Respiratory system

Question 1

VO2 max

Answer 1

maximum rate in which oxygen can be consumed, transported and utilised by the respiratory, cardiovascular and muscular systems

Question 2

external respiration

Answer 2

process of drawing oxygen into the body and expelling carbon dioxide back into the environment

Question 3

primary contributor to airflow resistance

Answer 3

airway diameter

Question 4

boyle’s law

Answer 4

as volume increases, pressure decreases

Question 5

fick’s first law of diffusion

Answer 5

gas moves from high to low concentration regions
proportional to concentration gradient

Question 6

expiratory muscles

Answer 6

none at rest
respond to increase in demand (exercise, altitude, illness)
contribute to control of breathing rate

Question 7

perfusion

Answer 7

transport of molecules to target tissues

Question 8

purpose of capillaries being one endothelial layer thick

Answer 8

reduces diffusion distance
slows down blood flow to allow more time for gas exchange to happen

Question 9

partial pressure

Answer 9

in a mixture of gases, is the pressure exerted by each individual gas molecule

Question 10

henry’s law

Answer 10

the concentration of dissolved gas equals the partial pressure of the gas, multiplied by its solubility

Question 11

low solubility of gas=

Answer 11

less gas exchange

Question 12

tidal volume

Answer 12

the amount of air that moves in or out of the lungs with each respiratory cycle

Question 13

minute ventilation, Ve

Answer 13

tidal volume x breathing frequency

Question 14

inspiratory reserve volume

Answer 14

the amount of air that can be inhaled, above that of the normal tidal volume

Question 15

expiratory reserve volume

Answer 15

the amount of air that can be expired, below that of normal tidal volume

Question 16

residual volume

Answer 16

the volume of air that remains in the lungs after a forced, maximal exhalation
prevents lungs collapsing
gas exchange can always occur

Question 17

capacities

Answer 17

the maximal volumes of air i the lung parenchyma (functional tissue) during a specific point in the respiratory cycle

Question 18

inspiratory capacity

Answer 18

maximal volume of air that can be inspired following a normal passive expiration
inspiratory reserve volume + tidal volume

Question 19

functional residual capacity

Answer 19

volume of air in the lungs following a normal passive expiration (expiratory reserve volume + residual volume)

Question 20

forced vital capacity

Answer 20

the total volume of air that can be expired following a maximal inspiration
inspiratory capacity + expiratory reserve volume

Question 21

total lung capacity

Answer 21

the total volume of air in the lungs following a maximal inhalation
inspiratory capacity + functional residual capacity

Question 22

forced expiratory volume

Answer 22

the amount of air that can be expired within the first second of a maximally forced expiration, following a maximal inhalation

Question 23

at rest, what is inspiration and expiration controlled by

Answer 23

brainstem (pons and medulla oblongata)
pneumotaxic centre (inspiratory centre)
apneustic centre (expiratory centre)

Question 24

chemoreceptors

Answer 24

detect changes in oxygen or carbon dioxide
feeds back to the respiratory centres in brain

Question 25

peripheral receptors (carotid and aortic)

Answer 25

emergency detection for low oxygen
carotid receptors provide rapid response
pH/CO2 detection system

Question 26

central (extracellular portion of brain)

Answer 26

slower response
steady state control

Question 27

reduction in partial pressure of carbon dioxide during exercise

Answer 27

ventilation increased to remove CO2
chemoreceptors in the peripheries respond
tidal volume increases
breathing frequency increases
facilitates gas exchange
capillary volume increases

Question 28

what causes ventilatory limitation

Answer 28

altitude
lung disease, eg cystic fibrosis