enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Timeline of human prenatal development - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_human_prenatal...

    The brain divides into 5 vesicles, including the early telencephalon. Leg buds form and hands form as flat paddles on the arms. Rudimentary blood moves through primitive vessels connecting to the yolk sac and chorionic membranes. The metanephros, precursor of the definitive kidney, starts to develop. The initial stomach differentiation begins. [5]

  3. History of birth control - Wikipedia

    en.wikipedia.org/wiki/History_of_birth_control

    During the same period Ali ibn Abbas al-Majusi (Persian) documented the use of pessaries made of rock salt for women for whom pregnancy may be dangerous. In the early 10th century the Persian Polymath Abu Ali al-Hussain ibn Abdallah ibn Sina (Persian), known in Europe as Avicenna, included a chapter on birth control in his medical encyclopedia ...

  4. Beginning of pregnancy controversy - Wikipedia

    en.wikipedia.org/wiki/Beginning_of_pregnancy...

    A protein called early pregnancy factor (EPF) is detectable in a woman's blood within 48 hours of ovulation if fertilization has occurred. However, testing for EPF is time-consuming and expensive; most early pregnancy tests detect human chorionic gonadotropin (hCG), a hormone that is not secreted until after implantation. Defining pregnancy as ...

  5. Human embryonic development - Wikipedia

    en.wikipedia.org/wiki/Human_embryonic_development

    The normal period of gestation (pregnancy) is about nine months or 36 weeks. The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus. The germinal stage takes around 10 days. [1] During this stage, the zygote divides in a process called cleavage.

  6. Human reproduction - Wikipedia

    en.wikipedia.org/wiki/Human_reproduction

    Pregnancy is the period of time during which the fetus develops, dividing via mitosis inside the uterus. During this time, the fetus receives all of its nutrition and oxygenated blood from the mother, filtered through the placenta , which is attached to the fetus' abdomen via an umbilical cord .

  7. Timelines of world history - Wikipedia

    en.wikipedia.org/wiki/Timelines_of_world_history

    These timelines of world history detail recorded events since the creation of writing roughly 5000 years ago to the present day. For events from c. 3200 BC – c. 500 see: Timeline of ancient history; For events from c. 500 – c. 1499, see: Timeline of post-classical history; For events from c. 1500, see: Timelines of modern history

  8. Human history - Wikipedia

    en.wikipedia.org/wiki/Human_history

    Human history or world history is the record of humankind from prehistory to the present. Modern humans evolved in Africa around 300,000 years ago and initially lived as hunter-gatherers . They migrated out of Africa during the Last Ice Age and had spread across Earth's continental land except Antarctica by the end of the Ice Age 12,000 years ago.

  9. Adams Synchronological Chart or Map of History - Wikipedia

    en.wikipedia.org/wiki/Adams_Synchronological...

    The design may have inspired later 'Maps of World History' such as the HistoMap by John B. Sparks, which chronicles four thousand years of world history in a graphic way similar to the enlarging and contracting nation streams presented on Adam's chart. Sparks added the innovation of using a logarithmic scale for the presentation of history.