lecture 31

Question 1

movement of air

Answer 1

• lungs expand as a result of the enlargement of the structure surrounding them
• contract the diaphragm-enlarges the vertical dimension
• elevate the rib cage to enlarge the transverse dimension

Question 2

lungs expand as result of

Answer 2

enlargement of structure surrounding them

Question 3

what enlarges the vertical dimension

Answer 3

contract the diaphragm

Question 4

what enlarges the transverse dimension

Answer 4

elevate the rib cage

Question 5

lungs and inner thoracic wall are covered with

Answer 5

a pleural lining

Question 6

types of pleura

Answer 6

visceral pleura, parietal pleura, mediastinal pleura, diaphragmatic pleura, costal pleura

Question 7

pleural membranes composed of what

Answer 7

elastic and fibrous tissue

Question 8

what is pleural membrane

Answer 8

saran wrap encasing the lungs, airtight seal

Question 9

what produces mucous solution

Answer 9

cuboidal cells within the lining

Question 10

what does pleural membrane create

Answer 10

an easy, low friction gliding of the lungs within the thorax

Question 11

negative pressure is maintained within thorax because why

Answer 11

there is no contact with outside atmosphere

Question 12

due to movement of pleural lining

Answer 12

lungs are able to follow the action of the muscles wo actually being attached to them

Question 13

because the surfaces of the two linings are infused with serous secretion

Answer 13

there is low friction making respiration more efficient

Question 14

diaphragm contracts

Answer 14

air flows in, increased volume, negative pressure

Question 15

diaphragm stops contracting

Answer 15

air flows out of lungs, decreased volume, positive pressure

Question 16

pressures of respiratory system

Answer 16

alveolar pressure, intrapleural pressure, subglottal pressure, intraoral pressure, atmospheric pressure

Question 17

all pressures are measured relative to what

Answer 17

atmospheric pressure treated as a constant 0 against which to compare respiratory pressure

Question 18

alveolar pressure

Answer 18

pressure that is present within the individual alveolus

Question 19

inhalation

Answer 19

air flows into the alveoli and the volume increases, when volume increases, pressure decreases - negative alveolar pressure

Question 20

exhalation

Answer 20

air flows out of the alveoli and volume decreases, when volume decreases, pressure increases - positive alveolar pressure

Question 21

intrapleural pressure is always

Answer 21

negative throughout respiration

Question 22

what is wrapped in this continual sheet of pleural lining

Answer 22

lungs, inner thorax, and diaphragm

Question 23

intrapleural pressure does what

Answer 23

keeps the lungs from collapsing

Question 24

why does intrapleural pressure remain negative

Answer 24

• lungs are in a state of continual expansion because the thorax is larger than the lungs
• lungs are never completely deflated because of the residual volume

Question 25

alveolar and intrapleural pressure

Answer 25

diaphragm contracts - air flows in, alveolar pressure drops, intrapleural pressure becomes more negative as the diaphragm pulls the diaphragmatic pleura diaphragm relaxes - air flows out, alveolar pressure increases, intrapleural pressure becomes less negative

Question 26

subglottal pressure

Answer 26

pressure measured beneath the level of the vocal folds

Question 27

subglottal pressure related to what

Answer 27

directly related to what is happening in the lungs as long as the vocal folds are open

Question 28

air flows into lungs

Answer 28

negative subglottal pressure

Question 29

air flows out of lungs

Answer 29

positive subglottal pressure

Question 30

what happens when vocal folds are closed

Answer 30

blocks air flow, immediate increase in subglottal air pressure, when pressure exceeds 3-5 cm H2O, the vocal folds will be blown open and voicing will begin

Question 31

intraoral pressure

Answer 31

respiratory pressure measured above the vocal folds within the oral cavity

Question 32

when vocal folds are open

Answer 32

intraoral, subglottal and alveolar pressure are the same

Question 33

closing the vocal folds causes

Answer 33

intraoral pressure to drop as the subglottal pressure increases

Question 34

four stages for gas exchange

Answer 34

- ventilation - distribution - perfusion - diffusion

Question 35

ventilation

Answer 35

air comes into respiratory pathway

Question 36

distribution

Answer 36

air is distributed to 300 million alveoli

Question 37

perfusion

Answer 37

oxygen poor blood migrates through to the 6 billion capillaries

Question 38

diffusion

Answer 38

actual gas exchange across the alveolar capillary membrane

Question 39

turbulence

Answer 39

- lungs expand, air courses through the bronchi - some slight turbulence at the bifurcation of the bronchi but the air generally flows unimpeded - a small irregularity such as mucus or muscle spasm can greatly increase resistance to airflow

Question 40

bronchitis

Answer 40

turbulence causes inefficiency in air flow which causes inefficiency in breathing