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 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
Search artcles published since 2007

November 14, 2012--------News Archive Return to: News Alerts


Human sperm with central sperm flagellum being digitally measured.



Jim Mossman: “No one’s ever looked at this before across sperm components.
What we show is that measurements on other sperm parts, such as the flagellum
that propels the sperm, can provide additional information about the quality
and consistency of sperm manufacture.”

Credit: David Orenstein/Brown University






WHO Child Growth Charts

       

Variation in Sperm Length Not a Good Sign

A new study finds the greater the inconsistency in the length of a sperm tail (flagellum), the lower the concentration of sperm that can swim well. Fertility clinicians have a potential new marker for fertility trouble that might trace back to how a patient’s sperm are being made

Perhaps variety is the very spice of life, but as a matter of producing human life, it could be the bane of existence. That’s the indication of a new study in the journal Human Reproduction that found men with wider variation in sperm length, particularly in the flagellum, had lower concentrations of sperm that could swim well. Those with more consistently made sperm seemed to have more capable ones.

The study is published online in the October 28, 2012 issue of the journal Human Reproduction.

“Our study reveals that men who produce higher concentrations of competent swimming sperm also demonstrate less variation in the size and shape of those sperm,” said Jim Mossman, a postdoctoral scholar at Brown University and lead author of the paper published in advance online Oct. 28. “It suggests that in some cases, testes are working more optimally to produce high numbers of consistently manufactured sperm, and vice versa.”

At the University of Sheffield, where Mossman did his doctoral studies, he and his co-authors measured the heads, midpieces, and flagella of 30 sperm per man, from 103 men randomly selected from a pool of about 500 who were recruited for a larger fertility study. They also measured other characteristics of each man’s semen, such as sperm concentration and motility, that the World Health Organization recognizes as important markers of fertility.

“The WHO suggests that measurements should be made on multiple components of sperm, but generally it’s only the sperm head that is considered,” Mossman said. “No one’s ever looked at this before across sperm components. What we show is that measurements on other sperm parts, such as the flagellum that propels the sperm, can provide additional information about the quality and consistency of sperm manufacture.”


The result of the novel analysis yielded two
overall findings. One was that men who had higher
mean flagellum length, total sperm length, and
flagellum-to-head length ratios had higher
concentrations of motile sperm.

But perhaps the more interesting finding was that the
greater the inconsistency of length in the sperm a man
manufactures, particularly with regard to the flagellum,
the lower his concentration of sperm that could swim well.


“The finding could give clinicians new insight into the diagnosis and treatment of male fertility problems, which accounts for up to 50 percent of the cases where couples struggle to conceive,” Mossman said. The research suggests that at least in some men, measurable inconsistency in sperm length may be a sign of trouble with his process of making sperm, a process known as spermatogenesis. That trouble, akin to a manufacturing line with poor quality control, could result in a lower concentration of good swimmers.

“This could be an indirect marker of testis function,” Mossman said.

Mossman acknowledged that there is nothing in the study that suggests what might cause spermatogenesis problems that would result in either inconsistent lengths or low concentrations of motile sperm.

“There are so many factors that govern sperm production, including environmental factors, genetic factors, and their interaction,” Mossman said. “As an andrologist and evolutionary biologist, I am very interested in what causes this variation and how that affects the phenotype of the sperm and its fertility potential.”

At Brown since earning his Ph.D. at Sheffield, Mossman has been working in the lab of David Rand, professor of biology in the Department of Ecology and Evolutionary Biolog, using fruit flies to study the influence of genetics on male fertility.

In addition to Mossman, the paper’s other authors are Jack Pearson, Harry Moore, and Allan Pacey, all of the University of Sheffield, which funded the research.

Original article: http://news.brown.edu/pressreleases/2012/11/sperm