1.2- RESPIRATORY SYSTEM

Question 1

What is tidal volume? and what happens during exercise? (2)

Answer 1

The volume of air breathed in and out without conscious effort

Increases

Question 2

During exercise, the demands for o2 for the muscles increases. How does an increase in blood co2 change the breathing rate? (4)

Answer 2

An increase in co2 is detected by Chemoreceptors
Send impules to the medulla in Brain (Respiratory centre)

The medulla sends impulses down the phrenic nerve to the breathing muscles

This increases the rate of contraction of diaphragm and external intercostal muscles so the breathing rate increases

Question 3

Gas exchange and o2 delivery influence performance in sporting activities.
Explain how oxygen diffuses from the lungs into the blood and how it is transported to the tissues (4)

Answer 3

• Diffusion definition
• Alveoli short diffusion pathway
• High pp of o2 in alveoli low pp in blood so diffuses into the blood
• Oxygen combines with hemoglobin to form oxyhemoglobin
• Some o2 dissolves in plasma

Question 4

Evaluate the effectiveness of continuous training for a rugby player.
Consider long term effects of this type of training on the respiratory system (8)

Answer 4

AO1- Continuous training is working for a prolonged period of time without rest.
Develops aerobic endurance
Invoves running cycling or swimming
Improves efficiency of gasous exchnage
Increases SA of alveli and capillary density
Strenghtens respiratory muscles
Tidal volume increases

A02-
Continous training increases aerobic endurance which is significant for a rugby player because they need aerobic endurance throughout the match to maintain performance
Will have long term effects on R system that will benefit the player . Improve eddiceincy of rugby player and allow him to supply muscles w more o2 due to increase in SA of alveoli and more capillaries. His respiratory muscles are strenghening which will alow him to breath deeper
Greater gaseosu exchange (more o2 into blood and more co2 diffueses out). Increases o2 carrying capacity of blood and allows him to use less anerobic respiration whcih maintains his accuracy throughout the game
Greater minute ventilation and tv = less fatigue

A03-
Rugby game mainly aerobic so continuois traing will improve aerobic endurance
Interval training also useful as he sprints in game
Weight training increase strenght to tackle