Respiratory Physiology

Question 1

Right Bronchial Tree

Answer 1

-more vertical/short, more chance of asperation pneumonia

Question 2

Diffusion

Answer 2

-Co2 diffuses 4x faster than O2
-co2 sensitive to changes in ventilation
-o2 sensitive to changes in ventilation and diffusion
-need blood flow, air, close to capillary wall, sufficient o2
-takes 1/2 time RBC is in capillary to diffuse

CO2:
-Co2 (capillary) 46 + C02 (alveloi) 40 = co2 goes into alveoli
-Co2 (capillary) 40 + C02 (tissue) 46 = co2 goes into vein

O2:
-O2 (capillary) 40 + O2 (alveloi) 100 = O2 goes into capillary
-O2 (capillary) 100 + O2 (tissue) 40 = O2 goes into tissue

Question 3

Hypercapnic

Answer 3

-increased Co2
-hypoventilation: increases Co2, lowers pH
>45 PaCo2

Question 4

Hypoxemia

Answer 4

-decreased blood o2
<80% PaO2

Question 5

Diaphram

Answer 5

-right sits higher
-tends to go upward with surgery and obesity

Question 6

FRC

Answer 6

Functional residual capacity
-exhale and have residual air in lungs

Question 7

Hypercompliant Lung

Answer 7

-stretches excessively without returning to normal during exhalation
-increased FRC, PaCo2, airway resistance
-Decreased PaO2, intrathoracic pressure

-COPD, Obstructive

Question 8

Hypocompliant Lung

Answer 8

-does not expand or contrac correctly
-decreased VC and RV
-increased work and pressure
-restrictive, obesity, surgery

Question 9

Tidal Volume

Answer 9

-500ml
-amount of air moved in and out in each breath
-decresed VC and RV
-increas

Question 10

Inspiratory Reserve Volume

Answer 10

-3000ml
-max inspiration after normal inspiration

-decrease with restrictive

Question 11

Expiratory Reserve Volume

Answer 11

-1100ml
-max one can expire after normal exhale

Question 12

Residual Volume

Answer 12

-1200ml
-volume of air left in lungs after max exhale
-FRC-ERV=RV (cannot be measured)

Question 13

Functional Residual Capacity

Answer 13

-volume of air in lungs after normal expiration
-RV + ERV
(cannot be measured)
-balances lung and chest wall forces

Question 14

Inspiratory Capacity

Answer 14

-max volume one can inspire
-TV+ IRV

-decrease with restrictive

Question 15

Vital Capacity

Answer 15

-max volume one can exchange in a respiratory cycle
-IRV+TV+ERV

-decrease with restrictive

Question 16

Total Lung Capacity

Answer 16

-air in lungs during full inflation
-IRV+TV+ERV+RV
-RV+VC=TLC
(cannot be measured)

-decrease with restrictive, increase obstructive

Question 17

FEV1

Answer 17

-forced expiratory volume in 1 sec
-80% of predicted/max
-based on age, gender, race, height

Question 18

FVC

Answer 18

-forced vital capacity’-how much can you force out and in

Question 19

FEV1/FVC

Answer 19

-percentage of vital capacity exhaled in 1 sec
->70% norm

Question 20

Dynamic Airways Resistance

Answer 20

-increases as lung volumes dec
-forced exhalation increases resistance

Obstructive: longer exhale, more air out
Restrictive: faster exhale, less air out

Question 21

Ventilation to Perfusion Ratio (V/Q)

Answer 21

-blood flow to alveoli must match ventilation or =hypoxemia
-changes with posture
-Norm: 0.8

Reduced: shunt, decreased ventilation to perfusion, blood shunted to other parts of the lung, vasoconstriction at arterioles to reduce BV, corrected with O2

Increased: dead space, increased ventilation to perfusion, vasodilation to increase BV, dead space

Question 22

Control of Respiration

Answer 22

-increased CO2 increases ventilation and breathing drive
-Decreased O2 weakly stimulates (<60)

Question 23

PaO2/Co2

Answer 23

-partial pressure of arterial O2 (80-100) /Co2 (35-45)

Question 24

SaO2

Answer 24

-o2 sat of arterial hemoglobin (>90%)

Question 25

HCO3-

Answer 25

Bicarbonate ion concentration (22-26)

Question 26

pH

Answer 26

-<7.4 acidic
->7.5 alkaline

7.35-7.45

Question 27

Hgb

Answer 27

-hemoglobin (12-16)

Question 28

Hypocapnia

Answer 28

-Hyperventilation: raises pH, reduces Co2
-PaCo2 <35

Question 29

Acid Base Regulation

Answer 29

-kidneys can extrete or retain HCO3 (slowly)

Increased Ecretion: low pH, metabolic acidosis
Decreased Extrcetion: high pH, metabolic alkalosis

-respiratory
Hyperventilation: raises pH, reduces Co2, respiratory alkalosis
Hypoventilation: increases Co2, lowers pH, respiratory acidosis