THEBODY’SENERGYPRODUCTION MACHINERYMALFUNCTIONS

What causes human bodies

TO AGE?AURICULAR MUSCLES CONTROL THE VISI-BLE PART OF THE EAR, BUT HUMANS HAVELOST THE ABILITY TO USE THEM: Othermammals use these muscles to detect prey andpredators. The auricular muscles help other

mammals localise sound and express emotion,according to Britannica. Unlike humans, animalslike cats have to move their ears to hear well.At best, some humans can wiggle their ears.

S ome times, errors start to appear in ourDNA. When DNA is replicated, the codemight not always be copied correctly –

parts could get misspelled, and sections couldbe accidentally inserted or deleted. These er-rors are not always caught by the mechanismsin our bodies that repair DNA. The geneticcode is a cell’s instruction manual, so as er-rors build up, they can wreak havoc. If the in-structions become unclear or wrong over time,that could break down the cell and even makeit turn cancerous. In old tissues, scientistshave observed that many cells have a lot of ac-cumulated genetic damage. If researchers canfigure out how to improve the mechanism thatrepairs DNA, they could improve and possi-bly delay the ageing process.

C ertain parts of your DNA are readand translated into physical traits. Agroup of proteins in your cells con-

trols which genes ultimately get expressed.This process is called epigenetic moderation,and it’s what ensures your skin cells are dif-ferent from brain cells, even though they usethe same set of DNA. But as we age, the pro-teins bound to DNA become looser and lessaccurate, and genes start to get expressed

when they shouldn’t be or silenced in error.This means some necessary proteins aren’tbeing made and harmful, unnecessaryproteins are. Scientists have foundthat reversing these types of er-rors in gene expression can im-prove some neurological ef-fects of ageing in mice, suchas memory impairment.

ERRORS APPEAR IN DNA

GENE EXPRESSION GOES AWRY

T elomeres are protec-tive caps at the endsof each strand of

DNA. Some scientistshave compared them tothe plastic tips ofshoelaces that keep themfrom fraying. Researchsuggests that every timecells divide, the tips ofthe chromosome becomeshorter. When the telom-eres are lost, chromo-somes become unstableand all kinds of problemsarise. The most notable isthat chromosomes can’treplicate correctly, and endup fragmented or with extra

parts that aren’t supposed to be there. These abnormalities usu-ally kill cells or make them dangerous. Scientists have figured outhow to increase levels of telomerase — an enzyme that can extendthe length of telomeres — in mice, and a study suggested that it canextend mice’s lifespan. When they lowered levels of telomerase in mice,the mice lived shorter lives.

TELOMERES MAY SHORTEN

A PENNYDROPPED FROM THE TOP

OF THE EMPIRE STATEBUILDING WILL KILL YOU: OnMythbusters, scientists deter-mined that a penny “travel-ling at terminal velocity can-not penetrate concrete orasphalt.” It won’t cause serious damage to a person,and even at the speed of sound, will still not damageflesh. At most, it could sting a little.

CRACKING YOUR KNUCKLES WILL GIVE YOUARTHRITIS: This was probablytold to you by people whocan’t stand the sound ofbones popping;cracking yourknuckles or other bodyparts will not give youarthritis. Dr RobertKlapper, anorthopaedic surgeonat Cedars-Sinai Medical Centerand co-director of their Joint

Replacement Program,explained on the hospital’s sitethat there is no harm to crack-ing your knuckles. “The noiseof cracking or popping in ourjoints is actually nitrogen bub-bles bursting in our synovialfluid,” he wrote.

ON AVERAGE, YOU SWALLOW EIGHT SPIDERS A YEARIN YOUR SLEEP: Scientific American claimed that spi-ders don’t intentionally crawl into a bed and they don’t

care about humans. “Spidersregard us much like they’d

regard a big rock,”Bill Shear, former

president of the AmericanArachnological Society

told the site. If asleeping person has

their mouth open, they’relikely snoring, creating vibra-

tions that warn spiders ofdanger and scare them off.

PROTEINS BECOME LESS STABLEAND ACCURATE IN THEIR ROLES

I n our cells, proteins are produced constantly, and theycontrol almost every function inside the cell. Theymove materials, carry signals, turn processes on and

off, and provide structural support for the cell. But pro-teins have to be recycled regularly because they lose theireffectiveness over time. As we age, our bodies lose theability to eliminate old proteins. If our bodies can’t turnover unusable proteins, they can build up and becometoxic. Protein accumulation is one of the major featuresof Alzheimer’s disease – proteins called beta-amyloid ag-gregate in the brain and result in the loss of nerve cells.

A s cells undergo stress andbecome damaged, theysometimes stop dividing

and become resistant to death.They turn into something scien-tists call “zombie cells,” which caninfect other cells in their vicinityand spread inflammation through-out the body. These cells are alsocalled senescent cells. Senescentcells accumulate with time andage, and scientists have found thateliminating senescent cells in old mice seems to reverse someof the effects of ageing. Similarly, when senescent cells wereinjected into young mice, they had debilitating and inflam-matory effects and were detrimental to overall health. Sev-eral drugs called senolytics are now being developed with thegoal of reducing senescent cells in the elderly to treat age-re-lated disease.

CELLS BECOME BAD AT COMMUNICATING

M itochondria produces energy in cells by con-verting oxygen and food into energy. As or-ganisms and their cells age, these mini power-

plants become more inefficient and dysfunctional. Whenthey don’t function properly, they can produce an al-

tered form of oxy-gen that cancause damageto DNA andproteins. In a study pub-lished in the journal Naturein June, scientists wereable to reverse wrinklesin mice by restoringthe function oftheir mito-chondria.

F or everything in the body to work, cellshave to be constantly communicatingwith each other. They send signals

through the blood and the immune system todo that. But as our bodies get older, cells becomeworse at communicating. Some cells becomeless responsive, which can turn them into in-flammation-causing senescent cells. Inflam-mation produced by these senescent cells fur-

ther blocks communication between healthy,functioning cells. With cells unable to commu-nicate, the immune system is unable to effec-tively clear out pathogens and senescent cells.Ageing also changes the level of inter-cellularcommunication across the endocrine and neu-roendocrine systems. Messages sent throughhormone molecules that circulate through thesesystems, such as insulin, tend to get lost.

HEY FOLKS! I’M EXPLORIA.

Understandingthe ageing

process will provide medicalbreakthroughsand help in the

treatment of fatal diseases

USELESS HUMANBODY PARTS LEFT

OVER FROM EVOLUTION5

THE APPENDIX MAY BE THE MOST COM-MONLY KNOWN USELESS ORGAN: Manyyears ago, the appendix may have helpedpeople digest plants that were rich in cellu-lose, Gizmodo reported. Plant-eating verte-brates still rely on their appendix to helpprocess plants, but the organ is not part ofthe human digestive system.

HUMAN EMBRYOSDEVELOP A TAIL

BETWEEN FIVE ANDEIGHT WEEKS AFTERCONCEPTION: The tail

vanishes by the time humansare born, and the remaining

vertebrae merge to form the coc-cyx, or tailbone. Tailbones helped our ancestors with mobility and

balance, but the tail shrank as humans learned to walk upright. Thecoccyx now serves no purpose in humans. Human infants are rarely born

with a vestigial tail, though it does happen, according to Britannica. Doctorscan remove the tail through surgery without major issues.

ARRECTOR PILI AREMUSCLE FIBRES THATPRODUCE GOOSEBUMPSWHEN THEY CONTRACT:Our ancestors, who hada lot more body hair,used these fibres to

their advantage, but we don’t have any use forthem now. For animals with thick fur, arrector pilican help provide insulation. The fibres can alsomake animals look bigger — porcupine benefitsfrom this phenomenon.

HUMANS NO LONGER NEED VERYPOWERFUL JAWS: It’s because

our diets have shifted towardssoft foods and cooked

grains. Our jaws are alsosmaller, so even the

wisdom tooth doesn’tfit properly.

CELLS DON’T DIE WHEN THEY’RE SUPPOSED TO

4 ‘FACTS’ everyonebelieves that aren’t

actually true

03EXPLORIA“Never doubt that a small group of thoughtful,

committed citizens can change the world; indeed,it's the only thing that ever has” Margaret Mead