September 4, 2012 | David F. Coppedge

More Reasons to Appreciate Your Body

There’s more going on under your skin than you possibly realize.

Lung brush:  Working 24×7, microscopic cilia lining your bronchial passages sweep your lungs clean, allowing you to survive in an atmosphere filled with pollutants.  Science Daily summarized a paper in Science that described “A Periciliary Brush Promotes the Lung Health by Separating the Mucus Layer from Airway Epithelia” (Button et al., Science, 24 August 2012: Vol. 337 no. 6097 pp. 937-941, DOI: 10.1126/science.1223012).  Science Daily said,

“The cilia are constantly beating, even while we sleep,” he says. “In a coordinated fashion, they push mucus containing foreign objects out of the lungs, and we either swallow it or spit it out. These cilia even beat for a few hours after we die. If they stopped, we’d be flooded with mucus that provides a fertile breeding ground for bacteria.”….

The researchers used a combination of imaging techniques to observe a dense meshwork in the periciliary layer of human bronchial epithelial cell cultures. The brush-like layer consists of protective molecules that keep sticky mucus from reaching the cilia and epithelial cells, thus ensuring the normal flow of mucus….

“This layer — this brush — seems to be very important for the healthy functioning of human airways,” according to Rubinstein. “It protects cells from sticky mucus, and it creates a second barrier of defense in case viruses or bacteria penetrate through the mucus. They would not penetrate through the brush layer because the brush is denser.”

Respiratory diseases such as COPD are apparently caused by the collapse of this brush layer.  The new findings, which replace old notions that the mucus rested on a liquid layer, may help people suffering from a variety of lung problems.  The BBC News write-up added this comment:

Prof Stephen Spiro, vice-chairman of the British Lung Foundation, said: “Mucus has a complex biological make-up and forms a vital part of the lungs’ defence mechanism against potentially harmful or irritating substances, which are inhaled as small particles.

“Research such as this helps our understanding [of] how this system works, and of the complex mechanisms deep within our lungs which protect us from the atmosphere we breathe in.”

The original paper did not mention evolution, except to say in passing, “Mucus clearance in the mammalian lung has evolved to trap and clear a wide variety of inhaled toxicants and infectious agents from airway surfaces,” passing the support for that claim to three other references.  Neither Science Daily nor the BBC saw fit to include evolution.

Muscle builder:  Early reports about irisin, a newly-discovered hormone that mimics the effects of exercise by converting white fat into brown fat (see Live Science Jan. 2012) may not pan out, according to Nature this week (Timmons et al., “Is irisin a human exercise gene?”, Nature 488, 30 August 2012, pp. E9–E10, doi:10.1038/nature11364).  Timmons et al. found only modest benefit in humans, particularly highly-active elderly people.  No need to despair, though: Science Daily just reported a “hulk protein” that may allow humans to grow stronger without working out.  Researchers found that mice with the Grb10 gene disrupted grow more muscular.  Don’t turn in your gym membership just yet, though, the researchers warned:  “the classic prescription still applies: lift heavy things, eat and sleep right, and have your hormones checked.”  They hope, though, that further understanding of these genetic processes may help people suffering from muscle-wasting diseases.

Protein attraction:  Your body’s proteins need to work together.  Cornell scientists have found how proteins can feel attractive forces as far as 20 nanometers, a considerable distance at their scale.  It involves fractal-like patterns in cell membranes that form near the “critical point of the liquid-liquid phase separation of the cell membrane, which is the subtle temperature and composition point at which the two phases separate.”  PhysOrg included this quote by Ben Machta, grad student and co-author of the study: “We were intrigued that it seems like biology does want to tune itself closely to this critical point.”

Gift-wrapped neurons:  Many neural cells come wrapped in myelin, a membranous, lipid-rich sheath that composes the “white matter” of the central nervous system. What does it do?  “The myelin sheath around nerve fibres serves to speed up electrical nerve signals, Nature News explained.  “But it turns out that it also supplies neurons with fuel to support their high metabolic activity.”  In particular, “lactate provided by or through the myelin sheath is crucial for neuronal survival.”  A diagram in the article reveals the complex interactions of astrocytes, oligodendrocytes, ATP and blood vessels in this feeding process.  The finding “expands the roles of myelin sheaths,” the authors said.  This is not necessarily the only known function of myelin, which “supports neurons in other, less-well-understood ways.”  Source: Rinholm and Bergerson, “Neuroscience: The wrap that feeds neurons,” Nature 487, 26 July 2012, pp. 435–436, doi:10.1038/487435a.

Work in your sleep:  Sleep learning is possible, reported Science Daily, because while you rest and dream, your brain is creating associations and memories of what you perceive through the senses, and these associations remain after you wake up.  Experiments at the Weizmann Institute of Science showed that sleeping participants given Pavlov-like associations of tones with odors retained the association when awake: when hearing the tone, they would breathe in deeply for memories of pleasant odors, but take short sniffs when the tone was associated with a foul odor – even when having no conscious memory of the association.  Researchers believe this finding suggests that “we could probably learn more complex information while we sleep,” but they expect limits.  Don’t place your homework under your pillow, for instance.  More detail provided in the coverage on Nature News August 26.

Support for circumcision:  Parents worrying about the decision whether to circumcise their baby boy might elect to do so, now that medical doctors from the American Association of Pediatrics endorsed it August 27.  The AAP feels it can reduce sexually-transmitted diseases and improve boys’ health, such as reducing risk of penile cancer and urinary tract infections.  Some disagree strongly with tampering with nature on philosophical or religious grounds; some worry about complications for the baby.  Although still controversial, the AAP believes ” the medical benefits outweigh the risks of the procedure” and advises insurance companies to pay for it.  Source: Nature News, August 28; see also Live Science, which also reported August 20 that a drop in circumcisions would boost health care costs.

Circumcision remains a parental choice; if undertaken, it should be for health reasons, not religious reasons.  For Christians, the apostle Paul declared that “circumcision is nothing and uncircumcision is nothing” in terms of ceremonial significance, “but keeping the commandments of God” is what counts (I Cor. 7:19).  In Romans he proved that circumcision is no longer a requirement for pleasing God, from whom salvation is by grace alone through faith.  In Galatians, he strongly condemned the Judaizers who insisted that Christians must be circumcised, declaring them to be hypocrites: “As many as desire to make a good showing in the flesh, these would compel you to be circumcised, only that they may not suffer persecution for the cross of Christ. For not even those who are circumcised keep the law, but they desire to have you circumcised that they may boast in your flesh.  But God forbid that I should boast except in the cross of our Lord Jesus Christ, by whom the world has been crucified to me, and I to the world. For in Christ Jesus neither circumcision nor uncircumcision avails anything, but a new creation.” (Galatians 6:12-15).  Nevertheless, he did have Timothy circumcised to avoid offense as the young disciple entered a ministry to a mixed church of Jews and Gentiles (Acts 16:1-3).  Some people get really adamant about their positions for or against circumcision, but consider: God would not have required a seriously damaging procedure for his people the Jews in the Old Testament; they did, after all, do a pretty good job of being fruitful and multiplying.  If you agree with the AAP that the benefits outweigh the risks, or if you have some pragmatic reason, like wanting your boy to fit the cultural norm, have at it.  If you want your boy to remain all natural, you will not thereby displease God.

We hope all the stories in this entry will remind us all how “fearfully and wonderfully made” we are (Psalm 139), from the level of the whole body all the way down to the individual proteins in our cells.  Browse through our “Human Body” category to read about many more wonders that make human life precious.  Be grateful again today to your Maker, and promote the sanctity of human life in your voting and behavior.

 

 

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Comments

  • justme says:

    I was enthralled watching a documentary on PBS years ago about how the human brain works and develops. It made me a much better parent, particularly during my children’s adolescence. Real knowledge about physiology can make a very real difference in your personal relationships, rendering them even more satisfying. Then you don’t have to rely on any ‘just so’ stories…

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