Lecture 9 - Control Of Ventilation In Exercise

Question 1

What happens to ventilation during exercise?

Answer 1

Increase in ventilation, increase in blood flow to the face, sweat, heart rate

Question 2

What happens towards the end of vigorous exercise?

Answer 2

Generation of lactic acid

Question 3

How many phases are there during exercise?

Answer 3

5 phases

Question 4

What parts of the body are important in the mechanics of exercise?

Answer 4

The diagram and intercostal muscles

Question 5

What happens during inhalation?

Answer 5

The rib cage lifts up and out

Question 6

What type of processes is exhalation?

Answer 6

Passive but not necessarily during exercise which is where the internal intercostal muscles help.they contract and force the ribcage down expelling air faster

Question 7

What muscles help keep the airways open

Answer 7

Quadratic lumborum - a paired muscle of the left and right posterior abdominal wall (backs muscles) - also accessory muscles help

Question 8

What does it mean if someone is bent over after exercise?

Answer 8

It is the most comfortable position to keep the airways open as much as possible

Question 9

What is the 1st phase of ventilation?

Answer 9

The increase in ventilation is abrupt and immediate

Question 10

What is the 2nd stage of ventilation?

Answer 10

Ventilation increases further, trying to reach a steady state to match demand with supply

Question 11

What types of exercise to you reach a form of steady state?

Answer 11

Light and moderate exercise

Question 12

What is phase 3 of ventilation during exercise?

Answer 12

The steady state, where you maintain the exercise you are doing

Question 13

What controls the rate and depth of ventilation?

Answer 13

Apnostic centre

Question 14

What controls and coordinates ventilation?

Answer 14

The pneumotaxic centre

Question 15

What centre can override the other?

Answer 15

The aponstic centre can override the pneumotaxic centre

Question 16

What specific type of exercise is it important than the Apnostic centre doesn’t override the pneumotaxic centre?

Answer 16

In swimming - you wouldn’t want to have an abrupt start of ventilation when your face is under water - need to be able to control or coordinate when ventilation is appropriate

Question 17

What do the apnostic and pneumotaxic centre work under?

Answer 17

The dorsal group - they act through the diaphragm and intercostal muscles

Question 18

What causes an abrupt increase in ventilation?

Answer 18

Active limbs - you get a central command response when you start moving arms and limbs - which is matched to exercise and increases ventilation

Question 19

What would happen if you didn’t have an abrupt start?

Answer 19

Sprinter would probably pass it mid way through the 100metres due to lack of oxygen - this can be trained

Question 20

What is an important experiment that was carried out for frequency and load?

Answer 20

Duffin 2014, legs were connected by bamboo canes and duck tape. Two participants sat on a chair on a treadmill. Treadmill switched on and limbs were moving but they weren’t actually moving - was used to measure the ventilation rate

Question 21

What 2 things were tested on the treadmill?

Answer 21

The speed and gradient of the treadmill

Question 22

Increasing the speed =

Answer 22

A bigger increase in ventilation

Question 23

Increase the gradient =

Answer 23

Increased the load

Question 24

What does the speed of active limbs give?

Answer 24

Gives more of a response and increases ventilation to a greater and quicker rate

Question 25

Slow drive for ventilation =

Answer 25

Limbs are as active in frequency but putting a lot of load on

Question 26

What potential mechanism causes an increase in further ventilation?

Answer 26

Trying to match the demand by sensing the demand by central chemoreceptors

Question 27

What is most of the input through?

Answer 27

Active limbs, producing byproducts of respiration - generating lactic acid at Low levels which changes the blood pH

Question 28

What picks up a change in pH?

Answer 28

Peripheral chemoreceptors - start to change the partial pressure of CO2 which increases ventilation

Question 29

What do active limbs work through?

Answer 29

The dorsal group

Question 30

What is the final phase?

Answer 30

Small fine tuning of supply to meet demand - involves central command but with peripheral chemoreceptors

Question 31

What is the cause of abrupt reduction?

Answer 31

Central command is taken away, slower level of reduction back to resting levels

Question 32

Describe maximal exertion

Answer 32

Massive increase in ventilation rates, don’t get a steady state because you are trying to match demand, towards the end of maximal exertion you start to see a reduction in CO2

Question 33

What causes a change in blood pH - controls of ventilation?

Answer 33

Increase in lactic acid, hydrogen ion

Question 34

What types of respiration can be seen in maximal exertion?

Answer 34

Aerobic and anaerobic towards the end of exercise which is when lactic acid is produced and pH will decrease

Question 35

What is the anaerobic threshold?

Answer 35

At AT, where you start to rapidly produce lactic acid, from here ventilation increases further which is why more CO2 is expired

Question 36

What is the limiting factor of exercise?

Answer 36

The capacity to both carry and utilise the oxygen before you start to response anaerobically which is the cause of lactic acid

Question 37

What can be used to synthetically increase red blood cels?

Answer 37

Synthetic substances - increases mitochondria and there is more capacity to carry oxygen and use it

Question 38

How is recovery helped?

Answer 38

By the hypothalamus, panting can help with ventilation, increase in body temperature