thoracic squeeze

thoracic squeeze

also called  Lung Squeeze,  

      compression of the lungs and thoracic (chest) cavity that occurs during a breath-holding dive under water. During the descent, an increase in pressure causes air spaces and gas pockets within the body to compress.

      The lungs (lung) are among the few bodily organs that are influenced by pressure differences.

      Because the lung tissue is elastic and interspersed with tubules and sacs of air, it is capable of some enlargement when air is inhaled and some shrinkage when it is exhaled. Too much air causes rupture of lung tissue, while too little air causes compression and collapse of the lung walls.

      As external pressure on the lungs is increased in a breath-holding dive (in which the diver's only source of air is that held in his lungs), the air inside the lungs is compressed, and the size of the lungs decreases. If one descends to a depth of 100 feet (about 30 metres), the lung shrinks to about one-fourth its size at the surface. Excessive compression of the lungs in this manner causes tightness and pain in the thoracic cavity. If compression continues, the delicate lung tissue may rupture and allow tissue fluids to enter the lung spaces and tubules. The outer linings of the lungs (pleural sacs) may separate from the chest wall, and the lung may collapse.

      The predominant symptom felt by the diver is pain when the pressure becomes too great; this can be relieved by ascending. If the thoracic squeeze has been sufficient to cause lung damage, the diver may have difficulty in breathing, may exhale frothy blood, and may even become unconscious. Artificial respiration may be necessary if the breathing has stopped. Any symptoms of thoracic squeeze call for prompt medical attention.

      Animals such as seals and whales that descend to much greater depths than man on a single breath of air have special adaptations to help them. The sperm whale is reported to dive to 3,300 feet (about 1,000 metres), more than 10 times the depth that man can tolerate. These aquatic mammals have been found to have more elastic chest cavities than man; their lungs, even when reduced, do not separate from the chest wall; and their bodies are adapted to use the gases in the bloodstream more conservatively.

* * *


Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Robert Croft (diver) — Robert Croft is a free diver who, in 1967, became the first person to free dive beyond the depth of 200 feet. Croft was a US Navy diving instructor in 1962 at the US Naval Submarine Base New London submarine school in Groton, Connecticut. At the… …   Wikipedia

  • taravana syndrome — ▪ pathology       form of decompression sickness that is most frequently seen in pearl divers in Japan and the Polynesian islands. These skin divers acquire their pearls by making breath holding dives down to depths as great as 165 feet (about 50 …   Universalium

  • muscle — muscleless, adj. muscly, adj. /mus euhl/, n., v., muscled, muscling, adj. n. 1. a tissue composed of cells or fibers, the contraction of which produces movement in the body. 2. an organ, composed of muscle tissue, that contracts to produce a… …   Universalium

  • digestive system, human — Introduction  the system used in the human body for the process of digestion. The human digestive system consists primarily of the digestive tract (alimentary canal), or the series of structures and organs through which food and liquids pass… …   Universalium

  • GALS — (standing for Gait, Arms, Legs, Spine) is a brief musculoskeletal screening test devised to detect neurological, musculoskeletal or functional deficits in patients.It consists of an initial set of screening questions and a sequence of examination …   Wikipedia

  • Hyperbaric medicine — Hyperbaric medicine, also known as hyperbaric oxygen therapy (HBOT) is the medical use of oxygen at a higher than atmospheric pressure. Uses Several therapeutic principles are made use of in HBOT: *The increased overall pressure is of therapeutic …   Wikipedia

  • Poliomyelitis — Polio redirects here. For the virus, see Poliovirus. Not to be confused with poliosis, a condition of the hair being or becoming white or grey. Poliomyelitis Classification and external resources A man with an atrophie …   Wikipedia

  • Vasectomy — Diagram showing the usual location of a vasectomy. Background Birth control type Sterilization First use 1899 (experiments fro …   Wikipedia

  • Ibadan — Infobox Settlement official name =Ibadan other name = native name = nickname = settlement type = motto = imagesize = 300px image caption = Street scene in Ibadan flag size = image seal size = image shield = shield size = image blank emblem =… …   Wikipedia

  • Subconjunctival hemorrhage — DiseaseDisorder infobox Name = Subconjunctival hemorrhage ICD10 = ICD10|H|11|3|h|10 ICD9 = ICD9|372.72 A subconjunctival hemorrhage (or subconjunctival haemorrhage) is bleeding underneath the conjunctiva. The conjunctiva contains many small,… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”