The graph shows how a student’s breathing rate changed during and after exercise. Describe and explain how would you expect the student's heart rate to change during the 16-minute period shown on the graph.

The demand of the body for oxygen is increased during exercise because the metabolism is increased. Since the muscles need more amount of energy to do exercise. The glucose (C 6 H 12 O 6 ) in the muscles is oxidised as fast as possible by the cells to release energy. Thus, they need more oxygen. During exercise, to cope up with the need of a body, the blood circulation also increases so that supply of oxygen is not hampered. From the given graph we can see that the respiratory rate of the student is increasing from 12 breaths per minute to a maximum of 25 breaths per minute. As he breathes fast and deeply, we can say that the heart rate will also increase as he continues doing exercise. Initially, the heart rate is low which will become maximum at the 5th minute and starts decreasing after the 14th minute.

The graph shows how a student’s breathing rate changed during and after exercise. Calculate the increase in the student’s breathing rate from when he started to do exercise, to its maximum rate.

From the given graph, we can interpret that the rate of respiration of the student when he started to do the exercise was 12-13 breaths per minute. The maximum respiratory rate during exercise was 25 breaths per minute. Thus, we can say that during exercise, the respiratory rate of this student increased from 12 breaths to 25 breaths per minute.

The graph shows how a student’s breathing rate changed during and after exercise. Calculate how long it took after he finished his exercise for his breathing to return to normal.

We know that the respiratory rate increases during exercise. According to the graph, The breathing rate of the student started to increase after he did exercise, from 12 breaths per minute to 25 breaths per min. He stopped doing exercise on the eleventh minute and the breathing rate became normal on 16th minute. Thus, we can say that the breathing rate became normal after five minutes.

The graph shows how a student’s breathing rate changed during and after exercise. Explain why his breathing rate does not return to normal immediately after he stopped exercise.

Since the demand of the body for oxygen is increased and the muscles need more amount of energy to do exercise. The glucose (C 6 H 12 O 6 ) in the muscles is oxidised as fast as possible by the cells. Thus, they need more oxygen. So during exercise, to cope up with the need of the body, the muscles start oxidising glucose by anaerobic respiration. It results in the accumulation of lactic acid. At this stage, the body is under oxygen debt. It requires oxygen to return the body to normal. So as the boy stops doing exercise, the amount of oxygen required to remove the lactic acid is utilised. Thus, the respiratory rate and heart rate does not come to normal straight away.

The volume of air in the lungs and the rate at which it is exchanged during inspiration and expiration was measured. The following diagram shows a group of lung volume and capacities: Study the diagram carefully and explain briefly the following: (a) Tidal volume (b) Inspiratory reserve volume (c) Expiratory reserve volume (d) Vital capacity (e) Residual volume

Lungs are the primary respiratory organs. They have specific capacities to hold the air inhaled. The respiratory volumes or the lung capacities in an adult human are as follows: (a) Tidal volume – It is the air breathed in and out during normal breathing. It is equal to 500mL. (b) Inspiratory reserve volume – It is the amount of air that can be drawn in forcibly over and above the tidal air. It is referred to as IRV or complemental air and is equal to 3000mL. (c) Expiratory reserve volume – It is the amount of air that can be expelled out forcibly after a normal expiration. It is referred to as ERV or supplemental air and is equal to 1000mL. (d) Vital capacity (VC) – It is the volume of air that can be inhaled and exhaled by maximum inspiration and expiration respectively and is about 4500mL. (e) Residual volume (RV) – Even after forcible expiration, there is some air left in the lungs and is referred to as residual volume. It is about 1500mL.

Lung volume is also called respiratory volume An instrument called a Spirometer helps in measuringRespiratory volumes

EASY

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

The Total Lung Capacity

(TLC)

is the total volume of air accomodated in the lungs at the end of a forced inspiration. This includes:

MEDIUM

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

A person breathes in some volume of air by forced inspiration after having a forced expiration. The quantity of air taken in is

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

The graph shows how a student’s breathing rate changed during and after exercise. Question Image

Describe and explain how would you expect the student's heart rate to change during the 16-minute period shown on the graph.

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

The graph shows how a student’s breathing rate changed during and after exercise. Question Image

Calculate the increase in the student’s breathing rate from when he started to do exercise, to its maximum rate.

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

The graph shows how a student’s breathing rate changed during and after exercise. Question Image

Calculate how long it took after he finished his exercise for his breathing to return to normal.

MEDIUM

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

Tidal volume is equal to vital capacity of lung.

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

Suggest three ways in which the gas exchange system responds to the demands of exercise.

MEDIUM

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

What is residual air? What is its role?

MEDIUM

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

The lungs always contain residual volume of air.

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

A girl breathed into a machine that recorded the volume of the air that she breathed in and out. The results were recorded as a graph of volume against time. The diagrams show results obtained when she was resting and when she was exercising. Question Image

Use the second graph to find the volume of the first breath that she took while she was exercising.(Remember to include the unit in your answer)

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

A girl breathed into a machine that recorded the volume of the air that she breathed in and out. The results were recorded as a graph of volume against time. The diagrams show results obtained when she was resting and when she was exercising. Question Image

Use the first graph to find the volume of the first breath that she took while she was resting.(Remember to include the unit in your answer)

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

A girl breathed into a machine that recorded the volume of the air that she breathed in and out. The results were recorded as a graph of volume against time. The diagrams show results obtained when she was resting and when she was exercising. Question Image

Describe the mechanism that brought these changes in the rate and depth of breathing helped the girl's body.

EASY

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

Explain the term tidal volume.

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

The graph shows how a student’s breathing rate changed during and after exercise. Question Image

Explain why his breathing rate does not return to normal immediately after he stopped exercise.

MEDIUM

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

From the following relationships between respiratory volume and capacities, mark the correct option:
(i) Inspiratory Capacity (IC) = Tidal Volume + Residual Volume
(ii) Vital Capacity (VC) = Tidal Volume (TV) + Inspiratory Reserve Volume (IRV) + Expiratory Reserve Volume (ERV)
(iii) Residual Volume (RV) = Vital Capacity (VC) - Inspiratory Reserve Volume (IRV)
(iv) Tidal Volume (TV) = Inspiratory Capacity (IC) - Inspiratory Reserve Volume (IRV) Codes

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

A girl breathed into a machine that recorded the volume of the air that she breathed in and out. The results were recorded as a graph of volume against time. The diagrams show results obtained when she was resting and when she was exercising. Question Image

Use the first graph to find how many breaths per minute the girl took while she was resting.

HARD

Science>Biology>Respiratory System>Respiratory Volumes and Capacities

A girl breathed into a machine that recorded the volume of the air that she breathed in and out. The results were recorded as a graph of volume against time. The diagrams show results obtained when she was resting and when she was exercising. Question Image