refractory period

Examples of refractory period in the following topics:

• The Action Potential and Propagation

  • First is depolarization, followed by repolarization and a short period of hyperpolarization.
  • A period of increased potassium permeability results in excessive potassium efflux before the potassium channels close.
  • The propagation of action potential is independent of stimulus strength but dependent on refractory periods.
  • The period from the opening of the sodium channels until the sodium channels begin to reset is called the absolute refractory period.
  • During this period, the neuron cannot respond to another stimulus, no matter how strong.

• Male Sexual Response

  • After orgasm and ejaculation, a refractory period usually ensues, characterized by loss of erection, a decline in any sex flush, decreased interest in sex, and a feeling of relaxation associated with the action of the neurohormones oxytocin and prolactin.
  • The intensity and duration of the refractory period can be very short in a highly aroused young man in a highly-arousing situation, perhaps without even a noticeable loss of erection.

• Penis

  • A refractory period succeeds the ejaculation, and sexual stimulation precedes it.

• Plantar Fasciitis

  • It is commonly associated with long periods of weight bearing.
  • Treatment options for plantar fasciitis include rest, massage therapy, stretching, weight loss, night splints, motion control running shoes, physical therapy, cold therapy, heat therapy, orthotics, anti-inflammatory medications, injection of corticosteroids and surgery in refractory cases.

• Homeostatic Responses to Shock

  • At the refractory stage, the vital organs have failed and shock can no longer be reversed.

• Development of the Respiratory System

  • Lung development can be divided into distinct stages: the pseudoglandular period, the canalicular period, and the terminal saccular period.
  • The pseudoglandular period (also known as "glandular period") spans weeks six to 16 and during this time the developing lung resembles an endocrine gland.
  • Respiration is not possible during this phase and fetuses born during this period are unable to survive.
  • Respiration is possible towards the end of this period, but few fetuses born during this time will survive.
  • The terminal saccular period spans from week 26 to birth.

• Development of Hearing and Balance

  • Critical periods have been identified for the development of the hearing and vestibular system.
  • Critical periods have been identified for the development of hearing and the vestibular system.
  • Hence, disruption of maturation during this period can cause changes in normal balance and movement through space.
  • Moreover, exposure to abnormal vestibular stimuli during the critical period is associated with irregular motor development.
  • First reports on critical periods came from deaf children and animals that received a cochlear implant to restore hearing.

• Periodic Abstinence

  • Periodic abstinence refers to abstaining from sexual intercourse during the fertile days of a menstrual cycle.
  • Most menstrual cycles have several days at the beginning that are infertile (pre-ovulatory infertility), a period of fertility, and then several days just before the next menstruation that are infertile (post-ovulatory infertility).
  • For these women, the rhythm method formula incorrectly identifies a few fertile days as being in the infertile period.
  • This schematic of a typical female menstrual cycle shows that periods of ovulation are taken in account to be a period of abstinence in calendar-based contraception methods.

• Interactions of Skeletal Muscles

  • The time between the stimulus and the initiation of contraction is termed the latent period, which is followed by the contraction period.
  • Taken all together these three periods are termed a twitch.
  • The time between stimulation and contraction is termed the latent period.
  • Together these three periods form a single muscle twitch,

• Introduction to Pregnancy and Human Development

  • Pregnancy is the period of gestation from the fertilization of an egg, through development of a fetus, and ending at birth.
  • In women who have a menstrual-cycle length of four weeks, this is approximately 40 weeks from the start of their last normal menstrual period.
  • In many societies' medical or legal definitions, human pregnancy is somewhat arbitrarily divided into three trimester periods as a means to simplify reference to the different stages of prenatal development.
  • This staging method is used only for the first 56 days in humans (prior to the fetal period).