Respiratory system (quiz)

Question 1

Outline how oxygen is transported in the blood. (2)

Answer 1

Combines with or in haemoglobin
Dissolved in plasma

Question 2

Define the terms breathing frequency and tidal volume and give a resting value for each. (6)

Answer 2

Breathing frequency
The number of inspirations or expirations per minute
11-15breaths/minute
Tidal volume:
The volume of air inspired or expired per breath
500ml
Minute Ventilation:
The volume of air inspired or expired per minute
5.5 - 7.5 litres/minute

Question 3

Describe the process of oxygen diffusion at the alveoli during exercise (6)

Answer 3

oxygen diffuses from the alveoli to the blood down the diffusion gradient
there is a high partial pressure of oxygen in the alveoli
during exercise muscles usemoreoxygen
so… there is a lower partial pressure of oxygenin the blood
there is a larger or steeper diffusion gradient of oxygen
moreoxygen diffuses or moves from the alveoli to the blood

Question 4

An athlete has a tidal volume of 0.5 litres and a breathing frequency of 12 breaths per minute. Calculate the athlete’s minute ventilation using these values. Show your workings. (2)

Answer 4

Minute ventilation = tidal volume x breathing frequencyor0.5 x 12
6 L/min

Question 5

During a 5000 metre race, the athlete’s tidal volume increases. Explain how neural control of breathing causes this to happen (2)

Answer 5

Receptors to respiratory control
Inspiratory centre stimulates nerves to increasedepthof breathing
Phrenic nerve stimulates diaphragm to contractmorestrongly
Intercostal nerves stimulate external intercostals to contractwithmoreforce
Recruitment of Sternocleidomastoid

Question 6

Explain why the minute ventilation of the trained individual is lower at rest than that of the untrained individual. (3)

Answer 6

More efficient gas exchange at alveoli
More efficient transport of oxygen
More efficient use of oxygen at muscles

Question 7

Tidal volume changes during exercise and recovery. Describe the role of proprioceptors in the control of these changes (3)

Answer 7

During exercise
Proprioceptors detect movement
Send messages to respiratory control centre
Increasedstimulation of diaphragm and respiratory muscles
During recovery
Proprioceptors detect that movement has stopped or reduced
Reducedstimulation of diaphragm and respiratory muscles

Question 8

During exercise the working muscles have an increased need for oxygen. Assess how changes in the pressure gradient and the dissociation of oxyhaemoglobin affect oxygen diffusion at the working muscles during exercise. (6)

Answer 8

Gradient is steeper or increased
pp of O2in working muscles is reduced
Because the working muscles are using more O2foraerobic respiration
Diffusion of O2from capillary to muscle is increased
More O2diffuses into the muscle
Gradient is steeper or increased
pp of O2in working muscles is reduced
Because the working muscles are using more O2foraerobic respiration
Diffusion of O2from capillary to muscle is increased
More O2diffuses into the muscle

Question 9

Describe the mechanics of breathing which cause inspiration at rest (3)
10

Answer 9

Externalintercostals contractanddiaphragm contracts and flattens
Upwardandoutward movement of the rib cage
This increases the volume of the thoracic cavity
Causing a reduction in pressure in the lungs
Gases moves from an area of high to low pressure

Question 10

Explain why a trained athlete will have a lower minute ventilation at rest than an untrained individual, despite having identical tidal volumes (2)

Answer 10

More efficient O2gaseous exchange
Higher Red blood cell count
Lower breathing frequency

Question 11

Compare the process of gas exchange at the muscles during exercise to resting conditions (4)

Answer 11

During exercise the partial pressure O2is lower in muscles than at rest
During exercise the partial pressure CO2is higher in muscles than at rest
Steeper diffusion gradient during exercise
More O2 diffuses at a faster rate during exercise
Oxyhaemoglobin dissociation curves shifts to right during exerciseorBohr shift
Haemoglobin dissociates O2more readily to muscles during exercise

Question 12

During exercise the mechanics of breathing change. Explain the role of the sternocleidomastoid muscle in respiration during exercise. (4)

Answer 12

Contraction of sternocleidomastoid during inspiration
Causes rib cage to move up and out
Causes a greater increase in volume of thoracic cavity
Causes a greater drop in pressure in lungs
Causes more air to be drawn into lungs
Relaxation of sternocleidomastoid during expiration
Allows rib cage to move down and in

Question 13

Analyse the changes in the mechanics of breathing as exercise increases which would enhance the performance of an endurance swimmer. (4)

Answer 13

Externalintercostals and diaphragm contract with more forcewhichincreases the volume of thoracic cavitymore
Causing a greater decrease in pressure in the lungswhich meansmore air enters lungs
Sterncleidomastoid assistwhich meanslower pressure and therefore more air in
Internal intercostals contract toreducevolume of thoracic cavity
Causing increase in pressure in the lungswhich meansair is forced out of the lungs
Expiration becomes anactiveprocess to increase breathing rate
Greater volumes of air in/outmeansmore gas exchange and therefore more O2to working muscles

Question 14

Describe the mechanics of breathing for inspiration at rest. (4)

Answer 14

Externalintercostals contract
Diaphragm contracts or flattens
Pulls or moves the rib cage upandout
Increasing the volume of the thoracic cavity or thorax or lungs
Decreasing the pressure within thoracic cavity or thorax or lungs
Forcing air into the lungs

Question 15

Describe the mechanics of breathing for inspiration during exercise. (5)

Answer 15

Air moves from high to lowpressure
The diaphragm flattens or contracts withgreaterforce
Theexternalintercostal muscles contract withgreaterforce
Additional muscles are recruited (sternocleidomastoid)
The rib cage moves upandoutfurther
Volume of thethoraciccavity increasesmore
Pressure of thethoraciccavity decreasesmore
Moreair enters the lungs causing anincreaseddepth of breathing

Question 16

Describe the short term effects of exercise on gas exchange at the alveoli. (4)

Answer 16

Blood in capillaries at the lungs has a lower partial pressure of oxygen
Air in alveoli has a higher ppO2
Gases diffuse from an area of high to low concentration
More oxygen diffuses from alveoli to blood
Blood in capillaries at lungs has higher ppCO2
Air in alveoli has lower ppCO2
More CO2 diffuses from the blood to the alveoli

Question 17

Explain why more oxygen dissociates from the blood into the muscle cell during exercise. (5)

Answer 17

Gas or oxygen moves from a high partial pressure to low partial pressure
The musclesuse moreoxygen
Increasedoxygen dissociation fromhaemoglobin/ Bohr’s shift
There is alowerpartial of oxygen in the muscle
There is a high or the same partial pressure in the capillary or blood.
There is agreaterdiffusion gradient of oxygen between the capillary and the muscle
There is an increase in body temperature
There is anincreaseof carbon dioxide in the muscle
There is anincreasein acidity

Question 18

The aerobic capacity of a sports performer is affected by their age and gender. Statetwoother factors that affect aerobic capacity (2)

Answer 18

Individual physiological make-up or genetics
Training

Question 19

Contrast the mechanics of expiration at rest with the mechanics of expiration during exercise (5)

Answer 19

Expiration during exercise is activewhereasexpiration at rest is passive
Internal intercostals contract during exercisebutnot at rest
Ribs come downwardsandinwardsfurtherduring exercise than at rest
Diaphragm forced into relaxed shapemore quicklyin exercise than at rest
Volume in thoracic cavity decreasesmoreduring exercise than at rest
Pressure in thoracic cavity increasesmoreduring exercise than at rest
More air expired faster during exercise than at rest