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Dry drowning is when a person's lungs become unable to extract oxygen from the air, due primarily to: For the village in Tibet, see Lung, Tibet. ... This article is about the chemical element and its most stable form, or dioxygen. ... Look up air in Wiktionary, the free dictionary. ...

• Muscular paralysis
• Puncture wound to the torso (affecting ability of diaphragm to create respiratory movement)
• Changes to the oxygen-absorbing tissues
• Persistence of laryngospasm when immersed in fluid
• Breathing for too long any gas other than oxygen that does not kill the patient on its own. (e.g. Helium)

The person may effectively drown without any sort of fluid. In cases of dry drowning in which the victim was immersed, very little fluid is aspirated into the lungs. The laryngospasm reflex essentially causes asphyxiation and neurogenic pulmonary edema (oedema). Paralysed redirects here. ... The human torso Torso is an anatomical term for the greater part of the human body without the head and limbs. ... In the anatomy of mammals, the diaphragm is a shelf of muscle extending across the bottom of the ribcage. ... In medicine, laryngospasm is an uncontrolled/involuntary muscular contraction (spasm) of the laryngeal cords. ... General Name, symbol, number helium, He, 2 Chemical series noble gases Group, period, block 18, 1, s Appearance colorless Standard atomic weight 4. ...

Dry drowning can occur clinically, or due to illness or accident, or be deliberately (and repeatedly) induced in torture (waterboarding). Illness (sometimes referred to as ill-health) can be defined as a state of poor health. ... A railing accidentally collapses at a college football game, spilling fans onto the sidelines An accident is something going wrong unexpectedly. ... For other uses, see Torture (disambiguation). ... Painting of waterboarding at Cambodias Tuol Sleng Prison, by former inmate Vann Nath. ...

Pathophysiology

The pathophysiology of this form of pulmonary edema is multifactorial. Pathophysiology is the study of the disturbance of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from a disease or abnormal syndrome or condition that may not qualify to be called a disease. ... Pulmonary edema is swelling and/or fluid accumulation in the lungs. ...

In normal breathing, the diaphragm contracts, causing it to drop and increase the air volume of the lungs (lungs are above the diaphragm). This increase causes a partial vacuum in the lungs. Breathing transports oxygen into the body and carbon dioxide out of the body. ... For other types of diaphragm, see Diaphragm. ... Look up Vacuum in Wiktionary, the free dictionary. ...

When water or other foreign bodies are inhaled, laryngospasm occurs and the person's larynx spasms shut. As a result, the partial vacuum created by contracting the diaphragm cannot be filled by the inrush of air into the lungs, and the vacuum persists. In an attempt to force air in through the spasmed larynx, the person may breathe deeper and more labored, but this only increases the partial vacuum inside the chest. In medicine, laryngospasm is an uncontrolled/involuntary muscular contraction (spasm) of the laryngeal cords. ... The larynx (plural larynges), colloquially known as the voicebox, is an organ in the neck of mammals involved in protection of the trachea and sound production. ... A spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ, or a similarly sudden contraction of an orifice. ...

The heart continues to beat normally during this time, and blood continues to circulate, though pulmonary oxygen and carbon dioxide gas exchange is markedly reduced. The volume of blood in the pulmonary circulation increases, by pulling in more blood from the abdomen, head, arms and legs - abnormally large volumes of this blood enter the pulmonary circulation via the superior and inferior vena cavae (great veins) in response to the persistent partial vacuum. From the vena cavae, the increased blood volume flows through the right atrium and into the right ventricle. The blood volume is great enough to stretch out the ventricle, similar to water entering a balloon. The heart and lungs, from an older edition of Grays Anatomy. ... The superior and inferior venae cavae are the veins that return the blood from the body into the heart. ...

The ventricle typically responds to this increased volume of blood by contracting and pumping with increased strength - a phenomenon known as the Frank-Starling mechanism. On being ejected from the right ventricle, the blood is forced into the pulmonary artery and thence to the pulmonary circulation. The Frank-Starling law of the heart (also known as Starlings_law) states that when the diastolic filling of the heart is increased or decreased with a given volume, the displacement of the heart increases or decreases with the same volume. ...

In the lungs, the nature of the vasculature changes. The vessels which carry deoxygenated blood (the pulmonary arteries) to the lungs become extremely narrow - narrow enough that red blood cells have to pass through in single file. The walls of the vasculature also become extremely thin to allow oxygen to enter the red blood cells and carbon dioxide to leave. In the case of dry drowning, however, there is no oxygen available in the lungs; there is only a partial vacuum. This partial vacuum draws some of the fluid from the vasculature and into the airspaces of the lungs, creating pulmonary edema, and the patient is now drowning in their own fluids. The pulmonary arteries carry blood from the heart to the lungs. ...

At the same time, the sympathetic nervous system responds to the emergency of the closed larynx. Among other things, it constricts much of the body's vasculature. This vasoconstriction increases the blood pressure against which the left ventricle must pump, and may cause enough backpressure to ripple back through the left ventricle, into the left atrium, and into the pulmonary vasculature. This additional pressure on the blood in the lungs' blood vessels exacerbates the edema described above. The Sympathetic Nervous System (SNS) is a branch of the autonomic nervous system. ...

Additionally, the actions of the sympathetic nervous system can damage the lungs' vasculature, allowing even more fluid to escape into the lungs' airspaces.

See also

• Splitting of S2 (heart sounds) in which the normal changing intrathoracic (inside the chest) pressures of breathing influence the timing of events in the heart.
• Circulatory system

Front of thorax, showing surface relations of bones, lungs (purple), pleura (blue), and heart (red outline). ... For transport in plants, see Vascular tissue. ...

External links

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