"Medical Physiology Lung Structure and Function Jeffrey Freedman" MARY

Question 1

Give the equation for ventilation.

Answer 1

v = f x TV
v is ventilation, aka minute volume
f is frequency of breathing, ie 15 bpm
TV is tidal volume (L/breath) - the amount of volume that goes into a lung in 1 breath
similar to the CO = SV x HR equation

Question 2

Water vapor pressure is a function of:

Answer 2

temperature

Question 3

What is the conductive zone of the lung?

Answer 3

First 16 branches - trachea, bronchi, bronchioles and terminal bronchioles

Question 4

What is the respiratory zone of the lung?

Answer 4

Last 7 branches - respiratory bronchioles, alveolar ducts, alveolar sacs

Question 5

In the conducting zone, the ciliated surface moves mucous secreted by _______.

Answer 5

Goblet cells

Question 6

What cells line alveoli?

Answer 6

Type I alveolar epithelial cells

Question 7

What cells make surfactant?

Answer 7

Type II alveolar cells

Question 8

What are the functions of surfactant?

Answer 8

Coat alveoli
Lowers surface tension making it easier to inhale
Increase the mechanical stability of the lung

Question 9

T/F: The epithelium of the respiratory zone does not contain cilia or goblet cells.

Answer 9

True

Question 10

How do macrophages that engulf foreign matter leave the lung?

Answer 10

Lymphatic system

Question 11

When is oxygen equilibrium achieved?

Answer 11

When the PP of O2 in the alveolar gas is the same as the pulmonary capillary blood. The same is true for CO2.

Question 12

Why does oxygen in blood NOT contribute to blood pressure?

Answer 12

According to Henry’s law of solubility, when dissolved in a liquid, the gas does not exert pressure.

Question 13

What is shunt flow?

Answer 13

1% of the cardiac output, the bronchial flow, is known as the shunt flow bc it bypasses the gas exchanging portion of the lung and drains into the pulmonary vein. As a result, the oxygenated blood in the pulmonary vein returning to the left heart is a mixture of blood that has equilibrated with alveolar gas and a small amount of blood with the composition of mixed venous blood.

Question 14

In diseased lungs, some alveoli may not contact the capillary blood at all, alveoli that are ventilated by not perfused constitute _______.

Answer 14

Alveolar dead space

Question 15

In diseased lungs, some alveoli are ventilated but not perfused. Other alveoli are perfused but not ventilated; the gas in these alveoli represents _______.

Answer 15

trapped volume

Question 16

What is the respiratory quotient?

Answer 16

Ratio of tissue metabolic production of CO2 and consumption of O2 in tissue. RQ = 0.85 for normal diet, 1 for carbs, 0.7 for pure fat

Question 17

The ___________ is measured by analysis of inspired and expired gas at the level of the lung.

Answer 17

respiratory exchange ratio (RE), ratio of CO2/O2

Question 18

End-capillary blood has PcO2 of _____ mm Hg, and PcCO2 of 40 mm HG, the same partial pressures as in alveolar gas.

Answer 18

104

Question 19

What is anatomic dead space?

Answer 19

The part of the lungs that can receive air but not exchange gas, so the air sits there until it is expired with the rest of the gas, but it’s not used (helps to make up mixed expired gas)

Question 20

Read pg. 576 in the notes

Answer 20

because it does not lend itself well to cards.