Week 11

Question 1

Minute ventilation is…

Answer 1

volume of air inspired/expired in 1 minute (in L/min)

Question 2

Minute ventilation can increase by increasing ____ or ____

Answer 2

tidal volume or breathing frequency

Question 3

Minute ventilation at rest is about ___L/min

Answer 3

8-10

Question 4

Maximal rates of ventilation can exceed ___L/min in large endurance athletes

Answer 4

200

Question 5

Ventilation increases in proportion to ___ uptake at lower intensities and disproportionately more as maximum VO2 is approached

Answer 5

O2

Question 6

Circulatory & ventilatory responses to progressive exercise both involve:

Answer 6

a) A volume that is related to body mass (stroke volume, tidal volume)
b) A size-independent time-defined factor (HR, breathing frequency)

Question 7

SV +/or heart rate —>

Answer 7

CO

Question 8

Tidal volume +/or breathing frequency —>

Answer 8

Minute ventilation

Question 9

Maximal minute ventilation is not an expression of the limits of ventilatory capacity. It also reflects the influences of excessive CO2 produced by the buffering of lactate and the need to reduce ____ _____.

Answer 9

metabolic acidosis

Question 10

Vital capacity is the…

Answer 10

maximum amount of air that can be expelled from lungs during maximal inhalation

Question 11

Vital capacity increases with age in direct/indirect proportion to body size

Answer 11

direct

Question 12

Both absolute and relative (adjusted for body size) forced vital capacity is greater in ____ than _____ at ALL ages.

Answer 12

males, females

Question 13

At rest, absolute tidal volume _____ with lung growth. However, the proportion of vital capacity used for ___ ____ declines as children age

Answer 13

increases, tidal volume

Question 14

As children age, what three processes decline?

Answer 14

• Resting breathing frequency
• tidal volume as a % of vital capacity
• relative minute ventilation

Question 15

Absolute minute ventilation _____ with age.

Answer 15

increases

Question 16

At rest: Absolute increases in minute ventilation are driven by absolute increases in tidal volume whilst _____ _____ declines during childhood. However, when expressed relative to body size, resting ____ ____ decreases during childhood

Answer 16

breathing frequency, tidal volume

Question 17

Absolute maximal minute ventilation increases as lung volume increases, but it can also be influenced by maturational changes in _____ ______ and factors governing cellular acidosis.

Answer 17

lactate production

Question 18

A study found that maximal minute ventilation was relatively stable in ___ but declined in ___

Answer 18

boys, girls

Question 19

A study found a fairly stable relative maximal minute ventilation in boys. Decline after ..?

Answer 19

Teenage years

Question 20

Breathing frequency at maximal exercise slowly _____ with age during childhood, and values are independent of body size (no difference found in M vs F)

Answer 20

declines

Question 21

Absolute values of tidal volume at maximal exercise _____ with growth in accord with greater lung dimensions—> The breathing frequency (fR) to tidal volume (VT) ratio therefore falls as a child grows–>Studies unsure whether greater ratio in boys or girls

Answer 21

increase

Question 22

Maximal exercise: as children grow, maximal ______ _____ slows, and absolute maximal minute ventilation and absolute maximal tidal volume increase

Answer 22

breathing frequency

Question 23

The energy expenditure of the breathing muscles to achieve minute ventilation is influenced by both …?

Answer 23

• the compliance of the lungs and chest wall

- resistance to airflow within the airways

Question 24

The compliance of the lungs ______ during childhood, particularly in the early years, at the same time airway resistance ____

Answer 24

improves, diminishes

Question 25

Suggests, energy demands of ventilation during exercise may be greater in _________, although evidence is lacking for high intensities

Answer 25

small children

Question 26

Greater reliance on breathing frequency (as opposed to tidal volume) increases the ventilatory work needed to overcome ____ _____ (in children)

Answer 26

airway resistance

Question 27

Adults: tidal volume increases to 60% vital capacity, and at higher intensities increases are provided by increased ???????

Answer 27

breathing frequency

Question 28

Children: some evidence indicates a linear increase in tidal volume and plateau in breathing frequency at 67% peak exercise However, other evidence suggests similar patterns to adults. i.e. increase reliance on _____ -_____ at higher intensities

Answer 28

breathing frequency

Question 29

Does dead-space change with age?

Answer 29

A study found no age-related differences in dead space for a given tidal volume in boys aged 9-15, cycling at same workload

Question 30

End tidal CO2 during exercise is ______ in children than in adults

Answer 30

lower

Question 31

Lactate production is ___ in children compared with adults

Answer 31

lower

Question 32

There is ____ metabolic acidosis (i.e. higher pH) in children than adults

Answer 32

less

Question 33

Children ventilate ___ than adults during first rest intervals to exhale a given amount of CO2, allowing them to regulate their PaCO2 to a lower level.

Answer 33

more

Question 34

Do adults or children ventilate (breathe) more?

Answer 34

Children (declines with age)

Question 35

During exercise the transit time for O2 to move from the alveoli into the pulmonary capillaries is ___

Answer 35

reduced (can lead to arterial hypoxaemia)

Question 36

Ventilatory drift:

Answer 36

increases in breathing frequency and minute ventilation, but decline in tidal volume

Question 37

Ventilatory drift is generally linked to increase in...

Answer 37

metabolic heat production and core temperature

Question 38

Lung compliance is ___ and airway resistance is ___ in children, but these approach adult values in the later years

Answer 38

less, greater

Question 39

Normal arterial oxygenation is maintained in ____ at maximal exercise, but data in child athletes is lacking

Answer 39

children

Question 40

Children demonstrate characteristics of ventilatory drift during sustained steady-state exercise similar/different to adults

Answer 40

similar

Question 41

During childhood, increases in absolute minute ventilation at rest are driven by..?

Answer 41

Increases in absolute tidal volume

Question 42

When considering maximal exercise, what happens to the breathing frequency to tidal volume ratio as children grow?

Answer 42

It falls, i.e. greater dependence on increases in tidal volume during exercise

Question 43

Why might the energy demands of ventilation during exercise be greater in small children compared with older children or young adults?

Answer 43

Greater airway resistance