4-21 pt 2

What is Dalton's Law?

total pressure exerted in a mixture is equal to the sum of partial pressures of the individual gases

where is alveolar gas exchange?

between blood in pulmonary capillaries and alveoli

where is systemic gas exchange?

between blood in systematic capillaries and systematic cells

why does partial presssure in alveoli differ from atm pressure?

-air mixes with air in anatomic dead space
-oxygen diffuses out of alveoli into blood/CO2 diffuses from blood into alveoli
-more water vapor in alveoli

within alveoli what is state of partial pressures of respiratory gases?

relatively stable

where is percent and partial pressure of O2 greatest?

alveoli

where is percent and partial pressure of CO2 greatest?

atmosphere

what does the partial pressues in systematic crlls refelct?

cellular respiration
(uses O2, produces CO2)

when are partial presssures constant?

resting normal conditions

when are partial pressures not constant?

circulating blood

compared to alveoli, what is systematic cells O2?

lower

compared to alveoli, what is systematic cells CO2?

higher

what is henry's law?

At a given temperature the solubility of a gas in a liquid is directly proportional to
-partial pressure of gas in air
-solubility coefficient of the gas in the liquid

what is the solubility in a gas equal to?

-partial pressure of gas in air
-solubility coefficient of the gas in the liquid

what is role of partial pressure?

force that drives gas into a liquid

what is the solubility coefficent?

volume of gas that dissolves in a specified volume of a liquid at a given temperature and pressure

what is the solubility coefficient dependent on?

interactions btw molecules of the gas and liquid

where is more water vapor present?

alveoli

what is solubility of different gases in water?

varies

how much more soluble is CO2 than O2?

24 times

how much more soluble is O2 than N?

2 times

what do gases with lower solubility rates require to 'push' the gas into the liquid?

high presssure gradients

what is decompression sickness?

diver submerges beyond certain depth and returns too quickly to shore

N goes into blood b/c high pressure-dissolved N bubbles out while in blood

what is decompression sickness treated with?

hyperbaric oxygen chambers

what are hyperbaric oxygen chambers?

increase O2 partial pressure
additional O2 can dissolve in blood

what is PO2 value in alveoli?

ALVEOLAR GAS EXCHANGE

104 mmHg

what is PO2 value if blood entering pulmonary capillaries?
ALVEOLAR GAS EXCHANGE

40 mmHg

how does oxygen travel from alveoli to capillaries?

diffuses in respiratory membrane

when does O2 stop diffusing?

once blood CO2 is equal to that of alveoli

what is value of PCO2 in alveolli?
ALVEOLAR GAS EXCHANGE

40 mmHg

what is value of PCO2 in blood of pulmonary capillaries?
ALVEOLAR GAS EXCHANGE

45 mmHg

how does CO2 move regarding alveoli and blood?

blood to alveoli
high to low

what characteristics of the respiratory membrane help efficent gas exchange?

large surface area-alveoli
minimal thickness

what is ventilation perfusion coupling?

Ability of bronchioles to regulate airflow and arterioles to regulate blood flow

what actions alter ventilation?

bronchodilation
bronchoconstriction

what causes bronchiodilation?

increases PCO2

what actions alter perfusion?

arteriole dilation and constriction

when do arterioles dilate?

decreased PCO2
increased PO2

what structure does perfusion deal with?

arterioles

what structure does ventilaiton deal with?

bronchioles

what is emphysema?

irreversable loss of pulmonary gas exchange surface area
inflammation of air passageways near terminal bronchioles
destruction of elastic tissue and alveoli

what is emphysema caused by?

smoking

what is value of PO2 in systemic cells?
SYSTEMATIC GAS EXCHANGE

40 mmHg

what is value of PO2 in systematic capillaries?
SYSTEMATIC GAS EXCHANGE

95 mmHg

what is value of PCO2 in systematic cells?
SYSTEMATIC GAS EXCHANGE

45 mmHg

why are levels in alveoli relatively constant during alveolar gas exchange?

fresh air continuously enters

why are levels in systemic cells constant during systemtic gas exchange?

oxygen delivers at same rate it is used unless strenuous activity

what is the movement of oxygen in systemic gas exchange?

system capillaries to cells

what is the movement of CO2 in systemic gas exchange?

system cells to blood

what is the movement of O2 in alveolar gas exchange?

alveoli to capillaries

what is movement of CO2 in alveolar gas exchange?

blood to alveoli

what is the solubility coefficient of water?

low

what does blood's ability to transport O2 depend on?

solubility coefficient
hemmoglobin

what does oxygen attatch to in hemoglobin?

Fe

What percent of O2 is bound to hemoglobin?

98.%

What is HbO2?

oxyhemoglobin (with oxygen bound)

What is Hhb?

deoxyhemoglobin (without bound oxygen)

What is oxyhemoglobin?

hemoglobin bound to oxygen

What is deoxyhemoglobin?

hemoglobin without oxygen

what is transportation of CO2?

dissolved in plasma
amine group of hemoglobin
bicarbonate in plasms

What is carbaminohemoglobin?

CO2 attatched to amine group of globin inside hemoglobin

what is most common means of transport of CO2?

bicarbonate dissolved in plasma

How does CO2 form bicarbonate?

diffuses into RBC and combines with H2O to form bicarbonate and H+

what does hemoglobin transport?

oxygen-Fe
carbon dioxide-globin
H ions-globin

what happens if one substance binds to hemoglobin?

causes shape change (conformational change)
releases other two substances

what is the oxygen hemoglobin saturation curve?

A graph relating the saturation of hemoglobin to partial pressure of oxygen

how many oxygen molecules can hemoglobin bind to?

4- one on each Fe

why is the percent O2 saturation important?

the amount of O2 bound to available hemoglobin

what happens to rate of PO2 as saturation increases?

increases

what is the cooperative binding effect?

each O2 that binds causes a change in hemoglobin making it easier for next O2 to bind

when do small changes occur on saturation curve?

PO2 higher than 60 mmHg

what is saturation at 60 mmHg?

90%

what is hemoglobin saturation in pulmonary capillaries?

98%

when can saturation reach 100%?

pressure above 1 atm
-hyperarbic oxygen chambers

what is altitude sickness caused by?

decrease in alveolar PO2 and low oxygen saturation

how much of the oxygen is released from hemoglobin at systemic capillaries?

some, not all

what is stauration as leaves the lungs?

98%
sea level

what is saturation after passing systemic cells at rest?

75%

how much transported O2 is released?

20-25%

what is oxygen reserve?

The amount of oxygen that remains bound to the hemoglobin after passing through the systemic capillaries

when is oxygen reserve used?

increased metabolic rates

how does exercise impact saturation?

drops-35%

how does temperature impact O2 release from hemoglobin?

decreases hemoglobin's hold on oxygen

how does H+ binding to hemoglobin impact O2 release from hemoglobin?

causes conformational change-knocks O2 off

decreases O2 ability to bind

What is the Bohr effect?

a decrease in the amount of oxygen associated with hemoglobin and other respiratory compounds in response to a hydrogen binding

What is 2,3 DPG?

a molecule in RBC

what is role of 2,3 DPG?

bind to hemoglobin and releases additional oxygen

what stimulates RBC for the production of 2,3 DPG?

growth and puberty hormones- GH, thyroid, EP

what does binding of carbon dioxide to hemoglobin cause?

release of O2

What is the Haladane effect?

release of O2-changes shape
INCREASES Co2 binding

what causes a right shift in the saturation curve?

decrease oxygen affinity
-increase temp
-increase H

what causes a left shift in saturation curve?

increase oxygen affinity to hemoglobin
-decreased temp
-decrease H

What is hyperventilation?

breathing rate or depth above body's demand

PO2 rises
PCO2 falls

What is hypocapnia?

little low CO2 in hyperventilating

what does low CO2 cause in hyperventilation?

vasoconstriction

what happens to H+ concentration in hyperventilation?

decrease

what pH is associated w high H?

acidic

what pH is associated with low H?

basic

what is respiratory alkalosis?

decrease in H-basic
no buffer help

-part of hyperventilation-

What is hypoventilation?

decreased rate or depth of air movement into the lungs