the respiratory system

Question 1

the pathway of air:

Answer 1

nose -> pharynx -> larynx -> trachea -> bronchi and bronchioles -> alveoli

Question 2

what are the 2 main functions of the respiratory system

Answer 2

1. pulmonary ventilation - the inspiration and expiration of air
2. gaseous exchange - external respiration = the movement of oxygen into the bloodstream and co2 into the lungs - internal respiration = the release of oxygen respiring cell for energy production and collection of waste products

Question 3

what is the relationship between breathing frequency, tidal volume and minute ventilation

Answer 3

minute ventilation = tidal volume x breathing frequency

Question 4

what was the average values at rest of breathing frequency

Answer 4

12 breathes per minute

Question 5

what was the average values at rest of tidal volume

Answer 5

0.5 litres

Question 6

what was the average values at rest of minute ventilation

Answer 6

6 l/min

Question 7

what is the value for endurance athletes of breathing frequency

Answer 7

10 breathes per minute

Question 8

what is the value for endurance athletes of tidal volume

Answer 8

0.5 litres

Question 9

what is the value for endurance athletes of minute ventilation

Answer 9

5 l/min - respiratory system is more efficient

Question 10

what is the definition of breathing frequency

Answer 10

the amount of breaths taken per minute
units = breath peer minute

Question 11

what is the definition of tidal volume

Answer 11

the amount of air per breath
units = ml

Question 12

what is the definition of minute ventilation

Answer 12

the volume of air inspired or expired per minute
units = l/min

Question 13

what happens in terms of the mechanics of breathing with inspiration

Answer 13

When we inhale the intercostal muscles (between the ribs) and diaphragm contract to expand the chest cavity. The diaphragm flattens and moves downwards and the intercostal muscles move the rib cage upwards and out. This increase in size decreases the internal air pressure and so air from the outside (at a now higher pressure than inside the thorax) rushes into the lungs to equalise the pressures.

Question 14

what happens in terms of the mechanics of breathing with expiration

Answer 14

When we exhale the diaphragm and intercostal muscles relax and return to their resting positions. This reduces the size of the thoracic cavity, thereby increasing the pressure and forcing air out of the lungs.

Question 15

what is the tidal volume on a spirometer

Answer 15

the amount of air that moves in or out of the lungs with each respiratory cycle. It measures around 500 mL in an average healthy adult male and approximately 400 mL in a healthy female.

Question 16

what is the inspiration reserve volume on a spirometer

Answer 16

The extra volume of air that can be inspired with maximal effort after reaching the end of a normal, quiet inspiration

Question 17

what is the expiratory reserve volume on a spirometer

Answer 17

The extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration

Question 18

what is the vital capacity on a spirometer

Answer 18

the greatest volume of air that can be expelled from the lungs after taking the deepest possible breath.

Question 19

what is the residual volume on a spirometer

Answer 19

the volume of air that cannot be expelled from the lungs, thus causing the alveoli to remain open at all times.

Question 20

what is the total lung capacity on a spirometer

Answer 20

the volume of air in the lungs upon the maximum effort of inspiration

Question 21

how do we increase breathing depth and rate (during exercise) for inspiration

Answer 21

we recruit two additional muscles to allow us to increase the depth of breathing:
-sternocleidomastoid -> muscle in the neck attached to the sternum. Helps lift the rib cage higher
-pectoralis minor -> muscle in the chest, attached to top of rib cage helps lift rib cage higher
= result is the volume of the thoracic cavity increases more than at rest and therefore larger pressure difference and more air rushes in

Question 22

how do we increase breathing depth and rate (during exercise) for expiration

Answer 22

two muscles which help increase the pressure on the thoracic cavity:
-internal intercostals -> muscle on the inside of the rib cage, helps squeeze the ribs back towards the lungs
-rectus abdominus -> abdominal muscles work in conjunction with diaphragm to squeeze the lungs from below
= result in the volume of the thoracic cavity is decreased more than at rest and therefore more pressure is put on the lungs and more air rushes out.

Question 23

what is the respiratory control centre (RCC)

Answer 23

situated in the brain and controls respiration rate depth

Question 24

what is the inspiratory centre (IC)

Answer 24

the part of the RCC that controls inspiration

Question 25

what is the expiratory centre (EC)

Answer 25

the part of the RCC that controls expiration

Question 26

what is the phrenic nerve

Answer 26

the nerve that stimulates the diaphragm to contract

Question 27

what is the intercostal nerve

Answer 27

the nerve that stimulates the external intercostals to contract

Question 28

how do the RCC, EC, IC all work together to allow breathing

Answer 28

1. the bodies neural and chemical control detect changes (chemo, bar etc) 2. these then inform the rcc which controls the IC and the EC 3. the IC increases stimulation of the phrenic and intercostal nerves so the diaphragm and intercostals contract with more force. This also stimulates the additional muscles ( sterno.. & pectorals minor) to contract. Volume of chest cavity increase pressure drops, air rushes in.

Question 29

what is the definition of gaseous exchange

Answer 29

the movement of oxygen and carbon dioxide at the lungs and at the muscles by the process of diffusion

Question 30

what is the definition of diffusion

Answer 30

the movement of gas down a diffusion gradient from am area of high partial pressure to an area of low partial pressure

Question 31

what is the diffusion gradient

Answer 31

the difference between the two pressures. The diffusion gradient is like a slide and the gases travel from top to bottom. ( steepness -> slower, faster)

Question 32

what is the definition of partial pressure

Answer 32

the pressure a gas exerts within a mixture of gases. Can be written ppo2 or ppco2

Question 33

what are the two types of gaseous exchange that occur

Answer 33

external respiration and internal respiration

Question 34

where do the two types happen

Answer 34

external - at the lungs internal - at the muscles

Question 35

what is the gaseous exchange between

Answer 35

external - alveoli and capillaries internal - capillaries and muscles

Question 36

the movement of o2

Answer 36

external - from: alveoli to: capillaries internal - from: capillaries to: muscles

Question 37

the movement of co2

Answer 37

external - from: capillaries to: alveoli internal - from: the muscles to: the capillaries

Question 38

how does the oxygen move during gaseous exchange

Answer 38

external - there is a higher ppO2 in the alveoli than the blood. O2 travels down diffusion gradient into blood internal - higher ppCO2 in the blood than in the muscles . CO2 moves down the diffusion gradient into the muscles

Question 39

how does the carbon dioxide move during gaseous exchange

Answer 39

external - higher ppco2 in blood than alveoli o2 travels down diffusion gradient into alveoli internal - higher ppCO2 in the muscle than blood. Co2 travels down the diffusion gradient into the blood

Question 40

describe the effect of exercise on gaseous exchange at the alveoli (4marks)

Answer 40

more oxygen is used during exercise so the deoxygenated blood returning to the lungs has a lower pp02 than at rest. Therefore there is a steeper diffusion gradient between alveoli and blood. This causes a faster and more efficient gaseous exchange and more 02 moves from the alveoli and combines with the haemoglobin in the blood. muscles are producing more Co2 during exercise. Deoxygenated blood returning to the lungs has a higher ppCo2 than at rest. therefore there is a steeper gradient between the blood and the alveoli. This causes faster and more efficient gaseous exchange and more Co2 moves from the blood into alveoli to be expired.

Question 41

what is the definition of association

Answer 41

when 02 combines with haemoglobin through diffusion at the lungs to give oxyhemoglobin.

Question 41

what is the definition of saturated

Answer 41

the amount of oxygen combined with haemoglobin usually expressed as a % and depends on pp02. haemoglobin is 100% saturated at lungs

Question 42

what is the definition of disassociation

Answer 42

when 02 releases from haemoglobin through diffusion at the muscles

Question 43

what is the definition of oxyhemoglobin dissociation curve

Answer 43

shows us the relationship between pp02 and % saturation of haemoglobin

Question 44

what is the definition of affinity

Answer 44

how much the 02 wants to associate. 02 will associate slowly so start with and then increase

Question 45

the oxyhemoglobin dissociation curve at rest

Answer 45

- at the lungs haemoglobin is 100% saturated with 02 - at the muscles haemoglobin is 75% saturated with 02 - at rest, 25% of 02 dissociates with haemoglobin and diffuses into muscles

Question 46

the oxyhemoglobin dissociation curve during exercise

Answer 46

the curve changes and moves -> this is because during exercise we increase the levels of co2 in the blood and therefore this lowers the affinity of the 02 with the haemoglobin - it takes longer for association to take place and therefore longer for the graph to show 100% saturation

Question 47

what happens to the oxyhemoglobin curve as exercise intensity increases

Answer 47

1. oxygen - > the muscles are using more 02, so decreased pp02 inside the muscle. Therefore there is a steeper diffusion gradient between the blood and muscle. This causes more 02 to dissociate from haemoglobin. 2. carbon dioxide - > the muscles are producing more co2, so increased ppco2 inside the muscles. Therefore there is a steeper diffusion gradient between the muscle and blood. This causes more co2 to diffuse into the blood. 3. Body Temperature - > the BT increases, o2 is more likely to dissociate from the haemoglobin 4. Acidity - > lactic acid and carbonic acid increases acidity levels in the blood. This makes o2 more likely to dissociate haemoglobin. when acidity increases.