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AS level PE. Respiratory system. Discus mechanics of breathing Inspiration Expiration Air is distributed to the lungs by way of the Trachea Primary bronchi (Also secondary/tertiary) Bronchioles alveoli. Respiratory system – 3 main processes. Pulmonary respiration
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AS level PE Respiratory system
Discus mechanics of breathing • Inspiration • Expiration • Air is distributed to the lungs by way of the • Trachea • Primary bronchi (Also secondary/tertiary) • Bronchioles • alveoli
Respiratory system – 3 main processes • Pulmonary respiration • The breathing of air into and out of the lungs • External respiration • Exchange of O2 and CO2 between the lungs and the blood • Internal respiration • Exchange of O2 and CO2 between the blood and muscle tissues
RESPIRATORY VOLUMES AT REST • Tidal volume • Amount of air inhaled and exhaled with each breath (approx 500ml) • Frequency (f) • Rate of breathing • Minute Ventilation • VE = TV X f • Residual volume • Volume of air remaining in the lungs (1200ml)
RESPIRATORY VOLUMES AT REST (Cont’d) • Inspiratory reserve vol • Expiratory reserve volume
LUNG CAPACITIES • Inspiratory capacity = IRV + TV • Expiratory capacity = ERV + TV • Vital capacity • Maximal vol of air that can be expired after maximal inspiration • Total lung capacity • Maximal volume of air contained in the lungs after a maximal inspiration • TLC = TV + IRV + ERV + RV
Gaseous Exchange • Gaseous exchange refers to the exchange of gases, namely O2 and CO2 and relies on a process called diffusion • What is Diffusion?? • PP – partial pressure of a gas is the pressure it exerts within a mixture of gases • Gases always move from an area of high pressure to an area of low pressure
Inspired air – PO2 -159 , PCO2 -0.3 • Trachea – PO2 – 149, PCO2 – 0.3 • Pulmonary veins – PO2-100, PCO2 -40 • Heart • Body tissues – PO2 – 40, PCO2 - 46
MYOGLOBIN – RED PIGMENT IN MUSCLES THAT STORES O2 AND TRANSPORTS O2 TO THE MITOCHONDRIA • 02 – muscle cells (hb – myoglobin) -- by product – CO2 CO2 travels in blood as carbonic acid (70%), Carbaminohaemoglobin(20%) & 7% plasma
TASK • IN GROUPS OF 3-4 YOU HAVE 5-10MINS TO DISCUSS AND PRESENT THE MECHANICS OF RESPIRATION DURING EXERCISE • MECHANICS • LUNG VOLUME CHANGES DURING EXERCISE • SKIPPING ROPES • CONES & PAPER
MECHANICS OF RESPIRATION DURING EXERCISE • What muscles are involved? • Inspiration – SCOM(sternocleidomastoid), scalenes & pec minor • Expiration – internal intercostals & rectus abdominals / obliques • See p.96 • Discuss the ventilatory response to light, moderate and heavy exercise
LUNG VOLUME & EXERCISE • Tidal volume – 500ml 3-4litres • Frequency – 12-15 40-60 • VE – 6-7.5l 120-180l • IRV – 3100ml decreases • ERV – 1200ml slightly decreases • Vital capacity – 4800ml slight decrease • Residual volume – 1200ml slight increase • Total lung capacity – 6000ml slight decrease
EXERCISE CHANGES TO GASEOUS EXCHANGE BOTH EXTERNAL & INTERNAL RESPIRATION INCREASE DURING EXERCISE IN ORDER TO INCREASE THE SUPPLY OF O2 TO THE WORKING MUSCLES