KIN 3304 1nd Edition Lecture 28Outline of Last Lecture I. Muscles of InspirationII. Muscles of ExpirationIII. Muscles of Inspiration and ExpirationIV. SpirometryV. Lung Volume and Capacities ChartVI. NumbersVII. Fick’s EquationOutline of Current Lecture I. PressureII. DCIIII. DCSIV. AGEV. Lung Overexpansion InjuriesVI. Patent Foramen OvaleVII. Nitrogen NarcosisVIII. O2 ToxicityIX. CNS O2 ToxicityX. HypocapniaThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.XI. HypercapniaXII. Carbon Monoxide PoisoningXIII. High Pressure Nervous SyndromeCurrent LectureI. Pressurea. Pressure: the continuous physical force exerted on or against an object by something in contact with itb. Pressure = force/areac. Pressure is measured in atmospheres as pound per square inchd. Water is about 800 times more dense than aire. The pressure we feel exerted on our body in 10 miles of air is equaled by a mere 33 feet of sea wateri. So for every 33 feet of sea water, we gain 1 atm1. Edge of space to sea level = 1 atm2. 33 feet of sea water = 2 atm f. Pressure is one of the main factors to consider when discussing diving physiologyII. DCIa. Decompression Illnessi. A term used to describe illness that result from a reduction in the ambient pressure surrounding a bodyb. 3 typesi. DCS, decompression sicknessii. AGE, arterial gas embolismiii. Lung overexpansion injuriesIII. DCSa. Decompression sicknessb. AKA caisson disease or “the bends”c. 2.8 cases per 10,000 divesi. Male 2.6 times greater risk than femalesd. First people to get this were construction workersIV. AGEa. An embolism is anything in the blood stream that can block blood flowi. AGE then is a bubble on arterial sideb. Can block blood to parts of the bodyV. Lung Overexpansion Injuriesa. Pneumothoraxi. Rupture of a lung in pleural cavity collapsing the lung either partially or completely b. Mediastinal Emphysemai. Air is trapped in center of chest pressing on heart and major blood vesselsc. Subcutaneous Emphysemai. Occurs frequently in conjunction with mediastinal emphysema d. Most people die just 30 feet underVI. Patent Foramen Ovalea. Relatively little effect on non-diversb. Bubble can be found in blood after divesi. Normally trapped by the lungs and filtered outii. Bubbles in people with PFO bypass the lungs and can lead to complications such as DCSVII. Nitrogen Narcosisa. Pressure incurred while diving cause gases to dissolve into the blood allowing a higher percentage to reach nervous systemb. This higher amount causes narcotic effect such as euphoria or anesthesiai. Like laughing gas (N2O) that dentists usec. You can pass out under waterVIII. O2 Toxicitya. The air we are breathing is 78% N, 20.93% O2, 0.03% CO2 and 1% trace gasesb. Pure O2 can be lethal beyond 30 ft.c. Deeper depths and higher concentrations of O2 raise risk of O2 Toxicityd. 2 Types of O2 Toxicityi. Pulmonaryii. Central Nervous SystemIX. CNS O2 Toxicitya. Far more serious than pulmonary toxicityi. CNS toxicity doesn’t have a useful PO2 and time relationshipb. Symptoms relate to CNS including visual disturbances, ear disturbances, nausea, twitching, irritability, and dizzinessc. Most serious problem is hyperoxic seizureX. Hypocapniaa. Hypocania – lack of CO2b. From either voluntary hyperventilation or unintentional (due to stress or freight)c. Can lead to shallow water blackoutXI. Hypercapniaa. Usually the result of over exertion, but can be from dead air spaces (mask, snorkel)b. Related to skip breathingi. Causes headaches, confusion, and a feeling of air starvationii. Loss of consciousness is your body’s way of resetting proper breathing, but is problematic for diversXII. Carbon Monoxide Poisoninga. Contaminated air can contain carbon monoxideb. Hemoglobin binds with CO 20x more readily than O2i. Bind forms carboxyhemoglobinii. Can take 8 to 12 hours to eliminate once in the respiratory systemc. Increased pressure allows O2 to continue bonding at depth but as the diver ascends and pressure is reduced, O2 bonding fails and diver passes outXIII. High Pressure Nervous Syndromea. Related to deep divingi. Can happen as shallow as 300 ft. but more commonly associated with depths beyond 400 ft.b. Symptomsi. Hand tremors, cramps, nausea, vertigo loss of coordinationc. No clear causei. Results from helium interfering1. Can be offset by narcotic effect of using nitrogen or
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