Respiratory Phys Part Ii

Front 1

Pulmonary arteries carry _ blood, while bronchial arteries carry _.

Back 1

deoxygenated;
oxygenated

Front 2

Pulmonary capillary surface area (>,<,=) systemic capillary surface area.

The pulmonary resistance is (>,<,=) systemic resistance

Back 2

>, greater than.

< much less (2.0 mmHg/L/min compared to 19.6)

Front 3

Regional differences in ventilation are due to:

Back 3

Variability of airway resistance and compliance as well as the effect of gravity

Front 4

patients with obstructive pulmonary diseases breath __

Back 4

slowly and deeply

Front 5

In the upright position at the base of the lung:
Pleural pressure is __
Transpulmonary pressure is _
Alveolar ventilation is _

Back 5

more positive (or less negative)

decreased

greater

Front 6

In the upright position at the base of the lung (vs. at the top of the lung):
Alveoli are _
Compliance is _
Ventilation (V/t) is _

Consequently, the conditions for gas exchange are (most/least) favorable in the basal parts compared to the apex

Back 6

smaller

greater

greater

most

Front 7

Both blood flow and ventilation are less at the apex of the lung, yet the V/P ratio is increased. Explain this

Back 7

Blood flow decreases more than Ventilation at the top of the lung, With the denominator decreasing, it makes sense that the overall ratio would increase.

*It's important to note that even though ratios are higher at the apex, the conditions for gas exchange are still more favorable at the base

Front 8

Hypoxemia can be caused by what?

Back 8

Hypoventilation, Diffusion limitation, Shunt (right to left), ventilation perfusion mismatching

Front 9

In hypoventilation,
PAO2 and PaO2 are _, PACO2 and PaCO2 are _, and AaDO2 is _.

Back 9

reduced; increased; normal

Front 10

A physiological shunt is what?

Back 10

a lung without ventilation but with perfusion.

Could be due to a mucous obstruction, airway edema, bronchospasm, foreign body, or a tumor

Front 11

What are common causes of VP mismatching?

Back 11

Pulmonary embolism, chronic obstructive disease, interstitial lung disease, vascular disorders

Front 12

What is an average minute volume for a 70kg male?

Back 12

7500 ml/min

This is the total air volume that enters and leaves the lung per minute

Front 13

Is alveolar ventilation different than minute ventilation? Explain.

Back 13

Alveolar ventilation is the total air volume exchanged, not all of the minute volume gets exchanged. To calculate, Alveolar ventilation is the tidal volume - dead space volume x breaths/min.
Minute ventilation is just tidal volume x breaths/min

Front 14

What is Boyle's Law?

Back 14

Boyle’s law describes how pressure and volume are related.

P1V1 = P2V2

Front 15

What is Dalton's law?

Back 15

the total pressure of a mixture of gases is the sum of their fraction of the total.

Front 16

Rate the partial pressures of N2, O2, CO2, and H20 at sea level

Back 16

N2>>O2>>H2O>CO2

Front 17

What is the concentration of O2 in the atmosphere?

What about N2?

Back 17

.21

.79

Front 18

Vapor pressure of water depends on _

Back 18

temperature.

At 100 ˚C water vapor pressure = 760 mmHg, but at 0 ˚C water vapor pressure = 5 mmHg

Front 19

The PO2 of alveolar air is (greater/less) than expired air.

The PCO2 of alveolar air is (greater/less) than expired air.

Back 19

less

greater

Front 20

_ concentration is higher in atmospheric air than alveolar air

Back 20

O2

Front 21

Concentration of _ is lower in atmospheric air than alveolar air

Back 21

CO2

Front 22

Rapid & shallow breathing pattern _ VA
Slow and deep breathing pattern _ VA.
Explain this.

Back 22

reduces; enhances.

Understand the concept of anatomic dead space. This is number is constant in the same person.
To calculate VA; Subtract the dead space from the tidal volume and multiply by the number of breaths/min. The smaller the tidal volume, the less air gets exchanged with each breath.

Front 23

(T/F) The concentration of a particular gas changes with altitude.

Back 23

False.

Ex: The concentration of O2 is always .21. The PRESSURE changes with altitude, not the concentration

Front 24

Why is the partial pressure of gases reduced at the lung surface compared to atmospheric air?

Back 24

The air in the lungs is 'humidified', which will reduce the partial pressure of all gases at the lung surface.

The wet air saturates the air, meaning the partial pressure of water contributes to the total pressure and displaces some of the total gases. Ie. Instead of total pressure of gases being 760 mmHg, at the lung interface it is only 713

Front 25

PO2 is (higher/lower) in expired air vs alveolar air.

PCO2 is (higher/lower) in expired air vs alveolar air

Back 25

higher

lower

*Think about how oxygen is going to want to go into the lungs, and CO2 would want to leave

Front 26

Mixing of atmospheric air with dead space air and alveolar air creates a _ in PO2 and a _ in PCO2 by the time air reaches the alveoli

Back 26

fall

rise

Front 27

A 180 lb male has how much dead space?

Back 27

180....1 ml Vd per lb of weight

Front 28

What does R mean?

If R = 0.8 then what?

Back 28

R is respiratory gas quotient, meaning how much CO2 is produced per O2 consumed.

If R=0.8 (normal circumstances), then more oxygen is taken up than CO2 released into the alveoli

Front 29

Since PCO2 in atmosphere is nearly _, PACO2 is directly proportional to CO2 from where?

Back 29

zero

production by the tissues

The rate of CO2 leaving the lungs is determined by alveolar ventilation rate VA. Therefore PACO2 is inversely proportional to VA

Front 30

PAO2 is _ to VA.

PACO2 is _ to VA

Back 30

proportional

inversely proportional

Front 31

Ficks Law?

Back 31

diffusion= {(P difference) x area /thickness} x (solubility/square root of MW)

Front 32

What is an example of a substance that is diffusion limited?

Back 32

CO (equilibrium is never reached)

Front 33

What is an example of a substance that is perfusion limited?

Back 33

N2O (equilibrium is reached very early on)

Front 34

O2 reaches equilibrium within _sec. or approximately _the distance through the capillary bed

Back 34

0.25

1/3

Front 35

What state must the heme be in for reversible O2 binding?

Back 35

ferrous (Fe2+)

Front 36

Iron prefers 6 ligands, in heme it is bound to 4 _, the 5th site is occupied by _, and the 6th site is _.

Back 36

4 pyrrole nitrogens

imidazole nitrogen

available for O2 binding (this is vacant in deoxyHb and deoxyMb)

Front 37

Mb O2 binding plot is described by a _; the P50 is approximately _ mmHg where a low P50 reflects a _ O2 affinity by Mb

Back 37

hyperbola
4
high

Front 38

In Hb, The first O2 binding to iron pulls the _ from below into the plane of the _ ring. This causes the shift that changes the binding strength f neighboring sites

Back 38

Histidine

protoporphyrin

Front 39

At PO2 of 40, O2 is _% saturated.

At a PO2 of 25 mmHg, O2 is _% saturated

Back 39

75%

50%

Front 40

In increase in P50 means there is (increased/decreased) affinity of Hb for O2.

Back 40

decreased

This is another way of saying the curve has shifted to the right

Front 41

Explain, on a chemical level, why an increase in CO2 would decrease the affinity of Hb for O2.

Back 41

CO2 binds to the Hb N terminus. Carbamino-Hb decreases O2 affinity

Also, the CO2 is converted to carbonic acid and H+ so there are more protons for the Bohr effect

Front 42

An increase in PO2 does what to Hb, with regards to 2,3 BPG?

Back 42

An increase in PO2 causes the central pocket to collapse (where 2,3 BPG binds), which releases the 2,3 BPG.

*In chronic hypoxia, this doesn't happen, so the 2,3 BPG is more bound to the beta SUs of Hb

Front 43

In CO poisoning, oxygen content of blood is greatly _, but the Po2 of the blood may be _

(T/F) There are symptoms of hypoxia such as cyanosis

Back 43

reduced;

normal.

False
*Since, Po2 is not reduced, the carotid and aortic chemoreceptors are not stimulated, and therefore reflex respiration is absent

Front 44

The key regulator of Hb production is _ that is sensed by the _

Back 44

local tissue hypoxia

kidney

Front 45

In response to hypoxia, the kidney releases _, which is a _ hormone working through _ receptors

Back 45

erythropoietin
peptide
tyrosine kinase

This hormone stimulates bone marrow

Front 46

What are the three ways CO2 is transported?

Back 46

Gaseous and dissolved CO2 in plasma
Carbamino compounds
Bicarbonate (HCO3-)

Front 47

What is the Haldane effect?

Back 47

When O2 binds Hb, CO2 is released.

*This happens because when O2 binds Hb it becomes a stronger acid, acidic Hb has less affinity for CO2, and increased acidity releases excess H ions which reverse carbonic anhydrase rxn

Front 48

Rhythmic breathing depends on a continuous (tonic) inspiratory drive from the __ and on intermittent (phasic) expiratory inputs

Back 48

DRG Dorsal Respiratory Group

Front 49

The respiratory control center is in the _ of the _.

The Dorsal is _ and the Ventral is _

Back 49

reticular formation of the medulla oblongata.

Inspiratory; inspiratory and expiratory

Front 50

The apneustic center is in the _, and the pneumotaxic center is in the _.

Back 50

lower pons;

upper pons

Front 51

Activation of the pneumotaxic center causes a (increase/decrease) in tidal volume, and a (increase/decrease) in respiratory rate

Back 51

decrease

increase

Front 52

Stimulation of central chemoreceptors depends largely on the _ entry into the CSF and subsequent __

Back 52

free CO2 entry

hydration to H+

Front 53

Central Chemoreceptors can be stimulated either _ or _.

Back 53

directly (via an increase in [H])

indirectly (via an increase in PaCO2 and subsequent increase in H) - main pathway

Front 54

Peripheral chemoreceptors contain _ cells, which contain NTs that are release in response to ... (3).

Back 54

glomus

decrease PaO2 (physically dissolved O2, not O2 bound to Hb..ventilation increases when PaO2 is <60mmHg)
Increase PaCO2
Increase H

Front 55

Ventilation increases when PaO2 is _

Back 55

<60mmHg

Front 56

In peripheral chemoreceptors, low PaO2 does what (chemically)?

Back 56

closes K+ channels and depolarizes glomus cell. The depolarizatioon opens VG Ca channels, triggering transmitter release.

Front 57

Most of the chemoreceptor response comes from central or peripheral chemoreceptors?

Back 57

central (those found in the medulla)

Front 58

J receptors are located _, are stimulated by _, and result in _.

Back 58

in walls of pulmonary microvessels;

vascular emboli, interstitial edema, and capsaicin

rapid and shallow breathing (tachypnea)

Front 59

The _receptors are thought to be responsible for the psychological sensation of "air hunger“ (dyspnea, or sensation of labored breathing and "shortness" of breath)

Back 59

J

Front 60

What are the afferent signals from irritant receptors?

Back 60

via the Vagus, trigeminal or olfactory nerve to stimulate coughing or sneezing

Front 61

Hering-Breuer Inflation reflex results in _

Back 61

cessation of inspiration

Front 62

The Hering-Breuer Deflation reflex results in _

Back 62

initiation of inspiration

Front 63

The _ reflexes are detectable in infants and are probably important in regulating the work of breathing

Back 63

Hering Breuer

Front 64

[HCO3-] is regulated mainly by _

Back 64

the kidney

Front 65

In arterial blood, the [HCO3-] should be = _ ?

Back 65

24 mEq/L

Front 66

The kidneys compensate for respiratory acidosis with an increase in _

Back 66

net acid excretion (NAE)

Front 67

The kidneys compensate for _ with a decrease in net acid excretion (NAE)

Back 67

respiratory alkalosis

Front 68

Regarding the acid-base nomogram, metabolic alkalosis will have what values?

Back 68

Higher pH than 7.4;

High plasma [HCO3]

Front 69

Regarding the acid-base nomogram, metabolic acidosis will have what values?

Back 69

Low blood pH

low plasma [HCO3]

Front 70

In respiratory acidosis, the patient has _ pH, and _ [HCO3]

Back 70

low

high

Front 71

In respiratory alkalosis, the patient has _ pH and _ [HCO3]

Back 71

high

low

Front 72

pH is closer to normal in chronic or acute cases for respiratory alkalosis/acidosis?

Bicarb is closer to normal in chronic or acute cases?

Back 72

chronic

acute

Front 73

Patient has lower than normal pH, and lower than normal bicarb. How would you describe their condition?

Back 73

Metabolic acidosis

Front 74

Patient has lower than normal pH, and higher than normal bicarb, how would you describe their condition?

Back 74

respiratory acidosis

Front 75

What is the general rule regarding PCO2 and pH, when it comes to determining whether or not it is a respiratory or metabolic disorder

Back 75

If the PCO2 contributes to the pH conditions, this indicates respiratory acid base disturbance