Vasoconstriction shine tsarin ilimin lissafi wanda ke haifar da diamita na jijiyoyin jini na jiki ta raguwa ta hanyar murƙushe tsokar da ke yin rufin jijiyoyin jini (arteries, veins). Ana iya haifar da shi saboda dalilai da dalilai da yawa, amma a kowane hali don amsawa nan da nan don daidaitawa da ake buƙata, musamman don dakatar da zubar jini.

Vasoconstriction tsari ne na halitta wanda ya ƙunshi rage diamita na jijiyoyin jini, ta hanyar ƙanƙancewar ƙwayoyin tsokar sa. Ayyukanta na gaba sun yi daidai da vasodilation; duka motsi ya ƙunshi abin da ake kira vasomotricity.

Vasoconstriction yana da fa'ida ta iyakance, alal misali, zub da jini lokacin da raunin jijiyoyin jini ya bayyana. Wannan shine farkon matakin hemostasis. Cibiyoyin jijiya na vasoconstrictor sune asalin wannan injin, amma kuma hormones angiotensin, adrenaline da noradrenaline. Vasoconstriction saboda haka yana haifar da raguwar hauhawar jini a cikin gabobin da ake tambaya. Fuskokin jirgin ruwa za su manne tare, su zama manne.

Akwai abubuwa da yawa waɗanda ke haifar da vasoconstriction a cikin jiki. Mafi na kowa shine lalacewar ƙwayoyin tsoka, waɗanda jijiyoyinsu na jini, ta hanyar ƙuntatawa, za su dakatar da zubar jini.

Wasu abubuwa kuma suna haifar da wannan ƙarar:

• Serotonin, wanda platelet ta saki;
• Kunna masu karɓar raɗaɗi waɗanda ke wucewa ta cikin tsarin juyayi (catecholamines, adrenaline, noradrenaline);
• Wasu gubobi ko samfuran da ke cikin abinci (misali caffeine).

Bayan waɗannan dalilai na farko, ana iya saita injin vasoconstriction yayin daidaita musayar zafi a cikin jiki, wanda ya haɗa da juyayi, endocrine, zuciya da tsarin numfashi.

Lokacin da zafin jiki ya faɗi, a cikin yanayin sanyi sosai misali, mutum zai iya lura da bayyanar vasoconstriction na fata: wannan sabon abu yana ba da damar ware kyallen takarda na tsakiyar jiki. Ƙuntataccen diamita na jijiyoyin jini a gefen jiki yana da tasirin sake haifar da “gradient” (bambanci) a zafin jiki tsakanin fata da gabobin zuciya, huhu, kwakwalwa, koda. Tare da hauhawar jini da hauhawar sautin tsarin juyayi, wannan vasoconstriction yana ƙara yawan bugun zuciya. Wannan yana haifar da ƙaruwa 10% a cikin ƙwayar plasma na ja da farin sel, platelets, amma kuma cholesterol da fibrinogen. Sakamakon: karuwar danko na jini kusa da 20%.

A ƙarshe, lokacin da jikin ku ya yi sanyi, thermostat na cikin gida yana kunna ta atomatik kuma yana ƙona adadin kuzari mai yawa. Bukatun zuciya da buƙatun iskar oxygen suma suna ƙaruwa.

Danniya, alhakin? 

Hakanan, damuwa na iya zama alhakin kunna vasoconstriction. Ta hanyar aikin adrenaline, yana aika saƙon damuwa na lokaci, tasoshin za su yi aiki don ƙarfafa diamitarsu, na ɗan lokaci.

nicotine

Nicotine yana haifar da vasoconstriction a cikin arteries, yana rage yawan zubar jini, sabili da haka adadin iskar oxygen da ake ba wa kyallen takarda da guba da aka cire daga kyallen guda ɗaya.

Wannan vasoconstriction yana juyawa kuma yana ɓace 'yan awanni bayan shan sigari. Vasoconstriction ya zama na dindindin yayin rana, ga masu yawan shan sigari.

Cututtuka masu yuwuwa

A ƙarshe, vasoconstriction na iya zama alamar cutar mai yuwuwar, maye ko envenomation. Misali, ciwon Raynaud yana bayyana ta vasoconstriction mai yawa na ƙananan tasoshin a cikin ƙarshen jiki (hannu, ƙafa), musamman lokacin yanayin sanyi ko damuwa. Wannan cutar tana haifar da asarar isasshen jini zuwa yankin da abin ya shafa da jin zafi lokacin da jinin ya koma waɗannan wuraren.

Vasoconstriction na iya haifar da maganin miyagun ƙwayoyi, don iyakance wasu zub da jini a takamaiman yanayi.

Wannan motsi na jijiyoyin jini shine kishiyar tasirin vasoconstriction sabili da haka yayi daidai da haɓaka girman tasoshin ta hanyar fadadawa.

Ana samun wannan fadada ta hanyar shakatawa tsokar da ke kewaye da jijiyoyin jini.

Dalilin vasodilation shine:

• Zafi;
• Rashin lafiya, guba, ha'inci;
• Rashin lafiyan, kumburi (edema);
• Barasa yana da tasirin vasodilator kuma yana fadada jijiyoyin jini a cikin kwakwalwa;
• Sanadiyyar magani, kamar magungunan hawan jini.

A cikin yanayin na ƙarshe, mutumin da ke fama da hauhawar jini yana da tasoshin da suka yi "kunkuntar" don hawan jini da ake yi a jijiyoyin su, yana lalata su. Don haka za mu yi amfani da magani don faɗaɗa tasoshinsa don rage hawan jini.