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Welcome to The Visible Embryo, a comprehensive educational resource on human development from conception to birth.

The Visible Embryo provides visual references for changes in fetal development throughout pregnancy and can be navigated via fetal development or maternal changes.

The National Institutes of Child Health and Human Development awarded Phase I and Phase II Small Business Innovative Research Grants to develop The Visible Embryo. Initally designed to evaluate the internet as a teaching tool for first year medical students, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than one million visitors each month.

Today, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than 1 million visitors each month. The field of early embryology has grown to include the identification of the stem cell as not only critical to organogenesis in the embryo, but equally critical to organ function and repair in the adult human. The identification and understanding of genetic malfunction, inflammatory responses, and the progression in chronic disease, begins with a grounding in primary cellular and systemic functions manifested in the study of the early embryo.

WHO International Clinical Trials Registry Platform

The World Health Organization (WHO) has created a new Web site to help researchers, doctors and
patients obtain reliable information on high-quality clinical trials. Now you can go to one website and search all registers to identify clinical trial research underway around the world!




Pregnancy Timeline

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Female Reproductive System

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Disclaimer: The Visible Embryo web site is provided for your general information only. The information contained on this site should not be treated as a substitute for medical, legal or other professional advice. Neither is The Visible Embryo responsible or liable for the contents of any websites of third parties which are listed on this site.
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No dirivative works may be made or used for commercial purposes.


Pregnancy Timeline by SemestersFetal liver is producing blood cellsHead may position into pelvisBrain convolutions beginFull TermWhite fat begins to be madeWhite fat begins to be madeHead may position into pelvisImmune system beginningImmune system beginningPeriod of rapid brain growthBrain convolutions beginLungs begin to produce surfactantSensory brain waves begin to activateSensory brain waves begin to activateInner Ear Bones HardenBone marrow starts making blood cellsBone marrow starts making blood cellsBrown fat surrounds lymphatic systemFetal sexual organs visibleFinger and toe prints appearFinger and toe prints appearHeartbeat can be detectedHeartbeat can be detectedBasic Brain Structure in PlaceThe Appearance of SomitesFirst Detectable Brain WavesA Four Chambered HeartBeginning Cerebral HemispheresFemale Reproductive SystemEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterSecond TrimesterFirst TrimesterFertilizationDevelopmental Timeline
CLICK ON weeks 0 - 40 and follow along every 2 weeks of fetal development

Google Search artcles published since 2007

Home | Pregnancy Timeline | News Alerts |News Archive Feb 12, 2015


The kidney is divided into two major structures: the outer cortex and the inner medulla.
These structures take the shape of 8 to 18 cone-shaped lobes. Nephrons are the urine-producing structures of the kidney and span the cortex and medulla.
Imaage and text: Wikipedia.org




Secrets of how our kidneys develop

Striking images reveal new insights into how the kidney develops from a group of cells into a complex organ.

Researchers at the University of Edinburgh's Roslin Institute used time-lapse imaging to capture mouse kidneys growing in the laboratory. The research is published in the journal eLife.

Through these images, the scientists identified a key molecule — beta-catenin — that instructs cells to become nephrons which are the kidney's specialised filters that take waste from the blood and make it into urine. A gradient version of beta-catenin forms along the inside layer of the growing nephron and instructs cells to form lobes within the structure.

By changing the activity of beta-catenin in various locations, researchers learned they could instruct cells to form different parts of the nephron.

Video 2. Time-lapse capture of nephron formation
Video 2. Time-lapse capture of nephron formation

If nephrons do not work correctly, a wide range of health problems, from abnormal water and salt loss to dangerously high blood pressure, can occur. Their findings will help the scientists to grow nephrons in the lab that can be used to study more in depth how kidneys function. Also, the use of time-lapsed imaging means that, rather than requiring different litters of mice to study different developmental stages, the same animals can be studied over time. This leads to a significant reduction in the number of animals needed for this type of research.

"By using time lapse imaging, we can get detailed information about the signals that control how kidneys form at different time-points in development. This means that we can use fewer animals and obtain much more information than normal imaging techniques."

Dr Nils Lindstrom, of the University of Edinburgh

The different segments of the nephron and glomerulus in the kidney balance the processes of water homeostasis, solute recovery, blood filtration, and metabolite excretion. When segment function is disrupted, a range of pathological features are presented. Little is known about nephron patterning during embryogenesis. In this study, we demonstrate that the early nephron is patterned by a gradient in β-catenin activity along the axis of the nephron tubule. By modifying β-catenin activity, we force cells within nephrons to differentiate according to the imposed β-catenin activity level, thereby causing spatial shifts in nephron segments. The β-catenin signalling gradient interacts with the BMP pathway which, through PTEN/PI3K/AKT signalling, antagonises β-catenin activity and promotes segment identities associated with low β-catenin activity. β-catenin activity and PI3K signalling also integrate with Notch signalling to control segmentation: modulating β-catenin activity or PI3K rescues segment identities normally lost by inhibition of Notch. Our data therefore identifies a molecular network for nephron patterning.

The research is published today in the journal eLife and was funded by the National Centre for the Replacement, Refinement and Reduction of Animals in Research. The Roslin Institute receives strategic funding from the Biotechnology and Biological Sciences Research Council.

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