Ch 37 Respiration pt 1

Question 1

Which muscles raise the ribcage in inspiration? Which is most important?

Answer 1

Important: external intercostals
others: sternocleidomastoid, scaleni, anterior seratti

Question 2

Which muscles pull the ribcage down in expiration?

Answer 2

Abdominal recti, internal intercostals

Question 3

What is transpulmonary pressure?

Answer 3

The difference between pressure in the alveoli and the pleural pressure

Question 4

Which force determines the majority of lung elastic forces? What determines the rest?

Answer 4

2/3 of lung elastic forces is determined by fluid-air surface tension forces in the alveoli. The other 1/3 is via tissue elastic forces

Question 5

What are the most important components of surfactant?

Answer 5

-dipalmitoyl phosphatidylcholine
-Calcium ions
-surfactant apoproteins

Question 6

What are the 3 types of work required to expand the lungs (work of inspiration)?

Answer 6

-Compliance/elastic work
-Tissue resistance work
-Airway resistance work

Question 7

What is compliance work?

Answer 7

The work required to expand the lungs against the chest and elastic forces

Question 8

What is tissue resistance work?

Answer 8

The work required to overcome the viscosity of the lung and chest wall structures

Question 9

What is airway resistance work?

Answer 9

The work required to overcome airway resistance to move air into the lungs

Question 10

What is tidal volume?

Answer 10

Vol of air inspired or expired with each breath

Question 11

What are inspiratory and expiratory reserve volumes?

Answer 11

The amount of air that can be inspired or expired when full force is used

Question 12

What is residual volume?

Answer 12

Vol left in the lungs after the most forceful expiration

Question 13

How do you determine inspiratory capacity?

Answer 13

Tidal volume + inspiratory reserve. Represents the air normally

Question 14

What is functional residual capacity?

Answer 14

Expiratory reserve + residual volume. The amount of air left in the lungs after normal expiration

Question 15

How do you calculate total capacity of the lungs?

Answer 15

Vital capacity + residual volume

Question 16

Which portion of air is expired from the lungs first?

Answer 16

Dead space air

Question 17

What is the difference between anatomic and physiologic dead space?

Answer 17

Physiologic dead space includes unused alveoli in addition to non-ventilated airway space

Question 18

Which airways contain the least smooth muscle?

Answer 18

Respiratory bronchioles (most terminal)

Question 19

In which airways does the most airway resistance occur?

Answer 19

The larger bronchi and bronchioles near the trachea

Question 20

Stimulation of which receptors can cause dilation of the bronchial tree?

Answer 20

Beta adrenergic receptors

Question 21

How does acetylcholine influence the bronchioles?

Answer 21

Causes mild to moderate bronchiolar constriction

Question 22

What effect does atropine have on the bronchioles?

Answer 22

Blocks acetylcholine and stops constriction

Question 23

What effect do histamine and slow reactive substance of anaphylaxis have on the bronchioles?

Answer 23

Active constriction