Physiological Effects of Pressure on Man and Cetaceans

Physiological Effects of Pressure on Man and CetaceansAir and water atomic number 18 al vogues exerting twinge on every object or organism on Earth. Pressure is the office or weight exerted on an object per unit area in order to move it (Anderson, 2011). It is mensurable in bar or atmosphere (ata as an abbreviation) and changes depending on the place on Earth touch organisms in different ways. Despite that entirely three groups within this study belong to the class class Mammalia, they all evolved in different ways adapting them to their environment. Being cetaceans the group who is entirely aquatic including whales, dolphins and porpoises (The Editors of Encyclopdia Britannica and G. Mead, 2014). Pinnipeds are the group of fin-footed mammals who overtake most of their period in the water, however, coming to shore to rest or mate and it includes seals, sea lions and walrus (NOAA, 2014).Therefore, it is aimed to analyse and compare the effectuates of pressure in globe, cetac eans and pinnipeds as swell up as comparing accomplishable adaptions of each one.At sea level, despite universe imperceptible any object or world is subject to the pressure exerted by the look defined as one bar/ata.When going submerged to the pressure exerted by the water the pressure of air at sea level has to be added. When the meridian drops every 10 meters below sea level the pressure increases by 1 bar/ata nonnegative the one at the surface (PADI, 1996). Resulting in 2 bar/ata and so the pressure underwater dissolve change as demonstrated in figure 1.Figure 1. The relation between Depth and Pressure. (PADI, 1996)However, if the nosedive is made in a submarine to a depth of 120m/396 feet the crew inside will suave be subject to 1 bar of the pressure of the air and the submarine would be the one subjected to the pressure of 24bar/ata from the water and air combined (Martin, 1997).Gas ExchangesAll mammals have a bidirectional respiratory placement that isnt prepared fo r living permanently underwater like fish are. In a respiratory organisation like this, gas exchanges occur by using the same airways. They start to inhale oxygen (O2) at the surface before diving and at some point, all must return to release century dioxide (CO2) and inhale again (Martin, 1997). The exchange itself occurs in the alveoli within the lungs, organism the O2 transported to different parts of the body by the circulatory system and the CO2 expelled back through the nose or mouth in humans and pinnipeds and through the blowhole in cetaceans according to WhaleFacts.org and NOAA.Cetaceans and pinnipeds being well vary to a marine living they can hold longer underwater between dives comparing to humans who need scuba sky to dive heavyseter and for longer.At first, could be assumed that in the case of cetaceans the reason for longer dive time or deeper dives is lung coat. However, according to Whale and Dolphin Conservation (WDC) comparing whale average body and lung siz e to the one of a human, a whales lungs take 4% less space in their bodies than a humans. Therefore, the key isnt in the lungs but in the blood and haemoglobin c erstrtation which in a whales is 30% higher than in a human. This helps the whale to storage more than O2 in their bloodstream and muscle tissues instead of inside their lungs and this way avoid depth related complications. And the same can be verified in some deep diver pinnipeds (Kooyman and Ponganis, 1998).The personal effects of pressure on body cavitiesAs these three groups belong the Class Mammalia they all share three main body cavities which are normally filled with air, ears, sinuses and lungs.With air being a gas it changes volume along with pressure changes, so when pressure increases air get stiff and tends to decrease in volume.On one hand in humans this results in feeling an unconformable squeeze in the ear sinus and mask when using scuba gear. If these areas arent regularly equalised by adding air to them during a dive can end up in an eardrum rupture or a large headache (PADI, 1996).On the another(prenominal) hand, in cetaceans, evolutionary adaptations occurred within the hearing mechanism and sinus to be suited for water-borne sounds. Adaptations such as the fusion of the middle and inner ear capsules allowed cetaceans to better ascertain sounds underwater however without being able to do the same to air-borne sounds (Au, Fay, and Popper, 2000).Similarly, to humans hearing pinnipeds ears more adapted to interpret air-borne sounds as most of the communication between individuals occurs above water. Although they do hear sufficiently well underwater (Riedman, 1990).Finally, the lungs commonly to all three groups the main rule is not holding your breath in all while diving. During ascends as pressure decreases air volume increases and not realising it can cause lung rupture (PADI, 1996).Among other major depth related consequences are barotrauma, decompression sickness or the bend s and nitrogen narcosis. decompression Sickness (DCS)While underwater the organism accumulates nitrogen and due to not being used, it must be expelled which normally happens with each exhalation. If the amount of excess nitrogen is too high when ascending the nitrogen go forth the tissue, forms large bubbles that can cause symptoms from dizziness, tingling and numbness to in unspeakable cases unconsciousness and death.It is commonly called by divers as the bends due to the nitrogen bubbles being trapped in the joint discourteous air area and not allowing them to bend their joints without pain.With a wide range of noticeable signs and varying from mild to contribute it is difficult to diagnose DCS in humans. In the case of cetaceans despite study made by Jepson et al. show a lot of individuals with bubble lesions, it cannot be assumed that all cetaceans mass stranding are related to severe cases of DCS when actually it was not possible to determine the origin of those bubbles.Ni trogen NarcosisThis symptom is a result of a direct toxic effect of high nitrogen pressure in the body and it is similar to being under the effect of alcohol. May affect human divers at different depths but once it starts only gets worse has the depth increases and can be deadly as divers under this effect will commit dangerous actions while diving (Martin, 1997).It can also be associated with cases of DCS as it unremarkably happens before DCS.Regardless of being completely aquatic, semi-aquatic or terrestrial, all three groups may suffer from the effects of pressure like DCS and nitrogen narcosis.Being completely terrestrial humans are the most unnatural ones. Cetaceans are the most adapted group to life underwater, however, it is not safe to assume yet that this way of life that they are less affected or even immune to DCS nitrogen narcosis as the origin of the bubbles, that at first would be characteristic of DCS, was not determined by Jepson et al. studies.Nonetheless it is p ossible to say twain cetaceans and pinnipeds retrieve and storage oxygen a lot more efficiently than human beings thus more efficiently avoiding DCS (Kooyman and Ponganis, 1998).TextAnderson, M. (2011) The Physics of Scuba Diving. Available at https//www.dawsonera.com/abstract/9781908062512 (Accessed 19 February 2017).Au, W.W.L., Fay, R.R. and Popper, A.N. (2000) Hearing by whales and dolphins. (12 Vols). New York, NY Springer New York. Chapter 2Martin, L. (1997) Scuba diving explained Questions and answers on physiology and medical aspects of scuba diving. Flagstaff, AZ Best Publishing Company.PADI (1996) PADI open water diver manual. Santa Ana, CA Atlantic Books.Ponganis, P.J. (2015) Diving physiology of marine mammals and Seabirds. join Kingdom Cambridge University Press.National Oceanic Atmospheric Administration (NOAA) (2014) Whats the difference between seals and sea lions? Available at http//oceanservice.noaa.gov/facts/seal-sealion.html (Accessed 24 February 2017).Riedman, M. (1990) The pinnipeds Seals, sea lions, and walruses. Berkeley University of California Press.Whale and Dolphin Conservation (WDC) (no date) How do whales breathe? Available at http//uk.whales.org/blog/2012/10/how-do-whales-breathe (Accessed 24 February 2017).WhaleFacts.org (ed.) (2017) Whale Anatomy. Available at http//www.whalefacts.org/whale-anatomy/ (Accessed 24 February 2017).Images Figure 1PADI (1996) PADI open water diver manual. Santa Ana, CA Atlantic Books.