November 1, 2023

Question 1

VT =

Answer 1

tidal volume (about 500mls)

VT = VD (dead space ventilation/about equal to body weight in pounds; pounds to mls) + VA (alveolar ventilation/gas exchange)

Question 2

Vital capacity?

Answer 2

inspire as much as possible and then expire as much as possible

VC = IRV + VT + ERV

Question 3

Inspiratory capacity =

Answer 3

maximal inspiration above normal inspiration

IC = VT + IRV

Question 4

TLC =

Answer 4

RV + ERV + VT + IRV

Question 5

Residual volume (about 20%) =

Answer 5

air remaining in the lung at all times

Question 6

what is the formula for minute ventilation (VE)

Answer 6

VE = VT x F

F = frequency = 12 breaths/min

Question 7

why is Total minute ventilation reduced in Trained people during submaximal exercise

Answer 7

Total minute ventilation is reduced because…

Produce less lactic acid, less acidosis, lower pH change, lower hydrogen ion concentration (high H+ drive increase in ventilation); greater reliance on aerobic system

Decreased sensitivity to neural and chemical CO2 and H+ that drives an increase in VE (doesn’t respond to the same degree)

Question 8

why is Total minute ventilation is higher in untrained people during submaximal exercise

Answer 8

Ventilate at a higher rate

Question 9

what are the characteristics of Minute Ventilation (VE) During graded exercise to VO2 max (Trained people):

Answer 9

Ventilate at a lower rate during submaximal exercise

Curve is shifted to the right

Ventilatory threshold is at 70-80% of VO2 max

Have stronger respiratory muscles

160L/min of air

Question 10

what are the characteristics of Minute Ventilation (VE) During graded exercise to VO2 max (Untrained people):

Answer 10

Ventilate at a higher rate

Ventilatory threshold is at 50-60% of VO2 max

140L/min of air

Ventilatory threshold is at lactate threshold

Question 11

True or False: Minute ventilation keeps going up even as VO2 plateaus

Answer 11

True

(VE does not limit VO2 max; lung is not a physiological factor)

Question 12

True or False: First depth increases (taking advantage of reserve volumes), but not frequency; when we get to 50% of VO2 max, then the frequency starts going up

Answer 12

true

Question 13

PB (barometric pressure) =

760 mmHg =

Answer 13

sum of partial pressures of gases

PN2 + PO2 + PH2O + PCO2

Question 14

Partial pressure =

Answer 14

fraction of the gas in the air x PB

Question 15

PI =

Answer 15

pressure of air inspired

PO2= 160
PCO2 = 0.3

Question 16

PA =

Answer 16

pressure in alveoli

PO2= 105
PCO2 = 40

Question 17

Pa =

Answer 17

arterial pressure (pressure in blood)

PO2= 100
PCO2 = 40

Question 18

PT =

Answer 18

pressure in tissue

PO2= 5
PCO2 = >50

Question 19

hypoxemia

Answer 19

Low PaO2 (less than 100)

Question 20

Hypercapnia

Answer 20

high PaCO2 concentration

due to the inability of the lung to clear CO2, can lead to respiratory acidosis and loss of consciousness (want to maintain CO2 around 40)

Question 21

acidosis

Answer 21

The more H+ the more acidic your blood

Question 22

Hypocapnia:

Answer 22

Due to hyperventilation, can lead to alkalosis, brain blood vessel constriction, dizziness, loss of consciousness

Blowing off excess CO2 (not driven by metabolism)

CO2 is a vasodilator (keeps blood vessels open)

Hypocapnia = constriction

Question 23

what are the 5 barriers for diffusion of gases at the lung

Answer 23

alveolar membrane

interstitial fluid

capillary membrane

Plasma

red blood cell

O2 and CO2 move in opposite directions of each other through these barriers

Question 24

what are the effects of acute exercise on capillaries

Answer 24

HR goes up, stroke volume goes up, mean arterial pressure goes up

All of these things open up capillaries

Diffusion capacity plateaus when all capillaries are open

Question 25

what are the effects of endurance training on capillaries

Answer 25

Diffusion capacity is higher than untrained

Because at rest, a trained person has more capillaries (whether open or closed)

Training increases lung capillary angiogenesis (making more capillaries)

This means greater diffusion of O2 at rest