How blood pressure works - Wilfred Manzano

Kako deluje krvni pritisk - Wilfred Manzano

Translator: Nika Kotnik Reviewer: Matej Divjak

If you lined up all the blood vessels in your body,

Če bi vse žile v tvojem telesu postavili v vrsto,

they'd be 95,000 kilometers long

bi bile dolge 95.000 kilometrov,

and everyday, they carry the equivalent of over 7,500 liters of blood,

in vsak dan nosijo več kot 7.500 litrov krvi,

though that's actually the same four or five liters recycled over and over,

čeprav je pravzaprav to samo štiri ali pet litrov, recikliranih znova in znova,

delivering oxygen, and precious nutrients

ki nosijo kisik in dragocena hranila,

kot je glukoza in aminokisline k telesnim tkivom.

like glucose and amino acids to the body's tissues.

All that blood exerts a force on the muscular walls of the blood vessels.

Vsa ta kri deluje s silo na mišične stene krvnih žil.

That force is called blood pressure,

Ta sila se imenuje krvni pritisk

in raste ter pada s fazami srčnega utripa.

and it rises and falls with the phases of the heartbeat.

It's highest during systole,

Najvišji je v sistoli,

when the heart contracts to force blood through the arteries.

ko se srce skrči, da potisne kri skozi arterije,

This is your systolic blood pressure.

To je tvoj sistolični krvni pritisk.

When the heart is at rest between beats,

Ko srce miruje med utripi,

blood pressure falls to its lowest value, the diastolic pressure.

pritisk pade na najnižjo vrednost, diastolični pritisk.

A typical healthy individual produces a systolic pressure

Sistolni pritisk zdravega posameznika je

between 90 and 120 millimeters of mercury,

od 90 do 120 milimetrov živega srebra,

and diastolic pressure between 60 and 80.

in diastolični pritisk med 60 do 80.

Gledano skupaj, je normalna vrednost malo manj kot 120 skozi 80.

Taken together, a normal reading is a bit less than 120 over 80.

The blood traverses the landscape of the body

Kri potuje skozi telesna prostranstva

through the pipes of the circulatory system.

skozi cevi cirkulatornega sistema.

In any plumbing system,

V vsaki vodovodni napeljavi

several things can increase the force on the walls of the pipes:

lahko več stvari poveča silo, ki deluje na stene cevi:

the properties of the fluid,

lastnosti tekočine,

extra fluid,

dodatna tekočina,

or narrower pipes.

ali ožje cevi.

So if the blood thickens,

Če se torej kri zgosti,

a higher pressure is needed to push it, so the heart will pump harder.

je potreben večji pritisk, da jo potisne naprej, zato srce bolj dela.

A high-salt diet will lead to a similar result.

Prehrana z veliko soli vodi v podoben rezultat.

The salt promotes water retention,

Sol spodbuja zadrževanje vode,

and the extra fluid increases the blood volume and blood pressure,

in dodatna tekočina poveča volumen krvi in krvni pritisk,

and stress, like the fight or flight response,

in stres, kot naprimer odziv beg ali boj,

releases hormones, like epinephrine and norepinephrine

sprosti hormone, kot adrenalin in noradrenalin

that constrict key vessels,

ki zoži žile,

increasing the resistance to flow and raising the pressure upstream.

poveča upor in dvigne pritisk.

Blood vessels can usually handle these fluctuations easily.

Krvne žile lahko ta nihanja ponavadi dobro prenašajo.

Elastic fibers embedded in their walls make them resilient,

Elastična vlakna v njihovih stenah jih naredijo odporne,

but if your blood pressure regularly rises above about 140 over 90,

ampak, če se tvoj pritisk redno dviga nad 140 skozi 90

what we call hypertension, and stays there,

čemur rečemo hipertenzija, in tam ostaja,

it can cause serious problems.

lahko povzroči resne probleme.

That's because the extra strain on the arterial wall

To je zato, ker povečan pritisk na arterijske stene

can produce small tears.

lahko povzroči drobne raztrganine.

When the injured tissue swells up,

Ko ranjeno tkivo oteče,

substances that respond to the inflammation,

se substance, ki se odzivajo na vnetje,

like white blood cells, collect around the tears.

kot so bele krvničke, zberejo okrog raztrganin.

Fat and cholesterol floating in the blood latch on, too,

Maščoba in holesterol, ki krožita v krvi, se prav tako pritrdita gor

in sčasoma se naberejo in zgradijo plak,

eventually building up to form a plaque

that stiffens and thickens the inner arterial wall.

ki strdi in zadebeli notranjo plast arterije.

This condition is called atherosclerosis,

Ta bolezen se imenuje ateroskleroza,

and it can have dangerous consequences.

in ima lahko nevarne posledice.

If the plaque ruptures, a blood clot forms on top of the tear,

Če se ta plak raztrga, se na vrhu oblikuje krvni strdek,

clogging the already narrowed pipe.

ki zamaši že tako zoženo žilo.

If the clot is big enough,

Če je strdek dovolj velik,

it can completely block the flow of oxygen and nutrients to cells downstream.

lahko popolnoma zaustavi pretok kisika in hranil celicam.

In vessels that feed the heart,

V žilah, ki prehranjujejo srce,

that will cause a heart attack,

to povzroči srčni infarkt,

when oxygen-deprived cardiac muscle cells start to die.

ko celice srčne mišice, ki jim primanjkuje kisika, začnejo odmirati.

If the clot cuts off blood flow to the brain,

Če strdek prepreči dotok krvi v možgane,

it causes a stroke.

povzroči kap.

Dangerously clogged blood vessels can be widened

Nevarno zožene krvne žile lahko razširimo

by a procedure called an angioplasty.

s procesom imenovanim angioplastika.

There, doctors thread a wire through the vessel

Zdravniki skozi žilo vstavijo žico

to the obstructed site,

do mesta zamašitve

and then place a deflated balloon catheter over the wire.

in nato namestijo prazen balonski kateter čez žico.

When the balloon is inflated, it forces the passageway open again.

Ko se balon napihne, s tem povzroči, da se obtok povrne.

Sometimes a rigid tube called a stent

Včasih vstavimo rigidno cevko, imenovano stent,

is placed in a vessel to held hold it open,

v žilo, da jo drži odprto,

da lahko kri prosto teče

letting the blood flow freely

to replenish the oxygen-starved cells downstream.

in s tem oskrbi celice, ki jim primanjkuje kisika.

Staying flexible under pressure is a tough job for arteries.

Ostati prožen pod pritiskom je za arterije težka naloga.

The fluid they pump is composed of substances

Tekočina, ki jo črpajo, je sestavljena iz snovi,

that can get sticky and clog them,

ki lahko postanejo lepljive in jih zamašijo,

and your typical healthy heart beats about 70 times a minute,

in tipično zdravo srce bije približno 70-krat na minuto,

and at least 2.5 billion times during an average lifetime.

in naredi vsaj 2,5 milijarde utripov v življenju.

That may sound like an insurmountable amount of pressure,

To morda zveni kot nepremostljivo velik pritisk,

but don't worry, your arteries are well suited for the challenge.

a ne skrbi, tvoje arterije so za ta pritisk dobro opremljene.