Resp 1 - West Ch 1 Structure And Fcn

Front 1

What mechanism moves oxygen and CO2 between air and blood?

Back 1

simple diffusion - from an area of high to low partial pressure

Front 2

Fick's Law:
The amount of gas that moves across a sheet of tissue is proportional to the _____ of the sheet by inversely proportional to its ______

Back 2

area

thickness

Front 3

What is the smallest airway without alveoli?

Back 3

Terminal Bronchioles

Front 4

What bronchi make up the conducting airway?
What is the function?

Back 4

Trachea and terminal bronchioles

To lead inspired air to the gas exchange region of the lung

Front 5

The ______ airway is considered anatomical dead space. Its volume is about ___ml

Back 5

conducting (no alveoli)

150 ml

Front 6

Which branches are in the respiratory zone?

What is the volume?

Back 6

respiratory bronchioles and alveolar ducts (both lined with alveoli)

2.5-3 L at rest

Front 7

What is an acinus?

Back 7

The portion of the lung distal to a terminal bronchiole - its an anatomical unit.

Front 8

INSPIRATION:
increase in volume due to
1) contraction of the ______ which descends
2) action of the _______ ______ which raise the ribs

Back 8

diaphragm

intercostal muscles

Front 9

Air enters the system through bulk flow up until the ______ bronchioles. After that the method of gas velocity is ______ which is rapid

Back 9

terminal

diffusion (in the respiratory zone)

Front 10

Where does inhaled dust frequently settle in the lungs and why?

Back 10

Terminal bronchioles - the velocity of gas falls rapidly there

Front 11

A normal breath of about ____ml requires a distending pressure of less than _ cm water.

Back 11

500

3

Front 12

What is the normal air flow rate during normal inspiration?

Back 12

1 liter/sec

Front 13

What is the diameter of a pulmonary capillary?
What is the thickness of the blood-gas barrier?

Back 13

10micrometers - just large enough for a RBC

less than 3 micrometers

Front 14

What is the normal pulmonary arterial pressure?
What is the normal pulmonary flow rate?

Back 14

15mmHg (20cm water)

6 L/min (same as the heart)

Front 15

About how long does a RBC spend in capillary network? How many alveoli does it transverse?

Back 15

3/4 sec, 2-3 alveoli

this is all the time it takes to reach equilibrium

Front 16

Why don't the alveoli collapse as easily as a 0.3mm diameter structure should?

Back 16

Type II pneumocytes produce surfactant which dramatically lowers the surface tension of the alveolar lining layer

Front 17

Large particles are filtered where?
Smaller deposit where? What happens to it?
What happens to particles that get engulfed in alveoli?

Back 17

Nose
conducting airways (terminal bronchiole) - mucus sweeps debris up to the epiglottis where its swallowed
macrophages eat it, lympatics or blood removes it

Front 18

Concerning the blood-gas barrier of the human lung:
A.The thinnest part of the blood-gas barrier has a thickness of about 3 m.
B.The total area of the blood-gas barrier is about 1 square meter.
C.About 10% of the area of the alveolar wall is occupied by capillaries.
D.If the pressure in the capillaries rises to unphysiologically high levels, the blood-gas barrier can be damaged.
E.Oxygen crosses the blood-gas barrier by active transport.

Back 18

Answer: D. High intracaillary hydrostatic pressures will lead to interstitial and eventual alveolar edema of the blood-gas barrier. This will result in impairment of gas transport.
Answers A B & C are low estimates for each of the parameters.
Answer E. There is no evidence for active transport of oxygen at any site in the body.

Front 19

When oxygen moves through the thin side of the blood-gas barrier from the alveolar gas to the hemoglobin of the red blood cell it traverses the following layers in order
A. Epithelial cell, surfactant, interstitium, endothelial cell, plasma, red cell membrane.
B.Surfactant, epithelial cell, interstitium, endothelial cell, plasma, red cell membrane.
C.Surfactant, endothelial cell, interstitium, epithelial cell, plasma, red cell membrane.
D.Epithelium, interstitium, endothelial cell, plasma, red cell membrane.
E.Surfactant, epithelial cell, interstitium, endothelial cell, red cell membrane.

Back 19

B

Front 20

What is the PO2 (in mmHg) of moist inspired gas of a climber on the summit of Mt. Everest (assume barometric pressure is 247 mmHg)?
A. 32
B. 42
C. 52
D. 62
E. 72

Back 20

B
PO2 = PB x FO2
PB (dry air) = (247 - 47)mmHg note: partial pressure of water at body temp,
PH2O= 47mmHg

FO2 = 0.2093 (the fraction of O2 in the air)

Front 21

Concerning the airways of the human lung:
A.The volume of the conducting zone is about 50 ml.
B.The volume of the rest of the lung during resting conditions is about 5.0 liters.
C.A respiratory bronchiole can be distinguished from a terminal bronchiole because the former has alveoli in its walls.
D.On the average there are about three branchings of the conducting airways before the first alveoli appear in their walls.
E.In the alveolar ducts the predominant mode of gas flow is diffusion rather than convection.

Back 21

E is correct-distances are short enough for diffusion to be effected.
Answer A: 150 ml is the average dead space (anatomical) volume for a 70 Kg man and is essentially the conducting zone.
Answer B: To high closer to 3.0 liter
Answer C False- the definition is reversed.
Answer D: False. The respiratory bronchioles start at generation 17

Front 22

Concerning the blood vessels of the human lung:
A.The pulmonary veins form a branching pattern which matches that of the airways.
B.The average diameter of the capillaries is about 50 m.
C.The bronchial circulation has about the same blood flow as the pulmonary circulation.
D.On the average blood spends about ¾ sec in the capillaries under resting conditions.
E.The mean pressure in the pulmonary artery is only about 100 mmHg at rest.

Back 22

D Correct Pulmonary blood flow velocity is exceedingly high
Answer A False The pulmonary arteries follow the airways.
Answer B. False Capillary diameter is closer to 50 m.
Answer C. The bronchial circulation is a small fraction of pulmonary circulation.
Answer E. False – The pulmonary artery is only about 15 mmHg.