Why do we sweat? - John Murnan

Prevodilac: Milena Lakic Lektor: Ivana Korom

The finish line's in sight and you put on an extra burst of speed.

Linija cilja je na vidiku i ti dodaješ još jedan nalet brzine.

As your legs pick up the pace, your breathing gets deeper,

Dok tvoje noge pojačavaju tempo, disanje ti se produbljuje,

your heart pounds faster,

srce ti lupa jače,

and sweat pours over your skin.

i znoj obliva tvoju kožu.

How does this substance suddenly materialize

Kako se ova supstanca iznenada materijalizuje

and what exactly is its purpose?

i šta je tačno njena svrha?

There are a number of scenarios that can make us sweat:

Postoje razne stvari zbog kojih se znojimo:

eating spicy foods,

začinjena hrana,

nervousness,

nervoza,

and when we're sick.

ili bolest.

But exercise is probably the most familiar and common.

Ali vežbanje je verovatno najpoznatije i najuobičajnije.

In that case, sweating happens as a response to movement

U tom slučaju, znojenje se dešava kao reakcija na pokret

triggered deep inside your cells.

koji se aktivira duboko u tvojim ćelijama.

As you increase your pace, your muscles work harder,

Dok pojačavaš tempo, tvoji mišići se naprežu,

increasing their demand for energy.

povećavajući svoju potrebu za energijom.

A process called cellular respiration

Proces koji se naziva ćelijsko disanje

consumes glucose and oxygen to form ATP,

troši glukozu i kiseonik kako bi formirao ATP,

the energy currency of the cell.

energetsku valutu ćelije.

Much of this process takes place in structures called mitochondria.

Veliki deo ovog procesa se odigrava u strukturama nazvanim mitohondrije.

The more you move,

Što se više krećeš,

the harder mitochondria work to supply your body with energy.

mitohondrije rade napornije da snabdeju tvoje telo energijom.

All this work comes at a cost, though.

Sav ovaj rad ima svoju cenu, doduše.

As the cells break down the ATP, they release heat.

Dok ćelije razgrađuju ATP, one oslobađaju toplotu.

The heat stimulates temperature sensors throughout your body.

Toplota stimuliše temperaturne senzore u celom tvojem telu.

Those receptors detect the excess heat being produced by your muscle cells

Ti receptori detektuju višak toplote koju proizvode tvoje mišićne ćelije

and communicate that information to the hypothalamus,

i prenose tu informaciju do hipotalamusa,

which regulates body temperature.

koji reguliše telesnu temperaturu.

The hypothalamus responds

Hipotalamus reaguje

by sending signals out through the sympathetic nervous system

tako što šalje signale kroz ceo simpatički nervni sistem

to the sweat glands in your skin.

do znojnih žlezda u tvojoj koži.

These are distributed all over the body

One se rasprostiru kroz celo tvoje telo,

with especially high concentrations on the palms of your hands,

a posebno su koncentrisane na dlanovima tvojih ruku,

the soles of your feet,

tabanima,

and on your head.

i glavi.

When a sweat gland first receives the signal,

Kada isprva znojna žlezda primi signal,

the fluid surrounding the cells in its coiled base

tečnost koja okružuje ćelije u spiralnoj bazi

contains high amounts of sodium and chloride.

sadrži velike količine natrijuma i hlora.

The cells pump these ions into a hollow tube

Ćelija pumpa ove jone u šuplju cev

that runs through the sweat gland.

koja prolazi kroz znojnu žlezdu.

Then, because it's saltier inside the tube than outside,

Onda, pošto je unutar cevi slanije nego spolja,

water moves into the tube by osmosis.

voda se kreće u cevi putem osmoze.

As what's called the primary secretion builds up in the bottom of the tube,

Dok se ono što se naziva primarnim lučenjem gomila na dnu cevi,

water pressure pushes it up into the long straight part of the duct.

vodeni pritisak ga gura gore u dugački, pravi deo kanala.

Before it seeps onto the skin,

Pre nego što izbije na koži,

cells lining the tube will reclaim as much salt as possible

ćelije koje oblažu cev će pokupiti koliko god je moguće soli

so the process can continue.

da bi proces mogao da se nastavi.

The water in sweat absorbs your body's heat energy

Voda u znoju apsorbuje toplotnu energiju tvog tela

and then evaporates off of you when it reaches the surface,

i onda ispari sa tebe kada stigne do površine,

which in turn lowers your temperature.

zauzvrat snižavajući temperaturu tela.

This process, known as evaporative cooling,

Ovaj proces, poznat kao hlađenje isparavanjem,

was an important adaptation for our ancestors.

bio je važno prilagođavanje za naše pretke.

This cooling effect isn't only helpful during exercise.

Ovaj efekat hlađenja ne pomaže samo prilikom vežbanja.

We sweat in many other scenarios, too.

Takođe se znojimo u mnogim drugim situacijama.

Eating particularly spicy food makes some people sweat profusely from their faces.

Nekim ljudima se obilno znoji lice kada jedu izuzetno začinjenu hranu.

That happens because spices trigger the same neural response in the brain

To se dešava zato što začini pokreću istu nervnu reakciju u mozgu

that activates temperature receptors, which usually respond to increased heat.

koja aktivira temperaturne receptore, koji obično reaguju na povećanje toplote.

Sweating is also part of the fight or flight response

Znojenje je takođe deo "bori se ili beži" reakcije,

stimulated by stressful scenarios, like asking someone on a date

koju stimulišu stresne situacije kao što je pozivanje nekog na sastanak

or interviewing for a job.

ili odlazak na razgovor za posao.

This happens because adrenaline stimulates muscle activity

Ovo se dešava zato što adrenalin stimuliše aktivnost mišića

and causes blood vessels to widen,

i uzrokuje širenje krvnih sudova,

two responses that increase heat and trigger the sweating response.

dve reakcije koje povećavaju toplotu i pokreću znojnu reakciju.

And sweating also occurs when we get sick.

I znojenje se takođe dešava kada se razbolimo.

When we're feverish, we sweat because infections

Kada smo grozničavi, znojimo se zato što infekcije

stimulate the hypothalamus to increase muscle activity,

stimulišu hipotalamus da poveća aktivnost mišića,

which in turn releases more energy as heat.

a to zauzvrat oslobađa više energije u vidu toplote.

That increases your overall temperature,

To povećava tvoju ukupnu temperaturu,

a protective mechanism that makes your body less habitable for infectious agents.

zaštitni mehanizam koji čini tvoje telo manje nastanjivim za infektivne agense.

Like with running, sweating helps your body vent that heat.

Kao i kod trčanja, znojenje pomaže tvom telu da oslobodi tu energiju.

When the fever's over or you've won your race,

Kada groznica nestane ili kada pobediš u trci,

your temperature receptors sense the decrease in heat

tvoji temperaturni receptori osete smanjenje toplote

and the hypothalamus brings your sweating response to an end.

i hipotalamus prekida znojnu reakciju.

In some cases, like after a run,

U nekim slučajevima, kao nakon trčanja,

the hypothalamus also signals to your body

hipotalamus takođe signalizira tvom telu

that you need to replenish the water that you've oozed out.

da moraš da nadoknadiš vodu koja je iscurila.

So, when you're pushing yourself to reach that next goal,

Dakle, kada budeš gurao sebe da postigneš naredni cilj,

you can think of sweat as your body's very own calibrator,

možeš da misliš o znoju kao o sopstvenom kalibratoru tvog tela,

enabling you to go that extra mile.

koji ti omogućava da istrčiš tu dodatnu milju.