pulmonary

Question 1

What is the function of pleural cavity?

Answer 1

• act as vacuum to prevent lungs from collapsing

- negative pressure

Question 2

Where is the most common location of aspiration?

Answer 2

right inferior lobe due to right main stem(bronchi) is more inferior and straight down

Question 3

What increases lung’s tendency to collapse?

Answer 3

• elastin and collagen in lungs

- water surface tension in alveoli increases its tendency to collapse

Question 4

Where is costophrenic angle and why is it important?

Answer 4

• angle formed when lungs and diaphragm meet (corner)

- important to look for fluid accumulation between pleural cavity

Question 5

When is interpleural pressure positive and negative?

Answer 5

• positive when exhaling and diaphragm recoils

- negative when inhaling and diaphragm contraction

Question 6

What are the main muscles of inspiration?

Answer 6

• Diaphragm (quiet breathing)

- external intercostals (heavy breathing) bring the ribs up

Question 7

What are the muscles of expiration?

Answer 7

• abds

- internal intercostals(bring the ribs down)

Question 8

For severe respiratory distress, what accessory muscles are used?

Answer 8

• sternocleidomastoid
• serratus anterior
• scaleni
  requires huge energy but not efficient to get air in

Question 9

How is alveolar pressure affected by the size of the radius?

Answer 9

• Law of laplace (p= 2T/r)

- pressure in a small alveoli will be higher than the pressure in the bigger alveoli(radius)

Question 10

What is trans-pulmonary pressure?

Answer 10

• difference between alveolar and pleural pressure

- if 0, lungs gonna collapse

Question 11

What are surfactants?

Answer 11

• secreted by type 2 alveolar epithelial cells
• reduces surface tension in alveoli to 1/2 - 1/12th
• decreases greater amount of surface tension in the smaller alveoli

Question 12

What holds bronchioles open?

Answer 12

• transpulmonary pressure (difference between alveolar and pleural pressure)