Block VI - Respiratory

Question 1

What is the vital capacity?

Answer 1

The max volume that can be inspired after max expiration

Question 2

In which form is most of the CO2 in arterial blood carried?

Answer 2

As bicarbonate in plasma

Question 3

What is the normal arterial oxygen carrying capacity?

Answer 3

1.34 ml O2/gHB x gHb in 100 mL blood

Question 4

If PaO2 is 100, hemo concentration is 12 g/100mL, and Saturation is 97%, what is concentration of O2 bound to hemo?

Answer 4

12x1.34x.97 = 15.6 ml o2 / 100 ml blood

Question 5

PB is 523 torr, pt has hyperventilated in response to hypoxia, pao2 is 70 torr and R = 0.83. What is PaCO2? Water vapor pressure in airway is 47

Answer 5

25. Alveolar air equation pao2 = pio2 - (paco2/r) where pio2 = 0.21(pb-47)

Question 6

What happens to the oxygen binding on hemoglobin when blood temp increases?

Answer 6

Less oxygen carrying at the same po2 with temperature increase.

Question 7

When the respiratory muscles are relaxed in a normal person with open airways, what is the volume of the lungs?

Answer 7

Function residual capacity (FRC)

Question 8

Does muscle directly control lung movement?

Answer 8

No muscle directly attaches to the lungs. Lungs are wrapped by two layers of pleura membranes, the pressure in the space between is always more negative than alveolar

Question 9

During normal quiet inspiration, what change will the intrapleural pressure be?

Answer 9

More negative

Question 10

How are inspired gases mixed in alveolar space?

Answer 10

Simple diffusion

Question 11

A subject with deadspace of 150 breathed 10 breaths per minute with tidal volume of 500. What is alveolar ventilation?

Answer 11

3.5 liters per minute

Question 12

In general, what is the relationship between body weight and conducting deadspace?

Answer 12

1 mL per pound

Question 13

What are the effects of acidity, DPG, and temp on oxyhemoglobin dissociation curve?

Answer 13

Increasing acidity, DPG, or temp of blood will shift curve to right

Question 14

As mixed venous blood enters and travels through capillaries in well-ventilated areas of the lung, what happens to the blood pH?

Answer 14

pH increases

Question 15

What is the effect on increase in arterial CO2 on ventilation?

Answer 15

It will stimulate both the peripheral and the central chemoreceptors and thus increase ventilation

Question 16

What do you expect on the CO2 response curve with acclimation to altitude?

Answer 16

Shift to the left (that is increase the respiratory response to a give arterial PCO2)

Question 17

What is the effect of H ion concentration on peripheral chemoreceptor activity?

Answer 17

Activity increases linearly with H concentration in ranges of 40-45 mEq/L

Question 18

What is the vital capacity?

Answer 18

Max volume that can be inspired after max expiration

Question 19

Is terminal bronchioles belong to the respiratory zone?

Answer 19

No. The respiratory zone consists of respiratory bronchioles, alveolar ducts, alveolar sacs

Question 20

What type of flow is the movement of air into the airways?

Answer 20

Bulk flow

Question 21

How does the radius influence airway resistance?

Answer 21

Poiseuille states inverse to 4th power

Question 22

What are the alveolar pressures in the absence of surfactant two alveoli of different size sharing an alveolar duct?

Answer 22

Have different alveolar pressure (Psmall > Plarge)

Question 23

What is the ratio of FEV1/FVC as % - the proportion of total volume of air that can be expired in the first second of expiration of normal individual?

Answer 23

80%

Question 24

According to Fick’s first law, how do gases diffuse from alveoli to the cells that are related to the membrane thickness?

Answer 24

Flow is inversely proportional to membrane thickness

Question 25

How does COPD differ from asthma?

Answer 25

Lung inflammation in asthma can be triggered. COPD is not this and does not respond well to anti-inflammatory. COPD presents evidence of permanent damage with plugging of airways

Question 26

What change in the concentration of diphosphoglycerate DPG will shift an oxygen saturation curve to the left?

Answer 26

Decrease

Question 27

Whicc is effect of CO on the oxygen saturation curve?

Answer 27

Shift curve to left

Question 28

In which form the majority of O2 is transported in the blood?

Answer 28

Bound to hemoglobin

Question 29

What is the critical enzyme used in CO2 transport?

Answer 29

Carbonic anhydrase. It catalyzes CO2 and H20 to bicarb in lung and peripheral tissues

Question 30

What do Boyle’s Henry’s, Dalton’s, and Laplace laws refer to?

Answer 30

• Boyle: P1V1=P2V2
• Henry: partial pressure is same on both sides of liquid-air border
• Dalton: in the air, total pressure is sum or partials
• Laplace: smaller diameter produces higher pressure due to surface tension

Question 31

What change in lung compliance under medical conditions?

Answer 31

Increase in emphysema, decrease in fibrosis, no change in asthma

Question 32

What is tidal volume?

Answer 32

The lung volume change during a normal inspiration and expiration cycle

Question 33

What forms of CO2 in blood?

Answer 33

10% CO2 in plasma, 30 HbCO2, 60 HCO3-

Question 34

What is the major form of )2 in blood?

Answer 34

98.5% binds to hemoglobin

Question 35

What is the effect of PO2 on oxygen saturation of hemoglobin?

Answer 35

O2 binding to hemoglobin increases with PO2 when it is less than 80, no significant increase beyond 80

Question 36

What is the function of carbonic anhydrase in the alveolar capillaries and in the muscle capillaries, respectively?

Answer 36

In lungs, converts bicarb to CO2 and H20. in Periph, does the reverse.