Respiratory Physiology

Question 1

Functions of the lungs

Answer 1

gas exchange
pH maintenance via retention or elimination of CO2
Conversion of ANG1 to ANG2 for blood pressure control

Question 2

Pressure and volume relationship

Answer 2

inversely related

Question 3

air will flow from areas —

Answer 3

high pressure to low pressure

Question 4

Is inspiration an active or passive process?

Answer 4

active

Question 5

primary inspiratory muscles

Answer 5

diaphragm (phrenic nerve fires –> diaphragm contracts)
external intercostals (elevate ribs –> increase transverse diameter)
external intercostals (evert ribs –> increase AP diameter)

Question 6

Accessory inspiratory muscles

Answer 6

Sternocleidomastoid
Serratous anterior
Scalenes
Pectoralis

Question 7

Is expiration a passive or active process?

Answer 7

passive

Question 8

Muscles for forced expiration

Answer 8

internal intercostals
abdominal muscles

Question 9

Pressure and volume for inspiration

Answer 9

Volume increases –> pressure in lungs decreases –> air flow from atmosphere into lungs

Question 10

Pressure and volume for expiration

Answer 10

Volume decreases –> pressure increases –> air flows out

Question 11

Conducting zone

Answer 11

nasal cavity
pharynx
trachea
bronchus
bronchioles

Question 12

What is considered the anatomic dead space?

Answer 12

conducting zone; no gas exchange occurs here

Question 13

volume in conducting zone/dead space

Answer 13

150 mL
1/3 of tidal volume

Question 14

What is surfactant created by?

Answer 14

Type 2 pneumocytes

Question 15

What is the alveolar epithelium created by?

Answer 15

type 1 pneumocytes

Question 16

Volume in the respiratory zone

Answer 16

3L

Question 17

Does diffusion occur actively or passively?

Answer 17

passively

Question 18

Diffusion is directly proportional to

Answer 18

pressure difference (P1-P2; AA gradient)
Surface area
temperature
solubility (easier to offload CO2 than to transfer O2 over)

Question 19

Diffusion is inversely proportional to

Answer 19

molecular size
thickness of membrane

Question 20

alveolar dead space (pathologic)

Answer 20

Alveoli not receiving blood supply –> no gas exchange

shallow rapid breathing –> decreased alveolar ventilation –> decreased O2/CO2 exchange

deep slow breathing –> increased alveolar ventilation –> increased O2/CO2 exchange

Question 21

High V/Q

Answer 21

Pulmonary HTN, PE

blood is not getting perfused

Question 22

Low V/Q

Answer 22

emphysema due to decreased ventilation

Question 23

positive pressure causes

Answer 23

tension pneumothorax

valsalva

Question 24

Causes of less negative pressure

Answer 24

emphysema –> less recoil

leads to air trapping

Question 25

Cause of zero pressure

Answer 25

birth stab wound without valve spontaneous pneumothorax

Question 26

what decreases our lung's ability to collapse

Answer 26

surfactant decreases surface tension which decreases our lung's ability to collapse

Question 27

How is compliance related to surface tension and elasticity

Answer 27

inversely related

Question 28

Who do we worry about not having enough surfactant?

Answer 28

premies

Question 29

Alveolar ventilation

Answer 29

amount of volume involved in gas exchange

Question 30

Normal V/Q ratio

Answer 30

0.8, 80%

Question 31

When is pressure lowest

Answer 31

mid inspiration

Question 32

when is pressure highest

Answer 32

mid expiration

Question 33

Is transmural pressure always positive or always negative

Answer 33

always positive

Question 34

Least resistance

Answer 34

alveoli due to higher surface area

Question 35

Premature babies are at high risk of lung collapse so we put them on

Answer 35

positive pressure breathing stimulate surfactant production via steroids or thyroxine or prolactin

Question 36

Compliance

Answer 36

expansibility of lungs change in volume divided by change in pressure (if increased compliance then you are able to get air in)

Question 37

Emphysema and compliance

Answer 37

increased compliance --> decreased recoil think of an old sock and a useless rubber band

Question 38

Pulmonary fibrosis and compliance

Answer 38

decreased compliance --> increased recoil think about compression stockings that are very strong and difficult to stretch

Question 39

Alpha 1 antitrypsin deficiency and compliance

Answer 39

decreased elastin --> decreased lung recoil --> increased compliance

Question 40

Eupnea

Answer 40

normal breathing

Question 41

Hypopnea

Answer 41

decreased breathing

Question 42

Hyperpnea

Answer 42

increased breathing

Question 43

Apnea

Answer 43

no breathing

Question 44

Orthopnea

Answer 44

erect breathing CHF

Question 45

platypnea

Answer 45

flat breathing

Question 46

trepopnea

Answer 46

side breathing CHF or fibrosis of one lung