Starter Quick Quiz!! What 2 ways does air enter the body? What are the 2 muscles involved with breathing at rest What happens when these muscles contract to thoracic cavity volume? Lung pressure increases when respiratory muscles contract or relax? What is the function of the pulmonary pleura? What is tidal volume? What is minute ventilation? Name 5 bones which surround the lungs and abdominals? https://www.youtube.com/watch?v=hc1YtXc_84A Nasal and oral cavities Diaphragm and external intercostals Increases Relax Reduce friction The amount of air breathed in or out per breath The amount of air breathed in or our per minute Post it notes

Mechanics of Breathing Learning Objectives Know the muscles involved during respiration during exercise Understand the changes occur during exercise Be able to explain the changes in the mechanics of breathing during physical activity

The Basics Two key processes: Inspiration Air passes into the lungs Expiration Air leaves the lungs Thoracic cavity volumes Lung air pressure Air movement Muscles Movement Learning Objectives Know the muscles involved during respiration during exercise Understand the changes occur during exercise Be able to explain the changes in the mechanics of breathing during physical activity

The Basics Two key processes: Inspiration Air passes into the lungs Expiration Air leaves the lungs Both processes have five steps Each step causes the following step to happen Thoracic cavity volumes Lung air pressure Air movement Muscles Movement Learning Objectives Know the muscles involved during respiration during exercise Understand the changes occur during exercise Be able to explain the changes in the mechanics of breathing during physical activity

Key muscles in Respiration

Thoracic cavity volume At Rest INSPIRATION (ACTIVE) EXPIRATION (PASSIVE) Muscle action Movement Thoracic cavity volume Lung air pressure Movement of air

Thoracic cavity volume During Exercise INSPIRATION (ACTIVE) EXPIRATION (PASSIVE) Muscle action Movement Thoracic cavity volume Lung air pressure Movement of air

Breathing at rest INSPIRATION (ACTIVE) EXPIRATION (PASSIVE) Muscle action Diaphragm and external intercostals contract Diaphragm and external intercostals relax Movement Diaphragm flattens/pushed down Ribs/sternum up and out Diaphragm pushed upwards Ribs/sternum in and down Thoracic cavity volume Volume increases Volume decreases Lung air pressure Decreases below atmospheric air Increases above atmospheric air Movement of air Air rushes into lungs Air rushes out of lungs

Breathing during exercise INSPIRATION (ACTIVE) EXPIRATION*** Muscle action Diaphragm and external intercostals contract Sternocleidomastoid, scalenes and pectoralis minor contract Diaphragm and external intercostals relax Internal intercostals, rectus abdominals and obliques contract (active) Movement Diaphragm flattens with more force Increased lift of Ribs/sternum Diaphragm pushed upwards harder and with more force Ribs/sternum pulled in and down Thoracic cavity volume Greater increase in volume Greater decrease in volume Lung air pressure Decreases further below atmospheric air Increases further above atmospheric air Movement of air More air rushes into lungs More air pushed out of lungs

Starter - Respiratory Volumes Tidal volume  Vital capacity  **Residual volume  Total lung capacity  Minute Ventilation (VE) 

Respiratory Volumes

Vital capacity + Residual volume Tidal volume x Frequency Respiratory Volumes Tidal volume  The amount of air breathed in or out during normal respiration/per breath (around 500ml) Vital capacity  The maximum amount of air that can be exhaled after a maximum inhalation (usually tested with a spirometer) **Residual volume  The volume of air that remains in the lungs after the individual has breathed out as much as he can Total lung capacity  The total volume of air that the lung can contain Vital capacity + Residual volume Minute Ventilation (VE)  Total volume of air taken into the lungs per minute Tidal volume x Frequency 500 x 15 = 7500ml/min = 7.5L/min

Calculations Tital Volume (TV) x Frequency (f) = Minute Ventilation (VE) TV (ml) x f (breaths per beat) = VE (bpm) You can measure the performance of the heart by its output – Tidal Volume (TV): The volume of air inspired or expired per breath – approx. 500ml at rest Frequency (f): The number of breaths taken in one minute – approx. 12-15 breaths at rest Minute Ventilation (VE): The volume of air inspired or expired in one minute – 6L/min at rest Learning Objectives Know the muscles involved during respiration during exercise Understand the changes occur during exercise Be able to explain the changes in the mechanics of breathing during physical activity

Lung volumes during exercise Tidal Volume (TV): 3-4 litres Frequency (f): 40-60 Minute Ventilation (VE): 120 L/min and up to 180+L/min in trained athletes Respiration increases in line with exercise intensity in order to supply O2 to the working muscles Tidal volume and frequency increase at lower intensities At maximal output, frequency continues to increase

Lung capacity training Step 1: Sit upright in a comfortable chair without touching the backrest. Place both hands on your chest and abdomen to feel them rise and fall as you breathe in and out. Step 2: Breathe in as deeply as you can. Time your breaths so you are breathing in for three seconds, holding your breath for two seconds, then breathing out for three seconds. Repeat this process for 20 breaths. Step 3: Breathe in as deeply as you can. Focus on expanding your chest rather than expanding your abdomen as you breathe in. In (3 secs), hold (2 secs), out (3 secs). Repeat this process for 20 breaths. Step 4: Inhale by first concentrating on expanding your abdomen, then continue inhaling while concentrating on expanding your chest. Hold this breath for two seconds, then exhale, concentrating on emptying your chest first, then your abdomen. Continue this process for 20 breaths. Step 5: Inhale deeply to fill your lungs completely, then exhale the full contents of your lungs into your empty balloon. You do not need to blow up the balloon all the way; focus on blowing as much air as you can into it with a single breath. The resistance of the balloon will help you strengthen and expand your lungs. Learning Objectives Know the muscles involved during respiration during exercise Understand the changes occur during exercise Be able to explain the changes in the mechanics of breathing during physical activity

Gaseous Exchange Now we know how air is supplied to the body, lets look at how O2 and CO2 are exchanged Gaseous exchange relies on a process called diffusion Gases move from an area of high pressure to an area of low pressure The difference between the high and low pressure is called the diffusion gradient The bigger the gradient the greater the diffusion and gaseous exchange that can occur Learning Objectives Know the muscles involved during respiration during exercise Understand the changes occur during exercise Be able to explain the changes in the mechanics of breathing during physical activity

Partial pressure You need to understand this to be able to understand gaseous exchange Basically the pressure exerted by a particular gas within a mixture of gases Gases always move from high partial pressure to low partial pressure The difference between the high and low pressure is called the diffusion gradient; the larger the gradient, the larger the diffusion / gaseous exchange that takes place You don’t have to know values but they may help you understand the process Learning Objectives Know the muscles involved during respiration during exercise Understand the changes occur during exercise Be able to explain the changes in the mechanics of breathing during physical activity

Breathing at rest KEY TERM: MYOGLOBIN Red pigment in muscles that stores and transports O2 to mitochondria within muscles EXTERNAL RESPIRATION (alveoli air to alveolar capillaries) INTERNAL RESPIRATION (blood in capillaries to tissue cell walls) Where does it occur? alveolar-capillary membrane tissue-capillary membrane What is the change? O2 in alveoli diffuses to blood CO2 in blood diffuses to alveoli O2 in blood diffuses to myoglobin within tissue CO2 in tissue diffuses to blood Why? O2 PP in the alveoli is higher than PP in the blood CO2 PP in the blood is higher than PP in the alveoli O2 PP in the blood is higher than PP in the tissue CO2 PP in the tissue is higher than PP in the blood How is Oxygen transported in the blood? 97% Hb as HbO2 3% in Blood Plasma

Membranes Learning Objectives Know the muscles involved during respiration during exercise Understand the changes occur during exercise Be able to explain the changes in the mechanics of breathing during physical activity

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