Exam 2: Pulm Physio Flashcards Preview

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Flashcards in Exam 2: Pulm Physio Deck (44):
1

(pulm volumes graph)

(pulm volumes graph)

2

Gas-exchange airways include:

Respiratory bronchioles
Alveolar ducts
Alveoli

3

Alveolar cells:

Type 1: gas exchange (super thin)
Type 2: surfactant production

4

Airway generation at which gas exchange begins:

~16

5

What is the respiratory exchange ratio?

The ratio of O2 in via food and CO2 out via metabolism

6

Protective benefits of faster exhalation than inhalation & mechanism by which this is accomplished:

Encourages elimination of dust & mucus/debris

Airways open during inhalation (slower gas velocity) and vice versa during exhalation

7

Why are spinal cord injury patients prone to pneumonia?

Can often breath, but not cough

8

ANS effects on airways:

Epinephrine opens airways

9

Function of alvolar pores:

Allow for collateral airflow if other alveoli ducts get clogged

10

Effects of interstitial thickening:

Harder for O2 to diffuse through

(CO2 is slightly polar and can pass through more easily)

11

Only thing between pleura:

Pleural fluid

12

Function of scalene muscles in breathing:

Lift the ribs

13

Function of trapezius in breathing:

None

14

Formula for alveolar surface tension:

P * R / wall thickness

15

Compliance is:

Ability to accept change in volume

16

Function of surfactant:

↓ surface tension of water

17

Relative pleural pressure during inspiration/end inspiration/expiration/end expiration:

Slightly negative at rest; more negative during inspiration; less negative (or even positive) during expiration

18

Under normal conditions, ventilation rate is driven by:

CO2

19

Under hypoxic conditions, ventilation is driven by:

Arterial CO2 tension (sensed by carotid body)

20

PO2, PCO2 in inspired air:

PO2: 159mmHg
PCO2: 0.3mmHg

21

PO2, PCO2, PH2O in alveolar air:

PO2: 104mmHg
PCO2: 40mmHg

22

PO2, PCO2 in pulmonary vein:

PO2: 100mmHg
PCO2: 40mmHg

23

PO2, PCO2 at tissues:

PO2: 40mmHg
PCO2: 46mmHg

24

PO2, PCO2 in pulmonary artery:

PO2: 40mmHg
PCO2: 46mmHg

25

Fetal hgb has ____ affinity to O2 than normal hgb:

Higher; needs to "steal" O2 from the maternal blood in the placenta

26

Factors that increase oxyhemoglobin affinity:

Alkalosis (↑pH) or ↓ PCO2
↓ temperature
↓ 2,3 DPG
Carboxyhemoglobin/methemoglobin
Abnormal hgb

These are associated with decreased metabolism and thus decreased O2 need (so INCREASED affinity)

27

Factors that decrease oxyhemoglobin affinity:

Acidosis (↓ pH) or ↑ PCO2
↑ temperature
↑ 2,3 DPG - can be from high altitude
Abnormal hgb

These are associated with increased metabolism and stress, so decreased affinity/increased O2 delivery is a good thing

Left shift for Lounging around
Right shift for Running from a bear

28

Define P50 and how it is associated with the oxyhemoglobin dissociation curve:

The PaO2 at which hgb is 50% saturated; normally 26.6mmHg

Decreased affinity = high P50
Increased affinity = low P50

29

CO2 is ____x more soluble than O2:

30x

30

Most abundant protein in blood:

Hgb

31

90% of CO2 in the blood is found in this form:

Bound to hgb (the amino end, not the O2 binding site)

32

O2 content of blood equation:

1.34 * Hgb * SpO2 (+ 0.0003 * PO2)

33

Pulmonary response to hypoxia:

Vasoconstriction (unique to lungs) - shunts blood to better-ventilated regions

34

Hypoxia affecting the entire lungs can cause:

Pulmonary HTN

35

Pulmonary response to acidemia:

Pulmonary artery constriction

36

Describe high V/Q:

Impaired perfusion to alveolus means alveolar dead space and less oxygenated blood rejoining the system

37

Describe low V/Q or shunt:

Blocked ventilation (low V/Q) or collapsed alveolus (shunt) means no oxygenation of blood in that region

38

Describe lung zone I:

Hyperinflated alveoli, crushed capillaries
PA > Pa > PV
No blood flow

39

Describe lung zone II:

Pa > PA > PV
Blood flow occurs
Alveolar pressure compresses venules

40

Describe lung zone III:

Sad alveoli, engorged capillary
Pa > PV & PA
Blood flow fluctuates depending on PA and PV

41

Ideal FEV1/FVC:

>90%

42

Spirometry measures:

Inspiratory reserve volume
Expiratory reserve volume
Vital capacity

43

Changes in the pulmonary system with aging:

Loss of elastic recoil
Stiffening of chest wall (↓ compliance)
Alterations in gas exchange
↑ in flow resistance
↓ vital capacity due to ↑ residual volume

44

Point in fetal development at which cuboidal epithelium in alveoli turns into type 1 cells:

28 weeks
(Type II cells not working; these preemies need surfactant)