Vasoconstriction bụ usoro physiological nke na-eme ka dayameta nke arịa ọbara nke anụ ahụ na-ebelata site na mkpụkọ nke akwara ndị mejupụtara mkpuchi nke arịa ọbara (arịa, veins). Enwere ike ime ya n'ihi ọtụtụ ihe na ihe kpatara ya, ma n'ọnọdụ ọ bụla maka nzaghachi ozugbo maka mgbanwe dị mkpa, karịsịa iji kwụsị ọbara ọgbụgba.

Vasoconstriction bụ usoro sitere n'okike nke na-agụnye ibelata dayameta nke arịa ọbara, site na mbelata nke akwara akwara ya. Omume ya na-emegide ya kwekọrọ na vasodilation; mmegharị abụọ ahụ gụnyere ihe a na-akpọ vasomotricity.

Vasoconstriction nwere uru nke ịmachi, dịka ọmụmaatụ, ọbara ọgbụgba mgbe ọnya nke arịa ọbara pụtara. Nke a bụ akụkụ mbụ nke hemostasis. Ebe akwara vasoconstrictor dị na mmalite nke usoro a, kamakwa homonụ angiotensin, adrenaline na noradrenaline. Vasoconstriction na-eme ka mbelata ọbara na-eru n'ime akụkụ ahụ a na-ekwu. Elu nke ụgbọ ahụ ga-ejikọta ọnụ, ha na-aghọ ihe nrapado.

Enwere ọtụtụ ihe na-ebute vasoconstriction na ahụ. Ihe na-emekarị bụ mmebi nke mkpụrụ ndụ anụ ahụ, nke arịa ọbara ya, site na mgbochi, ga-akwụsị ọbara ọgbụgba.

Ụfọdụ ihe na-ebutekwa ike nke a:

• Serotonin, nke ewepụtara site na platelet;
• Ịkwalite ndị na-anabata ihe mgbu na-agafe na usoro ụjọ ahụ (catecholamines, adrenaline, noradrenaline);
• Ụfọdụ nsị ma ọ bụ ngwaahịa dị na nri (dịka ọmụmaatụ caffeine).

E wezụga ihe mbụ ndị a na-akpata, enwere ike ịmepụta usoro vasoconstriction n'oge nhazi nke mgbanwe okpomọkụ n'ime ahụ, gụnyere ụjọ, endocrine, obi na akụkụ iku ume.

Mgbe okpomọkụ ahụ na-adaba, n'oge ihu igwe dị oke oyi dịka ọmụmaatụ, mmadụ nwere ike ịhụ ọdịdị nke vasoconstriction akpụkpọ anụ: ihe a na-eme ka o kwe omume ikewapụ anụ ahụ dị n'akụkụ nke etiti ahụ. Mbelata nke dayameta nke arịa ọbara na mpụta nke ahụ nwere mmetụta nke ịmegharị "gradient" (iche) na okpomọkụ n'etiti akpụkpọ ahụ na akụkụ nke obi, ngụgụ, ụbụrụ, akụrụ. Na-esonyere ya na ọbara mgbali elu akwara na mmụba nke ụda nke usoro ụjọ ahụ, vasoconstriction a si otú a na-abawanye ọnụọgụ obi. Nke a na-eduga na mmụba 10% na mkpokọta plasma nke mkpụrụ ndụ ọbara uhie na nke ọcha, platelet, kamakwa cholesterol na fibrinogen. N'ihi ya: mmụba nke viscosity ọbara gburugburu 20%.

Na mmechi, mgbe ahụ gị na-edobe oyi, esịtidem thermostat na-atụgharị na-akpaghị aka na-ere ọkụ a pụtara nnukwu ego nke ume. Ihe chọrọ obi na ikuku oxygen na-abawanye.

Nchegbu, ọ dịịrị ya? 

Ọzọkwa, nchekasị nwekwara ike ịbụ ọrụ maka ịgbalite vasoconstriction. Site na omume nke adrenaline, na-eziga ozi nrụgide n'oge, ụgbọ mmiri ga-arụ ọrụ iji mee ka dayameta ha sie ike, nwa oge.

Nicotine

Nicotine na-akpata vasoconstriction na akwara, na-ebelata ọbara na-erugharị, ya mere ọnụọgụ oxygen na-enye anụ ahụ na nsị na-ekpochapụ n'otu anụ ahụ.

Vasoconstriction a na-atụgharị ma na-apụ n'anya awa ole na ole mgbe ise siga gasịrị. Vasoconstriction na-adịgide adịgide n'ụbọchị, maka ndị na-ese siga dị elu.

Ọrịa nwere ike ime

N'ikpeazụ, vasoconstriction nwere ike ịbụ ihe ịrịba ama nke ọrịa nwere ike ime, ịṅụbiga mmanya ókè ma ọ bụ envenomation. Dịka ọmụmaatụ, ọrịa Raynaud na-apụta ìhè site na oke vasoconstriction nke obere arịa dị na nsọtụ nke ahụ (aka, ụkwụ), karịsịa n'oge oyi ma ọ bụ nrụgide. Ọrịa a na-ebute mfu nke ọbara na mpaghara ahụ metụtara na mgbu mgbe mgbaba ọbara na-alaghachi n'otu ebe ahụ.

Vasoconstriction nwere ike ime site na ọgwụgwọ ọgwụ, iji gbochie ụfọdụ ọbara ọgbụgba n'ọnọdụ ụfọdụ.

Mmegharị vaskụla a bụ mmetụta dị iche nke vasoconstriction ya mere kwekọrọ na mmụba nke arịa ndị ahụ site na mgbasa.

A na-eme ka mgbasawanye a kwe omume site na izu ike nke uru ahụ gbara arịa ọbara.

Ihe na-akpata vasodilation bụ:

• Okpomọkụ;
• Ọrịa, nsị, envenomation;
• Nfụkasị ahụ, mmeghachi omume mkpali (edema);
• Mmanya na-egbu egbu nwere mmetụta vasodilator ma gbasaa arịa ọbara na ụbụrụ;
• Ihe kpatara ya bụ ọgwụ, dị ka ọgwụ hypertensive.

N'okwu nke ikpeazụ, onye nwere ọbara mgbali elu nwere arịa ndị dị oke "dị warara" maka ọbara mgbali elu na-eme na veins ha, na-emebi ha. Ya mere, anyị ga-eji ọgwụ gbasaa arịa ya iji belata ọbara mgbali.