gas exchange Flashcards
internal respiration
at tissues, O2 is released into the cells and CO2 is picked up from the cells
pulmonary arteries carry:
deoxygenated blood from lungs to heart
capillary network composed of:
pulmonary capillaries that wrap around alveoli- site of respiratory membrane. as blood is pumped through this respiratory membrane, gas exchange occurs
the respiratory membrane is:
highly permeable. respiratory and blood capillaries are thin, great surface in the lungs
some O2 is diffused into the…
plasmam
most O2 is picked up by…
erythrocytes- binds to hemoglobin.
carbon dioxide is released…
opposition direction of the O2, released from blood to alveoli
external respiration occurs as…
partial differences between pressure in oxygen and CO2 between pulmonary capillaries and alveoli.
difference in pressure between…
O2 from the alveoli and CO2 from pulmonary capillaries.
- this large difference in partial pressure allows O2 to quickly diffuse across respiratory membrane from alveoli into the blood
- partial pressure is also different between alveoli air and capillaries in blood, allowing CO2 to diffuse from blood to alveoli
internal respiration is
exchange at tissue level, simple diffusion due to partial pressure gradient
partial pressure of O2 in the tissues…
is lower than the partial pressure of O2 in the blood
this partial difference in internal respiration causes…
oxygen to diffuse from hemoglobin across interstitial space and enter tissue of the cell
by the time blood reaches the heart…
partial pressure of O2 has decreased but the partial pressure of CO2 has increased, blood is then pumped back to the lungs to be exhaled in external respiration
hemoglobin bound to oxygen is called:
oxyhemoglobin
when all 4 heme sites of hemoglobin are occupied…
saturated
higher temp promotes…
hemoglobin and oxygen to dissociate faster.
how does pH affect hemoglobin/oxygen diffusion?
higher, more basic pH inhibits dissociation of O2 from hemoglobin.
lower, more acidic pH promotes dissociation.
what enzyme in red blood cells causes carbonic acid?
carbonic anhydrase
carbonic anhydrase + carbonic acid create?
dissociate into bicarbonate and H ions
at pulmonary capillaries, rxn
of bicarbonate is reversed and we get CO2 and H20
what happens when carbon dioxide binds to hemoglobin?
carboaminohemoglobin
hyperventilation is
decreased CO2 and increased pH. may lead to asthma or emphysema
