Faoliyati reflektorii sistemai asab

Refleks. Kamonaki reflektori. Reaksiyai javobii organizmro ba angezandahoi beruni va dokhili, ki bo ishtiroki hatmii sistemai markazii asab ba amal meoyad, refleks menomand. Rohero, ki ba vositai on impulshoi asabi guzashta, refleksro ba amal meorand, kamonaki reflektori menomand. Kamonaki reflektori az panj qism:

• retseptor;
• torhoi markazshitob (afferenti);
• sistemai markazii asab;
• torhoi markazgurez (efferenti);
• uzvi harakat (mushakho, effektor) iborat ast. 

 Kamonaki reflektori az retseptor sar meshavad. Har yak retseptor barangezandahoi makhsus: rushnoi, sado, buy, harorat va gayraro dorad. Retseptor chunin barangezandahoro ba impulsi asab va signali sistemai asabi tabdil medihad. Impulshoi asab tabiati elektriki (barqi) doshta, bo pardai shokhahoi darozi neyronho pahn meshavand. In impulsho dar inson va hayvonot yakkhelaand.

Impulshoi asab az retseptor ba vositai torhoi hiskunanda khabarro ba sistemai markazii asab merasonand. Az sistemai markazi boshad, impulsho ba vositai torhoi harakatkunanda ba uzvhoi kori meravand. Ba tarkibi aksari kamonakhoi reflektori inchunin neyronhoi mobayniro, ki dar harommagz va magzi sar mavjudand, didan mumkin ast.

 Reflekshoi odam gunogun meshavand. Bazei onho khele soddaand. Masalan, hangomi suzan khalondan yo sukhtani pust faqat kashidani dast ba amal meoyad. Az tasiri moddahoi gunoguni kimiyovi rekhtani ashk, hangomi ba kovokii bini va rohhoi nafas dokhilshavii gardu chang va zarrachahoi begona sulfa va atsazaniro mushohida namudan mumkin ast.

Ahamiyati bahayajonoi va bozdori dar hosilshavii refleks.

Javob gardonidan ba angezandahoi gunogun faoliyati korii sistemai uzvhoro ba miyon meorad. Masalan, dast kashidan az jismi tafson faqat dar vaqti kashishkhurii baze mushakho va sust shudani mushakhoi digar ba amal meoyad. Dar in vaqt kori dil, nafaskashi va gayra ba tavri reflektori tagyir meyobad.

CHunin faoliyati ba ham muvofiqi reflektori dar sistemai markazii asab ba du holat:

• hayajonpaziri, ki faoliyatnokii neyronho va purzur gashtani reaksiyahoi reflektoriro tamin mekunad;
• bozdori, ki kori neyronho sust yo purra qat megardad, tasiri manfi merasonad. 

Sustshavii bozdori boisi hayajonpazirii nihoyat qavii sistemai asab shuda, onro zaif megardonad. Holati bozdoriro dar sistemai markazii asab olimi rus I.M.Sechenov avvalin marotiba soli 1862 dar tajribahoi khud kashf kardaast. 

Badtar olimoni digar ba monandi Gols, Ukhtomskiy, Danini-Ashner SHerrington bozdoriro dar qismhoi kanorii organizm va uzvhoi daruni muayyan kardaand. 

Savolho

1. Refleks chist?
2. Kamonaki refleksi chist va az kadom qismho iborat ast?
3. Retseptorho kadom vazifaro ijro mekunand?
4. Bahayajonoi va bozdori chist?