O2 & CO2 Flashcards

1
Q

why does O2 & CO2 matter to dentistry?

A

Understanding the basic fundamentals of gas exchange in the lungs and tissue is the foundation for understanding sedation

Dental anesthesia in toxic doses can cause respiratory depression: toxicity is more common in children (they weigh less)

The process of metabolism requires oxygen and creates CO2, therefore all tissues need oxygen and all tissues need to expel CO2

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2
Q

the respiratory system is composed of:

A

naso- oro- and laryngo-pharync, trachea, bronchi, bronchioles, and lungs

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3
Q

breathing in and out movement of the diaphragm

A
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4
Q

sinuses do what?

A

warm and humidify the air that we breath
trap pathogens from the air

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5
Q

where are the sinuses?

A
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6
Q

in dentistry, what procedures can interact with sinuses?

A

extractions/implants
root canals
dentures

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7
Q

epiglottis prevents ____ and ____ from getting into the respiratory system (aspiration/chocking)

A

food and drink

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8
Q

vocal cords are located…

A

right at the top of trachea (below epiglottis)

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9
Q

epiglottis is ____ when swallowing

A

depressed

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10
Q

intubation tube is placed…

A

in trachea past the epiglottis

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11
Q

alveoli is where _____ ________ happens

A

gas exchange

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12
Q

flow of O2 of respiratory system

A

breathe in O2
oral cavity
trachea
bronchi
bronchiole
alveolar sacs
crosses alveolar membrane and capillary membrane
blood

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13
Q

blood is our _____ ____ to transport gasses for and from metabolism

A

freeway system

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14
Q

O2 goes ___ the blood while CO2 comes ______ the blood at the lungs

A

O2 into blood
CO2 out of blood
*at lungs

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15
Q

O2 goes ___ the blood while CO2 comes ______ the blood at the tissues

A

O2 out of blood
CO2 into blood
*at tissues

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16
Q

what does each letter represent?

A

D: rate of diffusion
delta P: change in partial pressure
A: surface area
S: solubility constant
d: distance of diffusion
MW: molecular weight

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17
Q

limiting factors of diffusion of O2

A
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18
Q

CO2 is ____ soluble in blood than O2

A

more

*readily allows exchange at the tissues that need O2

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19
Q

oxygen delivery is the product of ___ ____

A

cardiac output

  • carries through Hb on RBCs
  • each RBC has many Hb molecules
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20
Q

Hb has __ subunits containing ___ with ferrous iron atom

A

Hb has 4 subunits containing heme with a ferrous iron atom

Hb is a protein

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21
Q

Hb: iron can reversibly bind to ___

A

O2
always diatomic oxygen (O2 not O)

“oxygenation”

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22
Q

diatomic oxygen

A

O2

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23
Q

As O2 binds, the affinity for the other 3 subunits to bind ____

A

increases

“cooperative binding”
each binding increases affinity for binding more
aka peer pressure

24
Q

hemoglobin/oxygen dissociation curve

A
25
Q

hemoglobin/oxygen dissociation curve: small changes in pO2 at the beginning results in _____ changes in SaO2

A

large

26
Q

affinity of Hb: 3 factors that change

A
  1. pH
  2. temperature
  3. concentration of 2,3 - diphosphoglycerate
27
Q

affinity of Hb: shifting right will ____ affinity

A

decrease affinity

right = decrease affinity = release

28
Q

affinity of Hb: shifting left will ____ affinity

A

increase

left = increase affinity = bind

29
Q

_____ in metabolic demand will decrease O2 in the blood

A

increase demand = decrease O2 blood

30
Q

Bohr Effect

A

drop in pH causes a decrease in affinity (shift right)

  • high levels of CO2 causes decreased pH therefore need O2 to be released
31
Q

what is 2,3 - diphosphoglycerate?

A

product of glycolysis

increases 2,3-bip and the curve shifts right

32
Q

increased metabolic load gives off more ____ into the blood

A

CO2

33
Q

Haldane Effect

A

deoxygenated blood has a higher capacity to bind CO2

ie: venous blood caries more CO2 than arterial blood

34
Q

CO2 is about __ x more soluble than O2 in the blood

A

20x more soluble

35
Q

Hb can bind __ CO2

A

4

*like O2

36
Q

vasodilation = _____ perfusion

A

increased

37
Q

if no blood is perfusing the alveoli, then…

A

no gas exchange occurs

38
Q

high levels of CO2 in the blood _____ pH

A

decreases
more H+
acidic

39
Q

bicarbonate buffer system

A

CO2 is converted to carbonic acid from carbonic anhydrase in RBs

40
Q

how can kidneys assist in buffering blood when there is too much CO2?

A

H+ excretion by kidneys

CO2 is discharged into alveoli and expired

41
Q

Bohr effect vs Haldane effect

A

Bohr: acidic blood and lowers the affinity

Haldane: deoxy RBsC have increased affinity for CO2

42
Q

ph of arterial blood is

A

7.4

43
Q

hypoxia

A

O2 deficiency at the level of the tissues

44
Q

causes of hypoxia

A
  • Decreased PO2 of arterial blood
  • Decreased amount of Hb to carry oxygen (anemia)
  • Low blood flow to a tissue (cutting off circulation)
  • Toxic product not allowing O2 to do its job (CO poisoning)
45
Q

hypoxia symptoms

A

the brain is affected first causing confusion, headache, impaired judgment

loss of consciousness

death

46
Q

respiratory complications

A

fluid in alveoli

inflammation in any part of the respiratory tract
—-asthma: bacterial, fungal, viral infections

spasms of the muscles
—-asthma and bronchospasm

COPD
—-emphysema and chronic bronchitis

47
Q

Who do we monitor oxygen levels in?

A
48
Q

Ways to measure safe oxygen levels in your
patients:

A

capnography: measuring levels of CO2 expired, not an exact measure for dentistry

pulse oximeters: measuring levels of O2 in blood

respiratory rate: Make sure your pt is breathing

49
Q

respiratory rate b/m (infant to adult

A
50
Q

sleep apnea

A

A serious breathing condition where breathing is irregular and will stop for a period of time while asleep

  • obese
  • large tongue
  • skeletal class II (no prominent chin)
51
Q

CO2 changes during CPR

A
52
Q

CPR: rescue breaths is on ___-___% oxygen flow

A

16-17% O2 flow

53
Q

gasses move ___ through the concentration gradient

A

downhill

from high to low pressure

54
Q

Hb _____ binds dour O2 molecules through _____ binding to deliver O2 through the body to the tissues

A

Hb reversibly binds 4 O2
through Cooperative binding

55
Q

what three factors impact the dissociation of O2 and Hb

A
  1. pH
  2. temperature
  3. 2,3-biphosphoglycerate