respiration Flashcards
steps for gas exchange
ventilation of the respiratory organ leads to gas exchange at the lungs, gases are transported through the body and gas exchange occurs at the tissue
Dalton’s law of partial pressures
the partial pressures of all gases in an environment add up to 100%
Henry’s law
the amount of movement of a liquid into a gas on contact depends on the pressure gradient, the solubility of the gas into the liquid, and temperature
altitude sickness
PO2 of roughly 51.7 is where humans begin losing consciousness, smaller animals lose it faster except for birds who do very well at high altitudes
Fick’s Law
flow rate is equal to a constant * area while considering partial pressures and the distance a gas must move; organisms without respiratory organs are fully dependent on this law
water breathing
one way movement across respiratory organs, lower metabolic rates, thermoconformers, extraction of oxygen is more difficult than on land
requirements to increase body size
increase in area and a decrease in distance for gas to travel; done by increased mixing of the environment or cell interiors, changing shape, or developing respiratory organs
lake titicaca frog
live at an extremely high altitude, has greatly reduced lungs and a very high affinity for oxygen, rarely surfaces to breathe, uses pronounced folds in the skin with cutaneous capillaries and bob in the water to constantly mix and provide fresh water to the capillaries
cutaneous respiration
gas exchange through the skin occurring in almost all organisms but better in some than others, most efficient in amphibians
amphibian skin
open flow of oxygen over the capillaries
fish gills
countercurrent flow of oxygen over the capillaries flowing in opposite directions
mammalian lungs
new and old oxygen mixes in a blind ended sac and becomes diluted blood runs along the alveoli or bottom of the sac; oxygen uptake is much less efficient than in the gills
bird lungs
unidirectional crosscurrent flow of oxygen over the capillaries; 2 breath cycle
counter current gas exchange
the medium and the blood flow in opposite directions in close proximity
lamellate gills
push water over the gills
external filament gills
increase surface area and movement of water
cross current gas exchange
system of multiple air sacs in which air is pushed in one direction which results in no mixing and no dilution; blood flows across the air sacs multiple times allowing the pick up of more O2
arthropod tracheal system
direct delivery of O2 to the tissues via spiracles
birds 2 breath cycle
the first breath pushes air to the posterior sacs and parabronchi, the second breath pushes air to the anterior sacs and exhalation with no mixing of the 2 breaths
thoracic cavity
where the lungs are located
air flow during ventilation
allowed via the pressure gradient where flow is inversly proportional to resistance, and surface tension decreased by surfactant
surfactant
prevents cohesion of water in the lungs by lowering surface tension
respiratory pigments
make it possible to carry high volumes of O2 in the blood, include hemoglobin, hemerythrin and hemocyanin all made up of a heme group and a metal
hemoglobin
prefers carrying oxygen than carbon dioxide, can carry up to 4 oxygen molecules; saturation depends on PO2 and the number of binding sites available
hemoglobin dissociation curve
uses the P50 of the respiratory pigment and describes how oxygen affinity increases as oxygen binds; a left shift has a higher affinity for oxygen while a right shift has a lower affinity for oxygen, a lower affinity makes it easier to drop of oxygen
Haldane effect
hemoglobin carries more CO2 at low O2 levels which increases the efficiency of removing CO2 and helps unload it at the lungs
CO2 transport
3 methods: dissolved in the plasma, bound to hemoglobin, or as a bicarbonate ion in the plasma as the result of chloride shift
medula
location of the brain signaling changes in respiration
chemoreceptors
sense PO2, PCO2, and H+ ions for respiratory control, central chemoreceptors located in the medulla, peripheral chemoreceptors located in the aortic arch and carotid artery
breathing at high altitudes
PO2 is lower at higher altitudes, body senses this and increases ventilation rate leading to alkalosis due to increased CO2 loss but no O2 uptake
acclimatization
takes roughly 11.4 days/km
