Lecture 8 respiratory changes across lifespan

Question 1

what are the two types of respiration?

Answer 1

Internal and external respiration

Question 2

what is external respiration?

Answer 2

occurs between the lungs and the outside environment
supply of O2
removal of CO2

Question 3

what is internal respiration?

Answer 3

occurs between the blood and the tissues (except lungs)
supply of O2 to the cells
removal of CO2 from the cells

Question 4

how is oxygen transported?

Answer 4

mostly by haemoglobin (98.5%)

Question 5

what is TV?

Answer 5

tidal volume = the amount of air that normally moves in and out

Question 6

what is F?

Answer 6

Breathing frequency

Question 7

what is VE

Answer 7

Expiratory ventilation

Question 8

what is V

Answer 8

ventilation

Question 9

How do you work out VE (expiratory ventilation)

Answer 9

VE = TV x f

Question 10

changes in respiratory function during growth

Answer 10

• lung begins to pouch 4 weeks
• alveoli develop last 3 months of foetal life and postnatally
• lung tissue grows as respiratory function matures

Question 11

at what age does the lung grow in volume area and surface area until? why?

Answer 11

age 6-8 and this is primarily due to an increase in the number of alveoli from 17 million - 300 million

Question 12

does lung volume grow proportionally to height?

Answer 12

yes

Question 13

how often do you breath at birth and what is the rate which breathing stabilizes at?

Answer 13

birth = 40 breaths per minute

stabilizes at 16 or 17 breaths per minute

Question 14

what are the 4 changes in the respiratory function in the aged?

Answer 14

they are morphological changes (shape), lung volume, gas exchange, ventilatory pump

Question 15

what are the morphological changes which occur in the respirastory system of the aged?

Answer 15

• decrease in alveolar surface area
• elastic recoil
• chest wall becomes stiffer

Question 16

what happens if lung elastic recoil? and when does this occur?

Answer 16

this occurs in the aged. this means the lung becomes for flaccid. as it becomes less elastic its resting volume increases.

Question 17

what are the changes in the lung volume in the aged?

Answer 17

Residual volume increases 25%
VC decreases 25%
TLC stays the same or decreases 5-10%
Decrease d/t inspiratory muscle strength

Question 18

what are the changes in the gas exchange in the aged?

Answer 18

• Decrease in diffusion of O2

- No change in the diffusion of CO2

Question 19

what are the changes in the ventilatory pump in the aged?

Answer 19

• inspiratory muscle strength decreases

- decreased respiratory centre sensitivity due to reduced CNS activity