Science Biology: Chord - ndiwo musimboti muviri mhuka

Chii kuita shark, pasi buruuru, mumwe Shato, njiva, Dolphin uye murume? Pakutanga, hapana zvakadaro unoshamisa kusiyana zvinenge kubva umwe, zvose chitarisiko uye chokwadi, chii vakadya uye kupi kurarama. Vangaita kutsanangura kubatana sayenzi zvipenyu?

The Chord - muviri kuumbwa panguva embryogenesis zvose izvi vagere Earth. Kubva iyo yakatanga? Ndezvipi mashandiro ari Chord uye chii vaanosangana mhuka? On the mubvunzo yakanga zvino, tinozowana mhinduro dzacho munyaya ino. Mienzaniso inopiwa pazasi, zvinoratidza kusiyana chordates vavo kutungamirira basa dzinongoitika zvinhu zvipenyu.

Zvinoitwa axial muviri vertebrates

Zvose zviri marongerwo uye kushanda kuri kusvika 42 zviuru mhando zvipenyu enzvimbo chordal mhando, kudzidza nezvezvinhu zvipenyu. The Chord - ndiyo huru anatomical nzira chinobatanidza zvinenge izvi mugomba chete hurongwa chimwe. It is kwakavharwa nenyama tambo, chine connective zvinyama masero, izvo anotitsigira yose muviri. The notochord riri pamwe mumuviri uye anoramba muupenyu mune mamwe marudzi, anonzi rezasi Chord. Ndivo vamiririri superclass jawless: lampreys uye hagfish. In cartilaginous nehove, Sharks uye mwaranzi, yose marangwanda rinoumbwa connective zvinyama uye ine chivako sezvo Chord. Iyewo, kunochengetwa izvi zvinenge upenyu.

Chii kwakaguma kwaita dzomunyika marangwanda

Chii zvinoreva Chord? Biology anofunga chitarisiko kwake Amphioxus, uye ipapo vamwe mhuka zvinokosha aromorphosis. Zvakatungamirira kukura mutsigiri maitiro uye sangano yakabuda kwemhuka munyika yokutanga. Izvi akavabvumira kuti kufadza zvinobatsira ari kukunda nyika uye kudzivisa kunyanya pakufurira masimba regiravhiti nezvimwe yaivhuvhuta zvakapoteredza zvinhu,.

In zvakawanda boka mhuka, akati vertebrate shwashwa yakatsiva axial beach mamiriro randinogara osseous zvinhu - vertebrae. Izvi zvinosanganisira vamiririri nemakirasi dzakawanda mhuka nyika, dzakadai amphibians, nezvinokambaira, neshiri uye mhuka. Nokuti upenyu hwemvura, kuva nomuzongoza, zvinosanganisira mapoka mhou nehove: carps, Clupeiformes, Perciformes, etc ...

Mune shanduka kwezvinhu zvose pamusoro mapoka mhuka dzakanga dzatora hune chinzvimbo Fauna of nyika. Izvi zvinotsigirwa tsvakurudzo munoiswa sayenzi uye zvipenyu. The Chord - ndiwo muviri, vachibvumira mhuka kukwikwidzana pamwe invertebrates vari kurwira kuvapo.

First chordates

zoologists zhinji, masayendisiti vaida kuwana mhuka, vane mamiriro kunganzi sezvo kubatana pakati invertebrates uye vertebrates. In pakati Russian embryologist XIX remakore Kovalevsky akatsanangura embryonic kukura unremarkable ugere Sea Black - Amphioxus dzose.

Translucent chisikwa kusvika 8 cm uye sezvinoita hove pasina musoro Chord rakaramba muupenyu hwake hwose. Amphioxus akaratidza imwe Transitional chimiro, kuvapo izvo kwenguva refu vaitsvaka zvipenyu. Chord - chivakwa, pakuonekwa izvo zvinoratidza zvakanaka yezvakaita shanduka nzira. Features embryonic mamiriro (kuvapo vatatu utachiona akaturikidzana) uye ontogenesis Amphioxus achisimbisa kubvuma kuti madzitateguru chordates ndivo zvipenyu vasina zvemukati marangwanda.

Bookmark ari axial marangwanda

Paumbwe Chord kubva zvinenge akasiyana riri pamusoro chete, kunyange zvazvo nguva penguva nenguva iyo ichi kunoitika anogona siyana. Somuenzaniso, munhu embryo connective tambo iri imwe yapfuura nguva embryo kukura, uye ayo Tab ndiko kudarika iya hove kana zvimwe vertebrates. The musana ekisero nuclei achiumbwa pasi Neural chubhu. Of chikuru intestinal mugove inonzi hordomezodermalnym manda hwapedyo nevaya vertebrates.

Biology uye Medicine zvakadzama izuchyut pezvakaitwa kuitika chehupenyu gastrulation unoratidza kutyora fetus, izvo zvinogona kunotoreva vasanyanye chinhanho, chitarisiko abnormalities uye rufu kacho. Kukundikana zvigadziriswe bogmærke axial nhengo: iri Neural chubhu, notochord, ura - ndiyo ngozi, saka zvakajairika nzira pamuviri rokutanga trimester kunokosha chaizvo utano mwana asati aberekwa.

Siyana uye kukosha mhando chordwise

The vamiririri ichi guru boka zvipenyu zviri saka zvakanaka kujairana kwezvakatipoteredza zvinhu zvakasiyana kuti yavaibatisa zvose zvipenyu panyika zvipenyu niches. Muna hydrosphere, musha vanopfuura zviuru 20. Fish zvipenyu kuti vanonzi chordates kupfuura kare, pamusoro pemvura uye kudzika lithosphere dzinozadzwa akawandisa mhando amphibians, nezvinokambaira uye mhuka, uye nyika uye mhepo ezvinhu inogarwa vanopfuura zviuru 8. Birds. By mhando Chord ndiye uye munhu vanhu vane zvokurarama nazvo vangasimudzira achinja chiso redu.