contração muscular - .• separação de cromossomas • dineína – usa os microtúbulos como

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  • Contrao muscular

  • Motores moleculares

    Miosina

    Usa a actina como substrato.

    Miosinas II: conrtao muscular

    Miosinas V: transporte de organelas

    Kinesina

    Usa os microtbulos como substrato.

    Transporte axonal antergrado

    Separao de cromossomas

    Dinena

    Usa os microtbulos como substrato.

    Transporte axonal retrgrado

    Movimentos de clios e flagelos

  • Motores moleculares usam a energia livre da

    hidrlise do ATP para gerarem conformaes

    moleculares que levam ao movimento

  • O msculo estriado

    esqueltico

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-14/figure-14-2https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-14/figure-14-2
  • A juno neuromuscular uma sinapse do tipo 1 para 1ou seja: 1 potencial de ao pr-sinptico causa 1 potencial de ao

    muscular

  • A unidade motora compreende o nervo motor

    mais as fibras que ele inerva

    Cada fibra recebe um

    terminal.

    O tamanho da unidade

    motora depende da

    funo do msculo.

    A unidade motora a

    unidade geradora de

    fora do msculo

  • A unidade motora compreende o nervo motor

    mais as fibras que ele inerva

    Rectus lateralis = 5

    Masseter = 640

    Gastrocnemius = 1800

  • O sarcmero

  • O sarcmero relaxado e

    contrado

  • https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-14/figure-14-8https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-14/figure-14-8
  • Principais protenas do sarcmero do

    msculo esqueltico

  • A formao da ponte cruzada e o ciclo

    do ATP

    Msculo relaxado

    Msculo contrado

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-14/figure-14-9https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-14/figure-14-9
  • Contrao do sarcmero1. Despolarizao da membrana ps-sinptica, sarcolema e tbulos T

    2. Mobilizao de Ca2+

    3. Ao do Ca2+ nos mecanismos regulatrios miofibrilares

  • Acoplamento excitao-contrao

    O que ?

    Mecanismo por qual o sinal eltrico (potencial

    de ao) se converte em uma ao mecnica

    (contrao).

    Para isso precisamos de um segundo

    menssageiro qumico:

    Clcio!

  • Mecanismos de acoplamento

  • A contrao do msculo esqueltico

    depende da despolarizao do sarcolema Sensor de potencial

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-1https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-1
  • Mecanismos de acoplamento no msculo

    esqueltico

  • Os tubulos T e a cisterna terminal

    esto em contato ntimo,

    formando as trades

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-5https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-5
  • O sensor de voltagem um canal de clcio (receptor de DHP) acoplado a

    um canal de clcio do retculo sarcoplasmtico (receptor de rianodina)

  • O acoplamento EC no msculo esqueltico

    mecnico

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-7https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-7
  • A Ca-ATPase reticular (SERCA) retorna

    o clcio sarcoplasmtico aos nveis

    basais

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-8https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-8
  • A hipertermia maligna uma doena

    gentica do receptor de rianodina que

    desacopla a contrao da excitaoO RyR desses pacientes possui mutaes que conferem

    sensitividade a anestsicos volteis como o halotano

    Ensaio feito com msculo esqueltico de um paciente com hipertermi malignaUCLA Department of Anesthesiology

  • Mecnica da contrao do

    msculo esqueltico

  • Representao mecnica do

    msculo

    Matriz extracelular, sarcolemas vizinhos, ceitoesqueleto

    tendes

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/ch16-figure-text-01-ahttps://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/ch16-figure-text-01-a
  • A contrao do msculo esqueltico (twitch) acontece 30 a 40 ms aps o

    pico do potencial de ao e controlada pelo aumento do clcio

    Um nico AP libera clcio suficiente para saturar seus stios nas troponinas, porm

    de forma rpida

  • A fora mxima gerada pelo msculo esqueltico

    depende do intervalo da resposta de estmulos

    consecutivos

    Ttano

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-2https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-2
  • Medindo a relao entre fora e comprimento

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-3https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-3https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-4https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-4
  • Contrao isomtrica e isotnica

  • A fora de contrao isomtrica depende da quantidade de

    sobreposio entre os filamentos espessos e finos

    Tenso passiva = fora necessria para esticar o msculo relaxado

    Tenso total = tenso isomtrica mxima de um msculo em determinado comprimento

    Tenso ativa = diferena entre a tenso total do msculo contrado e a tenso passiva

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-5https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-5
  • A velocidade da

    contrao isotnica

    decai com o aumento

    da fora (load)

    aplicada

    Vo = velocidade maxima (atividade mxima de

    formao de pontes cruzadas)

    Fo = fora mxima produzida pelo msculo

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-6https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-6https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-7https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-7
  • Existem 3 tipos de msculos esquelticos

    FF = Rpidos fatigveis (tipo I)

    FR = Rpidos resistentes (tipo II)

    S = Sustentados (tipo II)

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-9https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/figure-16-9https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/ch16-figure-text-01-bhttps://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-16/ch16-figure-text-01-b
  • Diferenas entre as fibras

    Property White muscles (I) Red muscles (II)

    Twitch contraction time,

    msec

    Fast, 50-80 Slow, 100-200

    Minimum tetanic

    frequency

    60/sec 16/sec

    Myoglobin content Low High

    Primary source of ATP Glycolysis Oxidative

    phosphorylation

    Glycogen High Low

    Myosin-ATPase activity High Low

    Capillary blood flow Low High

    Fatiguability Easy Difficult

    Nerve fiber size Large Small

    Nerve fiber activity Intermittent, high

    frequency

    Continuous, low frequency

    Tension produced Larger Smaller

  • O Msculo estriado cardaco

  • O acoplamento no msculo cardaco

    qumico, envolvendo a libera de clcio

    induzida pelo clcio

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-10https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-10
  • O clcio no msculo cardaco expulso tanto pela SERCA

    como por mecanismos de membrana.

    https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/chapter-15/figure-15-9https://studentconsult.inkling.com/read/cellular-physiology-and-neurophysiology-blaustein-kao-matteson-2nd/