure breathing
in frogs, in addition to skin breathing, , a type of breathing that lowers the floor of the oral cavity, expanding it and drawing air into the mouth; used by amphibians.
negative pressure breathing
A breathing system in which air is pulled into the lungs as opposed to pushed diaphram helps inc lung volume
visceral pump
in some species, rhythmic movements during running cause visceral organs to slide forward and backward in the body cavity with each cavity helping to increase venhilation
tidal volume
volume of aire you inhale and exhale during normal breathing
vital capacity
the maximum amount of air that can be exhaled after a maximum inhalation (usually tested with a spirometer). combination of tidal, exp reserve, and insp reserve volumes, but NOT THE RESIDUAL VOLUME
residual volume
The amount of air that remains in the lungs after a person exhales as forcefully as he or she can. as we age, this increases at the expense of tidal volume
expiratory reserve volume
Amount of air that can be forcefully exhaled after a normal tidal volume exhalation
inspiratory reserve volume
Amount of air that can be forcefully inhaled after a normal tidal volume inhalation
inspiratory capacity
Tidal volume + inspiratory reserve volume. max amount of air you can inhale at once
A site of gas exchange in bird lungs. Parabronchi allow air to flow past the respiratory surface in just one direction. make animal less dense, helps flying, satisfyz high metabolism and need for oxygen; better at high altitudes
breathing control centers
a brain center that directs the activity of organs involved in breathing, medulla oblangata, and pons, use neg feedback and ph of blood and cspfluid co2 reacts with water, makes acid, lowers ph, increases breathing; at high altitudes, o2 sensors in aorta send alarm signals to increase breathing
partial pressure
the pressure of each gas in a mixture. diffusion depends on a difference in this
respiratory pigments
proteins that transport oxygen, greatly increase the amount of oxygen that blood can carry. hemocyanin found in mullosks, usually hemoglobin iron,
bohr shift
A lowering of the affinity of hemoglobin for oxygen, caused by a drop in pH; facilitates the release of oxygen from hemoglobin in the vicinity of active tissues.
carbon dioxide
7% becomes cabroxilic acid with oxygen, 23% is transported by hemoglobin, 70% is transported as bicarbonate ions
diving animals
big spleans, more oxygen retention, more myoglobin