Respiratory System Extras

Question 1

What are the two main functions of the respiratory system?

Answer 1

Pulmonary Ventilation (inspiration and expiration) and Gaseous Exchange (internal and external respiration)

Question 2

Describe the pathway of air into the lungs

Answer 2

nasal cavity > pharynx > larynx > trachea > bronchi > bronchioles > alveoli

Question 3

Describe the alveoli

Answer 3

one cell thick and lined with fluid

Question 4

2 ways oxygen can be transported

Answer 4

Haemoglobin (97%) and blood plasma (3%)

Question 5

3 ways carbon dioxide can be transported

Answer 5

Water (as carbonic acid - 70%), haemoglobin (23%) and blood plasma (7%)

Question 6

What is f and what is it measured in?

Answer 6

Breathing rate (breaths per minute)

Question 7

What is the resting rate of f?

Answer 7

12-15 breaths per minute

Question 8

What is TV and what is it measured in?

Answer 8

Tidal Volume (ml)

Question 9

What is an average resting TV?

Answer 9

500ml

Question 10

What is VE and what is it measured in?

Answer 10

Minute Ventilation (l/min)

Question 11

What is an average resting VE?

Answer 11

7.5l/min or 7500ml/min

Question 12

Equation for VE

Answer 12

f x TV = VE

Question 13

Mechanics of inspiration at rest

Answer 13

• External intercostals contract to lift the rib cage up and out
• Diaphragm contracts and flattens
• Thoracic cavity volume increases
• Pressure decreases
• Air rushes into the lungs

Question 14

Mechanics of inspiration during exercise

Answer 14

• additional muscles recruited for more force (sternocleidomastoid and pectoralis minor)
• rib cage moves up and out more
• thoracic cavity volume increases more
• pressure decreases more
• more air rushes into the lungs

Question 15

Mechanics of expiration at rest

Answer 15

• this is a passive process
• External intercostals relax to lower the rib cage down and in
• Diaphragm relaxes and domes
• Thoracic cavity volume decreases
• Pressure increases
• Air rushes out of the lungs

Question 16

Mechanics of expiration during exercise

Answer 16

• this is an active process
• additional muscles recruited for more force (internal intercostals and rectus abdominis)
• rib cage moves down and in more
• thoracic cavity volume decreases more
• pressure increases more
• more air rushes out of the lungs

Question 17

RCC

Answer 17

Respiratory Control Centre

Question 18

IC

Answer 18

Inspiratory centre

Question 19

EC

Answer 19

Expiratory centre

Question 20

What is the role of the IC?

Answer 20

stimulates inspiratory muscles to contract at rest and during exercise

Question 21

What is the role of the EC?

Answer 21

inactive at rest but stimulates additional expiratory muscles to contract during exercise

Question 22

Where does the intercostal nerve go?

Answer 22

External intercostals

Question 23

Where does the phrenic nerve go?

Answer 23

Diaphragm

Question 24

What is the role of chemoreceptors and where are they located?

Answer 24

located in the aorta and carotid arteries - they detect an increase in blood acidity levels, increase in CO2 concentration and decrease in O2 concentration

Question 25

What is the role of thermoreceptors?

Answer 25

detect increased blood temperature

Question 26

What is the role of proprioceptors?

Answer 26

detect motor activity in the muscles and joints

Question 27

What is the role of baroreceptors and where are they located?

Answer 27

located in the lung tissue and bronchioles - they detect lung inflation

Question 28

How is the IC stimulated?

Answer 28

Chemoreceptors, thermoreceptors and proprioceptors inform the IC about exercise levels so the additional muscles can be recruited and contract with more force

Question 29

How is the EC stimulated?

Answer 29

Baroreceptors inform the EC about excessive stretch on the lung walls so the additional expiratory muscles can be recruited and contract with more force

Question 30

What is Gaseous Exchange?

Answer 30

movement of gases across a membrane

Question 31

What is the impact of exercise on gaseous exchange?

Answer 31

There will be a steeper diffusion gradient which will increase the rate of diffusion

Question 32

What is external respiration?

Answer 32

exchange of gases between the lungs (alveoli) and the blood

Question 33

What happens to O2 during external respiration?

Answer 33

it moves from a high pp in the alveoli into the low pp in the blood down the diffusion gradient

Question 34

oxygen + haemoglobin

Answer 34

oxyhaemoglobin

Question 35

What happens to CO2 during external respiration?

Answer 35

it moves from a high pp in the blood to the low pp in the alveoli down the diffusion gradient

Question 36

carbon dioxide + haemoglobin

Answer 36

carbaminohaemoglobin

Question 37

What is internal respiration?

Answer 37

exchange of gases between the blood and the muscles

Question 38

What happens to O2 during internal respiration?

Answer 38

it moves from the high pp in the blood to the lower pp in the muscles down the diffusion gradient

Question 39

What happens to CO2 during internal respiration?

Answer 39

it moves from the high pp in the muscles to the lower pp in the blood down the diffusion gradient

Question 40

What happens to O2 and CO2 during external respiration during exercise?

Answer 40

they diffuse quicker because the diffusion gradient steepens due to the change in partial pressure

Question 41

What happens to O2 and CO2 during internal respiration during exercise?

Answer 41

they diffuse quicker because the diffusion gradient steepens due to the change in partial pressure

Question 42

What happens to the oxyhaemoglobin dissociation curve during exercise?

Answer 42

it shifts to the right

Question 43

What makes the oxyhaemoglobin dissociation curve shift to the right?

Answer 43

- decrease in partial pressure of oxygen - increased temperature, blood acidity levels and CO2 levels (Bohr shift)

Question 44

What happens to the oxyhaemoglobin dissociation curve during recovery?

Answer 44

it shifts to the left

Question 45

What makes the oxyhaemoglobin dissociation curve shift to the left?

Answer 45

- increased partial pressure of oxygen - decreased temperature, blood acidity levels and CO2 levels

Question 46

What happens to breathing rate (f) during exercise?

Answer 46

it increases linearly with exercise intensity levels until it plateaus at around 50-60 breaths per minute

Question 47

What happens to breathing rate (f) during sub-maximal exercise?

Answer 47

it can plateau because the oxygen supply has met the demand

Question 48

What happens to tidal volume (TV) during exercise?

Answer 48

it increases linearly with exercise intensity until it plateaus at around 3 litres

Question 49

What happens to tidal volume (TV) during sub-maximal exercise?

Answer 49

it plateaus because increased breathing rate does not allow enough time to increase tidal volume

Question 50

What happens to minute ventilation (VE) during exercise?

Answer 50

it increases linearly with exercise intensity

Question 51

What happens to minute ventilation (VE) during sub-maximal exercise?

Answer 51

1. initial anticipatory rise 2. rapid increase at the start 3. plateaus throughout sustained activity as supply has met demand 4. rapid then more gradual decrease

Question 52

What happens to minute ventilation (VE) during maximal exercise?

Answer 52

1. initial anticipatory rise 2. rapid increase at the start 3. VE continues to increase due to growing demand for oxygen 4. rapid then more gradual decrease