BRS Physio Lung

Question 1

Volume inspired or expired with each normal breath

Answer 1

Tidal volume

Question 2

Volume that can be inspired over and above the tidal volume

Answer 2

Inspiratory reserve volume

Question 3

Volume that can be expired after the expiration of a tidal volume

Answer 3

Expiratory reserve volue

Question 4

Volume that remains in the lungs after maximal expiration

Answer 4

Residual volume

Question 5

Cannot be measured by spirometry

Answer 5

Residual volume

Question 6

Volume of the conducting airways; usually about 150mL

Answer 6

anatomic dead space

Question 7

The volume of the lungs that does not participate in gas exchange; depends on the following variables: physiologic dead space, tidal volume, PAO2 = PaO2, and PCO2 of expired air

Answer 7

physiologic dead space

Question 8

The volume remaining in the lungs after a tidal volume is expired

Answer 8

Functional residual capacity

Question 9

Volume of air that can be forcibly expired after a maximal inspiration

Answer 9

Vital capacity, or forced vital capacity

Question 10

Volume of the lungs after maximal inspiration; cannot be measured by spirometry

Answer 10

Total lung capacity

Question 11

In obstructive lung disease, such as asthma, FEV1 is reduced more than FVC, so FEV1/FVC is (blank)

Answer 11

decreased

Question 12

In restrictive lung disease, such as fibrosis, both FEV1 and FVC are reduced so FEV1/FVC is (blank)

Answer 12

normal or increased

Question 13

When are expiratory muscles used?

Answer 13

During exercise, or when the airway resistance is increased because of disease (asthma)

Question 14

Compliance is inversely related to these two things

Answer 14

Elastance

Stiffness

Question 15

When the pressure outside of the lungs is (blank), the lungs expand and lung volume increases

Answer 15

negative

Question 16

When the pressure outside of the lungs is (blank), the lungs collapse and lung volume decreases

Answer 16

positive

Question 17

Inflation of the lungs follows a different curve than deflation of the lung. This difference is called (blank).

Answer 17

hysteresis

Question 18

At high expanding pressures (expiration), compliance is lowest, the lungs are least distensible, and the curve (blank)

Answer 18

flattens

Question 19

At FRC, the collapsing force of the lung and the expanding force on the chest wall are (blank), therefore the system is in (blank)

Answer 19

equal and opposite; equilibrium

Question 20

As a result of these two opposing forces, intrapleural pressure is (blank)

Answer 20

negative

Question 21

If air is introduced into the intrapleural space, as seen in pneumothorax, the intrapleural pressure becomes equal to (blank). The lung will collapse and the chest wall will spring outward.

Answer 21

atmospheric pressure

Question 22

What happens to lung compliance with emphysema? The lung-chest wall tries to compensate by increasing (blank), which leads to a barrel-shaped chest.

Answer 22

It increases

FRC

Question 23

What happens to lung compliance with fibrosis? The lung-chest wall tries to compensate by adopting a decreased (blank).

Answer 23

It decreases

FRC

Question 24

(blank) results from the attractive forces between liquid molecules lining the alveoli

Answer 24

Surface tension

Question 25

According to Leplace's law, collapsing pressure of alveoli is directly proportional to (blank) and indirectly proportional to (blank).

Answer 25

surface tension; radius

Question 26

(blank) alveoli have low collapsing pressure and are easy to keep open

Answer 26

Large

Question 27

In the absence of (blank), small alveoli have the tendency to collapse. This is called (blank).

Answer 27

Surfactant; atelectasis

Question 28

Surfactant reduces (blank) by disrupting the intermolecular forces between liquid molecules. This reduction in surface tension prevents collapse of small alveoli and increases (blank).

Answer 28

surface tension; compliance

Question 29

Surfactant is synthesized by (blank) and consists primarily of (blank).

Answer 29

Type II pneumocytes; DPPC

Question 30

When is surfactant present in the fetus?

Answer 30

24-26 weeks

Question 31

Airflow to the lungs is driven by the (blank) between the mouth and the alveoli.

Answer 31

Pressure difference

Question 32

The higher the airway resistance, the (blank) the flow.

Answer 32

lower

Question 33

According to Poiseuille's law, (blank) has a powerful influence on the resistance of an airway.

Answer 33

radius

Question 34

Major source of airway resistance is in the (blank). You would think it would be the smallest airways, but it is not, because of their parallel arrangement.

Answer 34

medium-sized bronchi

Question 35

(blank) are associated with greater traction and decreased airway resistance. Patients with increased airway resistance (asthma) learn to breathe with (blank) to offset airway resistance

Answer 35

High lung volumes | Higher lung volumes

Question 36

At rest, before inspiration, alveolar pressure equals (blank). Intrapleural pressure is (blank)

Answer 36

atmospheric pressure; negative

Question 37

During inspiration, alveolar pressure becomes (blank), and the pressure gradient between the atmosphere and the alveoli allows air to flow in. Intrapleural pressure becomes more (blank).

Answer 37

negative; negative

Question 38

During expiration, alveolar pressure becomes (blank) than atmospheric pressure, which reverses the pressure gradient and allows air to flow out of the lungs. Intrapleural pressure returns to (blank) during passive expiration.

Answer 38

higher (more positive); resting value

Question 39

During forced expiration, intrapleural pressure becomes (blank), which compresses the airways and makes expiration more difficult.

Answer 39

Positive

Question 40

Asthma is a (blank) disease in which expiration is impaired, leading to air trapping and a (blank) FRC.

Answer 40

obstructive; increased

Question 41

COPD is a combo of (blank) and (blank). It is an obstructive disease with (blank) lung compliance.

Answer 41

emphysema; chronic bronchitis; increased

Question 42

In asthma, what happens to FVC? FEV1? FEV1/FVC?

Answer 42

Decreased; decreased; decreased

Question 43

In COPD, what happens to FVC? FEV1? FEV1/FVC?

Answer 43

decreased; decreased; decreased

Question 44

COPD patients can be referred to as (blank) if they have mild hypoxia, because they maintain alveolar ventilation.

Answer 44

Pink puffers

Question 45

COPD patients can be referred to as (blank) if they have severe hypoxemia with cyanosis, because they do not maintain alveolar ventilation.

Answer 45

Blue bloaters

Question 46

What makes the PO2 of arterial blood slightly lower than that of alveolar air?

Answer 46

About 2% of systemic cardiac output bypasses the pulmonary circultion; physiologic shunt

Question 47

Things that shift the O2 binding curve to the left

Answer 47

Decreased temp Increased pH Decreased CO2 Decreased BPG

Question 48

CO2 is produced in the tissues and is carried to the lungs in the venous blood in three forms

Answer 48

1. dissolved CO2 2. carbaminohemoglobin (CO2 bound to Hb) 3. HCO3- (major form)

Question 49

In the RBCs, CO2 combines with H20 to form (blank), a reaction that is catalyzed by (blank)

Answer 49

H2CO3 | Carbonic anhydrase

Question 50

H2CO3 dissociates into (blank) and (blank). (blank) can then leave the RBC via exchange for Cl-.

Answer 50

H+ and HCO3-; HCO3-

Question 51

In the lungs, the reverse reaction occurs. HCO3- enters the RBC in exchange for chloride. HCO3- combines with H+ to form (blank), which can then decompose into (blank) and (blank). This is how CO2 is expired.

Answer 51

H2CO3; CO2 and H20

Question 52

When a person is standing, blood flow is unevenly distributed because of the effect of gravity. Where is blood flow highest?

Answer 52

at the base

Question 53

Compare PA, Pa, Pv in zones 1, 2, and 3

Answer 53

Zone 1: PA>Pa>Pv Zone 2: Pa>PA>Pv Zone 3: Pa>Pv>PA

Question 54

What drives blood flow in zone 2?

Answer 54

Difference between arterial and alveolar pressure

Question 55

What drives blood flow in zone 3?

Answer 55

Difference between arterial and venous pressures

Question 56

In the lungs, hypoxia causes (blank), which is the opposite response from other organs. This effect is important, because it redirects blood to well-ventilated areas.

Answer 56

vasoconstriction

Question 57

Right to left shunts always result in a decrease in (blank), because of the admixture of venous blood with arterial blood.

Answer 57

PaO2

Question 58

Left to right shunts, such as a patent ductus arteriosus, do not cause a decrease in (blank).

Answer 58

PaO2

Question 59

In a normal lung, the V/Q ratio is approximately (blank).

Answer 59

0.8

Question 60

Is the V/Q ratio higher or lower at the base?

Answer 60

Lower

Question 61

A piece of steak caught in the trachea would cause a V/Q ratio that approaches (blank), while a pulmonary embolism may cause a V/Q ratio that approaches (blank).

Answer 61

zero; infinity

Question 62

The medullary respiratory center is located in the reticular formation and contains that (blank) and the (blank).

Answer 62

dorsal respiratory group; ventral respiratory group

Question 63

Primarily responsible for inspiration and generates the basic rhythm for breathing

Answer 63

Dorsal respiratory group

Question 64

Primarily responsible for expiration; not active during normal, quiet breathing when expiration is passive

Answer 64

Ventral respiratory croup

Question 65

Located in lower pons; stimulates inspiration

Answer 65

apneustic center

Question 66

Located in the upper pons; inhibits inspiration

Answer 66

pneumotaxic center

Question 67

Breathing can be under voluntary control by the (blank).

Answer 67

cerebral cortex

Question 68

Central chemoreceptors are located in the medulla, and are sensitive to the (blank) of the CSF. Decreased (blank) produces increase in breathing rate.

Answer 68

pH; pH

Question 69

(blank) diffuses from arterial blood into the CSF because (blank) is lipid soluble and readily crosses the blood-brain barrier.

Answer 69

CO2; CO2

Question 70

What do peripheral chemoreceptors respond to?

Answer 70

Decreases in PaO2 Increases in PaCO2 Increases in arterial [H+]

Question 71

PO2 must decrease to levels below (blank) before breathing is stimulated by peripheral chemoreceptors.

Answer 71

60mmHg

Question 72

The response of peripheral chemoreceptors to CO2 is less important than the response of (blank) to CO2.

Answer 72

central chemoreceptors

Question 73

Located in the smooth muscle of the airways | When stimulated by distention of the lungs, they produce a reflex decrease in breathing frequency (Hering-Breuer reflex)

Answer 73

Lung stretch receptors

Question 74

Located between the airway epithelial cells | Stimulated by noxious substances

Answer 74

Irritant receptors

Question 75

Located in the alveolar walls, close to the capillaries Engorgement of the pulmonary capillaries, such as may occur with left heart failure, stimulated these receptors and causes rapid shallow breathing

Answer 75

J receptors

Question 76

The mean values for (blank) and (blank) do not change during exercise. (blank) does not change during moderate exercise, either.

Answer 76

PO2; PCO2; arterial pH

Question 77

Hypoxemia stimulates renal production of (blank) which increases the production of RBCs and increases (blank).

Answer 77

erythropoietin; hemoglobin concentration

Question 78

A cause of airway obstruction in asthma is (blank). This can be corrected by administration of (blank).

Answer 78

bronchiolar constriction | B2-adrenergic stimulation

Question 79

If alveolar pressure were not (blank) than atmospheric pressure during inspiration, air would not flow in.

Answer 79

lower

Question 80

In a volume-pressure graph of the lung-chest wall system, when airway pressure is zero, the volume of the combined system is the (blank).

Answer 80

FRC