{"id":20215,"date":"2011-03-05T11:41:00","date_gmt":"2011-03-05T11:41:00","guid":{"rendered":"http:\/\/trainingsnews.com\/centrii-suprapontini-2"},"modified":"2011-03-05T11:41:00","modified_gmt":"2011-03-05T11:41:00","slug":"centrii-suprapontini-2","status":"publish","type":"post","link":"https:\/\/cvnextjob.com\/index.php\/2011\/03\/05\/centrii-suprapontini-2\/","title":{"rendered":"Centrii suprapontini"},"content":{"rendered":"
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Cercet\u0103ri experimentale au ar\u0103tat c\u0103 stimularea forma\u0163iunii reticulate pontomezencefalice, \u00een regiunea tegmentului mezencefalic \u015fi a substan\u0163ei cenu\u015fii periapeductale, produce unele modific\u0103ri ale activit\u0103\u0163ii cardiovasculare. \u00cen general, se admite c\u0103 zonele superioare \u015fi laterale ale substan\u0163ei reticulate pontomezencefalice produc excita\u0163ia, iar zonele inferomediale inhibi\u0163ia centrilor cardiovasculari bulbopontini.<\/span><\/div>\n
            Hipotalamusul de\u0163ine roluri esen\u0163iale \u00een integrarea \u015fi coordonarea activit\u0103\u0163ii cardiovasculare, prin influen\u0163ele stimulatoare sau inhibitoare pe care le exercit\u0103 asupra centrilor bulbopontini. Por\u0163iunea anteromedial\u0103 a hipotalamusului, ventral de aria preoptic\u0103, este regiunea care con\u0163ine neuroni depresori parasimpatici (vasodilatatori, termolitici, digestivi), ai c\u0103ror axoni ajun\u015fi \u00een regiunea pontobulbar\u0103, stabilesc conexiuni cu centrul cardiovasomotor. Por\u0163iunea posterolateral\u0103 a hipotalamusului, bogat\u0103 \u00een catecolamine, cuprinde neuroni simpatici, excitatori, care integreaz\u0103 \u015fi coordoneaz\u0103 activitatea sistemului simpatoadrenergic, stimularea acestei zone produc\u00e2nd tahicardie, vasoconstric\u0163ie, intensificarea metabolismului \u015fi a termogenezei. La nivelul hipotalamusului se realizeaz\u0103 integrarea reac\u0163iilor circulatorii \u00een cadrul unor modific\u0103ri adaptative mai complexe, necesitate de schimb\u0103rile survenite \u00een mediu \u015fi tot la acest nivel are loc integrarea componentelor vegetative cu cele somatice, hipotalamusul asigur\u00e2nd \u00een acela\u015fi timp producerea reac\u0163iilor somatovegetative complexe, adecvate diverselor acte comportamentale (alimentare, sexuale, ap\u0103rare).<\/span><\/div>\n
            Cerebelul, prin stimularea nucleului fastigial, poate determina prin intensificarea activit\u0103\u0163ii simpatice \u015fi diminuarea celei parasimpatice un reflex presor, care nu mai apare dup\u0103 sec\u0163ionarea tractului fastigiobulbar sau dup\u0103 distrugerea nucleului reticular paramedian.<\/span><\/div>\n
Centrii corticali, \u00een special sistemul limbic (via nucleii talamici anteriori), exercit\u0103 influen\u0163e importante asupra sistemului cardiovascular \u015fi de aceea se afirm\u0103 c\u0103 centrii pontobulbari, hipotalamici \u015fi sistemul limbic constitue releurile modulatoare esen\u0163iale ale regl\u0103rii func\u0163ionale a cordului \u015fi vaselor.    Experien\u0163a cotidian\u0103 confirm\u0103 participarea de necontestat a acestor forma\u0163iuni nervoase superioare \u00een reglarea cardiovascular\u0103, st\u0103rile emo\u0163ionale, frica, furia fiind \u00eenso\u0163ite constant de modific\u0103ri cardiovasculare.<\/span><\/div>\n
            Aria cortical\u0103 motoare, girusul sigmoid, lobul  temporal anterior, aria orbital\u0103 a lobilor frontali, amigdala produc, prin intermediul hipotalamusului, sau direct prin conexiunile cu centrii vasomotori pontobulbari, efecte excitatoare sau inhibitoare, depinz\u00e2nd de por\u0163iunea stimulat\u0103 \u015fi de intensitatea stimului. Scoar\u0163a cerebral\u0103 realizeaz\u0103 integrarea cea mai fin\u0103 \u015fi mai adecvat\u0103 a circula\u0163iei, \u00een cadrul modific\u0103rilor adaptative necesitate de variate condi\u0163ii fiziologice. Sub influen\u0163a stimulilor psihoemo\u0163ionali se produc importante modific\u0103ri hemodinamice, at\u00e2t prin implicarea sistemului de fibre simpatice colinergice cu origine cortical\u0103, c\u00e2t \u015fi prin desc\u0103rc\u0103ri de catecolamine din medulosuprarenale. De asemenea modific\u0103rile cardiovasculare ce se produc cu ocazia unor eforturi fizice repetate (atle\u0163i, muncitori) \u015fi care debuteaz\u0103 \u00eenc\u0103 \u00eenainte de efortul propriu-zis (\u00een drum spre stadion sau fabric\u0103), reprezint\u0103 o dovad\u0103 a influen\u0163elor corticale asupra circula\u0163iei, realizate prin intermediul unor reflexe condi\u0163ionate cardiovasculare.    Astfel epinefrita eliberat\u0103 \u00een cursul unor st\u0103ri emo\u0163ionale, eforturi fizice intense, ac\u0163ioneaz\u0103 nu numai asupra efectorilor, cresc\u00e2nd for\u0163a de contrac\u0163ie a miocardului \u015fi tonusului pere\u0163ilor arteriolari, dar \u015fi asupra baroreceptorilor din zonele reflexogene, modific\u00e2nd “nivelul variabilei controlate”, adic\u0103 a presiunii arteriale sistemice.<\/span><\/div>\n
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Cercet\u0103ri experimentale au ar\u0103tat c\u0103 stimularea forma\u0163iunii reticulate pontomezencefalice, \u00een regiunea tegmentului mezencefalic \u015fi a substan\u0163ei cenu\u015fii periapeductale, produce unele modific\u0103ri ale activit\u0103\u0163ii cardiovasculare. \u00cen general, se admite c\u0103 zonele superioare \u015fi laterale ale substan\u0163ei reticulate pontomezencefalice produc excita\u0163ia, iar zonele inferomediale inhibi\u0163ia centrilor cardiovasculari bulbopontini.             Hipotalamusul de\u0163ine roluri esen\u0163iale \u00een integrarea \u015fi coordonarea […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[11],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/posts\/20215"}],"collection":[{"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/comments?post=20215"}],"version-history":[{"count":0,"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/posts\/20215\/revisions"}],"wp:attachment":[{"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/media?parent=20215"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/categories?post=20215"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cvnextjob.com\/index.php\/wp-json\/wp\/v2\/tags?post=20215"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}