Ventilation and Control of Breathing Part 1

Question 1

Which 3 structures are in the respiratory zone

Answer 1

Respiratory bronchioles
Alveolar ducts
Alveolar sacs

Question 2

Flow and pressure in the lungs

Answer 2

Flow is high (entire CO from RV)

Pressure is low (25/8 mmHg)

Question 3

Ventilation depends on which 3 pressures

Answer 3

Atmospheric
Alveolar
Intrapleural

Question 4

2 main inspiration muscles

Answer 4

Diaphragm (main one)

External intercostals

Question 5

Accessory muscles for

1. Inspiration
2. Expiration

Answer 5

1. Scalenes, sternocleidomastoids

2. Abdominal muscles, internal intercostals

Question 6

Atelectasis

Answer 6

Alveolar collapse

Question 7

3 mechanical factors affecting ventilation

Answer 7

Surface tension of alveolar fluid
Compliance of lungs
Airway resistance

Question 8

Surfactant

Answer 8

Mix of phospholipids and protein
Secreted by type 2 alveolar cells
Lowers surface tension = increases compliance
Secretion stimulated by deep breaths

Question 9

Law of LaPlace

Answer 9

P = 2T/r

Without surfactant, air would flow from small alveoli into large ones and the small ones would collapse

Question 10

Minute ventilation

Answer 10

How much air gets to the alveoli in a minute

V = tidal volume x resp rate

Question 11

Volumes:

1. Tidal
2. IRV
3. ERV
4. RV

Answer 11

1. 500 mL
2. 3000 mL
3. 1000 mL
4. 1200 mL

Question 12

Capacities:

1. Inspiratory capacity
2. Vital capacity
3. FRC
4. Total LC

Answer 12

1. Vt + IRV = 3500 mL
2. Vt + IRV + ERV = 4500 mL
3. ERV + RV = 2200mL
4. Vt + ERV + IRV + RV = 5700 mL

Question 13

What measurement can you not get with spirometry

Answer 13

Residual volume

And therefore not total lung volume either