Respiratory system Exercise Physiology

Inhalation Nasal cavity Hairs: filter air Mucus: filters & moistens Blood vessels: warm air • Pharnyx (throat) • Larynx (voice box)- glottis, epiglottis • Trachea (wind pipe)- mucus & hairs. cartilage rings maintain shape. •Bronchi- Lungs (Bronchioles, alveoli)

Mechanics of breathing- Inhaling Pleural fluid- between lungs & chest wall two layers stick together during inhalation • Ribs move up and out b/c of external intercoastal muscles • Diaphragm- contracts downward. • as all the above happen the pressure inside the chest cavity drops & air flows in. diaphragm & ribs movement Path of air in respiratory tract

Mechanics of breathing- Exhaling Passive process Diaphragm relaxes & goes back up forcing air out Forces exhalation requires use of other muscles. (internal intercoastal muscles pec major, minor, traps, rhomboids) Respiration inhale - exhale 9min

Diffusion- Pressure differences Passive transport of gases High to low pressure Higher pressure in lungs (alveoli) than in capillaries. Higher pressure in blood vessels than in cells of tissues CO2 metabolic waste carried to lungs – diffuses into vessels and into lungs.

Oxygen Transport Transported 2 ways: Attached to hemoglobin - 98.5% Dissolved in blood plasma – 1.5% • Hemoglobin – contains iron, binds to oxygen. - oxyhemoglobin (with oxygen) - deoxyhemoglobin (without oxygen) - binding, unbinding- occurs in lungs

CO2 Removal Diffuses into blood stream then into alveoli 3 forms of Carbon dioxide Bicarbonate ions 70% Bond to hemoglobin 23% Dissolved in plasma 7% gas exchange in respiratory system 8min

What controls gas exchange? Bohr Effect- O2 levels in blood if the pH was lower than normal (normal physiological pH is 7.4), then hemoglobin does not bind oxygen as well. Lactic Acid & Carbonic Acid build up in blood- cause pH to be lower ( become more acidic) ● Respiration is controlled by the medulla oblongata