Gas Exchange in the Lungs

Question 1

What does Fick’s Law state?

Answer 1

The volume of gas diffusing per minute across a membrane is directly proportional to the membrane area, diffusion coefficient of the gas, and the partial pressure difference of the gas and diffusion of the gas is inverse to the membrane thickness (Vgas=AD(P1-P2)/T)

Question 2

What is hypercapnea?

Answer 2

Excessive carbon dioxide in the blood

Question 3

What is hypopnea?

Answer 3

Diminished depth and rate of respiration

Question 4

What is hyperpnea?

Answer 4

Abnormal increase in depth and rate or respiration

Question 5

What occurs when a Type I pneumocytes is damaged?

Answer 5

It is replace by a Type II which then differentiates into a Type I

Question 6

What is the purpose of the Pore of Kahn?

Answer 6

Connects alveoli to allow movement from one alveoli to another

Question 7

How do alveoli grow as we do?

Answer 7

Grow in number til age 8 and only decrease in size from there

Question 8

Normal tidal volume:

Answer 8

500mL

Question 9

Anatomic dead space volume:

Answer 9

150mL

Question 10

Amount that make it to alveoli:

Answer 10

350mL

Question 11

Difference between anatomic and alveolar dead space?

Answer 11

Anatomic: air does not touch alveoli for gas exchange
Alveolar: alveoli are not exchanging gas (no perfusion)

Question 12

Is V/Q greater or less than 1 in the apex?

Answer 12

Greater (nondependent region)

Question 13

Is V/Q greater or less than 1 in the base?

Answer 13

Less (dependent region)

Question 14

Is the base or the apex more compliant?

Answer 14

Base (apex is already expanded because gravity)

Question 15

What occurs to the V/Q ratio in patients with a emphysema?

Answer 15

It decreases because ventilation decreases but blood flow remains normal

Question 16

What is the ultimate goal of ventilation?

Answer 16

To keep alveolar respiratory gas partial pressures as close to atmospheric as possible

Question 17

What is the respiratory duty cycle?

Answer 17

One respiratory cycle of inspiration and expiration

Question 18

What costs more energy inspiration or expiration?

Answer 18

Inspiration

Question 19

What occurs to Tv as a diseased patient increases frequency of breathing?

Answer 19

Tv decreases

Question 20

What is the most energetically favorable breathing pattern for pulmonary fibrosis?

Answer 20

Shallow and rapid breathing (increased Tv means increase ATP)

Question 21

How to calculate mechanical ventilation for patients without pre-existing lung disease?

Answer 21

8mL/kg x 12 times a minute

Question 22

How to calculate mechanical ventilation for patients with chronic pre-existing lung disease?

Answer 22

10-10 rule 10mL/kg x 10 a minute

Question 23

How to calculate mechanical ventilation for patients with acute lung disease?

Answer 23

6mL/kg x 10-12 times a minute

Question 24

How many kg are in a lb?

Answer 24

.454 kg/lb

Question 25

What effect does resistance have on frequency of breathing?

Answer 25

Increased resistance leads to increased frequency