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Flashcards in lecture 2 Deck (18)
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1
Q

define Boyle’s law

A

the pressure of a gas tends to decrease as the volume of a gas increases

2
Q

each lung is enclosed in how many pleural membranes

A

2

3
Q

the pleural cavity is filled with what?

A

intrapleural fluid

4
Q

the visceral pleural membrane coats what?

A

the outer surface of the lungs

5
Q

the parietal pleural membrane coats what?

A

the inner surface of the ribs

6
Q

between the visceral pleural membrane and the parietal pleural membrane what will you find?

A

pleural fluid

7
Q

define pleurisy

A

inflammation of the pleura

8
Q

describe intrapleural pressure

A

-3mm subatmospheric

9
Q

what muscles does inspiration use?

A

external intercostal muscles and the diaphragm

10
Q

expiration is passive at rest but uses what muscles during severe respiratory load?

A

internal intercostals and adominal muscles

11
Q

apart from the external intercostals and the diaphragm what other muscles are used during inspiration?

A

sternocleidomastoids

scalenes

12
Q

at rest the diaphragm can be described as contracte or relaxed?

A

relaxed

13
Q

what is the pathophysiology of asthma

A

Asthma – over-reactive constriction of bronchial smooth muscle. Increases resistance, expiration difficult.

14
Q

define Intra-thoracic (Alveolar) Pressure (PA):

A

pressure inside the thoracic cavity, (essentially pressure inside the lungs). May be negative or positive compared to atmospheric pressure

15
Q

define Intra-pleural Pressure (Pip):

A

pressure inside the pleural cavity, ALWAYS negative (in healthy lungs at least!)

16
Q

Transpulmonary pressure (PT):

A

difference between alveolar pressure and intra-pleural pressure. ALWAYS positive (in health) because Pip is always negative. PT = Palv – Pip.

17
Q

what is the major determinant of airway resistance?

A

radii of the airways

18
Q

define transpulmonary pressure

A

is the difference between the alveolar pressure and the intrapleural pressure in the lungs. During human ventilation, air flows because of pressure gradients.