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QUESTÕES SISTEMA RENAL 1. O que é clearance ou depuração de uma substância? Como é medida e qual o seu significado fisiológico? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 2. O que é pressão efetiva de filtração? De quais fatores depende? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 3. Quais os requisitos para que uma substância possa ser usada para a medida da Taxa de Filtração Glomerular? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 4. O que acontece com o clearance de glicose quando se eleva sua concentração plasmática? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 5. A que se deve a glicosúria do diabetes mellitus? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 6. Por que normalmente não aparece proteína na urina? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 7. Quais os mais importantes tipos de proteinúria, e quais suas causas? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 8. No caso de uma substância com clearance maior que a inulina, de onde podem provir as moléculas excretadas na urina? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 9. A reabsorção de sódio é ativa ou passiva? Explique. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 10. O que é diurese osmótica? Qual o mecanismo da diurese osmótica induzida por sacarose ou manitol? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 11. Quais as vias pelas quais o sódio penetra no túbulo proximal? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 12. O que é absorção isosmótica de água? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 13. Onde é produzido o HAD? E qual sua função? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 14. Onde é produzida a aldosterona e qual sua função no balanço de sódio? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 15. Como é regulada a produção de aldosterona? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 16. Qual o papel do HAD no mecanismo de concentração urinária? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 17. Quais os mecanismos de regulação da ingestão de água? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 18. Quais fatores podem causar expansão isosmótica do volume extra-celular? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 19. Quais substâncias produzidas nos rins apresentam propriedades hipotensoras? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 20. O que é diurese causada por bloqueio de sódio? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 21. O que é mais vantajoso, o clearance de creatinina ou de inulina? Explique. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 22. Quais as características dos néfrons medulares? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 23. Qual o papel da anidrase carbônica na reabsorção do bicarbonato? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 24. De onde provém o NH3 secretado ao nível dos túbulos renais? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 25. Dê as funções exercidas pelos rins. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 26. Que fator estimula a produção de renina? ________________________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________ ________________________________________________________________________________________ 27. Por que a excreção é considerada uma função homeostática? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 28. Como os rins ajudam a manter o equilíbrio ácido-básico do sangue? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 29. O que se entende por mecanismo de osmorregulação? ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 30. O líquido intersticial que banha nossos tecidos é formado por componentes do plasma sangüíneo, filtrado através das paredes dos capilares. Neste processo intervêm, principalmente, dois mecanismos: pressão osmótica, resultante da existência de proteínas no sangue, e pressão da circulação sangüínea. Suponha que ocorram as três situações seguintes: (I) o rim passa a excretar grande quantidade de proteínas; (II) a pressão da circulação sangüínea diminua; (III) os capilares sanguíneos sejam obstruídos. Dentre as três situações acima, um aumento do líquido intersticial pode ser devido somente a qual(is) situação(ões)? Comente. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ Complete a figura e o parágrafo abaixo: A pressão arterial força a passagem de substâncias plasmáticas de 1 para _____ . Só não passa as ________________ ; portanto, em 3, a pressão _______________ deve ser __________ que em 1. A solução contida em 2 chama-se __________ e corresponde ao plasma sem _______________ . Quando uma solução, bastante diluída, chega a 4, é submetida a um processo de ___________ ; a água é reabsorvida por __________ e os sais, aminoácidos e glicose são reabsorvidos por _______________ , que envolve gasto de energia. Portanto, 5 recupera parte das substâncias que passaram de ______ para 2. Finalmente, a solução contida em 6 pode ser chamada de ___________ .