Welcome to The Visible Embryo

Home- - -History-- -Bibliography- -Pregnancy Timeline- --Prescription Drugs in Pregnancy- -- Pregnancy Calculator- --Female Reproductive System- News Alerts -Contact

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 ' million visitors each month.


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!



Home

History

Bibliography

Pregnancy Timeline

Prescription Drug Effects on Pregnancy

Pregnancy Calculator

Female Reproductive System

Contact The Visible Embryo

News Alerts Archive

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.
Content protected under a Creative Commons License.

No dirivative works may be made or used for commercial purposes.

Return To Top Of Page
Pregnancy Timeline by SemestersFemale Reproductive SystemFertilizationThe Appearance of SomitesFirst TrimesterSecond TrimesterThird TrimesterFetal 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 HemispheresEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterDevelopmental Timeline
Click weeks 0 - 40 and follow fetal growth
Google Search artcles published since 2007
 
December 23, 2011--------News Archive

Defending the Genome
New research illustrates how the genome adapts to a transposon invasion that threatens fertility in the fruit fly. The same mechanism may exist in humans.

Multiple Sclerosis Not an Immune System Disease
Recent research argues that multiple sclerosis, long viewed as primarily an autoimmune disease, is more similar to hardening of the arteries.

Toddlers Rely On Others To Monitor Their Speech
When grown-ups and kids speak, they listen to the sound of their voice and make corrections based on that auditory feedback - something toddlers can't do.

December 22, 2011--------News Archive

How Pregnancy Changes a Woman’s Brain
At no other time in a woman’s life does she experience such massive hormonal fluctuations as during pregnancy.

New Device To Support Improved Newborn Health
Fetal heart rate monitor also tracks how well an infant is using oxygen.

Weight Reduction Through Mindful Eating
Pregnancy is a time when heavy women tend to gain an excessive amount of weight and later find it very hard to lose.

December 21, 2011--------News Archive

Breast Cancer, Heart Disease Share Common Roots
Women who are at risk for breast cancer may also be at greater risk for heart disease.

Breastfeeding Promotes Healthy Growth
Breastfeeding lowers the growth hormones IGF-I and insulin, promoting slightly slower growth and reducing adult risk of overweight and diabetes.

First Months of Life Shape Flavor Preferences
Early dietary experience shapes salt preference of infants and preschoolers.

December 20, 2011--------News Archive

Babies Remember Even As They Seem to Forget
How much do babies remember about the world around them, and what details do their brains need to absorb to help them keep track of things and people?

Safer Treatment for Asthma, Allergies, Arthritis?
Found, a missing link between our biological clock and sugar metabolism which may avoid serious side effects of drugs used for asthma, allergies and arthritis.

Endometriosis Link to Inflammatory Bowel Disease
Increased risk of inflammatory bowel disease is found in women with endometriosis in a nationwide Danish study.

December 19, 2011--------News Archive

Gene Discovered that Causes Rare Infant Epilepsy
The childhood disorder PKD is linked to a mysterious gene found in the brain called PRRT2 - a gene with little resemblance to anything in the human genome.

Don't Buy Noisy Toys!
If listened to at arms length, some popular items can permanently damage children's hearing - and hearing loss is not curable.

Childhood Cancer Drugs Cure, Later Cause Problems
Study indicates that drug toxicity may be related to genetic factors increasing risk of cardiomyopathy significantly in individuals with two copies of specific gene.

WHO Child Growth Charts

BMI For Adults Widget


       



An article in the December 23, 2011 issue of The Quarterly Review of Biology argues that multiple sclerosis, long viewed as primarily an autoimmune disease, is not actually a disease of the immune system.

Dr. Angelique Corthals, a forensic anthropologist and professor at the John Jay College of Criminal Justice in New York, suggests instead that MS is caused by faulty lipid metabolism, in many ways more similar to coronary atherosclerosis (hardening of the arteries) than to other autoimmune diseases.

Framing MS as a metabolic disorder helps to explain many puzzling aspects of the disease, particularly why it strikes women more than men and why cases are on the rise worldwide, Corthals says. She believes this new framework could help guide researchers toward new treatments and ultimately a cure for the disease.

Multiple sclerosis affects at least 1.3 million people worldwide. Its main characteristic is inflammation followed by scarring of tissue called myelin, which insulates nerve tissue in the brain and spinal cord. Over time, this scarring can lead to profound neurological damage.

Medical researchers have theorized that a runaway immune system is at fault, but no one has been able to fully explain what triggers the onset of the disease. Genes, diet, pathogens, and vitamin D deficiency have all been linked to MS, but evidence for these risk factors is inconsistent and even contradictory, frustrating researchers in their search for effective treatment.

"Each time a genetic risk factor has shown a significant increase in MS risk in one population, it has been found to be unimportant in another," Corthals said. "Pathogens like Epstein-Barr virus have been implicated, but there's no explanation for why genetically similar populations with similar pathogen loads have drastically different rates of disease. The search for MS triggers in the context of autoimmunity simply hasn't led to any unifying conclusions about the etiology of the disease."

However, understanding MS as metabolic rather than an autoimmune begins to bring the disease and its causes into focus.

Corthals believes that the primary cause of MS can be traced to transcription factors in cell nuclei that control the uptake, breakdown, and release of lipids (fats and similar compounds) throughout the body.

Disruption of these proteins, known as peroxisome proliferator-activated receptors (PPARs), causes a toxic byproduct of "bad" cholesterol called oxidized LDL to form plaques on the affected tissue.

The accumulation of plaque in turn triggers an immune response, which ultimately leads to scarring. This is essentially the same mechanism involved in atherosclerosis, in which PPAR failure causes plaque accumulation, immune response, and scarring in coronary arteries.

"When lipid metabolism fails in the arteries, you get atherosclerosis," Corthals explains. "When it happens in the central nervous system, you get MS. But the underlying etiology is the same."

A major risk factor for disruption of lipid homeostasis is having high LDL cholesterol. So if PPARs are at the root of MS, it would explain why cases of the disease have been on the rise in recent decades.

Corthals: "In general people around the world are increasing their intake of sugars and animal fats, which often leads to high LDL cholesterol. So we would expect to see higher rates of disease related to lipid metabolism—like heart disease and, in this case, MS." This also explains why statin drugs, which are used to treat high cholesterol, have shown promise as an MS treatment.

The lipid hypothesis also sheds light on the link between MS and vitamin D deficiency. Vitamin D helps to lower LDL cholesterol, so it makes sense that a lack of vitamin D increases the likelihood of the disease—especially in the context of a diet high in fats and carbohydrates.

Corthals's framework also explains why MS is more prevalent in women.

"Men and women metabolize fats differently," Corthals said. "In men, PPAR problems are more likely to occur in vascular tissue, which is why atherosclerosis is more prevalent in men. But women metabolize fat differently in relation to their reproductive role. Disruption of lipid metabolism in women is more likely to affect the production of myelin and the central nervous system. In this way, MS is to women what atherosclerosis is to men, while excluding neither sex from developing the other disease."

In addition to high cholesterol, there are several other risk factors for reduced PPAR function, including pathogens like Epstein-Barr virus, trauma that requires massive cell repair, and certain genetic profiles. In many cases, Corthals says, having just one of these risk factors isn't enough to trigger a collapse of lipid metabolism. But more than one risk factor could cause problems. For example, a genetically weakened PPAR system on its own might not cause disease, but combining that with a pathogen or with a poor diet can cause disease. This helps to explain why different MS triggers seem to be important for some people and populations but not for others.

"In the context of autoimmunity, the various risk factors for MS are frustratingly incoherent," Corthals said. "But in the context of lipid metabolism, they make perfect sense."

Much more research is necessary to fully understand the role of PPARs in MS, but Corthals hopes that this new understanding of the disease could eventually lead to new treatments and prevention measures.

"This new framework makes a cure for MS closer than ever," Corthals said.

Angelique Corthals, "Multiple Sclerosis (MS) is not a disease of the immune system," The Quarterly Review of Biology 86:4 (December 2011).

The premier review journal in biology since 1926, The Quarterly Review of Biology publishes articles in all areas of biology but with a traditional emphasis on evolution, ecology, and organismal biology. QRB papers do not merely summarize a topic, but offer important new ideas, concepts, and syntheses. They often shape the course of future research within a field. In addition, the book review section of the QRB is the most comprehensive in biology.

Original article: http://www.eurekalert.org/pub_releases/2011-12/uocp-rcm122211.php

When grown-ups and kids speak, they listen to the sound of their voice and make corrections based on that auditory feedback. But new evidence shows that toddlers don't respond to their own voice in quite the same way, according to a report published online on December 22 in Current Biology, a Cell Press publication.
The findings suggest that very young children must have some other strategy to control their speech production, the researchers say.
"As they play music, violinists will listen to the notes they produce to ensure they are in tune," explained Ewen MacDonald of the Technical University of Denmark. "If they aren't, they will adjust the position of their fingers to bring the notes back in tune. When we speak, we do something very similar. We subconsciously listen to vowel and consonant sounds in our speech to ensure we are producing them correctly. If the acoustics of our speech are slightly different from what we intended, then, like the violinists, we will adjust the way we speak to correct for these slight errors. In our study, we found that four-year-olds monitor their own speech in the same way as adults. Surprisingly, two-year-olds do not."
That's despite the fact that infants readily detect small deviations in the pronunciation of familiar words and babble in a manner consistent with their native language. By the time they turn two, American children have an average vocabulary of about 300 words and appear well on their way to acquiring the sound structure of their native language.
In the experiment, adults, four-year-olds, and two-year-olds said the word "bed" repeatedly while simultaneously hearing themselves say the word "bad." (To elicit those utterances from the young children and toddlers, the researchers developed a video game in which players help a robot cross a virtual playground by saying the robot's 'magic' word "bed.")
"If they repeat this several times, adults spontaneously compensate, changing the way they say the vowel," MacDonald said. "Instead of saying the word 'bed,' they say something more like the word 'bid.'"
Four-year-olds adjusted their speech, too, the researchers show. The two-year-olds, on the other hand, kept right on saying "bed."
MacDonald says the results suggest a need to reconsider assumptions about how children make use of auditory feedback. It may be that two-year-olds depend on their parents or other people to monitor their speech instead of relying on their own voice. MacDonald notes that caregivers often do repeat or reflect back to young children what they've heard them say.
While this study involved children with normal speech development, MacDonald says they'll be exploring potential applications for understanding or addressing delayed and abnormal early speech development.