Respiratory system

Question 1

Define tidal volume

Answer 1

Volume of air inspired and expired per breath

Question 2

What is the resting tidal volume for trained and untrained individuals?

Answer 2

Trained = 500ml
Untrained = 500ml

Question 3

What is the maximal tidal volume for trained and untrained individuals?

Answer 3

Trained = 3-3.5l
Untrained = 2.5-3l

Question 4

Define breathing rate

Answer 4

Number of breathes per minute

Question 5

What is the resting breathing rate for trained and untrained individuals?

Answer 5

Trained = 11-12 breaths per minute
Untrained = 12-15 breaths per minute

Question 6

What is the maximal breathing rate for trained and untrained individuals?

Answer 6

Trained = 50-60 breaths per minute
Untrained = 40-50 breaths per minute

Question 7

Define minute ventilation

Answer 7

Volume of air inspired/expired per minute
Tidal volume X Breathing rate = Minute ventilation

Question 8

What is the resting minute ventilation for trained and untrained individuals?

Answer 8

Trained = 5.5-6 l/min
Untrained = 6-7.5 l/min

Question 9

What is the maximum minute ventilation for trained and untrained individuals?

Answer 9

Trained = 160-210 l/min
Untrained = 100-150 l/min

Question 10

What happens during inspiration at rest?

Answer 10

Diaphragm (flattens) and external intercostals contract
Ribs move up and out
Volume increases
Pressure inside the lungs becomes lower than outside
Air rushes into the lungs to equal the pressure

Question 11

What happens during inspiration during exercise?

Answer 11

Diaphragm (flattens), external intercostals, sternocleidomastoid and pectoralis minor contract
Ribs move up and out further
Volume increases greater
Pressure inside the lungs becomes lower than at rest than outside
More air rushes into the lungs to equal the pressure (increases the depth of breathing)

Question 12

What happens during expiration at rest?

Answer 12

Diaphragm (curves) and external intercostals relax
Ribs move down and in
Volume decreases
Pressure inside the lungs becomes higher than outside
Air rushes out of the lungs to equal the pressure

Question 13

What happens during expiration during exercise?

Answer 13

Diaphragm (curves) and external intercostals relax, and internal intercostals and rectus abdominus contract
Ribs move down and in further with force
Volume decreases more
Pressure inside the lungs becomes higher than at rest than outside
More air rushes out of the lungs to equal the pressure (increases the rate of breathing)

Question 14

What regulates breathing rate and depth?

Answer 14

Respiratory regulation centre

Question 15

What does the inspiratory centre do?

Answer 15

Stimulates inspiratory muscles to contract at rest/exercise

Question 16

What does the expiratory centre do?

Answer 16

Stimulates expiratory muscles to contract during exercise

Question 17

What happens to the RCC at rest?

Answer 17

Nerve impulses stimulate the inspiratory muscles
Intercostal nerve - external intercostals
Phrenic nerve - diaphragm

Question 18

What control mechanisms tell the RRC what to do during exercise?

Answer 18

Chemoreceptors: decrease oxygen and increase carbon dioxide and blood acidity
Thermoreceptors: increase in blood temp
Proprioceptors: detect motor activity
Baroreceptors: detect pressure changes

Question 19

What happens during inspiration (inspiratory centre)?

Answer 19

Chemo, proprio and thermo receptors send info to the RRC.
IC will increase the stimulation of diaphragm and intercostals
IC also recruits sternocleidomastoid and pectoralis minor to contract (increase depth of inspiration)

Question 20

What happens during expiration (expiratory centre)?

Answer 20

Baroreceptors sends info the the EC.
Stimulates internal intercostals and rectus abdominus
Increase rate of breathing

Question 21

Where do gases exchange during internal respiration?

Answer 21

Capillary blood - muscle cell = oxygen
Muscle cell - capillary blood = carbon dioxide

Question 22

Where do gases exchange during external respiration?

Answer 22

Alveoli - capillary blood = oxygen
Capillary blood - alveoli = carbon dioxide

Question 23

Describe external respiration at rest

Answer 23

Oxygen moves from a high pp in alveoli to a low pp in the capillary blood
Carbon dioxide moves from a high pp in capillary blood to a low pp in the alveoli

Question 24

Describe internal respiration at rest

Answer 24

Oxygen moves from a high pp in the capillary blood to a low pp in muscle cell
Carbon dioxide from a high pp in the muscle cells to a low pp in capillary blood

Question 25

What happens to both external and internal respiration during exercise?

Answer 25

Diffusion happens at a faster rate as the diffusion gradient steepens

Question 26

How many oxygen molecules can 1 haemoglobin carry?

Answer 26

4

Question 27

What happens to haemoglobin in lower partial pressures of oxygen?

Answer 27

Haemoglobin easily dissociates from oxygen

Question 28

What is the Bohr Shift?

Answer 28

A move to the right of the oxyhaemoglobin due to a higher dissociation of oxygen from haemoglobin.

Question 29

Why does the Bohr Shift occur?

Answer 29

Decrease in partial pressure of oxygen
Increase in partial pressure of carbon dioxide
Increase production of lactic acid and carbonic acids
Decrease in pH
Increase in blood and muscle temperature

Question 30

What is the impact of performance of the Bohr shift?

Answer 30

At any given partial pressure of oxygen the percentage saturation of oxyhaemoglobin is lower.
The dissociation of oxygen to respiring tissues is higher.
This enhances volume of oxygen available for diffusion.