Respiratory 3

Question 1

What are lung compliance and recoil?

Answer 1

How easily an elastic material can be stretched or inflated

Recoil: the ability of an elastic material to get back into its original position after stretching (inversely related to compliance)

Question 2

What is Emphysema in regard to compliance and recoiling?

Answer 2

disease with high compliance: (lungs stretch easily based on the pressure of the lung wall (P tp, transpulmonary)

more dead space, less O2 in alveoli?

-> expiration difficult

Question 3

What is the Compliance-recoil relation in fibrosis?

Answer 3

shows low compliance and high recoil (inspiration difficult)

Question 4

What is the relation between surface tension and pressure?

Answer 4

greater radius -> less pressure -> lower probability for the alveoli to collapse

smaller radius -> more pressure -> smaller alveoli tend more to collapse

Question 5

How does the lung prevent alveoli to collapse?

Answer 5

reduction of surface tension through surfactants produced by alveoli cell type 2

reminder: alveoli cell type 1 makes up the wall of the alveoli

Question 6

How is airway resistance defined?

Answer 6

R aw = delta Pressure / V (of air taken)

contraction of smooth muscle will increase Resistance
dilation will decrease R

Question 7

Which NS controls air resistance? (When we need more O2)

Answer 7

FIGHT OR FLIGHT: sympathetic
ß2 receptors: dilate bronchioles and relax smooth muscles in walls of airways

Question 8

How can lung capacity be measured?

Answer 8

Spirometer -> the amount of water you push away
the graph (output): Vol vs time -> Spirogram

Question 9

What is the tidal volume (TV)? (EXAM)

What is the inspiratory reserve volume (IRV)? (EXAM)

Answer 9

TV: the air we breathe in and out normally with each breathe (500 ml)

IRV: the amount of volume we can breathe in beyond the tidal volume (2100-3200 ml)

Question 10

What is the expiratory reserve volume (ERV)? (EXAM)

What is the residual volume (RV)?

Answer 10

(ERV): air that can be evacuated after tidal expiration (1000-1200 ml)

RV: air left in the lungs after strenuous expiration (there will always be air left)

Question 11

What is the inspiratory capacity (IC)?

What is the functional residual capacity (FRC)?

Answer 11

The total amount of air we can inspire after a tidal expiration (IRV + TV)

Amount of air remaining after a tidal expiration (ERV+RV)

Question 12

What is the vital capacity (VC)?

What is the total lung capacity (TLC)?

Answer 12

VC: the total amount of exchangeable air (TV + IRV + ERV)

TLC: sum of all lung volumes (6000 in males)

Question 13

Alveolar ventilation
similar to CO = SV * HR

Answer 13

Amount of air we breathe in and out in a minute:
Tidal volume (ml/breathe) * respiration rate (breaths/min) -> ml/min
- MINUS dead space: 150 * respiration rate

Reminder: CO: the amount of blood forced out of the heart by each ventricle per minute

Question 14

How is the area called where air doesn’t reach the alveoli? (EXAM)

Answer 14

dead space, air that stays in conduction airway, no alveoli (150 ml)

Question 15

How would you calculate alveoli ventilation? (EXAM)

Answer 15

TV * respiration rate MINUS dead space * respiration rate

Question 16

How is the lung itself supplied with oxygenated blood?

Answer 16

Through bronchial arteries arising from aorta, doesn´t supply alveoli with blood

Question 17

Explain the ventilation (airflow) - perfusion (blood flow) inequality!

Answer 17

The upper area of the lung has lower blood flow (due gravity) -> low partial pressure of CO2 (because less CO2-rich blood goes there) ->causing bronchoconstriction -> causing decreased airflow in that area

Question 18

What happens in areas that have decreased airflow? (due to disease)

Answer 18

Hypoxic pulmonary vasoconstriction

Less blood will be sent to this area, due to vasoconstriction -> because there is less airflow there (pO2 low)

Question 19

What drives the movement of gases between tissues, blood, and alveoli?

Answer 19

partial pressure, it goes from high pressure to low pressure and it flows until partial pressure in two areas are equalized

Question 20

What is hyperventilation?

Answer 20

increased alveolar ventilation -> through increased respiratory rate or tidal volume (it’s better to increase volume when you efficiently want to increase your rate=: more O2 to alveoli and more CO2 removed

f.e.: exercise

Question 21

What is hypoventilation?

Answer 21

reduced alveolar ventialtion -> less O2 in alveoli and less CO2 removed (more CO2)

f.e.: taking oxicodon; respiratory depression

Question 22

At what point is hemoglboin completley saturated?

Answer 22

at about 100 mm Hg, all 4 heme groups carry O2
(at the pulmonary venous end, when blood receives O2)

Question 23

At what point is blood considered deoxygenated?
How saturated is blood according to dissociation curve

Answer 23

in the venues of systemic circulation,
with the partial pressure of 40 mmHg, still saturated to 80%

Question 24

What is the effect of Hemoglobin in terms of partial pressure?

Answer 24

Hemoglobin and bound O2 do not contribute to partial pressure -> Hb will increase the amount of O2 to establish equilibrium again, which was pushed out of balance because of bound O2 to hemoglobin not contributing to partial pressure anymore

Question 25

Movement of oxygen from the lung to tissue:

Answer 25

O2 moves from alveoli to pulmonary capillary: 2% stays dissolved in plasma, 99% goes into the blood and binds to Hb -> HbO2 (oxyhemoglobin)

in tissue capillary: HbO2 releases O2 -> dissolved O2 moves from tissue capillary plasma to tissue

Question 26

What affects the release process of O2 from hemoglobin?
(EXAM)

Answer 26

Temperature and pH

Temperature: when we increase temperature, hemoglobin is more act to let go O2 -> makes sense: metabolic active tissues create heat, which facilitates Hb letting go of O2

pH = -log[H+], so as H+ goes up and acidity increases it facilitates Hb letting go O2
makes sense: metabolic active tissues sometimes create acid: f.e lactic acid

Question 27

Why is Hb affected by pH and temperature?
(EXAM)

Answer 27

Because it is a protein, and pH and temp. affects the function of proteins