A & P-Respiratory system Flashcards
The photograph below shows Chris Froome. He is a British cyclist and multiple Tour de France winner.
In 2015 he recorded a VO2 max score of 84.6 ml / kg / min. An average cyclist would have a VO2 max score of 40–42 ml / kg / min.
Analyse the factors which explain Chris Froome’s higher VO2 max and the effects these factors have on his performance.
(Total 8 marks)
AO1 – Knowledge of VO2 max and factors affecting this
e.g. VO2 max is maximum volume of oxygen that can be utilised per minute / unit of time. It is directly proportional to an athlete’s aerobic power. The higher your VO2 max the greater your aerobic power.
Factors that affect VO2 max include: Genetics, age, gender, physiology, training, lifestyle, body composition, drugs.
AO2 – Application of the factors affecting VO2 max to Chris Froome and comparison to average cyclist
e.g. Chris Froome has a high VO2 max due to the training he has undertaken. As a professional cyclist Froome will undergo high levels of continuous training spending hours on his bike at a time. This training will have affected his physiology, increasing his red blood cell count and the capillary density in his body.
Chris Froome’s higher VO2 max may be in part due to his age. As he is still relatively young / not old age will not be a limiting factor for his VO2 max. If the average cyclist is older the impact of aging may have started to decrease their VO2 max.
AO3 – Analysis / evaluation of the impact of Chris Froome’s increased VO2 max on performance and the relevance of the factors
e.g. having a high VO2 max means that Chris Froome has an increased oxygen carrying capacity and can supply his working muscles with more oxygen, increasing his lactate threshold. This ability to work at higher intensities without OBLA occurring will mean he is able to maintain a higher average speed over the duration of a long stage compared to that of an athlete with a lower VO2 max.
Although lifestyle factors such as smoking can have an influence on VO2 max and cycling performance, the difference between Chris Froome and an average cyclist could be minimal due to the typical lifestyle of a cyclist.
VO2 max can be largely influenced by genetic factors. Had Chris Froome not been born with good genetics for endurance sport it is unlikely he would have been able to achieve such a high VO2 max from training and lifestyle choices alone.
Credit other relevant analysis of the factors affecting Chris Froome’s high VO2 max and how they will impact performance.
For effective performance, games players require oxygen to be delivered to the muscles and carbon dioxide to be removed.
Explain how oxygen is taken up by haemoglobin from the lungs and released at the muscle site.
[3 marks]
- Forms oxyhaemoglobin / Hb O2
- At lungs – high partial pressure of O2 / blood – low partial pressure of O2.
- Haemoglobin becomes saturated.
- At muscles – low partial pressure of Oxygen / O2 / blood – high partial
pressure of O2. - Hence oxygen dissociates from haemoglobin.
- Mention of myoglobin.
Describe how an increase in carbon dioxide in the blood during exercise would lead to an increased breathing rate. [3 marks]
* Increased blood acidity/decreased blood pH. (1)
* Detected by chemoreceptors. (1)
* Impulse sent to the respiratory centre/medulla. (1)
* Increased impulses to respiratory muscles to contract faster. (1)
Accept named respiratory muscles including diaphragm/intercostal muscles/scalene/ sternocleidomastoid/pectorals/abdominals.
Accept any other appropriate description of how an increase in carbon dioxide in the blood during exercise would lead to an increased breathing rate.
Explain how and why a period of continuous exercise would impact the lung volumes in the graph above.
Tidal volume
Expiratory reserve volume
Residual volume
* (Tidal volume) would increase as performer needs more oxygen to working muscles (1)
* (Expiratory reserve volume) decreases due to the increase in tidal volume (1)
* (Residual volume) will stay the same as if it decreased the lungs would be at risk of collapse/not affected by continuous exercise (1)
Accept any other appropriate explanation of how and why a period of continuous exercise would impact the lung volumes in the graph.
The table below shows tidal volumes and respiratory rates when exercising at different intensities.
Calculate minute ventilation during medium intensity exercise. [total 2 marks]
Two marks for the correct answer with correct units: 60 l/min (2)
One mark for correct workings or correct answer without units: Respiratory Rate x Tidal Volume / 30 x 2 / 60 (1)
How does exercise affect the lung volumes labelled X and Y in the graph below.
A
X: Decreases Y: Decreases
B
X: Decreases Y: Stays the same
C
X: Stays the same Y: Decreases
D
X: Stays the same Y: Stays the same
B
Describe the process of gas exchange which occurs at a muscle.
[total 3 marks]
* Oxygen diffuses from the capillary to the muscle cells and carbon dioxide diffuses from the muscle cells to the capillary (1)
* Oxygen / carbon dioxide moves from areas of high concentration/partial pressure to areas of low concentration / partial pressure (1)
* Myoglobin transports and stores oxygen in the muscle / has a higher affinity to oxygen then haemoglobin / pulls more oxygen in to the muscle (1)
Accept any other appropriate description of how gas exchange occurs at a muscle.
Which one of these statements defines expiratory reserve volume?
A
Volume of air inspired and expired per breath.
B
Volume of air inspired and expired per minute.
C
Volume of air that can be forcibly expired after a normal breath.
D
Volume of air that remains in the lungs after expiration.
C
Smoking is a poor lifestyle choice because of the negative effect it can have on health and performance.
Identify one physiological effect of smoking on the respiratory system and explain its impact on performance in endurance events.
[total 4 marks]
AO1 (Physiological effects)
Carbon monoxide binds to haemoglobin rather than oxygen (1)
Nicotine constricts the bronchioles (1)
Damaged cilia (1)
Reduction in number / damaged alveoli (1)
Physiological effects must relate specifically to the respiratory system
Sub-max 1 mark
Award one mark for each of the following points.
AO2
Reduced gaseous exchange in the lungs / oxygen transport to the muscles (1)
AO3 (Impact on performance)
This decreases the athlete’s ability to utilise oxygen in energy production / work aerobically (1). This means they have less energy for their activity / slower time / fatigue quicker (due to working anaerobically) (1).
Accept other appropriate physiological effects of smoking on the respiratory system and explanations of the impact on performance in endurance events.
The diagram below shows the partial pressure of oxygen (pO2) and carbon dioxide (pCO2) in the alveoli and blood capillary.
Consider how oxygen and carbon dioxide move between the alveoli and the blood capillary. Refer to the diagram in your answer.
[Total 4 marks]
AO1
* By a process called diffusion which is the movement of gases from a high concentration / partial pressure to a low concentration / partial pressure (1)
AO2
Oxygen
* The partial pressure of oxygen is higher in the alveoli pO2 = 104 mmHg and lower in the blood pO2 = 40mmHg (1) and so moves / from the alveoli to the blood (1)
Carbon Dioxide
* The partial pressure of carbon dioxide is higher in the blood pCO2 = 46mmHg and lower in the alveoli pCO2 = 40mmHg (1) and so moves / diffuses from the blood into the alveoli (1) Accept any other suitable consideration of how oxygen and carbon dioxide move between the alveoli and blood capillary (1)
Max 4 marks
‘Tidal volume × respiratory frequency’ is an equation.
Which one of these physiological measures does the equation allow you to calculate?
A
Expiratory reserve volume
B
Inspiratory reserve volume
C
Minute ventilation
D
Residual volume
C
Describe how poor lifestyle choices may affect the respiratory system.
[Total 3 marks]
- Lack of exercise / poor diet – reduced cardiovascular endurance – inefficient gas exchange
- Smoking - increased breathlessness / damages cells lining trachea, bronchi and bronchioles
- Excess mucus - smoker’s cough
- Breaks down alveolar walls - reduces efficiency of gaseous exchange
- Oxygen transport affected - carbon monoxide from cigarettes combines with haemoglobin in red blood cells more readily than oxygen - reduces oxygen-carrying capacity of blood
- Reduced stamina / cardio-respiratory endurance
Evaluate the impact of long-term aerobic training and lifestyle choices on the respiratory system.
(Total 8 marks)
General points
- Improvements to efficiency of respiratory system after a few weeks of aerobic training
- Increased efficiency to take in / supply O2 to muscles
Effects of training
- Increased surface area of alveoli
- Increased capillary density around alveoli / muscle
- Increased a-VO2 difference
- Respiratory muscles (named - diaphragm, intercostals, sternocleidomastoid, scalenes, abdominals) strengthened
- Increased depth of breathing / decreased breath frequency
- Increased tidal volume / minute ventilation during maximal exercise
- Increased vital capacity / inspiratory / expiratory reserve volume
- Increased VO2 max
Smoking / oxygen transport
- Decreased efficiency of respiratory system to supply O2 to muscles
- Carbon monoxide reduces amount of O2 absorbed in blood
- Haemoglobin has greater affinity to CO than O2
AO2 Award up to three marks for:
- Greater amount of O2 diffused into blood / CO2 into alveoli
- Greater gaseous exchange / increase pulmonary diffusion
- Greater saturation of haemoglobin with oxygen
- Greater amount of O2 diffused into muscle / CO2 into blood
- Greater gaseous exchange / increased muscle and tissue diffusion
- Reduces or delays respiratory muscle fatigue
- Delays OBLA or lactate threshold
- Increased aerobic endurance
Effects of smoking
- Decreased gaseous exchange or diffusion gradient
- Increased likelihood of respiratory diseases / damage to respiratory structures
- Tar coats the airways / builds up in lungs and inhibits gaseous exchange
- Narrowing of air passages causing increase in respiratory resistance
AO3 Award up to three marks for:
- Aerobic exercise improves / smoking reduces aerobic endurance
- Types of aerobic training - continuous / altitude / fartlek
- Best type of training is one that will be maintained
- HIIT possibly best
Tidal volume and minute ventilation of a cyclist will vary at rest and during a race.
Define tidal volume and minute ventilation.
[total 2 marks]
Must state which term is being defined
- Tidal volume – Amount of air breathed in or out in one breath (1)
- Minute Ventilation – Amount of air breathed in or out per minute/tidal volume x number of breaths (1)
Accept other appropriate definition of tidal volume and minute ventilation.
Explain how the cyclists’ increase in minute ventilation allows them to maintain performance throughout the race.
[Total 3 marks]
AO3
- Increased oxygen exchange in the alveoli (1)
- Increased oxygen delivery to the working muscles (1)
- Working muscles are able to work aerobically/with oxygen (1)
- Less lactic acid produced (1)
- Increased rate of removal of carbon dioxide in the alveoli (1)
Max 3 marks