Why are pulmonary ateries in a pig smaller at the fetal stage?
443463
Fetal animals do not yet use their lungs.  The pulmonary arteries (which go to the lungs) are therefore not as well developed.
164624
A sheep's lungs inflate like a human's does, as one, not in parts.  The diaphram flexes, pressing downward, as the external intercostals flex, moving the ribcage outward, this causes the lungs to expand.  When they expand, the air pressure inside begins to drop (Boyle's Law), and the air outside begins to rush in in order to compensate for the pressure change.  How much depends on the depth of the breath taken (usually controlled by the amount of CO2 in the body), but it all works as a single unit.
807461
?? \n\nWhy would there be any disadvantages associated with adequate ventilation since breathing is occuring at a normal rate and the oxygen is being delivered to the cells?
508
those other two are, in that the babies lungs are filled with embryonic fluid, but he isnt 'breathing' as we would thing of it. everything that the baby needs to live while in the mothers womb, is receieved through the umbilical cord, including oxygen.
449435
nope... they have a difference level of chromosomes,\n\n\nthey more than liekly could try.. but the results would be more than likely dead and birth from physical problems such as no lungs, or no heart etc..\n\ndifferent animals have maanged to mate ouside thier chromosome levels, such as the donkey and horse, and the lion and tigers (Ligers).. normally these animals do not last a full age and have birth defects.
305078
Usually boys / men because they have a larger lung capacity (on average)
544768
The Lungs are made up of millions of tiny air sacs called alveoli. These alveoli are like the millions of little holes in a sponge.\n\nJust out of curiosity, did you feel them in a dissection or something?
568199
Trachea divides into bronchi, Bronchi divides into bronchioles and then inte alveoli. Alveoloi are called the air-sacs and they are involved in the air respiration process.\nSo the smallest branch of bronchi are the alveoli(plural)and alveolus(singular).
1144776
The pulmonary artery is approximately 1.2 inches in diameter.
1131878
It would be extremely  unlikely though there is a genetic disorder called alpha-1 antitrysin deficiency that may cause someone with the deficiency to develope emphysema  before the age of 40. In the case of a newborn I don't think its ever developed that quickly so if there is a breathing problem with a baby I think most doctors would look for another cause before even considering this because its extremely unlikely. There may be birth defects which cause symtoms much like emphysema and these too are rare.Ultrasounds are valuable tools to help discover these and they are often treatable and reversible.
780534
In normal breathing, air is drawn in through the bronchial passages and down into the increasingly fine network of tubing in the lungs called the alveoli, which are many thousands of tiny sacs surrounded by capillaries. These absorb the oxygen and transfer it into the blood. When toxins such as smoke are breathed into the lungs, the particles are trapped by the hairs and cannot be exhaled, leading to a localised inflammatory response. Chemicals released during the inflammatory response (trypsin, elastase, etc.) begin to break down the walls of alveoli (alveolar septum). This leads to fewer but larger alveoli, with a decreased surface area and a decreased ability to take up oxygen and lose carbon dioxide. The activity of another molecule called alpha 1-antitrypsin normally neutralizes the destructive action of one of these damaging molecules.\n\nAfter a prolonged period, hyperventilation becomes inadequate to maintain high enough oxygen levels in the blood, and the body compensates by vasoconstricting appropriate vessels. This leads to pulmonary hypertension. This leads to enlargement and increased strain on the right side of the heart, which in turn leads to peripheral edema (swelling of the peripherals) as blood gets backed up in the systemic circulation, causing fluid to leave the circulatory system and accumulate in the tissues.\n\nEmphysema occurs in a higher proportion in patient with decreased alpha 1-antitrypsin (A1AT) levels (alpha 1-antitrypsin deficiency, A1AD). In A1AD, inflammatory enzymes (such as elastase) are able to destroy the alveolar tissue (the elastin fibre, for example). Most A1AD patients do not develop clinically significant emphysema, but smoking and severely decreased A1AT levels (10-15%) can cause emphysema at a young age. In all, A1AD causes about 2% of all emphysema. However, smokers with A1AD are in the highest risk category for emphysema.
64697
Almost NIL.\n\nPVL occurs most commonly in premature infants born at less than 32 weeks' gestation and less than 1500 g birth weight. Most infants have a history of cardiorespiratory problems, such as respiratory distress syndrome or pneumonia, in association with hypotension or patent ductus arteriosus.
508990
During a surgery anaesthetics are administered. Many of these drugs ahave some irritant property and hence cause a rise in secretions of the airways. These secretion block the airway. The absorption of gases, by blood, results in collapse of that segment of lung (obstructive atelectasis).\nBecause the lower segments are the most dependent areas of lung , the problem is frequently seen there.\n\nMoreover, after the surgery, people tend to take shallow breaths (to avoid pain). This reduced expansion of lungs results in less effort to throw out the obstruction and hence aggravates the condition.
105618
There's a big difference in 30 to 35 weekers. I think the 30 weekers would be really small, maybe their skin is a bit more red, maybe translucent a bit. Pretty small, too. I can't remember exactly what weeks age everyone is but I work in an office with premie docs and those babies are really tiny.
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See\nhttp://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pulmonary.html
1077979
a pig lifespan is about 15
151172
Lungs fill with fluid as a consquence of many reasons.  One such biological reason can include decreased surfactant production by Type II pneumocytes in the lung.  This would result in an increase in the surface tension of fluid lining the alveolar endothelium.  The increase in surface tension of this fluid would pull the alveolus closed and could even eventually collapse it.